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Sample records for stable visual acuity

  1. Visual acuity test

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003396.htm Visual acuity test To use the sharing features on this page, please enable JavaScript. The visual acuity test is used to determine the smallest ...

  2. Repeatability of visual acuity measurement.

    Science.gov (United States)

    Raasch, T W; Bailey, I L; Bullimore, M A

    1998-05-01

    This study investigates features of visual acuity chart design and acuity testing scoring methods which affect the validity and repeatability of visual acuity measurements. Visual acuity was measured using the Sloan and British Standard letter series, and Landolt rings. Identifiability of the different letters as a function of size was estimated, and expressed in the form of frequency-of-seeing curves. These functions were then used to simulate acuity measurements with a variety of chart designs and scoring criteria. Systematic relationships exist between chart design parameters and acuity score, and acuity score repeatability. In particular, an important feature of a chart, that largely determines the repeatability of visual acuity measurement, is the amount of size change attributed to each letter. The methods used to score visual acuity performance also affect repeatability. It is possible to evaluate acuity score validity and repeatability using the statistical principles discussed here.

  3. 38 CFR 4.76 - Visual acuity.

    Science.gov (United States)

    2010-07-01

    ... DISABILITIES Disability Ratings The Organs of Special Sense § 4.76 Visual acuity. (a) Examination of visual acuity. Examination of visual acuity must include the central uncorrected and corrected visual acuity for... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Visual acuity. 4.76...

  4. Predicting visual acuity from detection thresholds.

    Science.gov (United States)

    Newacheck, J S; Haegerstrom-Portnoy, G; Adams, A J

    1990-03-01

    Visual performance based exclusively on high luminance and high contrast letter acuity measures often fails to predict individual performance at low contrast and low luminance. Here we measured visual acuity over a wide range of contrasts and luminances (low mesopic to photopic) for 17 young normal observers. Acuity vs. contrast functions appear to fit a single template which can be displaced laterally along the log contrast axis. The magnitude of this lateral displacement for different luminances was well predicted by the contrast threshold difference for a 4 min arc spot. The acuity vs. contrast template, taken from the mean of all 17 subjects, was used in conjunction with individual spot contrast threshold measures to predict an individual's visual acuity over a wide range of luminance and contrast levels. The accuracy of the visual acuity predictions from this simple procedure closely approximates test-retest accuracy for both positive (projected Landolt rings) and negative contrast (Bailey-Lovie charts).

  5. How to measure distance visual acuity

    Directory of Open Access Journals (Sweden)

    Janet Marsden

    2014-04-01

    Full Text Available Visual acuity (VA is a measure of the ability of the eye to distinguish shapes and the details of objects at a given distance. It is important to assess VA in a consistent way in order to detect any changes in vision. One eye is tested at a time.

  6. Evaluation of contrast visual acuity in patients with retinitis pigmentosa

    Science.gov (United States)

    Oomachi, Kazumi; Ogata, Kazuha; Sugawara, Takeshi; Hagiwara, Akira; Hata, Akira; Yamamoto, Shuichi

    2011-01-01

    Background The purpose of this study was to determine visual acuity at different contrast levels under photopic and mesopic conditions in patients with retinitis pigmentosa. Methods Sixty eyes of 31 normal controls, 92 eyes of 52 patients with retinitis pigmentosa without other ocular disorders (RP-1 group), and 20 eyes of 14 patients with retinitis pigmentosa with cataracts and without other ocular disorders (RP-2 group) were studied. Conventional visual acuity was measured using a conventional Landolt ring chart with 100% contrast and luminance of 150 cd/m2. All of the patients with retinitis pigmentosa had a decimal visual acuity better than 1.0. Contrast visual acuity was measured with the same Landolt ring chart with contrasts of 100% and 10% and under photopic (200 cd/m2) and mesopic (10 cd/m2) conditions. Decimal visual acuities were converted to logMAR units for the analyses. Results The 100% contrast visual acuity and the 10% contrast visual acuity determined under both photopic and mesopic conditions were significantly poorer in both the RP-1 and RP-2 groups than in the controls. The differences between the conventional visual acuity and the 100% contrast visual acuity were significantly greater in the RP-1 and RP-2 groups than in the controls under both photopic and mesopic conditions. The differences between the 100% contrast visual acuity and the 10% contrast visual acuity were not significant among the three groups under photopic and mesopic conditions. Conclusion Contrast visual acuities were greatly reduced in patients with retinitis pigmentosa with relatively well preserved conventional visual acuity, and the contrast visual acuity was largely influenced by ambient light levels in patients with retinitis pigmentosa. Although a longitudinal study for confirmation has to be performed, our findings indicate that contrast visual acuity is a better test to follow changes in visual function in patients with retinitis pigmentosa. PMID:22069346

  7. Gender and environmental influences on visual acuity in Owerri ...

    African Journals Online (AJOL)

    This study assessed the gender and environmental influences on visual function among adults in Owerri, Nigeria. Visual acuity (V.A.) is a measure of visual function in health and disease. Visual disability together with other disabling conditions is a barrier to development, yet there is little known about the visual acuity and ...

  8. Visual acuity and visual field impairment in Usher syndrome.

    Science.gov (United States)

    Edwards, A; Fishman, G A; Anderson, R J; Grover, S; Derlacki, D J

    1998-02-01

    To determine the extent of visual acuity and visual field impairment in patients with types 1 and 2 Usher syndrome. The records of 53 patients with type 1 and 120 patients with type 2 Usher syndrome were reviewed for visual acuity and visual field area at their most recent visit. Visual field areas were determined by planimetry of the II4e and V4e isopters obtained with a Goldmann perimeter. Both ordinary and logistic regression models were used to evaluate differences in visual acuity and visual field impairment between patients with type 1 and type 2 Usher syndrome. The difference in visual acuity of the better eye between patients with type 1 and type 2 varied by patient age (P=.01, based on a multiple regression model). The maximum difference in visual acuity between the 2 groups occurred during the third and fourth decades of life (with the type 1 patients being more impaired), while more similar acuities were seen in both younger and older patients. Fifty-one percent (n=27) of the type 1 patients had a visual acuity of 20/40 or better in at least 1 eye compared with 72% (n=87) of the type 2 patients (age-adjusted odds ratio, 3.9). Visual field area to both the II4e (P=.001) and V4e (Ptype 1 patients than type 2 patients. A concentric central visual field greater than 20 degrees in at least 1 eye was present in 20 (59%) of the available 34 visual fields of type 1 patients compared with 70 (67%) of the available 104 visual fields of type 2 patients (age-adjusted odds ratio, 2.9) with the V4e target and in 6 (21%) of the available 29 visual fields of type 1 patients compared with 36 (38%) of the available 94 visual fields of type 2 patients (age-adjusted odds ratio, 4.9) with the II4e target. The fraction of patients who had a visual acuity of 20/40 or better and a concentric central visual field greater than 20 degrees to the II4e target in at least 1 eye was 17% (n=5) in the type 1 patients and 35% (n=33) in the type 2 patients (age-adjusted odds ratio, 3

  9. Visual acuity in pelagic fishes and mollusks.

    Science.gov (United States)

    Gagnon, Yakir L; Sutton, Tracey T; Johnsen, Sönke

    2013-11-01

    In the sea, visual scenes change dramatically with depth. At shallow and moderate depths (cephalopods, and a gastropod using a custom-built apparatus. The hatchetfishes (Argyropelecus aculeatus and Sternoptyx diaphana) and the barrel-eye (Opisthoproctus soleatus) were found to have the best lenses, which may allow them to break the counterillumination camouflage of their prey. The heteropod lens had unidirectional aberrations that matched its ribbon-shaped retina. We also found that lens angular resolution increased with depth. Due to a similar trend in the angular separation between adjacent ganglion cells in the retinas of fishes, the perceived visual contrast at the retinal cutoff frequency was constant with depth. The increase in acuity with depth allows the predators to focus all the available light bioluminescent prey animals emit and detect their next meal. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. High visual acuity revealed in dogs.

    Science.gov (United States)

    Lind, Olle; Milton, Ida; Andersson, Elin; Jensen, Per; Roth, Lina S V

    2017-01-01

    Humans have selectively bred and used dogs over a period of thousands of years, and more recently the dog has become an important model animal for studies in ethology, cognition and genetics. These broad interests warrant careful descriptions of the senses of dogs. Still there is little known about dog vision, especially what dogs can discriminate in different light conditions. We trained and tested whippets, pugs, and a Shetland sheepdog in a two-choice discrimination set-up and show that dogs can discriminate patterns with spatial frequencies between 5.5 and 19.5 cycle per degree (cpd) in the bright light condition (43 cd m-2). This is a higher spatial resolution than has been previously reported although the individual variation in our tests was large. Humans tested in the same set-up reached acuities corresponding to earlier studies, ranging between 32.1 and 44.2 cpd. In the dim light condition (0.0087 cd m-2) the acuity of dogs ranged between 1.8 and 3.5 cpd while in humans, between 5.9 and 9.9 cpd. Thus, humans make visual discrimination of objects from roughly a threefold distance compared to dogs in both bright and dim light.

  11. High visual acuity revealed in dogs.

    Directory of Open Access Journals (Sweden)

    Olle Lind

    Full Text Available Humans have selectively bred and used dogs over a period of thousands of years, and more recently the dog has become an important model animal for studies in ethology, cognition and genetics. These broad interests warrant careful descriptions of the senses of dogs. Still there is little known about dog vision, especially what dogs can discriminate in different light conditions. We trained and tested whippets, pugs, and a Shetland sheepdog in a two-choice discrimination set-up and show that dogs can discriminate patterns with spatial frequencies between 5.5 and 19.5 cycle per degree (cpd in the bright light condition (43 cd m-2. This is a higher spatial resolution than has been previously reported although the individual variation in our tests was large. Humans tested in the same set-up reached acuities corresponding to earlier studies, ranging between 32.1 and 44.2 cpd. In the dim light condition (0.0087 cd m-2 the acuity of dogs ranged between 1.8 and 3.5 cpd while in humans, between 5.9 and 9.9 cpd. Thus, humans make visual discrimination of objects from roughly a threefold distance compared to dogs in both bright and dim light.

  12. Diagnosing cerebral visual impairment in children with good visual acuity.

    Science.gov (United States)

    van Genderen, Maria; Dekker, Marjoke; Pilon, Florine; Bals, Irmgard

    2012-06-01

    To identify elements that could facilitate the diagnosis of cerebral visual impairment (CVI) in children with good visual acuity in the general ophthalmic clinic. We retrospectively investigated the clinical characteristics of 30 children with good visual acuity and CVI and compared them with those of 23 children who were referred with a suspicion of CVI, but proved to have a different diagnosis. Clinical characteristics included medical history, MRI findings, visual acuity, crowding ratio (CR), visual field assessment, and the results of ophthalmologic and orthoptic examination. We also evaluated the additional value of a short CVI questionnaire. Eighty-three percent of the children with an abnormal medical history (mainly prematurity and perinatal hypoxia) had CVI, in contrast with none of the children with a normal medical history. Cerebral palsy, visual field defects, and partial optic atrophy only occurred in the CVI group. 41% of the children with CVI had a CR ≥2.0, which may be related to dorsal stream dysfunction. All children with CVI, but also 91% of the children without CVI gave ≥3 affirmative answers on the CVI questionnaire. An abnormal pre- or perinatal medical history is the most important risk factor for CVI in children, and therefore in deciding which children should be referred for further multidisciplinary assessment. Additional symptoms of cerebral damage, i.e., cerebral palsy, visual field defects, partial optic atrophy, and a CR ≥2 may support the diagnosis. CVI questionnaires should not be used for screening purposes as they yield too many false positives.

  13. Empiric determination of corrected visual acuity standards for train crews.

    Science.gov (United States)

    Schwartz, Steven H; Swanson, William H

    2005-08-01

    Probably the most common visual standard for employment in the transportation industry is best-corrected, high-contrast visual acuity. Because such standards were often established absent empiric linkage to job performance, it is possible that a job applicant or employee who has visual acuity less than the standard may be able to satisfactorily perform the required job activities. For the transportation system that we examined, the train crew is required to inspect visually the length of the train before and during the time it leaves the station. The purpose of the inspection is to determine if an individual is in a hazardous position with respect to the train. In this article, we determine the extent to which high-contrast visual acuity can predict performance on a simulated task. Performance at discriminating hazardous from safe conditions, as depicted in projected photographic slides, was determined as a function of visual acuity. For different levels of visual acuity, which was varied through the use of optical defocus, a subject was required to label scenes as hazardous or safe. Task performance was highly correlated with visual acuity as measured under conditions normally used for vision screenings (high-illumination and high-contrast): as the acuity decreases, performance at discriminating hazardous from safe scenes worsens. This empirically based methodology can be used to establish a corrected high-contrast visual acuity standard for safety-sensitive work in transportation that is linked to the performance of a job-critical task.

  14. 21 CFR 886.1150 - Visual acuity chart.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Visual acuity chart. 886.1150 Section 886.1150 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1150 Visual acuity chart. (a) Identification...

  15. Visual Acuity in Primary School Pupils in Lagos, Nigeria | Okoro ...

    African Journals Online (AJOL)

    ... in visual acuity. Conclusion: Eye defects occur among school children with potential negative effects. Pre-school entry eye examinations and regular screening is advocated and glasses should be made available for children with refractive error. Keywords: Visual Acuity, Screening, School Children, School Health ...

  16. Gender and environmental influences on visual acuity in Owerri ...

    African Journals Online (AJOL)

    olayemitoyin

    1Optometry Unit, Eye Clinic, Federal Medical Centre, Owerri, Imo State, 2Department of Physiology, College ... Visual acuity (V.A.) is a measure of visual function in health and disease. ..... environment especially during harmattan and dry.

  17. Visual acuity and stereoacuity among mentally retarded children.

    Science.gov (United States)

    Letourneau, J E; Beaulne, C; Duplessis, L

    1992-12-01

    To evaluate the reliability and the validity of Landolt Rings and of the Frisby Test as measures of visual acuity and stereoacuity, respectively, the visual acuity of 30 mentally retarded children was measured with Landolt Rings shown as games, the Sjögren Test, the Dot Visual Acuity Test and stereoacuity with the Frisby Test. Subjects were tested 3 times over a period of 3 weeks to measure the reliability of the tests. No significant difference was observed among these tests. The validity of the Landolt Rings was measured by a correlation of .55 for the highest logMAR values of the Sjögren Test with the highest logMAR values of the Landolt Rings. Visual acuity was systematically lower on the Dot Visual Acuity Test. The Frisby Test was not reliable among a group of 16 normal children who improved systematically over 3 weeks.

  18. [Schoolchildren's visual acuity in the dynamics of learning].

    Science.gov (United States)

    Bezrukikh, M M; Voinov, V B; Kul'ba, S N; Shurygina, I P

    2014-12-01

    The results of the screening study of the acuity of schoolchildren between 7 and 17 years old living in Rostov Region of the Russian Federation are discussed in the article. The method of computer optometry was used to measure acuity. 93772 pupils, 48621 girls and 45151 boys, from 150 schools participated in this examination. It was found that there is sustained growth of those with low acuity (0,2 and less) among children of both sexes from junior group (7 years) to the senior (17). The signs of the decline in visual acuity among girls (14%) are manifested earlier than in boys (8%). The decline in visual acuity among 7-8-year-old children is about 3%. While comparing children from rural areas with those from big cities a true dependence of the parameter (acuity) on the factors (city and sex) was found.

  19. Photometric Compliance of Tablet Screens and Retro-Illuminated Acuity Charts As Visual Acuity Measurement Devices.

    Science.gov (United States)

    Livingstone, I A T; Tarbert, C M; Giardini, M E; Bastawrous, A; Middleton, D; Hamilton, R

    2016-01-01

    Mobile technology is increasingly used to measure visual acuity. Standards for chart-based acuity tests specify photometric requirements for luminance, optotype contrast and luminance uniformity. Manufacturers provide some photometric data but little is known about tablet performance for visual acuity testing. This study photometrically characterised seven tablet computers (iPad, Apple inc.) and three ETDRS (Early Treatment Diabetic Retinopathy Study) visual acuity charts with room lights on and off, and compared findings with visual acuity measurement standards. Tablet screen luminance and contrast were measured using nine points across a black and white checkerboard test screen at five arbitrary brightness levels. ETDRS optotypes and adjacent white background luminance and contrast were measured. All seven tablets (room lights off) exceeded the most stringent requirement for mean luminance (≥ 120 cd/m2) providing the nominal brightness setting was above 50%. All exceeded contrast requirement (Weber ≥ 90%) regardless of brightness setting, and five were marginally below the required luminance uniformity threshold (Lmin/Lmax ≥ 80%). Re-assessing three tablets with room lights on made little difference to mean luminance or contrast, and improved luminance uniformity to exceed the threshold. The three EDTRS charts (room lights off) had adequate mean luminance (≥ 120 cd/m2) and Weber contrast (≥ 90%), but all three charts failed to meet the luminance uniformity standard (Lmin/Lmax ≥ 80%). Two charts were operating beyond manufacturer's recommended lamp replacement schedule. With room lights on, chart mean luminance and Weber contrast increased, but two charts still had inadequate luminance uniformity. Tablet computers showed less inter-device variability, higher contrast, and better luminance uniformity than charts in both lights-on and lights-off environments, providing brightness setting was >50%. Overall, iPad tablets matched or marginally out

  20. Photometric Compliance of Tablet Screens and Retro-Illuminated Acuity Charts As Visual Acuity Measurement Devices.

    Directory of Open Access Journals (Sweden)

    I A T Livingstone

    Full Text Available Mobile technology is increasingly used to measure visual acuity. Standards for chart-based acuity tests specify photometric requirements for luminance, optotype contrast and luminance uniformity. Manufacturers provide some photometric data but little is known about tablet performance for visual acuity testing. This study photometrically characterised seven tablet computers (iPad, Apple inc. and three ETDRS (Early Treatment Diabetic Retinopathy Study visual acuity charts with room lights on and off, and compared findings with visual acuity measurement standards. Tablet screen luminance and contrast were measured using nine points across a black and white checkerboard test screen at five arbitrary brightness levels. ETDRS optotypes and adjacent white background luminance and contrast were measured. All seven tablets (room lights off exceeded the most stringent requirement for mean luminance (≥ 120 cd/m2 providing the nominal brightness setting was above 50%. All exceeded contrast requirement (Weber ≥ 90% regardless of brightness setting, and five were marginally below the required luminance uniformity threshold (Lmin/Lmax ≥ 80%. Re-assessing three tablets with room lights on made little difference to mean luminance or contrast, and improved luminance uniformity to exceed the threshold. The three EDTRS charts (room lights off had adequate mean luminance (≥ 120 cd/m2 and Weber contrast (≥ 90%, but all three charts failed to meet the luminance uniformity standard (Lmin/Lmax ≥ 80%. Two charts were operating beyond manufacturer's recommended lamp replacement schedule. With room lights on, chart mean luminance and Weber contrast increased, but two charts still had inadequate luminance uniformity. Tablet computers showed less inter-device variability, higher contrast, and better luminance uniformity than charts in both lights-on and lights-off environments, providing brightness setting was >50%. Overall, iPad tablets matched or marginally out

  1. Testbed for High-Acuity Imaging and Stable Photometry

    Science.gov (United States)

    Gregory, James

    This proposal from MIT Lincoln Laboratory (LL) accompanies the NASA/APRA proposal enti-tled THAI-SPICE: Testbed for High-Acuity Imaging - Stable Photometry and Image-Motion Compensa-tion Experiment (submitted by Eliot Young, Southwest Research Institute). The goal of the THAI-SPICE project is to demonstrate three technologies that will help low-cost balloon-borne telescopes achieve diffraction-limited imaging: stable pointing, passive thermal stabilization and in-flight monitoring of the wave front error. This MIT LL proposal supplies a key element of the pointing stabilization component of THAI-SPICE: an electronic camera based on an orthogonaltransfer charge-coupled device (OTCCD). OTCCD cameras have been demonstrated with charge-transfer efficiencies >0.99999, noise of 90%. In addition to supplying a camera with an OTCCD detector, MIT LL will help with integration and testing of the OTCCD with the THAI-SPICE payload’s guide camera.

  2. A case-control study of visual acuity in onychocryptosis.

    LENUS (Irish Health Repository)

    Hogan, Aisling M

    2012-02-01

    BACKGROUND: There are many theories surrounding the etiology of ingrown toenails (IGTN). Few factors have been formally assessed, but it is widely accepted that a poor nail cutting technique has a causative role. AIM: To investigate the hypothesis that decreased visual acuity may lead to inadequate nail cutting and the formation of IGTN. METHODS: A prospective case-control study was performed. Near and distance visual acuity were tested on a population with IGTN (n = 19) and compared with that of an age- and sex-matched control cohort (n = 24) who underwent epidermal cyst excision in the same tertiary referral center. Comparisons of visual acuity were made between groups by Mann-Whitney U-test. Differences were taken to be significant if P < 0.05. Institutional Review Board approval was sought and granted. RESULTS: No significant difference in visual acuity (near or distance) was demonstrated between patients with IGTN and the control group (P = 0.33). CONCLUSION: Visual acuity does not appear to play a significant role in the development of IGTN.

  3. Visual acuity outcomes in eyes with flat corneas after PRK.

    Science.gov (United States)

    Varssano, David; Waisbourd, Michael; Minkev, Liza; Sela, Tzahi; Neudorfer, Meira; Binder, Perry S

    2013-06-01

    To evaluate the impact of corneal curvatures less than 35 diopters (D) after photorefractive keratectomy (PRK) on visual acuity outcomes. Visual acuity outcomes of 5,410 eyes that underwent PRK from January 2006 to November 2010 were retrospectively analyzed for the impact of postoperative corneal curvatures on visual outcomes. All procedures were performed on a single platform (Allegretto 200Hz excimer laser; Alcon Laboratories, Inc., Irvine, CA). Main outcome measures were postoperative corrected distance visual acuity (CDVA) and loss of CDVA. Corneas with a measured or a calculated postoperative flat meridian less than 35 D and those with a measured postoperative steep meridian less than 35 D had worse postoperative CDVA than corneas with meridians of either 35 D or more (P ≤ .021). However, the preoperative CDVA was worse in the flatter curvatures in all comparisons performed (P ≤ .024). Consequently, the measured or calculated meridian curvature had no effect on CDVA loss (P ≥ .074). Postoperative corneal keratometry values (flat and steep meridians) less than 35 D did not have a predictive effect on the risk of losing visual acuity following myopic PRK performed on the Allegretto 200Hz excimer laser. Copyright 2013, SLACK Incorporated.

  4. Comparative visual acuity of coleoid cephalopods.

    Science.gov (United States)

    Sweeney, Alison M; Haddock, Steven H D; Johnsen, Sönke

    2007-12-01

    The pelagic realm of the ocean is characterized by extremely clear water and a lack of surfaces. Adaptations to the visual ecology of this environment include transparency, fluorescence, bioluminescence, and deep red or black pigmentation. While the signals that pelagic organisms send are increasingly well-understood, the optical capabilities of their viewers, especially for predators with camera-like vision such as fish and squid, are almost unknown. Aquatic camera-like vision is characterized by a spherical lens focusing an image on the retina. Here, we measured the resolving power of the lenses of eight species of pelagic cephalopods to obtain an approximation of their visual capabilities. We did this by focusing a standard resolution target through dissected lenses and calculating their modulation transfer functions. The modulation transfer function (MTF) is the single most complete expression of the resolving capabilities of a lens. Since the optical and retinal capabilities of an eye are generally well-matched, we considered our measurements of cephalopod lens MTF to be a good proxy for their visual capabilities in vivo. In general, squid have optical capabilities comparable to other organisms generally assumed to have good vision, such as fish and birds. Surprisingly, the optical capability of the eye of Vampyroteuthis infernalis rivals that of humans.

  5. Socio-Demographic Factors Associated With Loss Of Visual Acuity ...

    African Journals Online (AJOL)

    The study was designed to identify the sociodemographic factors, which significantly affect the visual acuity of glaucoma patients at presentation. It is a prospective study of 154 new patients with a diagnosis of primary open angle glaucoma seen over 1 year and 8 months at the eye clinic of the University of Benin Teaching ...

  6. P3-4: Binocular Visual Acuity in Exotropia

    Directory of Open Access Journals (Sweden)

    Heekyung Yang

    2012-10-01

    Full Text Available Purpose: To investigate binocular interaction of visual acuity in patients with intermittent exotropia and its relationship with accommodative responses during binocular vision. Methods: Sixty-seven patients with intermittent exotropia of 8 years or older were included. Binocular visual acuity (BVA and monocular visual acuity (MVA were measured in sequence. Accommodative responses of both eyes were measured using the WAM-5500 autorefractor/keratometer (GrandSeiko, Fukuyama, Japan during binocular and monocular viewing conditions at 6 m. Accommodative responses during binocular vision were calculated using the difference between the refractive errors of binocular and monocular vision. Main outcome measures: Binocular interactions of visual acuity were categorized as binocular summation, equivalency, or inhibition. The prevalence of the 3 patterns of binocular interaction was investigated. Accommodative responses were correlated with differences between BVA and better MVA. Results: Most patients (41 patients, 61.2% showed binocular equivalency. Binocular inhibition and summation were noted in 6 (9.0% and 20 (29.9% patients, respectively. Linear regression analysis revealed a significant correlation between binocular interaction and accommodative responses during binocular vision (p < .001. Accommodative responses significantly correlated with the angle of exodeviation at distance (p = .002. Conclusions: In patients with intermittent exotropia, binocular inhibition is associated with increased accommodation and a larger angle of exodeviation, suggesting that accommodative convergence is a mechanism that maintains ocular alignment. Thus, BVA inhibition may be attributed to diminishing fusional control in patients with intermittent exotropia.

  7. Astronauts Cooper and Conrad prepare cameras during visual acuity tests

    Science.gov (United States)

    1965-01-01

    Astronauts L. Gordon Cooper Jr. (left), command pilot, and Charles Conrad Jr., pilot, the prime crew of the Gemini 5 space flight, prepare their cameras while aboard a C-130 aircraft flying near Laredo. The two astronauts are taking part in a series of visual acuity experiments to aid them in learning to identify known terrestrial features under controlled conditions.

  8. Analysis of relationship among visual evoked potential, oscillatory potential and visual acuity under stimulated weightlessness

    Directory of Open Access Journals (Sweden)

    Jun Zhao

    2013-05-01

    Full Text Available AIM: To observe the influence of head-down tilt simulated weightlessness on visual evoked potential(VEP, oscillatory potentials(OPsand visual acuity, and analyse the relationship among them. METHODS: Head-down tilt for -6° was adopted in 14 healthy volunteers. Distant visual acuity, near visual acuity, VEP and OPs were recorded before, two days and five days after trial. The record procedure of OPs followed the ISCEV standard for full-field clinical electroretinography(2008 update. RESULTS: Significant differences were detected in the amplitude of P100 waves and ∑OPs among various time points(P<0.05. But no relationship was observed among VEP, OPs and visual acuity. CONCLUSION: Head-down tilt simulated weightlessness induce the rearrange of blood of the whole body including eyes, which can make the change of visual electrophysiology but not visual acuity.

  9. Outcome of visual acuity after surgical removal of pituitary adenomas

    Directory of Open Access Journals (Sweden)

    Grković Desanka

    2013-01-01

    Full Text Available Introduction. Pituitary adenomas with suprasellar extension may produce anterior visual pathway compression, resulting in characteristic visual deficit. Surgical decompression of these structures prevents further visual deterioration and its postop­ erative recovery. Objective. The aim of this study was to investigate pre­ and postoperative visual acuity (VA in patients with pituitary ad­ enomas, and to detect the influence of prognostic factors, such as symptoms duration, degree of visual acuity reduction and tumor size in the assessment of the prognosis of postoperative visual function. Methods. We analyzed 40 consecutive patients who fulfilled three criteria: evidence of preoperative visual dysfunction, transsphenoidal or transfrontal tumor resection and hystologically verified pituitary adenoma. A visual examination was performed under standard conditions, pre and postoperatively (10 days, one month and six months after surgery. A paired t­test was used to assess the differences of pre­ and postoperative characteristics values, and the Chisquare test of independence in the assessment of the influence of prognostic factors. Results. Postoperative improvement of VA was seen in 84.61% patients (68% eyes. Eyes with preoperative mild and moderate degree of VA reduction showed improvement in 89.65% eyes in contrast to 22.60% eyes with preoperative severe reduction of VA, which was all statistically significant. Eyes in patients with tumor smaller than 20 mm had improvement of VA in 91.66% eyes, while eyes with tumor larger than 40 mm had improvement of VA in 61.11% eyes, which was statistically significant. When symptoms duration was below two years the improvement of VA was detected in 65.38% eyes as related to 50% eyes with symptoms duration exceeding two years, which was not statistically significant. Conclusion. Pituitary adenomas commonly cause visual impairment. Postoperatively the majority of patients show a distinct improvement of

  10. Should we add visual acuity ratios to referral criteria for potential cerebral visual impairment?

    Science.gov (United States)

    van der Zee, Ymie J; Stiers, Peter; Evenhuis, Heleen M

    To determine whether the assessment of visual acuity ratios might improve the referral of children with (sub)normal visual acuity but at risk of cerebral visual impairment. In an exploratory study, we assessed visual acuity, crowding ratio and the ratios between grating acuity (Teller Acuity Cards-II) and optotype acuity (Cambridge Crowding Cards) in 60 typically developing school children (mean age 5y8m±1y1m), 21 children with ocular abnormalities only (5y7m±1y9m) and 26 children with (suspected) brain damage (5y7m±1y11m). Sensitivities and specificities were calculated for targets and controls from the perspective of different groups of diagnosticians: youth health care professionals (target: children with any visual abnormalities), ophthalmologists and low vision experts (target: children at risk of cerebral visual impairment). For youth health care professionals subnormal visual acuity had the best sensitivity (76%) and specificity (70%). For ophthalmologists and low vision experts the crowding ratio had the best sensitivity (67%) and specificity (79 and 86%). Youth health care professionals best continue applying subnormal visual acuity for screening, whereas ophthalmologists and low vision experts best add the crowding ratio to their routine diagnostics, to distinguish children at risk of visual impairment in the context of brain damage from children with ocular pathology only. Copyright © 2016 Spanish General Council of Optometry. Published by Elsevier España, S.L.U. All rights reserved.

  11. [Determining visual acuity with LH symbols and Landolt rings].

    Science.gov (United States)

    Gräf, M; Becker, R

    1999-08-01

    Lea (LH) symbols seem to be favourable for visual acuity assessment in childhood. The symbols of the LH test are well standardized and applicable to preschool children. We compared the visual acuity determined by LH single symbols (LH) and the acuity measured with the Landolt-C (LC). 138 cooperative subjects aged 7 to 91 years were examined. Their visual acuity was either normal or reduced due to various etiologies. Their refractive error was corrected. The monocular LH and LC were determined by a 3/4 criterion (study 1). In 19 healthy subjects aged 21 to 58 years, acuity was reduced stepwise by 5 different calibrated occlusives (study 2). A Lighthouse single symbol book (LH symbols) was used at a distance of 3 m. LC was determined at a distance of 5 m. The luminance of the test field was 180-200 cd/m2. The right eye of each patient and the amblyopic eye of the squinting patients was taken for statistical evaluation. The strabismic patients' interocular differences of LC and LH were compared. Within study 1, LC ranged from 0.02 to 2.0 and LH from 0.03 to 2.5. LH overestimated LC by 1.4 lines on an average (t-test p 1 line, 85.7% resp. 90% of the strabismic amblyopic patients with an interocular LC difference > 1 resp > 2 lines were detected. In study 2, LC ranged from 0.1 to 1.6, LH from 0.12 to 2.0. The mean difference LH-LC was 1.3 lines. The regression equation was lgLH = 0.91 lgLC + 0.08 (r = 0.95). LH symbols allow a reliable measurement of recognition acuity. Due to the design of the symbols, they are excellently suitable for application to preschool children. Age related normal values should be established. The systematic difference between the LC acuity and the LH acuity measured with the Lighthouse LH single symbol book by 1.4 lines has to be considered.

  12. Relationships between luminance and visual acuity in the rhesus monkey

    Science.gov (United States)

    Cavonius, C. R.; Robbins, D. O.

    1973-01-01

    1. The ability of rhesus monkeys to detect the gap in Landolt ring test-objects that were presented against background luminances between 5 × 10-5 cd/m2 and 5 × 103 cd/m2 was compared with similar human data. 2. At high luminance-levels the acuity of human observers is slightly better than that of rhesus, but rhesus have better acuity at scotopic luminance-levels. Both species have distinct photopic and scotopic acuity functions that cross at 6 × 10-3 cd/m2. 3. The threshold for light detection is estimated to be the same for both species when specified in quanta incident on the retina. 4. It is concluded that the receptor and neural mechanisms that mediate visual-acuity function similarly in rhesus and man, and that the differences in acuity that were measured in the two species may be attributed to optical rather than to physiological factors. PMID:4199366

  13. Eye size and visual acuity influence vestibular anatomy in mammals.

    Science.gov (United States)

    Kemp, Addison D; Christopher Kirk, E

    2014-04-01

    The semicircular canals of the inner ear detect head rotations and trigger compensatory movements that stabilize gaze and help maintain visual fixation. Mammals with large eyes and high visual acuity require precise gaze stabilization mechanisms because they experience diminished visual functionality at low thresholds of uncompensated motion. Because semicircular canal radius of curvature is a primary determinant of canal sensitivity, species with large canal radii are expected to be capable of more precise gaze stabilization than species with small canal radii. Here, we examine the relationship between mean semicircular canal radius of curvature, eye size, and visual acuity in a large sample of mammals. Our results demonstrate that eye size and visual acuity both explain a significant proportion of the variance in mean canal radius of curvature after statistically controlling for the effects of body mass and phylogeny. These findings suggest that variation in mean semicircular canal radius of curvature among mammals is partly the result of selection for improved gaze stabilization in species with large eyes and acute vision. Our results also provide a possible functional explanation for the small semicircular canal radii of fossorial mammals and plesiadapiforms. Copyright © 2014 Wiley Periodicals, Inc.

  14. [Dice test--a simple method for assessment of visual acuity in infants with visual deficits].

    Science.gov (United States)

    Rohrschneider, K; Brill, B; Bayer, Y; Ahrens, P

    2010-07-01

    Determination of visual acuity in low vision infants or patients with additional cerebral retardation is difficult. In our low vision department we used dice of different sizes and colors as well as other defined objects to determine visual acuity (VA). In this study we compared the results of the dice test with conventional tests for measurement of visual acuity. A total of 88 children with different causes of visual impairment e.g. albinism, retinal scars, retinopathy of prematurity (ROP), achromatopsia and optic atrophy etc., were included in this longitudinal study. Median follow-up time was 8.7 years (range 2.9-18.9 years). The first reliable examination was performed between the ages of 4 and 24 months (median 11 months). We estimated VA depending on the edge length of the dice, which were recognized at a distance of 30 cm, while 4 mm complied with VA 20/200. Best corrected binocular visual acuity was compared between the dice test, measurement with the Lea symbols and with numbers or Landolt rings. Estimation of visual acuity using the dice test was possible at the end of the first year of life (median 11 months, range 4-27 months). Although observation is limited to visual acuity results in the low vision range between light reaction and 20/120 there was nearly complete agreement between all three VA measurements. Visual acuity ranged from light perception to 20/20 with a median of 20/100. In 39 patients visual acuity was 20/200 or less at the end of the observation period. Visual acuity estimation overestimated visual acuity only in 5 out of the 88 patients, while in all of the patients with later acuity measurements better than 20/200, our best value of 20/200 was achieved. Using simple visual objects, such as dice with different colors and size down to an edge length of 4 mm, it is possible to estimate visual acuity in low vision infants within the first year of life. This option is also very helpful in patients who are not able to perform other visual

  15. A new Snellen's visual acuity chart with 'Indian' numerals.

    OpenAIRE

    Al-Salem, M

    1987-01-01

    'Indian' numerals, which are popular among the Arab population, were used to devise a new Snellen's visual acuity chart. The new chart has the advantages of a reading chart. It keeps the patient's interest, does not miss alexic patients, and is quicker to perform. It is also devoid of the many disadvantages of a kinetic response chart (the capital E letter or Landolt's broken rings), especially that of the limited option of test objects.

  16. Desktop publishing and validation of custom near visual acuity charts.

    Science.gov (United States)

    Marran, Lynn; Liu, Lei; Lau, George

    2008-11-01

    Customized visual acuity (VA) assessment is an important part of basic and clinical vision research. Desktop computer based distance VA measurements have been utilized, and shown to be accurate and reliable, but computer based near VA measurements have not been attempted, mainly due to the limited spatial resolution of computer monitors. In this paper, we demonstrate how to use desktop publishing to create printed custom near VA charts. We created a set of six near VA charts in a logarithmic progression, 20/20 through 20/63, with multiple lines of the same acuity level, different letter arrangements in each line and a random noise background. This design allowed repeated measures of subjective accommodative amplitude without the potential artifact of familiarity of the optotypes. The background maintained a constant and spatial frequency rich peripheral stimulus for accommodation across the six different acuity levels. The paper describes in detail how pixel-wise accurate black and white bitmaps of Sloan optotypes were used to create the printed custom VA charts. At all acuity levels, the physical sizes of the printed custom optotypes deviated no more than 0.034 log units from that of the standard, satisfying the 0.05 log unit ISO criterion we used to demonstrate physical equivalence. Also, at all acuity levels, log unit differences in the mean target distance for which reliable recognition of letters first occurred for the printed custom optotypes compared to the standard were found to be below 0.05, satisfying the 0.05 log unit ISO criterion we used to demonstrate functional equivalence. It is possible to use desktop publishing to create custom near VA charts that are physically and functionally equivalent to standard VA charts produced by a commercial printing process.

  17. Perceptual Learning in Children With Visual Impairment Improves Near Visual Acuity

    NARCIS (Netherlands)

    Huurneman, Bianca; Boonstra, F. Nienke; Cox, Ralf F. A.; van Rens, Ger; Cillessen, Antonius H. N.

    PURPOSE. This study investigated whether visual perceptual learning can improve near visual acuity and reduce foveal crowding effects in four-to nine-year-old children with visual impairment. METHODS. Participants were 45 children with visual impairment and 29 children with normal vision. Children

  18. Perceptual Learning in Children With Visual Impairment Improves Near Visual Acuity

    NARCIS (Netherlands)

    Huurneman, B.; Boonstra, F.N.; Cox, R.F.A.; van Rens, G.H.M.B.; Cillessen, A.H.N.

    2013-01-01

    Purpose. This study investigated whether visual perceptual learning can improve near visual acuity and reduce foveal crowding effects in four- to nine-year-old children with visual impairment. Methods. Participants were 45 children with visual impairment and 29 children with normal vision. Children

  19. Perceptual learning in children with visual impairment improves near visual acuity

    NARCIS (Netherlands)

    Huurneman, B.; Boonstra, F.N.; Cox, R.F.; Rens, G. van; Cillessen, A.H.

    2013-01-01

    PURPOSE: This study investigated whether visual perceptual learning can improve near visual acuity and reduce foveal crowding effects in four- to nine-year-old children with visual impairment. METHODS: Participants were 45 children with visual impairment and 29 children with normal vision. Children

  20. Perceptual Learning in Children With Visual Impairment Improves Near Visual Acuity

    NARCIS (Netherlands)

    Huurneman, B.; Boonstra, F.N.; Cox, R.F.A.; Rens, G.H.M.B. van; Cillessen, A.H.N.

    2013-01-01

    PURPOSE. This study investigated whether visual perceptual learning can improve near visual acuity and reduce foveal crowding effects in four-to nine-year-old children with visual impairment. METHODS. Participants were 45 children with visual impairment and 29 children with normal vision. Children

  1. Changes in brain morphology in albinism reflect reduced visual acuity.

    Science.gov (United States)

    Bridge, Holly; von dem Hagen, Elisabeth A H; Davies, George; Chambers, Claire; Gouws, Andre; Hoffmann, Michael; Morland, Antony B

    2014-07-01

    Albinism, in humans and many animal species, has a major impact on the visual system, leading to reduced acuity, lack of binocular function and nystagmus. In addition to the lack of a foveal pit, there is a disruption to the routing of the nerve fibers crossing at the optic chiasm, resulting in excessive crossing of fibers to the contralateral hemisphere. However, very little is known about the effect of this misrouting on the structure of the post-chiasmatic visual pathway, and the occipital lobes in particular. Whole-brain analyses of cortical thickness in a large cohort of subjects with albinism showed an increase in cortical thickness, relative to control subjects, particularly in posterior V1, corresponding to the foveal representation. Furthermore, mean cortical thickness across entire V1 was significantly greater in these subjects compared to controls and negatively correlated with visual acuity in albinism. Additionally, the group with albinism showed decreased gyrification in the left ventral occipital lobe. While the increase in cortical thickness in V1, also found in congenitally blind subjects, has been interpreted to reflect a lack of pruning, the decreased gyrification in the ventral extrastriate cortex may reflect the reduced input to the foveal regions of the ventral visual stream. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Fluctuation in visual acuity during soft toric contact lens wear.

    Science.gov (United States)

    Chamberlain, Paul; Morgan, Philip B; Moody, Kurt J; Maldonado-Codina, Carole

    2011-04-01

    To quantify changes in visual acuity (VA) with soft toric contact lenses as a result of lens movement and/or rotational instability caused by versional eye movements. A novel chart for vision assessment at near (40 cm) for soft toric contact lenses (VANT chart),consisting of a central, color-coded logMAR panel and eight peripheral letter targets set on a white background measuring 60 × 40 cm was constructed. In the developmental phase of the work, 10 subjects (20 eyes) wore 2 toric lenses in random order, and the impact of rapid and delayed eye versions in 8 directions of gaze on VANT acuity was investigated. In phase 2, 35 subjects (68 eyes) wore 4 toric lenses in random order, and a streamlined clinical protocol using the VANT chart was implemented. Standard assessments of toric lens fit and distance VA were also performed. Testing in the first phase showed no difference for change in VA for rapid vs. delayed version movements, (p = 0.17) but acuity reduction was greater for diagonal compared with horizontal/vertical versions (p = 0.06). As such, testing in phase 2 proceeded using rapid, diagonal versions only. In this second phase, there were differences for low-contrast distance VA measures between lens types (p = 0.02) and for both VANT baseline acuity (p = 0.03) and postversion acuity (p = 0.04), but no differences were found between lenses for magnitude of vision loss (p = 0.91), which was about one line. No relationship was established between the magnitude of vision loss and measured rotational stability (p = 0.75). This work has demonstrated that conventional approaches to measuring VA do not fully replicate the "real world" experience of soft toric lens wearers. The VANT chart has shown that VA is reduced immediately after versional eye movements and suggests that more dynamic methods of assessing visual performance should be considered for soft toric contact lens wearers, especially given the apparent inability of lens stability measurements to predict

  3. Photovoltaic restoration of sight with high visual acuity

    Science.gov (United States)

    Lorach, Henri; Goetz, Georges; Smith, Richard; Lei, Xin; Mandel, Yossi; Kamins, Theodore; Mathieson, Keith; Huie, Philip; Harris, James; Sher, Alexander; Palanker, Daniel

    2015-01-01

    Patients with retinal degeneration lose sight due to gradual demise of photoreceptors. Electrical stimulation of the surviving retinal neurons provides an alternative route for delivery of visual information. We demonstrate that subretinal arrays with 70 μm photovoltaic pixels provide highly localized stimulation, with electrical and visual receptive fields of comparable sizes in rat retinal ganglion cells. Similarly to normal vision, retinal response to prosthetic stimulation exhibits flicker fusion at high frequencies, adaptation to static images and non-linear spatial summation. In rats with retinal degeneration, these photovoltaic arrays provide spatial resolution of 64 ± 11 μm, corresponding to half of the normal visual acuity in pigmented rats. Ease of implantation of these wireless and modular arrays, combined with their high resolution opens the door to functional restoration of sight. PMID:25915832

  4. Grating-acuity in children. Normal values of visual acuity in children up to 13 years as assessed by the acuity card procedure.

    Science.gov (United States)

    Schenk-Rootlieb, A J; van Nieuwenhuizen, O; van Zoggel, J; van der Graaf, Y; Willemse, J

    1992-09-01

    The acuity card procedure proved to be a useful method for assessing visual acuity in children. Normal values of visual acuity measured by this method had already been assessed in children up to four years. To enable application of the test in older children this study obtained values in a group of 396 normal children, aged three months to 13 years. The mean curve as well as the 10th centile was calculated in different age groups. A considerable variation of acuity values causing a 'dip' in the 10th centile was found in the ages 18 to 24 months. A smaller 'dip' was found in the ages 48 to 52 months. This has to be attributed to behavioural properties connected with age. The results obtained in the group of children under four years of age corresponded fairly well with other studies. In schoolchildren a fair agreement could also be found between the data obtained using the acuity card procedure and the data obtained with the Landolt-C rings. Obtaining normal values for the acuity card procedure in children covering a wide age range facilitates recognition of visual handicap in children who are difficult to assess.

  5. Distinct eye movement patterns enhance dynamic visual acuity

    Science.gov (United States)

    Palidis, Dimitrios J.; Wyder-Hodge, Pearson A.; Fooken, Jolande; Spering, Miriam

    2017-01-01

    Dynamic visual acuity (DVA) is the ability to resolve fine spatial detail in dynamic objects during head fixation, or in static objects during head or body rotation. This ability is important for many activities such as ball sports, and a close relation has been shown between DVA and sports expertise. DVA tasks involve eye movements, yet, it is unclear which aspects of eye movements contribute to successful performance. Here we examined the relation between DVA and the kinematics of smooth pursuit and saccadic eye movements in a cohort of 23 varsity baseball players. In a computerized dynamic-object DVA test, observers reported the location of the gap in a small Landolt-C ring moving at various speeds while eye movements were recorded. Smooth pursuit kinematics—eye latency, acceleration, velocity gain, position error—and the direction and amplitude of saccadic eye movements were linked to perceptual performance. Results reveal that distinct eye movement patterns—minimizing eye position error, tracking smoothly, and inhibiting reverse saccades—were related to dynamic visual acuity. The close link between eye movement quality and DVA performance has important implications for the development of perceptual training programs to improve DVA. PMID:28187157

  6. Distinct eye movement patterns enhance dynamic visual acuity.

    Science.gov (United States)

    Palidis, Dimitrios J; Wyder-Hodge, Pearson A; Fooken, Jolande; Spering, Miriam

    2017-01-01

    Dynamic visual acuity (DVA) is the ability to resolve fine spatial detail in dynamic objects during head fixation, or in static objects during head or body rotation. This ability is important for many activities such as ball sports, and a close relation has been shown between DVA and sports expertise. DVA tasks involve eye movements, yet, it is unclear which aspects of eye movements contribute to successful performance. Here we examined the relation between DVA and the kinematics of smooth pursuit and saccadic eye movements in a cohort of 23 varsity baseball players. In a computerized dynamic-object DVA test, observers reported the location of the gap in a small Landolt-C ring moving at various speeds while eye movements were recorded. Smooth pursuit kinematics-eye latency, acceleration, velocity gain, position error-and the direction and amplitude of saccadic eye movements were linked to perceptual performance. Results reveal that distinct eye movement patterns-minimizing eye position error, tracking smoothly, and inhibiting reverse saccades-were related to dynamic visual acuity. The close link between eye movement quality and DVA performance has important implications for the development of perceptual training programs to improve DVA.

  7. Experimental validation of a Bayesian model of visual acuity.

    LENUS (Irish Health Repository)

    Dalimier, Eugénie

    2009-01-01

    Based on standard procedures used in optometry clinics, we compare measurements of visual acuity for 10 subjects (11 eyes tested) in the presence of natural ocular aberrations and different degrees of induced defocus, with the predictions given by a Bayesian model customized with aberrometric data of the eye. The absolute predictions of the model, without any adjustment, show good agreement with the experimental data, in terms of correlation and absolute error. The efficiency of the model is discussed in comparison with image quality metrics and other customized visual process models. An analysis of the importance and customization of each stage of the model is also given; it stresses the potential high predictive power from precise modeling of ocular and neural transfer functions.

  8. Is theta burst stimulation applied to visual cortex able to modulate peripheral visual acuity?

    Directory of Open Access Journals (Sweden)

    Sabrina Brückner

    Full Text Available Repetitive transcranial magnetic stimulation is usually applied to visual cortex to explore the effects on cortical excitability. Most researchers therefore concentrate on changes of phosphene threshold, rarely on consequences for visual performance. Thus, we investigated peripheral visual acuity in the four quadrants of the visual field using Landolt C optotypes before and after repetitive stimulation of the visual cortex. We applied continuous and intermittend theta burst stimulation with various stimulation intensities (60%, 80%, 100%, 120% of individual phosphene threshold as well as monophasic and biphasic 1 Hz stimulation, respectively. As an important result, no serious adverse effects were observed. In particular, no seizure was induced, even with theta burst stimulation applied with 120% of individual phosphene threshold. In only one case stimulation was ceased because the subject reported intolerable pain. Baseline visual acuity decreased over sessions, indicating a continuous training effect. Unexpectedly, none of the applied transcranial magnetic stimulation protocols had an effect on performance: no change in visual acuity was found in any of the four quadrants of the visual field. Binocular viewing as well as the use of peripheral instead of foveal presentation of the stimuli might have contributed to this result. Furthermore, intraindividual variability could have masked the TMS- induced effects on visual acuity.

  9. [The relationship between eyeball structure and visual acuity in high myopia].

    Science.gov (United States)

    Liu, Yi-Chang; Xia, Wen-Tao; Zhu, Guang-You; Zhou, Xing-Tao; Fan, Li-Hua; Liu, Rui-Jue; Chen, Jie-Min

    2010-06-01

    To explore the relationship between eyeball structure and visual acuity in high myopia. Totally, 152 people (283 eyeballs) with different levels of myopia were tested for visual acuity, axial length, and fundus. All cases were classified according to diopter, axial length, and fundus. The relationships between diopter, axial length, fundus and visual acuity were studied. The mathematical models were established for visual acuity and eyeball structure markers. The visual acuity showed a moderate correlation with fundus class, comus, axial length and diopter ([r] > 0.4, P eyeball structure markers. The visual acuity should decline with axial length extension, diopter deepening and pathological deterioration of fundus. To detect the structure changes by combining different kinds of objective methods can help to assess and to judge the vision in high myopia.

  10. Effects of lighting and task parameters on visual acuity and performance

    Energy Technology Data Exchange (ETDEWEB)

    Halonen, L.

    1993-12-31

    Lighting and task parameters and their effects on visual acuity and visual performance are dealt with. The parameters studied are target contrast, target size and subject`s age; and also adaptation luminance, luminance ratio between task and its surrounding and temporal change in luminances are studied. Experiments were carried out to examine the effects of luminance and light spectrum on visual acuity. Young normally sighted, older and low vision people participated in the measurements. In the young and older subject groups the visual acuity remained unchanged at contrasts 0.93 and 0.63 at the luminance range of 15-630 cd/m{sub 2}. The results show that at contrasts 0.03-0.93 young and older subjects` visual acuity remained unchanged in the luminance range of 105-630 cd/m{sub 2}. In the low vision group, the changes in luminances between 25-860 cd/m{sub 2} did not have significant effects on visual acuity measured at high contrast 0.93, at low contrast, slight individual changes were found. The colour temperature of the light sources was altered between 2900-9500 K in the experiment. In the groups of the older, young and low vision subjects the light spectrum did not have significant effects on visual acuity, except for two retinitis pigmentosa subjects. On the basis of the visual acuity experiments, a three dimensional visual acuity model (VA-HUT) has been developed. The model predicts visual acuity as a function of luminance, target contrast and observer age. On the basis of visual acuity experiments visual acuity reserve values have been calculated for different text sizes

  11. Perceptual learning in children with visual impairment improves near visual acuity.

    Science.gov (United States)

    Huurneman, Bianca; Boonstra, F Nienke; Cox, Ralf F A; van Rens, Ger; Cillessen, Antonius H N

    2013-09-17

    This study investigated whether visual perceptual learning can improve near visual acuity and reduce foveal crowding effects in four- to nine-year-old children with visual impairment. Participants were 45 children with visual impairment and 29 children with normal vision. Children with visual impairment were divided into three groups: a magnifier group (n = 12), a crowded perceptual learning group (n = 18), and an uncrowded perceptual learning group (n = 15). Children with normal vision also were divided in three groups, but were measured only at baseline. Dependent variables were single near visual acuity (NVA), crowded NVA, LH line 50% crowding NVA, number of trials, accuracy, performance time, amount of small errors, and amount of large errors. Children with visual impairment trained during six weeks, two times per week, for 30 minutes (12 training sessions). After training, children showed significant improvement of NVA in addition to specific improvements on the training task. The crowded perceptual learning group showed the largest acuity improvements (1.7 logMAR lines on the crowded chart, P children in the crowded perceptual learning group showed improvements on all NVA charts. Children with visual impairment benefit from perceptual training. While task-specific improvements were observed in all training groups, transfer to crowded NVA was largest in the crowded perceptual learning group. To our knowledge, this is the first study to provide evidence for the improvement of NVA by perceptual learning in children with visual impairment. (http://www.trialregister.nl number, NTR2537.).

  12. Visual acuity with simulated and real astigmatic defocus.

    Science.gov (United States)

    Ohlendorf, Arne; Tabernero, Juan; Schaeffel, Frank

    2011-05-01

    To compare the effects of "simulated" and "real" spherical and astigmatic defocus on visual acuity (VA). VA was determined with letter charts that were blurred by calculated spherical or astigmatic defocus (simulated defocus) or were seen through spherical or astigmatic trial lenses (real defocus). Defocus was simulated using ZEMAX and the Liou-Brennan eye model. Nine subjects participated [mean age, 27.2 ± 1.8 years; logarithm of the minimum angle of resolution (logMAR), -0.1]. Three different experiments were conducted in which VA was reduced by 20% (logMAR 0.0), 50% (logMAR 0.2), or 75% (logMAR 0.5) by either (1) imposing positive spherical defocus, (2) imposing positive and negative astigmatic defocus in three axes (0, 45, and 90°), and (3) imposing cross-cylinder defocus in the same three axes as in (2). Experiment (1): there were only minor differences in VA with simulated and real positive spherical defocus. Experiment (2): simulated astigmatic defocus reduced VA twice as much as real astigmatic defocus in all tested axes (p < 0.01 in all cases). Experiment (3): simulated cross-cylinder defocus reduced VA much more than real cross-cylinder defocus (p < 0.01 in all cases), similarly for all three tested axes. The visual system appears more tolerant against "real" spherical, astigmatic, and cross-cylinder defocus than against "simulated" blur. Possible reasons could be (1) limitations in the modeling procedures to simulate defocus, (2) higher ocular aberrations, and (3) fluctuations of accommodation. However, the two optical explanations (2) and (3) cannot account for the magnitude of the effect, and (1) was carefully analyzed. It is proposed that something may be special about the visual processing of real astigmatic and cross-cylinder defocus-because they have less effect on VA than simulations predict.

  13. Presenting visual acuities in a new eye centre in Port Harcourt: initial ...

    African Journals Online (AJOL)

    Background: Visual acuity is a fundamental of an eye examination. It establishes in a quantitative way how well an eye can see. Apart from being a starting point in dealing with an eye, it is also a prognostic reference point and a medico-legal tool. Very few studies directly related to visual acuities are available as many ...

  14. Contributing factors to VEP grating acuity deficit and inter-ocular acuity difference in children with cerebral visual impairment.

    Science.gov (United States)

    Cavascan, Nívea Nunes; Salomão, Solange Rios; Sacai, Paula Yuri; Pereira, Josenilson Martins; Rocha, Daniel Martins; Berezovsky, Adriana

    2014-04-01

    To investigate contributing factors to visual evoked potential (VEP) grating acuity deficit (GAD) and inter-ocular acuity difference (IAD) measured by sweep-VEPs in children with cerebral visual impairment (CVI). VEP GAD was calculated for the better acuity eye by subtracting acuity thresholds from mean normal VEP grating acuity according to norms from our own laboratory. Deficits were categorized as mild (0.17 ≤ deficit children (66 males-57 %) with ages ranging from 1.2 to 166.5 months (median = 17.7) was examined. VEP GAD ranged from 0.17 to 1.28 log units (mean = 0.68 ± 0.27; median = 0.71), and it was mild in 23 (20 %) children, moderate in 32 (28 %) and severe in 60 (52 %). Severe deficit was significantly associated with older age and anti-seizure drug therapy. IAD ranged from 0 to 0.49 log units (mean = 0.06 ± 0.08; median = 0.04) and was acceptable in 96 (83 %) children. Children with strabismus and nystagmus had IAD significantly larger compared to children with orthoposition. In a large cohort of children with CVI, variable severity of VEP GAD was found, with more than half of the children with severe deficits. Older children and those under anti-seizure therapy were at higher risk for larger deficits. Strabismus and nystagmus provided larger IADs. These results should be taken into account on the clinical management of children with this leading cause of bilateral visual impairment.

  15. Visual acuity and quality of life in dry eye disease: Proceedings of the OCEAN group meeting.

    Science.gov (United States)

    Benítez-Del-Castillo, José; Labetoulle, Marc; Baudouin, Christophe; Rolando, Maurizio; Akova, Yonca A; Aragona, Pasquale; Geerling, Gerd; Merayo-Lloves, Jesús; Messmer, Elisabeth M; Boboridis, Kostas

    2017-04-01

    Dry eye disease (DED) results in tear film instability and hyperosmolarity, inflammation of the ocular surface and, ultimately, visual disturbance that can significantly impact a patient's quality of life. The effects on visual acuity result in difficulties with driving, reading and computer use and negatively impact psychological health. These effects also extend to the workplace, with a loss of productivity and quality of work causing substantial economic losses. The effects of DED and the impact on vision experienced by patients may not be given sufficient importance by ophthalmologists. Functional visual acuity (FVA) is a measure of visual acuity after sustained eye opening without blinking for at least 10 s and mimics the sustained visual acuity of daily life. Measuring dynamic FVA allows the detection of impaired visual function in patients with DED who may display normal conventional visual acuity. There are currently several tests and methods that can be used to measure dynamic visual function: the SSC-350 FVA measurement system, assessment of best-corrected visual acuity decay using the interblink visual acuity decay test, serial measurements of ocular and corneal higher order aberrations, and measurement of dynamic vision quality using the Optical Quality Analysis System. Although the equipment for these methods may be too large or unaffordable for use in clinical practice, FVA testing is an important assessment for DED. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Visual acuity after Ruthenium106 brachytherapy of choroidal melanomas

    International Nuclear Information System (INIS)

    Damato, Bertil; Patel, Imran M.; Campbell, Ian R.; Mayles, Helen M.; Errington, R. Douglas

    2005-01-01

    Purpose: To report on conservation of visual acuity after Ruthenium 106 (Ru-106) brachytherapy of choroidal melanoma. Methods and materials: This study was a noncomparative interventional case series of 458 patients with choroidal melanoma treated at a single center between January 1993 and December 2001. The intervention consisted of Ru-106 brachytherapy delivering minimum scleral and apex doses of 300 Gy and 80 Gy, respectively, using a 15-mm or 20-mm plaque. For discrete, posterior tumors, the plaque was positioned eccentrically with its posterior edge aligned with the posterior tumor margin. To ensure correct plaque positioning, any overlying extraocular muscles were dis-inserted, and the locations of both tumor and plaque edges were confirmed by transillumination and indentation. The main outcome measures were conservation of vision of 20/40 or better, 20/200 or better, and Counting Fingers or better, according to baseline variables. Results: The actuarial rate of conservation of 20/40 or better was 55% at 9 years, loss of such vision correlating with posterior tumor extension (p 106 brachytherapy of posterior choroidal melanoma achieves good conservation of vision if the tumor does not extend close to the optic nerve or fovea

  17. Female carpet weavers' visual acuity and effective factors: Fordu rural area of Qom

    Directory of Open Access Journals (Sweden)

    Khajenasiri F.

    2007-11-01

    Full Text Available Background: Healthy vision of workers is one of the important elements in carpet weaving industry which has essential role in improving of the job quality and efficiency. Visual acuity is the primary outcome measure in most studies involving eye diseases. Ihe aim of this study was determination of visual acuity and its effective factors in women carpet weaver in fordu rural area of Qom has been investigated.  Methods: In a cross-sectional (descriptive-analytical study visual acuity of 177 women carpet weaver has been determined. Job hours per day, job history, age, literacy, trauma history, diabetes history, family history of eye diseases, eye diseases history and family size  of subjects were determined .Results: The results of study indicated that the right eyes visual acuity of 72.4 % of women were desirable (0 - 0.8 and 27.6 % were undesirable (0.9-1.2. These results for the left eyes were 69.5 % and 30.5 % respectively. In addition, the result showed that with increasing the job hours and history and age, percent of women with undesirable both eyes visual acuity were increased. With higher literacy levels, percent of women with undesirable both eyes visual acuity decreased. In subjects with truma history, the undesirable visual acuity was higher. In this study the relation between visual acuity and job history, age, literacy, truma history and eye diseases history were statistically significant (in all cases P<0.05.Conclusions: High percentage of women carpet weaver were in undesirable  visual acuity and in this study the relation between visual acuity and job history, age, literacy, trauma history and eye diseases history were statistically significant (in all cases P<0.05.

  18. Development and clinical application of a color pediatric visual acuity chart

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    Shu-Guo Yin

    2014-12-01

    Full Text Available AIM: To introduce a new color pediatric visual acuity chart and its clinical application.METHODS:The color pediatric visual acuity chart was designed based on principle of visual angle. The optotype on the color chart had graphics. The progression rate of optotype size between 2 lines was 10(101/2 and 1.2589. A regular geometric progression of optotype sizes and distribution was employed to arrange 8 lines with 11 optotype on the color chart. The testing distance was 3m. The visual acuity score could be recorded as logarithm of the minimum angle of resolution notation or decimal notation. The reliability of naked distant measurements with this new chart was tested in one eye of 100 children(4 ~6 years oldtaking the Chinese national standard logarithm visual acuity chart standard. RESULTS: The color pediatric visual acuity chart and logarithmic chart controls, visual acuity test results that in the two groups had no significant difference(t=1.2671, P>0.05. Two sets of vision data existed positive correlation(r=0.924, PCONCLUSION:Children are easier to accept used new color pediatric visual acuity chart to inspect vision. New chart is reliability and apply to children's vision screening.

  19. Higher-order aberrations and visual acuity after LASEK.

    Science.gov (United States)

    Urgancioglu, Berrak; Bilgihan, Kamil; Ozturk, Sertac

    2008-08-01

    To determine ocular higher-order aberrations (HOAs) in eyes with supernormal vision after myopic astigmatic laser subepithelial keratomileusis (LASEK) and to compare the findings with those in eyes with natural supernormal vision. Ocular HOAs were measured after LASEK in 20 eyes of 12 myopic astigmatic patients with postoperative uncorrected visual acuity (UCVA) of >20/16 (group 1). Patients who were included in the study had no visual symptoms like glare, halo or double vision. The measurements were taken 8.3 +/- 3 months after LASEK surgery. In group 2 ocular HOAs were examined in 20 eyes of 10 subjects with natural UCVA of >20/16 as a control. Measurements were taken across a pupil with a diameter of 4.0 mm and 6.0 mm. Root-mean-square (RMS) values of HOAs, Z(3)-1, Z(3)1, Z(4)0, Z(5)-1, Z(5)1 and Z(6)0 were analyzed. The mean RMS values for each order were higher in group 1 when compared with group 2 at 4.0 mm and 6.0 mm pupil diameters. There was no statistically significant difference between groups in spherical and coma aberrations (P > 0.05). Mean RMS values for total HOAs were 0.187 +/- 0.09 microm at 4.0 mm and 0.438 +/- 0.178 microm at 6.0 mm pupil in group 1 and 0.120 +/- 0.049 microm at 4.0 mm and 0.344 +/- 0.083 microm at 6.0 mm pupil in group 2. The difference between groups in total HOAs was statistically significant at 4.0 mm and 6.0 mm pupil diameters (P < 0.05). Ocular HOAs exist in eyes with supernormal vision. After LASEK, the amount of HOAs of the eye increases under both mesopic and photopic conditions. However the amount of HOA increase does not seem to be consistent with visual symptoms.

  20. Método computadorizado para medida da acuidade visual A computerized method for visual acuity assessment

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    Patrícia Katayama Kjaer Arippol

    2006-12-01

    Full Text Available OBJETIVO: Elaborar e validar teste computadorizado para medida da acuidade visual de escolares. MÉTODOS: Foi elaborado teste computadorizado para determinação da acuidade visual utilizando os padrões das tabelas logarítmicas impressas adotadas na clínica oftalmológica. Foram avaliados 90 alunos da primeira série do ensino básico, oito estudantes do curso de Tecnologia Oftálmica da UNIFESP-EPM e 10 pacientes do ambulatório de Estrabismo do Departamento de Oftalmologia da UNIFESP-EPM. Todos os sujeitos foram avaliados pelo mesmo examinador e submetidos ao exame de acuidade visual monocular, pela tabela logarítmica de optotipos E impressa e do novo teste computadorizado no mesmo momento. Os participantes forneceram os seus consentimentos após esclarecimento. RESULTADOS: As análises estatísticas revelaram correlação excelente (r>0,75 entre os dois métodos, apesar da leve tendência apresentada pelo teste computadorizado em superestimar a acuidade visual quando comparado com o padrão-ouro. O teste computadorizado apresentou sensibilidade de 100% e especificidade de 94%. CONCLUSÕES: Os resultados obtidos nos permitem dizer que o teste computadorizado pode ser utilizado como novo recurso para triagem da qualidade visual dos escolares, por ser método rápido, de fácil aplicação, barato, automático e atrativo para as crianças. A automatização desvincula o aplicador da interpretação das respostas dadas pelo aluno testado, garante padronização do procedimento, que favorece as análises de acompanhamento e pode ser realizado por diferentes examinadores. Para melhor compreensão da efetividade do teste como instrumento de triagem visual, seria interessante instituí-lo nas escolas do curso básico, após treinamento dos professores para sua aplicação.PURPOSE: To elaborate and to validate a computerized test for visual acuity screening of school-age children. METHODS: We have created a computerized test for visual acuity

  1. VISUAL ABILITY IN AMBLYOPIC CHILDREN COMPARED TO CHILDREN WITH NORMAL VISUAL ACUITY

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    Zorica Tončić

    2016-03-01

    Full Text Available Vision rehabilitation in adults with low vision, even in children, is achieved with special devices, called low vision aids, LVA. The aim of the study is to determine the degree of visual function in amblyopic children and daily activities that are best related to those of normally sighted peers with normal visual acuity. The subjects were divided into two groups, matched 1:1 by age and gender: the first group consisted of 19 amblyopic children, and the second one consisted of 19 children with normal visual acuity. The questionnaire used to assess visual ability was Cardiff Visual Ability Questionnaire for Children (CVAQC, a reliable instrument for measuring visual ability in children with low vision. The study was conducted in the only rehabilitation center for amblyopic children in this region, so this is also a pioneer study. The overall result of CVAQC in amblyopic children was 1.287 log vs.-2.956, representing statistically significantly poorer visual ability in comparison to peers without vision deficit (p˂0.005. Amblyopic children function best in entertainment activities, especially in listening music (-2.31 log; as for sport, these children report swimming to be their favourite activity (-0.99 log. In the field of education they show best results in language acquisition (-0.79 log and the worst in mathematics (3.13 log. The greatest problem is reading small print texts books (2.61 log. Low vision children have poorer result of visual function in comparison to their peers with normal visual acuity. A precise deficit assessment in the most important spheres of life can be determined by using the questionnaires, so the rehabilitation can be rightly chosen.

  2. Recognition versus Resolution: a Comparison of Visual Acuity Results Using Two Alternative Test Chart Optotype

    OpenAIRE

    Jonathan S. Pointer

    2008-01-01

    Purpose: To quantify the difference between recognition (letter) and resolution (Landolt) visual acuity (VA) in a group of normally sighted subjects. Is it reasonable to assume that the two acuity measures are clinically equivalent? Methods: A pair of 6 m acuity test charts was produced: one comprised letters and the other Landolt broken rings. Construction of both charts conformed to the logMAR design format. Monocular VA was determined for the dominant eye of 300 screened and normally si...

  3. Visual acuity and visual skills in Malaysian children with learning disabilities

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    Muzaliha MN

    2012-09-01

    Full Text Available Mohd-Nor Muzaliha,1 Buang Nurhamiza,1 Adil Hussein,1 Abdul-Rani Norabibas,1 Jaafar Mohd-Hisham-Basrun,1 Abdullah Sarimah,2 Seo-Wei Leo,3 Ismail Shatriah11Department of Ophthalmology, 2Biostatistics and Research Methodology Unit, School of Medical Sciences, Universiti Sains Malaysia, Kelantan, Malaysia; 3Paediatric Ophthalmology and Strabismus Unit, Department of Ophthalmology, Tan Tock Seng Hospital, SingaporeBackground: There is limited data in the literature concerning the visual status and skills in children with learning disabilities, particularly within the Asian population. This study is aimed to determine visual acuity and visual skills in children with learning disabilities in primary schools within the suburban Kota Bharu district in Malaysia.Methods: We examined 1010 children with learning disabilities aged between 8–12 years from 40 primary schools in the Kota Bharu district, Malaysia from January 2009 to March 2010. These children were identified based on their performance in a screening test known as the Early Intervention Class for Reading and Writing Screening Test conducted by the Ministry of Education, Malaysia. Complete ocular examinations and visual skills assessment included near point of convergence, amplitude of accommodation, accommodative facility, convergence break and recovery, divergence break and recovery, and developmental eye movement tests for all subjects.Results: A total of 4.8% of students had visual acuity worse than 6/12 (20/40, 14.0% had convergence insufficiency, 28.3% displayed poor accommodative amplitude, and 26.0% showed signs of accommodative infacility. A total of 12.1% of the students had poor convergence break, 45.7% displayed poor convergence recovery, 37.4% showed poor divergence break, and 66.3% were noted to have poor divergence recovery. The mean horizontal developmental eye movement was significantly prolonged.Conclusion: Although their visual acuity was satisfactory, nearly 30% of the

  4. [Measuring contrast sensitivity using visual acuity tests in retinal and optic nerve diseases].

    Science.gov (United States)

    Sommer, E; Marré, E; Mierdel, P

    1990-01-01

    The luminance contrast needed to discern various test types was measured with monochromatic and achromatic light to detect discrete functional deficiencies of the retina and optic nerve in cases of normal visual acuity. Landolt rings corresponding to visual acuity levels from 0.04 to 1.0 were used as test types. A significant increase in the necessary minimum contrast was detectable with blue test light on large Landolt rings in patients with diabetic retinopathy, ocular hypertension and glaucoma and with green or yellow test light on medium-sized and small Landolt rings in patients with central serous chorioidopathy and optic atrophy. The additional contrast needed to reach the maximum visual acuity amounts to 14-100% compared with normal visual acuity, depending on the color of the test light and the diagnosis. The amount of contrast needed is greatest in retinal diseases, and it is therefore possible to a certain extent to distinguish these from diseases of the optic nerve.

  5. Perceptual learning improves contrast sensitivity, visual acuity, and foveal crowding in amblyopia.

    Science.gov (United States)

    Barollo, Michele; Contemori, Giulio; Battaglini, Luca; Pavan, Andrea; Casco, Clara

    2017-01-01

    Amblyopic observers present abnormal spatial interactions between a low-contrast sinusoidal target and high-contrast collinear flankers. It has been demonstrated that perceptual learning (PL) can modulate these low-level lateral interactions, resulting in improved visual acuity and contrast sensitivity. We measured the extent and duration of generalization effects to various spatial tasks (i.e., visual acuity, Vernier acuity, and foveal crowding) through PL on the target's contrast detection. Amblyopic observers were trained on a contrast-detection task for a central target (i.e., a Gabor patch) flanked above and below by two high-contrast Gabor patches. The pre- and post-learning tasks included lateral interactions at different target-to-flankers separations (i.e., 2, 3, 4, 8λ) and included a range of spatial frequencies and stimulus durations as well as visual acuity, Vernier acuity, contrast-sensitivity function, and foveal crowding. The results showed that perceptual training reduced the target's contrast-detection thresholds more for the longest target-to-flanker separation (i.e., 8λ). We also found generalization of PL to different stimuli and tasks: contrast sensitivity for both trained and untrained spatial frequencies, visual acuity for Sloan letters, and foveal crowding, and partially for Vernier acuity. Follow-ups after 5-7 months showed not only complete maintenance of PL effects on visual acuity and contrast sensitivity function but also further improvement in these tasks. These results suggest that PL improves facilitatory lateral interactions in amblyopic observers, which usually extend over larger separations than in typical foveal vision. The improvement in these basic visual spatial operations leads to a more efficient capability of performing spatial tasks involving high levels of visual processing, possibly due to the refinement of bottom-up and top-down networks of visual areas.

  6. EXAMINATION OF THE VISUAL ACUITY ON THE LCD OPTOTYPE WITH WHOLE-LINE AND INTERPOLATION METHOD

    OpenAIRE

    Zajíček Tomáš; Veselý Petr; Veselý Petr; Synek Svatopluk; Synek Svatopluk

    2012-01-01

    The goal of this work is to show the possibility of us using the LCD optotype in common optometrist practice. Furthermore two commonly used methods for measuring visual acuity will be compared. 69 respondents were used for the measurements. The respondents were divided into two groups according to the measured LCD optotype. The visual acuity was measured using the whole-line method on modified Snellen charts as well as the interpolation method on ETDRS charts. Measurements were taken on the S...

  7. Visual acuity in adults with Asperger's syndrome: no evidence for "eagle-eyed" vision.

    Science.gov (United States)

    Falkmer, Marita; Stuart, Geoffrey W; Danielsson, Henrik; Bram, Staffan; Lönebrink, Mikael; Falkmer, Torbjörn

    2011-11-01

    Autism spectrum conditions (ASC) are defined by criteria comprising impairments in social interaction and communication. Altered visual perception is one possible and often discussed cause of difficulties in social interaction and social communication. Recently, Ashwin et al. suggested that enhanced ability in local visual processing in ASC was due to superior visual acuity, but that study has been the subject of methodological criticism, placing the findings in doubt. The present study investigated visual acuity thresholds in 24 adults with Asperger's syndrome and compared their results with 25 control subjects with the 2 Meter 2000 Series Revised ETDRS Chart. The distribution of visual acuities within the two groups was highly similar, and none of the participants had superior visual acuity. Superior visual acuity in individuals with Asperger's syndrome could not be established, suggesting that differences in visual perception in ASC are not explained by this factor. A continued search for explanations of superior ability in local visual processing in persons with ASC is therefore warranted. Copyright © 2011 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  8. The validity of visual acuity assessment using mobile technology devices in the primary care setting.

    Science.gov (United States)

    O'Neill, Samuel; McAndrew, Darryl J

    2016-04-01

    The assessment of visual acuity is indicated in a number of clinical circumstances. It is commonly conducted through the use of a Snellen wall chart. Mobile technology developments and adoption rates by clinicians may potentially provide more convenient methods of assessing visual acuity. Limited data exist on the validity of these devices and applications. The objective of this study was to evaluate the assessment of distance visual acuity using mobile technology devices against the commonly used 3-metre Snellen chart in a primary care setting. A prospective quantitative comparative study was conducted at a regional medical practice. The visual acuity of 60 participants was assessed on a Snellen wall chart and two mobile technology devices (iPhone, iPad). Visual acuity intervals were converted to logarithm of minimum angle of resolution (logMAR) scores and subjected to intraclass correlation coefficient (ICC) assessment. The results show a high level of general agreement between testing modality (ICC 0.917 with a 95% confidence interval of 0.887-0.940). The high level of agreement of visual acuity results between the Snellen wall chart and both mobile technology devices suggests that clinicians can use this technology with confidence in the primary care setting.

  9. Visual Acuity does not Moderate Effect Sizes of Higher-Level Cognitive Tasks

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    Houston, James R.; Bennett, Ilana J.; Allen, Philip A.; Madden, David J.

    2016-01-01

    Background Declining visual capacities in older adults have been posited as a driving force behind adult age differences in higher-order cognitive functions (e.g., the “common cause” hypothesis of Lindenberger & Baltes, 1994). McGowan, Patterson and Jordan (2013) also found that a surprisingly large number of published cognitive aging studies failed to include adequate measures of visual acuity. However, a recent meta-analysis of three studies (LaFleur & Salthouse, 2014) failed to find evidence that visual acuity moderated or mediated age differences in higher-level cognitive processes. In order to provide a more extensive test of whether visual acuity moderates age differences in higher-level cognitive processes, we conducted a more extensive meta-analysis of topic. Methods Using results from 456 studies, we calculated effect sizes for the main effect of age across four cognitive domains (attention, executive function, memory, and perception/language) separately for five levels of visual acuity criteria (no criteria, undisclosed criteria, self-reported acuity, 20/80-20/31, and 20/30 or better). Results As expected, age had a significant effect on each cognitive domain. However, these age effects did not further differ as a function of visual acuity criteria. Conclusion The current meta-analytic, cross-sectional results suggest that visual acuity is not significantly related to age group differences in higher-level cognitive performance—thereby replicating LaFleur and Salthouse (2014). Further efforts are needed to determine whether other measures of visual functioning (e.g. contrast sensitivity, luminance) affect age differences in cognitive functioning. PMID:27070044

  10. Vernier But Not Grating Acuity Contributes to an Early Stage of Visual Word Processing.

    Science.gov (United States)

    Tan, Yufei; Tong, Xiuhong; Chen, Wei; Weng, Xuchu; He, Sheng; Zhao, Jing

    2018-03-28

    The process of reading words depends heavily on efficient visual skills, including analyzing and decomposing basic visual features. Surprisingly, previous reading-related studies have almost exclusively focused on gross aspects of visual skills, while only very few have investigated the role of finer skills. The present study filled this gap and examined the relations of two finer visual skills measured by grating acuity (the ability to resolve periodic luminance variations across space) and Vernier acuity (the ability to detect/discriminate relative locations of features) to Chinese character-processing as measured by character form-matching and lexical decision tasks in skilled adult readers. The results showed that Vernier acuity was significantly correlated with performance in character form-matching but not visual symbol form-matching, while no correlation was found between grating acuity and character processing. Interestingly, we found no correlation of the two visual skills with lexical decision performance. These findings provide for the first time empirical evidence that the finer visual skills, particularly as reflected in Vernier acuity, may directly contribute to an early stage of hierarchical word processing.

  11. Improvement of visual acuity by refraction in a low-vision population.

    Science.gov (United States)

    Sunness, Janet S; El Annan, Jaafar

    2010-07-01

    Refraction often may be overlooked in low-vision patients, because the main cause of vision decrease is not refractive, but rather is the result of underlying ocular disease. This retrospective study was carried out to determine how frequently and to what extent visual acuity is improved by refraction in a low-vision population. Cross-sectional study. Seven hundred thirty-nine low-vision patients seen for the first time. A database with all new low-vision patients seen from November 2005 through June 2008 recorded presenting visual acuity using an Early Treatment Diabetic Retinopathy Study chart; it also recorded the best-corrected visual acuity (BCVA) if it was 2 lines or more better than the presenting visual acuity. Retinoscopy was carried out on all patients, followed by manifest refraction. Improvement in visual acuity. Median presenting acuity was 20/80(-2) (interquartile range, 20/50-20/200). There was an improvement of 2 lines or more of visual acuity in 81 patients (11% of all patients), with 22 patients (3% of all patients) improving by 4 lines or more. There was no significant difference in age or in presenting visual acuity between the group that did not improve by refraction and the group that did improve. When stratified by diagnosis, the only 2 diagnoses with a significantly higher rate of improvement than the age-related macular degeneration group were myopic degeneration and progressive myopia (odds ratio, 4.8; 95% confidence interval [CI], 3.0-6.7) and status post-retinal detachment (odds ratio, 7.1; 95% CI, 5.2-9.0). For 5 patients (6% of those with improvement), the eye that was 1 line or more worse than the fellow eye at presentation became the eye that was 1 line or more better than the fellow eye after refraction. A significant improvement in visual acuity was attained by refraction in 11% of the new low-vision patients. Improvement was seen across diagnoses and the range of presenting visual acuity. The worse-seeing eye at presentation may

  12. Recognition versus Resolution: a Comparison of Visual Acuity Results Using Two Alternative Test Chart Optotype

    Science.gov (United States)

    Pointer, Jonathan S.

    2010-01-01

    Purpose To quantify the difference between recognition (letter) and resolution (Landolt) visual acuity (VA) in a group of normally sighted subjects. Is it reasonable to assume that the two acuity measures are clinically equivalent? Methods A pair of 6 m acuity test charts was produced: one comprised letters and the other Landolt broken rings. Construction of both charts conformed to the logMAR design format. Monocular VA was determined for the dominant eye of 300 screened and normally sighted optometric patients aged 16 to 40, each wearing an optical refractive (spectacle) correction. Results Letter acuity was superior to Landolt acuity (P≤0.0001). The mean paired acuity difference was -0.041 logMAR (standard deviation 0.034): the 95% limits of agreement were ±0.067 logMAR units or ±3.3 chart optotype. Repeatability was high and similar for each chart type (±2.1 and ±2.4 optotype for letter and Landolt, respectively). Gender, test sequence, and laterality of the dominant eye (left or right) were each non-statistically significant variables. Conclusions For normally sighted subjects wearing an optimal refractive correction, a bias was recorded in favour of recognition over resolution acuity: the clinical difference amounted to approximately 40% of one logMAR chart line, with similar high repeatability for either chart optotype. We conclude that the assumption of clinical equivalence between letter and Landolt acuity is reasonable under optimum test conditions.

  13. Out of sight, out of mind? Relations between visual acuity and cognition.

    Science.gov (United States)

    La Fleur, Claire G; Salthouse, Timothy A

    2014-10-01

    Prior research has established significant relations between measures of sensory ability and cognitive function in adults of different ages, and several explanations for this relation have been proposed. One explanation is that sensory abilities restrict cognitive processing, a second is that cognitive abilities influence assessments of sensory ability, and a third is that both sensory function and cognition are affected by a common, potentially age-based, third factor. These explanations were investigated using mediation and moderation analyses, with near visual acuity as the sensory measure and scores on visual speed tests and auditory memory tests as the cognitive measures. Measures of visual acuity, speed, and memory were obtained from three moderately large samples, two cross-sectional (N = 380, N = 4,779) and one longitudinal (N = 2,258), with participants ranging from 18 to 90 years of age. The visual acuity and cognitive measures had different age trajectories, and the visual acuity-cognition relations were similar in each 5-year age band. The results suggest that the age-related differences and changes in near visual acuity are unlikely to contribute to the age-related differences and changes in speed and memory measures.

  14. [Congenital lens subluxation: visual acuity outcomes and intraocular lens postoperative position].

    Science.gov (United States)

    Arraes, Caroline; Endriss, Daniela; Lobato, Francisco; Arraes, João; Ventura, Marcelo

    2010-01-01

    To evaluate the visual acuity outcomes and to investigate the intraocular lens (IOL) and endocapsular ring positions with ultrasound biomicroscopy in 17 eyes of 10 patients with congenital lens subluxation who underwent the same surgical technique, by the same surgeon. The study was performed in the ''Hospital de Olhos de Pernambuco'' and ''Fundação Altino Ventura''. The surgical technique consisted of phacoaspiration with implant of endocapsular ring and intraocular lens with one loop haptic amputated. The age varied from 7 to 22 years. Data on visual acuity (VA) before and after surgery, surgery follow-up period, and complications were analyzed. All patients underwent ultrasound biomicroscopy. The mean follow-up period was 2.8 years. There was a VA improvement in 17 (100%) eyes: in 12 eyes (70.6%) the visual acuity was better than 20/40; 4 (23.5%) ranged from 20/40 to 20/100, and 1 (5.9%) had visual acuity worse than 20/100, however better than the preoperative visual acuity. The posterior capsular opacification occurred in 10 eyes (58.9%). Ultrasound biomicroscopy showed that all IOL were partially decentralized, however without surpassing the pupil border limit. Endocapsular ring position was correct and there was a good capsular support in all cases. The evaluated surgical treatment provided good intraocular lens and endocapsular ring position, with VA improvement Thus, this technique is a viable, effective and safe option for the visual rehabilitation of patients with congenital lens subluxation.

  15. Visual Temporal Acuity Is Related to Auditory Speech Perception Abilities in Cochlear Implant Users.

    Science.gov (United States)

    Jahn, Kelly N; Stevenson, Ryan A; Wallace, Mark T

    Despite significant improvements in speech perception abilities following cochlear implantation, many prelingually deafened cochlear implant (CI) recipients continue to rely heavily on visual information to develop speech and language. Increased reliance on visual cues for understanding spoken language could lead to the development of unique audiovisual integration and visual-only processing abilities in these individuals. Brain imaging studies have demonstrated that good CI performers, as indexed by auditory-only speech perception abilities, have different patterns of visual cortex activation in response to visual and auditory stimuli as compared with poor CI performers. However, no studies have examined whether speech perception performance is related to any type of visual processing abilities following cochlear implantation. The purpose of the present study was to provide a preliminary examination of the relationship between clinical, auditory-only speech perception tests, and visual temporal acuity in prelingually deafened adult CI users. It was hypothesized that prelingually deafened CI users, who exhibit better (i.e., more acute) visual temporal processing abilities would demonstrate better auditory-only speech perception performance than those with poorer visual temporal acuity. Ten prelingually deafened adult CI users were recruited for this study. Participants completed a visual temporal order judgment task to quantify visual temporal acuity. To assess auditory-only speech perception abilities, participants completed the consonant-nucleus-consonant word recognition test and the AzBio sentence recognition test. Results were analyzed using two-tailed partial Pearson correlations, Spearman's rho correlations, and independent samples t tests. Visual temporal acuity was significantly correlated with auditory-only word and sentence recognition abilities. In addition, proficient CI users, as assessed via auditory-only speech perception performance, demonstrated

  16. Measuring the Influence of Galilean Loupe System on Near Visual Acuity of Dentists under Simulated Clinical Conditions

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    Iris Urlić

    2016-01-01

    Full Text Available Aim: The purpose of this study was to compare near visual acuity of dentists without optical aids (VSC with near visual acuity of those using the Galilean telescope system (VGA2 with magnification of x 2.5, and the distance of 350 mm in simulated clinical conditions. Methods: The study included 46 dentists (visual acuity 1.0 without correction. A visual acuity testing was carried out using a miniaturized Snellen visual acuity chart which was placed in the cavity of molar teeth mounted in a phantom head in simulated clinical conditions. Near visual acuity for the vicinity was examined: 1 without correction at a distance of 300-400 mm (VSC; 2 with Galilean loupes with magnification of x2.5, focal length of 350mm. Results: The distributions of near visual acuity recorded using VSC and VGA2, 5 systems were compared by the Wilcoxon Signed Rank test. The results obtained by Wilcoxon Signed Rank test pointed to a statistically significant difference in the distribution of recorded visual acuity between the VSC and VGA2 optical systems (W = - 403.5; p <0.001. Conclusion: If using the VGA2, 5 systems, higher values of the near visual acuity were recorded and subsequently compared to near visual acuity without magnifying aids (VSC.

  17. Impact of Near Work Activity on Visual Acuity among Junior High School Students

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    Raisha Pratiwi Indrawati

    2016-03-01

    Full Text Available Background: Uncorrected refractive error is experienced by at least 45 million productive-aged adults (aged 16–45 years old and 13 million children (aged 5–15 years old, and being the main cause of visual impairment in children worldwide and third cause of blindness in any age in Indonesia. Near work activity is estimated as one of environmental risk factor causing this refractive error, leading into decreased visual acuity. This study was conducted to analyse the impact of near work activity on visual acuity among junior high school students in Jatinangor Methods: This study was conducted in junior high school in Jatinangor, using cross sectional method. Total of 147 subjects were screened for visual impairment using Rapid Assessment of Avoidable Blindness (RAAB tumbling E chart and assesed for near work activity using questionnaire-guided interview method after informed consent had been obtained. Data were analysed using unpaired-T test and Mann-Whitney test. Results: Total diopter hours of near work activity among the group with visual acuity ≥6/18 and group with visual acuity <6/18 showed no significant difference (p=0.329, with latter group had less time-spent in near work activity. Similarly, each activity such as reading, watching TV, and using computer also showed no significant difference , except for playing games where the group with better visual acuity had shown significantly longer time spent than another group (p=0.018. Conclusions: Near work activity does not have impact on visual acuity among junior high school students, except for playing games

  18. Bevacizumab Injection in Patients with Age-Related Macular Degeneration Associated with Poor Initial Visual Acuity

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    Leila El Matri

    2012-01-01

    Full Text Available Purpose. To evaluate functional and anatomic effects of intravitreal bevacizumab in patients with neovascular AMD and initial low visual acuity. Methods. Retrospective case series of 38 eyes with neovascular AMD and initial visual acuity of 20/200 or less, treated with intravitreal bevacizumab injection. Results. Mean followup was 14.1 months ±7.1 (range: 5 to 24 months. Mean logMAR vision at baseline was 1.38 logMAR ±0.33, at 6 months was 1.14 logMAR ±0.37 (=0.001 and at 12 months was 1.22 logMar ±0.33 (=0.004. Mean baseline central retinal thickness was 431 μm ±159.7 at 6 months was 293.43 μm  ±122.79 (=10−4 and at 12 months was 293.1 μm  ±130 (=0.004. Visual acuity improved in both patients with or without prior PDT treatment. Conclusions. Intravitreal bevacizumab injection may increase the chance of visual acuity gain in neovascular AMD even in cases with initial low visual acuity.

  19. Visual Acuity is Related to Parafoveal Retinal Thickness in Patients with Retinitis Pigmentosa and Macular Cysts

    Science.gov (United States)

    Brockhurst, Robert J.; Gaudio, Alexander R.; Berson, Eliot L.

    2008-01-01

    Purpose To quantify the prevalence and effect on visual acuity of macular cysts in a large cohort of patients with retinitis pigmentosa. Methods In 316 patients with typical forms of retinitis pigmentosa, we measured visual acuities with Early Treatment Diabetic Retinopathy Study (ETDRS) charts, detected macular cysts with optical coherence tomography (OCT), and quantified retinal thicknesses by OCT. We used the FREQ, LOGISTIC, and GENMOD procedures of SAS to evaluate possible risk factors for cyst prevalence and the MIXED procedure to quantify the relationships of visual acuity to retinal thickness measured at different locations within the macula. Results We found macular cysts in 28% of the patients, 40% of whom had cysts in only one eye. Macular cysts were seen most often in patients with dominant disease and not at all in patients with X-linked disease (p = 0.006). In eyes with macular cysts, multiple regression analysis revealed that visual acuity was inversely and independently related to retinal thickness at the foveal center (p = 0.038) and within a ring spanning an eccentricity of 5° to 10° from the foveal center (p = 0.004). Conclusions Macular cysts are a common occurrence in retinitis pigmentosa, especially among patients with dominantly-inherited disease. Visual acuity is influenced by edema in the parafovea, as well as in the fovea. PMID:18552390

  20. Impact of Target Distance, Target Size, and Visual Acuity on the Video Head Impulse Test.

    Science.gov (United States)

    Judge, Paul D; Rodriguez, Amanda I; Barin, Kamran; Janky, Kristen L

    2018-05-01

    The video head impulse test (vHIT) assesses the vestibulo-ocular reflex. Few have evaluated whether environmental factors or visual acuity influence the vHIT. The purpose of this study was to evaluate the influence of target distance, target size, and visual acuity on vHIT outcomes. Thirty-eight normal controls and 8 subjects with vestibular loss (VL) participated. vHIT was completed at 3 distances and with 3 target sizes. Normal controls were subdivided on the basis of visual acuity. Corrective saccade frequency, corrective saccade amplitude, and gain were tabulated. In the normal control group, there were no significant effects of target size or visual acuity for any vHIT outcome parameters; however, gain increased as target distance decreased. The VL group demonstrated higher corrective saccade frequency and amplitude and lower gain as compared with controls. In conclusion, decreasing target distance increases gain for normal controls but not subjects with VL. Preliminarily, visual acuity does not affect vHIT outcomes.

  1. Visual Acuity Improvement in Continuous vs Divided Occlusion in Anisometropic Amblyopia.

    Science.gov (United States)

    Irfani, Irawati; Feriyanto, Feri; Oktarima, Primawita; Kartasasmita, Arief

    2018-01-01

    To compare visual acuity improvement between continuous and split part-time occlusion for the treatment of moderate and severe anisometropic amblyopia. Randomised clinical trials in 6 - 13 y.o children with moderate and severe anisometropic amblyopia. Each patient was consecutively selected with continuous or split part-time occlusion. Best corrected visual acuity's improvement was followed up to six weeks and statistical data were analyzed using chi square and unpaired t-test. Best corrected visual acuity's improvement was comparable between continuous and split part-time occlusion (0.20±0.27 vs 0.21±0.25; p = 0.79). Split part-time occlusion may be considered as an alternative treatment for moderate and severe anisometropic amblyopia treatment.

  2. PATTERN ELECTRORETINOGRAPHY IN RELATION TO KINETIC AND STATIC PERIMETRY AND VISUAL ACUITY IN RETINITIS PIGMENTOSA

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    Petra Popović

    2002-12-01

    Full Text Available Background. This study was conducted to assess whether pattern ERG is a sensitive test in evaluating the retinal function in patients with retinitis pigmentosa. We wanted to determine how pattern ERG, reflecting the activity of inner retinal layers, is related to other psychophysical tests such as perimetry and visual acuity.Methods. An analysis was performed on 50 eyes of 25 patients with typical rod-cone retinitis pigmentosa. The standard Snellen visual acuity was tested. Visual field sensitivity was measured with automated static perimetry (Octopus G2 program where mean defect was taken as an index of visual field loss. In kinetic perimetry (Goldmann the average radius of the visual field measured with target II/4 and V/4 was calculated. Transient pattern ERG and all five flash ERG responses were also measured according to ISCEV standards. Amplitudes of pattern ERG P50 and N95 waves were compared to results of visual acuity and visual field testing.Results. In our group of 25 RP patients with visual acuity ranging from 0.16 to 1.0, PERG responses were preserved much better than full field ERGs. 72% of them had still recordable PERG responses, while 48% had cone and only 32% maximal responses. Scotopic rod responses were extinguished in all eyes. The normalized amplitudes of the PERG responses were also much higher (43.5% than cone (22.5% or maximal responses (4.5%. A strong correlation of both P50 and N95 amplitudes with Octopus mean defect index was found. In kinetic perimetry the correlation with PERG amplitudes was also high, but it was better with II/4 than with V/4 target. Patients with high preserved ERG responses had good visual acuity. In all patients with visual acuity less than 0.4 both flash and pattern ERG responses were already absent.Conclusions. This study shows that pattern ERG is an objective and sensitive test in evaluating the functional visual loss in retinitis pigmentosa. Amplitudes of P50 and N95 responses are linearly

  3. Relationship between photoreceptor outer segment length and visual acuity in diabetic macular edema.

    Science.gov (United States)

    Forooghian, Farzin; Stetson, Paul F; Meyer, Scott A; Chew, Emily Y; Wong, Wai T; Cukras, Catherine; Meyerle, Catherine B; Ferris, Frederick L

    2010-01-01

    The purpose of this study was to quantify photoreceptor outer segment (PROS) length in 27 consecutive patients (30 eyes) with diabetic macular edema using spectral domain optical coherence tomography and to describe the correlation between PROS length and visual acuity. Three spectral domain-optical coherence tomography scans were performed on all eyes during each session using Cirrus HD-OCT. A prototype algorithm was developed for quantitative assessment of PROS length. Retinal thicknesses and PROS lengths were calculated for 3 parameters: macular grid (6 x 6 mm), central subfield (1 mm), and center foveal point (0.33 mm). Intrasession repeatability was assessed using coefficient of variation and intraclass correlation coefficient. The association between retinal thickness and PROS length with visual acuity was assessed using linear regression and Pearson correlation analyses. The main outcome measures include intrasession repeatability of macular parameters and correlation of these parameters with visual acuity. Mean retinal thickness and PROS length were 298 mum to 381 microm and 30 microm to 32 mum, respectively, for macular parameters assessed in this study. Coefficient of variation values were 0.75% to 4.13% for retinal thickness and 1.97% to 14.01% for PROS length. Intraclass correlation coefficient values were 0.96 to 0.99 and 0.73 to 0.98 for retinal thickness and PROS length, respectively. Slopes from linear regression analyses assessing the association of retinal thickness and visual acuity were not significantly different from 0 (P > 0.20), whereas the slopes of PROS length and visual acuity were significantly different from 0 (P < 0.0005). Correlation coefficients for macular thickness and visual acuity ranged from 0.13 to 0.22, whereas coefficients for PROS length and visual acuity ranged from -0.61 to -0.81. Photoreceptor outer segment length can be quantitatively assessed using Cirrus HD-OCT. Although the intrasession repeatability of PROS

  4. Visual Acuity Testing: Feedback Affects Neither Outcome nor Reproducibility, but Leaves Participants Happier.

    Science.gov (United States)

    Bach, Michael; Schäfer, Kerstin

    2016-01-01

    Assessment of visual acuity is a well standardized procedure at least for expert opinions and clinical trials. It is often recommended not giving patients feedback on the correctness of their responses. As this viewpoint has not been quantitatively examined so far, we quantitatively assessed possible effects of feedback on visual acuity testing. In 40 normal participants we presented Landolt Cs in 8 orientations using the automated Freiburg Acuity Test (FrACT, feedback was provided in 2 x 4 conditions: (A) no feedback, (B) acoustic signals indicating correctness, (C)visual indication of correct orientation, and (D) a combination of (B) and (C). After each run the participants judged comfort. Main outcome measures were absolute visual acuity (logMAR), its test-retest agreement (limits of agreement) and participants' comfort estimates on a 5-step symmetric Likert scale. Feedback influenced acuity outcome significantly (p = 0.02), but with a tiny effect size: 0.02 logMAR poorer acuity for (D) compared to (A), even weaker effects for (B) and (C). Test-retest agreement was high (limits of agreement: ± 1.0 lines) and did not depend on feedback (p>0.5). The comfort ranking clearly differed, by 2 steps on the Likert scale: the condition (A)-no feedback-was on average "slightly uncomfortable", the other three conditions were "slightly comfortable" (pFeedback affected neither reproducibility nor the acuity outcome to any relevant extent. The participants, however, reported markedly greater comfort with any kind of feedback. We conclude that systematic feedback (as implemented in FrACT) offers nothing but advantages for routine use.

  5. VISUAL ACUITY AND CLINICAL REFRACTION FOLLOWING IMPLANTATION OF VARIOUS MULTIFOCAL INTRAOCULAR LENSES

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    N. N. Temirov

    2015-01-01

    Full Text Available Aim. To analyze visual acuity, clinical refraction, and defocusing tolerance after the implantation of monofocal IOL with rotational asymmetric optic (Lentis Mplus 313 MF compared with Acrysof ReSTOR SN6AD1.Materials and methods. Phacoemulsification was performed in a total of 194 patients (288 eyes, i.e., 144 patients (188 eyes with cataract and 50 patients (100 eyes with presbyopia and high ametropia. The patients were divided into two groups. Study group included 132 patients (194 eyes implanted with Lentis Mplus while control group included 62 patients (94 eyes implanted with Acrysof ReSTOR. Uncorrected distance (5 m, intermediate (50‑70 cm, and near (20‑40 cm visual acuity under photopic (85 cd/m2 and mesopic (8 cd/m2 conditions were measured, objective and subjective refractometry were performed, and defocusing tolerance was evaluated.Results. Postoperatively, uncorrected distance and near visual acuity was high while intermediate visual acuity was moderately low. Lentis Mplus patients had better near and intermediate visual acuity under mesopic conditions as compared with Acrysof ReSTOR patients. Emmetropia (target refraction was achieved in 90.2% of study group patients and in 87.2% of control group patients. In patients implanted with Lentis Mplus, refraction was measured by subjective method. Optimal A-constant for Lentis Mplus and Acrysof ReSTOR was 118.0 and 118.6, respectively. Under defocusing, Lentis Mplus patients had better visual acuity than Acrysof ReSTOR patients. This indirectly confirms better intermediate vision.Conclusions. Lentis Mplus provides better vision at various distances that does not almost depend on light levels and induces minimal dysphotopsia. 

  6. Visual acuity and associated factors. The Central India Eye and Medical Study.

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    Vinay Nangia

    Full Text Available Visual acuity is a major parameter for quality of vision and quality of life. Information on visual acuity and its associated factors in rural societies almost untouched by any industrialization is mostly non-available. It was, therefore, the purpose of our study to determine the distribution of visual acuity and its associated factors in a rural population not marked influenced by modern lifestyle. The population-based Central India Eye and Medical Study included 4711 subjects (aged 30+ years, who underwent a detailed ophthalmologic examination including visual acuity measurement. Visual acuity measurements were available for 4706 subjects with a mean age of 49.5±13.4 years (range: 30-100 years. BCVA decreased significantly (P<0.001 from the moderately hyperopic group (0.08±0.15 logMAR to the emmetropic group (0.16±0.52 logMAR, the moderately myopic group (0.28±0.33 logMAR, the highly hyperopic group (0.66±0.62 logMAR and finally the highly myopic group (1.32±0.92 logMAR. In multivariate analysis, BCVA was significantly associated with the systemic parameters of lower age (P<0.001, higher level of education (P<0.001, higher body stature (P<0.001 and higher body mass index (P<0.001, and with the ophthalmic parameters of more hyperopic refractive error (spherical equivalent (P<0.001, shorter axial length (P<0.001, lower degree of nuclear cataract (P<0.001, and lower intraocular pressure (P = 0.006. The results suggest that in the rural population of Central India, major determinants of visual acuity were socioeconomic background, body stature and body mass index, age, refractive error, cataract and intraocular pressure.

  7. Posterior staphyloma in oculocutaneous albinism: another possible cause of reduced visual acuity.

    Science.gov (United States)

    Lee, Susan; Schimmenti, Lisa A; King, Richard A; Brilliant, Murray; Anderson, Jennifer L; Schoonveld, Cheri; Summers, C Gail

    2015-12-01

    Posterior staphyloma is typically associated with myopic degeneration and has not been recognized as a cause of reduced visual acuity in albinism. We report 3 cases of posterior staphyloma, each with oculocutaneous albinism (OCA) defined by phenotype and genotype. Two cases are biological sisters with OCA type 2; one was myopic and the other was hyperopic. The third case involves a man with OCA associated with Hermansky-Pudlak syndrome (HPS-5). Staphyloma may be another cause of reduced visual acuity in albinism, particularly with increasing age. It may occur in association with myopia or hyperopia. Copyright © 2015 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

  8. Acuidade visual: Medidas e notações Visual acuity: Measurements and notations

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    Harley E. A. Bicas

    2002-06-01

    Full Text Available Avaliações da função visual são muito complexas por dependerem de mecanismos aferentes, eferentes e cognitivos, além de fatores externos à pessoa examinada, como o tipo de estímulo e o de sua apresentação. O exame da acuidade visual é discutido em seus aspectos formais de definições, quantificações (critérios de medição de um ângulo e tamanho dos optotipos, notações (decimal ou fracionárias, escalas (representando relações angulares, lineares, logarítmicas e unidades em que os valores são expressos (recíproca do minuto de arco, número puro, freqüência espacial, decibéis e oitavas. Como conseqüência, referências numéricas sobre a acuidade visual e operações que as envolvem (p.ex., cálculo de valores médios, determinação de variações, relações entre elas podem levar a interpretações muito diferentes e até opostas num mesmo estudo, dependendo dos critérios nele empregados.Evaluations of the visual function are very intricate since they depend on afferent, efferent and cognitive mechanisms, besides external factors of the examined subject, such as the type of the stimulus and of its presentation. Testing the visual acuity is discussed in its formal aspects related to definitions, quantifications (criteria for the measurements of an angle, size of optotypes, notations (decimal or fractionary, scales (representing angular, linear or logarithmic relationships and units in which the values are expressed (reciprocal of minutes of arc, pure number, spacial frequency, decibels, octaves. As a consequence, numerical references about visual acuity and respective operations (e.g., calculations of average values, determinations of variations, relationships between them may lead to very different interpretations of a study, sometimes even opposite, according to the criteria which are used.

  9. Progressive improvement of impaired visual acuity during the first year after transsphenoidal surgery for non-functioning pituitary macroadenoma

    NARCIS (Netherlands)

    Dekkers, O. M.; de Keizer, R. J. W.; Roelfsema, F.; Vd Klaauw, A. A.; Honkoop, P. J.; van Dulken, H.; Smit, J. W. A.; Romijn, J. A.; Pereira, A. M.

    2007-01-01

    Improvement of visual field defects continues even years after the initial surgical treatment. Because this process of continuing improvement has not been documented for visual acuity, we audited our data to explore the pattern of recovery of visual acuity until 1 year after transsphenoidal surgery

  10. Effect of magnetic resonance imaging on near visual acuity

    OpenAIRE

    MOLINA BETANCUR, CARLOS ANDRÉS; ARBELÁEZ MEDINA, ANDRÉS IGNACIO; MOLINA BETANCUR, MERCEDES CECILIA; AGUDELO, LUZ MARINA; DONADO GÓMEZ, JORGE HERNANDO; VERGARA, JUAN CARLOS; PAULO, JOSÉ DAVID

    2007-01-01

    Objetivos: determinar la variación de la agudeza visual cercana en pacientes expuestos a campos magnéticos intensos por períodos cortos en estudios de resonancia magnética. Métodos: estudio descriptivo de una serie de casos, que incluyó 9 hombres y 31 mujeres alfabetas mayores de 40 años; debían tener una agudeza visual mejor de 20/200 y no estar bajo los efectos de medicamentos ansiolíticos. Estas personas fueron sometidas a procedimientos diagnósticos de resonancia magnética de cabeza y cue...

  11. Prevalence of high astigmatism, eyeglass wear, and poor visual acuity among Native American grade school children.

    Science.gov (United States)

    Harvey, Erin M; Dobson, Velma; Miller, Joseph M

    2006-04-01

    The purpose of this study was to examine the prevalence of astigmatism and poor visual acuity and rate of eyeglass wear in grade school children who are members of a Native American tribe reported to have a high prevalence of large amounts of astigmatism. Vision screening was conducted on 1,327 first through eighth grade children attending school on the Tohono O'odham Reservation. Noncycloplegic autorefraction was conducted on the right and left eye of each child using the Nikon Retinomax K+ autorefractor, and monocular recognition acuity was tested using ETDRS logarithm of the minimum angle of resolution (logMAR) letter charts. Tohono O'odham children had a high prevalence of high astigmatism (42% had > or = 1.00 D in the right or left eye) and the axis of astigmatism was uniformly with-the-rule. However, only a small percentage of children arrived at the vision screening wearing glasses, and the prevalence of poor visual acuity (20/40 or worse in either eye) was high (35%). There was a significant relation between amount of astigmatism and uncorrected visual acuity with each additional diopter of astigmatism resulting in an additional 1 logMAR line reduction in visual acuity. Uncorrected astigmatism and poor visual acuity are prevalent among Tohono O'odham children. The results highlight the importance of improving glasses-wearing compliance, determining barriers to receiving eye care, and initiating public education programs regarding the importance of early identification and correction of astigmatism in Tohono O'odham children.

  12. Effect of Target Location on Dynamic Visual Acuity During Passive Horizontal Rotation

    Science.gov (United States)

    Appelbaum, Meghan; DeDios, Yiri; Kulecz, Walter; Peters, Brian; Wood, Scott

    2010-01-01

    The vestibulo-ocular reflex (VOR) generates eye rotation to compensate for potential retinal slip in the specific plane of head movement. Dynamic visual acuity (DVA) has been utilized as a functional measure of the VOR. The purpose of this study was to examine changes in accuracy and reaction time when performing a DVA task with targets offset from the plane of rotation, e.g. offset vertically during horizontal rotation. Visual acuity was measured in 12 healthy subjects as they moved a hand-held joystick to indicate the orientation of a computer-generated Landolt C "as quickly and accurately as possible." Acuity thresholds were established with optotypes presented centrally on a wall-mounted LCD screen at 1.3 m distance, first without motion (static condition) and then while oscillating at 0.8 Hz (DVA, peak velocity 60 deg/s). The effect of target location was then measured during horizontal rotation with the optotypes randomly presented in one of nine different locations on the screen (offset up to 10 deg). The optotype size (logMar 0, 0.2 or 0.4, corresponding to Snellen range 20/20 to 20/50) and presentation duration (150, 300 and 450 ms) were counter-balanced across five trials, each utilizing horizontal rotation at 0.8 Hz. Dynamic acuity was reduced relative to static acuity in 7 of 12 subjects by one step size. During the random target trials, both accuracy and reaction time improved proportional to optotype size. Accuracy and reaction time also improved between 150 ms and 300 ms presentation durations. The main finding was that both accuracy and reaction time varied as a function of target location, with greater performance decrements when acquiring vertical targets. We conclude that dynamic visual acuity varies with target location, with acuity optimized for targets in the plane of motion. Both reaction time and accuracy are functionally relevant DVA parameters of VOR function.

  13. A comparison of behavioural (Landolt C) and anatomical estimates of visual acuity in archerfish (Toxotes chatareus).

    Science.gov (United States)

    Temple, S E; Manietta, D; Collin, S P

    2013-05-03

    Archerfish forage by shooting jets of water at insects above the water's surface. The challenge of detecting small prey items against a complex background suggests that they have good visual acuity, but to date this has never been tested, despite archerfish becoming an increasingly important model species for vertebrate vision. We used a modified Landolt C test to measure visual acuity behaviourally, and compared the results to their predicted minimum separable angle based on both photoreceptor and ganglion cell spacing in the retina. Both measures yielded similar estimates of visual acuity; between 3.23 and 3.57 cycles per degree (0.155-0.140° of visual arc). Such a close match between behavioural and anatomical estimates of visual acuity in fishes is unusual and may be due to our use of an ecologically relevant task that measured the resolving power of the part of the retina that has the highest photoreceptor density and that is used in aligning their spitting angle with potential targets. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Relationship between Outer Retinal Layers Thickness and Visual Acuity in Diabetic Macular Edema

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    Raymond L. M. Wong

    2015-01-01

    Full Text Available Purpose. To investigate the correlation of outer retinal layers (ORL thickness and visual acuity (VA in patients with diabetic macular edema (DME. Methods. Consecutive DME patients seen at the Retina Clinic of The University of Hong Kong were recruited for OCT assessment. The ORL thickness was defined as the distance between external limiting membrane (ELM and retinal pigment epithelium (RPE at the foveal center. The correlation between total retinal thickness, ORL thickness, and vision was calculated. Results. 78 patients with DME were recruited. The mean age was 58.1 years (±11.5 years and their mean visual acuity measured with Snellen chart was 0.51 (±0.18. The correlation coefficient between total retinal thickness and visual acuity was 0.34 (P < 0.001 whereas the correlation coefficient was 0.65 between ORL thickness and visual acuity (P < 0.001. Conclusion. ORL thickness correlates better with vision than the total retinal thickness. It is a novel OCT parameter in the assessment of DME. Moreover, it could be a potential long term visual prognostic factor for patients with DME.

  15. Visual training paired with electrical stimulation of the basal forebrain improves orientation-selective visual acuity in the rat.

    Science.gov (United States)

    Kang, Jun Il; Groleau, Marianne; Dotigny, Florence; Giguère, Hugo; Vaucher, Elvire

    2014-07-01

    The cholinergic afferents from the basal forebrain to the primary visual cortex play a key role in visual attention and cortical plasticity. These afferent fibers modulate acute and long-term responses of visual neurons to specific stimuli. The present study evaluates whether this cholinergic modulation of visual neurons results in cortical activity and visual perception changes. Awake adult rats were exposed repeatedly for 2 weeks to an orientation-specific grating with or without coupling this visual stimulation to an electrical stimulation of the basal forebrain. The visual acuity, as measured using a visual water maze before and after the exposure to the orientation-specific grating, was increased in the group of trained rats with simultaneous basal forebrain/visual stimulation. The increase in visual acuity was not observed when visual training or basal forebrain stimulation was performed separately or when cholinergic fibers were selectively lesioned prior to the visual stimulation. The visual evoked potentials show a long-lasting increase in cortical reactivity of the primary visual cortex after coupled visual/cholinergic stimulation, as well as c-Fos immunoreactivity of both pyramidal and GABAergic interneuron. These findings demonstrate that when coupled with visual training, the cholinergic system improves visual performance for the trained orientation probably through enhancement of attentional processes and cortical plasticity in V1 related to the ratio of excitatory/inhibitory inputs. This study opens the possibility of establishing efficient rehabilitation strategies for facilitating visual capacity.

  16. Creation of an Accurate Algorithm to Detect Snellen Best Documented Visual Acuity from Ophthalmology Electronic Health Record Notes.

    Science.gov (United States)

    Mbagwu, Michael; French, Dustin D; Gill, Manjot; Mitchell, Christopher; Jackson, Kathryn; Kho, Abel; Bryar, Paul J

    2016-05-04

    Visual acuity is the primary measure used in ophthalmology to determine how well a patient can see. Visual acuity for a single eye may be recorded in multiple ways for a single patient visit (eg, Snellen vs. Jäger units vs. font print size), and be recorded for either distance or near vision. Capturing the best documented visual acuity (BDVA) of each eye in an individual patient visit is an important step for making electronic ophthalmology clinical notes useful in research. Currently, there is limited methodology for capturing BDVA in an efficient and accurate manner from electronic health record (EHR) notes. We developed an algorithm to detect BDVA for right and left eyes from defined fields within electronic ophthalmology clinical notes. We designed an algorithm to detect the BDVA from defined fields within 295,218 ophthalmology clinical notes with visual acuity data present. About 5668 unique responses were identified and an algorithm was developed to map all of the unique responses to a structured list of Snellen visual acuities. Visual acuity was captured from a total of 295,218 ophthalmology clinical notes during the study dates. The algorithm identified all visual acuities in the defined visual acuity section for each eye and returned a single BDVA for each eye. A clinician chart review of 100 random patient notes showed a 99% accuracy detecting BDVA from these records and 1% observed error. Our algorithm successfully captures best documented Snellen distance visual acuity from ophthalmology clinical notes and transforms a variety of inputs into a structured Snellen equivalent list. Our work, to the best of our knowledge, represents the first attempt at capturing visual acuity accurately from large numbers of electronic ophthalmology notes. Use of this algorithm can benefit research groups interested in assessing visual acuity for patient centered outcome. All codes used for this study are currently available, and will be made available online at https://phekb.org.

  17. Lawn mower injuries as a cause of serious visual acuity impairment – Case reports

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    Monika Jasielska

    2017-05-01

    Lawn mower induced eye injuries are a significant cause of serious visual acuity impairment or blindness. The presented study shows that lawn mower eye injuries are still a therapeutic, social and economic problem, yet are very preventable with proper eye protection and patients’ education. Current prevention strategies are inadequate, and therefore should be updated.

  18. Lawn mower injuries as a cause of serious visual acuity impairment - Case reports.

    Science.gov (United States)

    Jasielska, Monika; Winiarczyk, Mateusz; Bieliński, Paweł; Mackiewicz, Jerzy

    2017-05-11

    [b]Abstract Objective.[/b] The aim of the study is to present four cases of lawn mowers injuries as a cause of serious visual acuity impairment. [b]Materials and Method[/b]. A retrospective study of four patients admitted in 2013-2015 to the Department of Vitreoretinal Surgery in Lublin with severe open or closed globe injury, one with an intraocular foreign body (IOFB). The presence of eye protective equipment was assessed, as well as visual acuity, eye tissue condition before and after treatment, and applied therapy. In all cases an improvement was achieved in local conditions. The intraocular foreign body was removed, wounds sutured and damaged tissues placed in position. All eyeballs were saved. In three cases, visual acuity was improved to a usable level. Three patients underwent pars plana vitrectomy, one with IOFB removal from the vitreous cavity. [b]Conclusions[/b]. Lawn mower induced eye injuries are a significant cause of serious visual acuity impairment or blindness. The presented study shows that lawn mower eye injuries are still a therapeutic, social and economic problem, yet are very preventable with proper eye protection and patients' education. Current prevention strategies are inadequate, and therefore should be updated.

  19. High-Acuity Information Is Retained through the Cortical Visual Hierarchy of Primates.

    Science.gov (United States)

    Chelazzi, Leonardo; Santandrea, Elisa

    2018-04-18

    Vision requires perception of both coarse layout and fine details of objects. In this issue of Neuron, Lu et al. (2018) describe a possible basis for the latter: neuronal clusters in area V4 coding high-acuity information, despite the tendency along the visual hierarchy to generate global representations of objects. Copyright © 2018 Elsevier Inc. All rights reserved.

  20. Influence of head posture on the visual acuity of children with nystagmus

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    Ana Carla Ramos Vieira da Costa

    2014-01-01

    Full Text Available Purpose: Evaluate the relationship between the postural alignment of the head and possible interference in the view of children. Methods: We evaluated 11 children between 2 and 7 years of age of both sexes, with the visually impaired, who had nystagmus and head lock position. The test Lea Grating Acuity Test® was used to collect measurements of visual acuity. This applied on two occasions: with and without postural alignment of the head. For reliability of the postural alignment of the head, the slopes were measured by Fisiologic® software. Results: The children had a poorer performance after physiological postural alignment. This poor performance is possible due to loss of position lock nystagmus to gain postural alignment, said to be ideal. Postural compensations were observed, and sharply increased eyestrain. Conclusion: The pursuit of traditional postural alignment affect the visual response of children with visual impairments.

  1. Effect of neodymium:YAG laser capsulotomy on visual function in patients with posterior capsule opacification and good visual acuity.

    Science.gov (United States)

    Yotsukura, Erisa; Torii, Hidemasa; Saiki, Megumi; Negishi, Kazuno; Tsubota, Kazuo

    2016-03-01

    To evaluate the effect of neodymium:YAG (Nd:YAG) laser capsulotomy on the visual function in patients with posterior capsule opacification (PCO) and good visual acuity. Keio University Hospital, Tokyo, Japan. Observational case series. Eyes were evaluated that had previous cataract surgery with a clinical diagnosis of PCO requiring Nd:YAG laser capsulotomy regardless of a good corrected distance visual acuity (CDVA) (at least 20/20). The CDVA, 10% low contrast visual acuity (LCVA), wavefront aberrations from the 3rd to 6th order, and retinal straylight were measured before and after Nd:YAG laser capsulotomy. The study included 16 eyes of 16 patients (10 men, 6 women; mean age 69.5 years ± 9.3 [SD]). The mean CDVA, LCVA, and straylight after Nd:YAG laser capsulotomy improved significantly (P The root mean square (RMS) of the 3rd Zernike coefficients (S3) and the RMS of the total higher-order aberrations (HOAs) from the 3rd to 6th order decreased significantly after capsulotomy (P The straylight correlated significantly with the total HOAs (r = 0.727, P = .002) and S3 (r = 0.748, P = .001) before capsulotomy. Subjective symptoms resolved after capsulotomy in all cases. Neodymium:YAG laser capsulotomy enabled a significant improvement in visual function even in patients with PCO with good visual acuity. Straylight measurements might be useful to determine the indications for Nd:YAG laser capsulotomy when patients report visual disturbances without decreased visual acuity. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  2. [The influence of IOL implantation on visual acuity, contrast sensitivity and colour vision 2 and 4 months after cataract surgery].

    Science.gov (United States)

    Ventruba, J

    2006-04-01

    To assess the change in visual acuity, contrast sensitivity and colour vision in relation to the time after cataract surgery and to the type of implanted IOL, and to compare visual functions by patients with one and two pseudophakic eyes. 45 cataract patients were examined before and then 2 and 4 month after the cataract surgery. Visual acuity (VA) was tested on logMAR optotype chart with Landolt rings, contrast sensitivity (CS) was tested on the Pelli-Robson chart and the SWCT chart. For colour vision (CV) testing, the standard Farnsworth D-15 test and the desaturated Lanthony D-15 test were used. The patients were divided into two groups--a group with one pseudophakic eye and a group with two pseudophakic eyes, and also according to the type of IOL--PMMA or hydrophobic acrylate that had been implanted. Control group was composed of phakic subjects with no ocular pathology. After the cataract surgery, in both groups there was a significant improvement in monocular and binocular VA (p test (p test (p tested by means of psychophysical methods of VA, CS and CV significantly improve and are stable 2 month after the surgery. The second eye surgery improves binocular visual functions the level of which doesn't differ from that of normal phakic subjects. There was no influence of the type of IOL on final state of VA, CS or CV.

  3. Relationship between socioeconomic deprivation 
or urban/rural residence and visual acuity before cataract surgery in Northern Scotland.

    Science.gov (United States)

    Chua, Paul Y; Mustafa, Mohammed S; Scott, Neil W; Kumarasamy, Manjula; Azuara-Blanco, Augusto

    2013-01-01

    To evaluate the influence of socioeconomic factors on visual acuity before cataract surgery. 
 The medical case notes of 240 consecutive patients listed for cataract surgery from January 1, 2010, at Grampian University Hospital, Aberdeen, were reviewed retrospectively. Patients with ocular comorbidity were excluded. Demographics, postal codes, and visual acuity were recorded. Scottish Index of Multiple Deprivation was used to determine the deprivation rank. Home location was classified as urban or rural. The effect of these parameters on preoperative visual acuity was investigated using chi-square tests or Fisher exact test as appropriate. 
 A total of 184 patients (mean 75 years) were included. A total of 127 (69%) patients had visual acuity of 6/12 or better. An association was found between affluence and preoperative visual acuity of 6/12 or better (χ2trend = 4.97, p = 0.03), with a significant rising trend across quintile of deprivation. There was no evidence to suggest association between geographical region and preoperative visual acuity (p = 0.63). 
 Affluence was associated with good visual acuity (6/12 or better) before cataract surgery. There was no difference in preoperative visual acuity between rural and urban populations.

  4. A Demonstration Project on Driving with Reduced Visual Acuity and a Bioptic Telescope System in the Netherlands

    NARCIS (Netherlands)

    Melis-Dankers, Bart J.M.; Kooijman, Aart C.; Brouwer, Wiebo H.; Busscher, Rens B.; Bredewoud, Ruud A.; Derksen, Peter H.; Amersfoort, Anoeska; IJsseldijk, Martin A.M.; Delden, Geert W. van; Grotenhuis, Thea H.P.A.; Witvliet, M.D.

    2008-01-01

    Background: In Europe, driving a passenger car is prohibited if binocular best corrected visual acuity (BCVA) is below 0.5 (20/40). Some US states allow people with reduced visual acuity to use a bioptic telescope system when driving. The aim of our study is to introduce a bioptic telescope system

  5. LASER PHOTOCOAGULATION IN DIABETIC MACULAR EDEMA: EFFECTS ON VISUAL ACUITY AND MACULAR EDEMA

    Directory of Open Access Journals (Sweden)

    M.H. Dehghan

    1999-06-01

    Full Text Available Due to the importance of clinically significant macular edema in diabetic patients, this study is aimed to determine if laser photocoagulation is effective in the treatment of clinically significant diabetic macular edema. In addition, the effects of risk factors arc surveyed* This is an existing data study considering patients with clinically significant diabetic macular edema, treated with argon-green laser photocoagulation in Labbafinejad hospital, department of lasertherapy, from 1995 to 1997. in 60 (42.6% eyes the treatment method was focal, in 22 (15.6% eyes grid, and in 59 (41.84 modified grid laser photocoagulation was performed. The results are based upon deterioration of visual acuity, occurance of moderate visual loss and improvement or persistence of CSME. We studied 114 eyes from 87 patients. Two years after initial treatment, visual acuity improved in 19.1% of eyes, unchanged in 9.5% and worsened in 71.4% of eyes. After this period the rate of moderate visual loss was 28.6% and CSME was improved in 23.8% of eyes. According to our study, baseline visual acuity and retinopathy severity were two important intervening factors in response to lasertherapy. Comparing our results with natural course of diabetic macular edema, indicates that in assessing visual outcome laser photocoagulation is an effective modality in treatment of CSME, but it is not effective in maintaining or improving visual acuity, which is due to patients delay in visiting ophthalmologists and paying not enough attention to follow-up visits.

  6. Improvement of visual acuity and VEP after optic nerve contusion by NGF and its safety analysis

    Directory of Open Access Journals (Sweden)

    Ming Zhao

    2018-02-01

    Full Text Available AIM:To investigate the effect of neuropathic factor(NGFon visual acuity and visual evoked potential(VEPin patients with optic nerve contusion. METHODS:Totally 78 patients(78 eyeswith optic nerve contusion were selected. From January 2013 to June 2016, 39 cases(39 eyeswere divided into observation group and control group respectively according to the random number table method. Prednisone, vitamins and mecobalamin tablets treatment were given to both groups, based on that, the observation group was given NGF treatment, continuous treatment of 2 courses(21d for a course of treatment. RESULTS: There was no significant difference in visual field defect and visual field sensitivity between the observation group and the control group before treatment(P>0.05. After treatment, the visual field defect degree of the observation group was smaller, the visual field sensitivity was better than that of the control group(PP>0.05. After treatment, the P100 wave latency of the observation group was significantly shorter than that of the control group(PPPCONCLUSION: NGF treatment for optic nerve contusion can significantly improve the patient's visual acuity, VEP indicators, reduce visual field defects, improve visual field sensitivity.

  7. Dynamic Visual Acuity and Landing Sickness in Crewmembers Returning from Long-Duration Spaceflight

    Science.gov (United States)

    Rosenberg, M.J.F; Peters, B.T.; Reschke, M. F.

    2016-01-01

    Long-term exposure to microgravity causes sensorimotor adaptations that result in functional deficits upon returning to a gravitational environment. At landing the vestibular system and the central nervous system, responsible for coordinating head and eye movements, are adapted to microgravity and must re-adapt to the gravitational environment. This re-adaptation causes decrements in gaze control and dynamic visual acuity, with astronauts reporting oscillopsia and blurred vision. Dynamic visual acuity (DVA) is assessed using an oscillating chair developed in the Neuroscience Laboratory at JSC. This chair is lightweight and easily portable for quick deployment in the field. The base of the chair is spring-loaded and allows for manual oscillation of the subject. Using a metronome, the chair is vertically oscillated plus or minus 2 cm at 2 Hz by an operator, to simulate walking. While the subject is being oscillated, they are asked to discern the direction of Landolt-C optotypes of varying sizes and record their direction using a gamepad. The visual acuity thresholds are determined using an algorithm that alters the size of the optotype based on the previous response of the subject using a forced-choice best parameter estimation that is able to rapidly converge on the threshold value. Visual acuity thresholds were determined both for static (seated) and dynamic (oscillating) conditions. Dynamic visual acuity is defined as the difference between the dynamic and static conditions. Dynamic visual acuity measures will be taken prior to flight (typically L-180, L-90, and L-60) and up to eight times after landing, including up to 3 times on R plus 0. Follow up measurements will be taken at R plus 1 (approximately 36 hours after landing). Long-duration International Space Station crewmembers will be tested once at the refueling stop in Europe and once again upon return to Johnson Space Center. In addition to DVA, subjective ratings of motion sickness will be recorded

  8. Low-level laser therapy improves visual acuity in adolescent and adult patients with amblyopia.

    Science.gov (United States)

    Ivandic, Boris T; Ivandic, Tomislav

    2012-03-01

    The purpose of this study was to examine the effects of low-level laser therapy (LLLT) on visual acuity in adolescent and adult patients with amblyopia. Currently, amblyopia can be treated successfully only in children. In this single-blinded, placebo-controlled study, 178 patients (mean age 46.8 years) with amblyopia caused by ametropia (110 eyes) or strabismus (121 eyes) were included. For LLLT, the area of the macula was irradiated through the conjunctiva from 1 cm distance for 30 sec with laser light (780 nm, 292 Hz, 1:1 duty cycle; average power 7.5 mW; spot area 3 mm(2)). The treatment was repeated on average 3.5 times, resulting in a mean total dose of 0.77 J/cm(2). No occlusion was applied, and no additional medication was administered. Best corrected distant visual acuity was determined using Snellen projection optotypes. In 12 patients (12 eyes), the multifocal visual evoked potential (M-VEP) was recorded. A control group of 20 patients (20 eyes) received mock treatment. Visual acuity improved in ∼90% of the eyes treated with LLLT (pamblyopia caused by ametropia and strabismus, respectively. The treatment effect was maintained for at least 6 months. The mean M-VEP amplitude increased by 1207 nV (pamblyopia caused by ametropia or strabismus.

  9. Use of the Dynamic Visual Acuity Test as a screener for community-dwelling older adults who fall.

    Science.gov (United States)

    Honaker, Julie A; Shepard, Neil T

    2011-01-01

    Adequate function of the peripheral vestibular system, specifically the vestibulo-ocular reflex (VOR; a network of neural connections between the peripheral vestibular system and the extraocular muscles) is essential for maintaining stable vision during head movements. Decreased visual acuity resulting from an impaired peripheral vestibular system may impede balance and postural control and place an individual at risk of falling. Therefore, sensitive measures of the vestibular system are warranted to screen for the tendency to fall, alerting clinicians to recommend further risk of falling assessment and referral to a falling risk reduction program. Dynamic Visual Acuity (DVA) testing is a computerized VOR assessment method to evaluate the peripheral vestibular system during head movements; reduced visual acuity as documented with DVA testing may be sensitive to screen for falling risk. This study examined the sensitivity and specificity of the computerized DVA test with yaw plane head movements for identifying community-dwelling adults (58-78 years) who are prone to falling. A total of 16 older adults with a history of two or more unexplained falls in the previous twelve months and 16 age and gender matched controls without a history of falls in the previous twelve months participated. Computerized DVA with horizontal head movements at a fixed velocity of 120 deg/sec was measured and compared with the Dynamic Gait Index (DGI) a gold standard gait assessment measurement for identifying falling risk. Receiver operating characteristics (ROC) curve analysis and area under the ROC curve (AUC) were used to assess the sensitivity and specificity of the computerized DVA as a screening measure for falling risk as determined by the DGI. Results suggested a link between computerized DVA and the propensity to fall; DVA in the yaw plane was found to be a sensitive (92%) and accurate screening measure when using a cutoff logMAR value of >0.25.

  10. Temporary marked impairment of visual acuity in a case of intraocular malignant lymphoma during radiation therapy

    International Nuclear Information System (INIS)

    Miyao, Yoko; Tada, Rei; Koizumi, Noriko; Yamada, Hideaki; Kinoshita, Shigeru; Ikeda, Tsunehiko

    2000-01-01

    A 56-year-old female was referred to us for blurring of both eyes since 2 years before. She had been diagnosed as chronic uveitis and responded poorly to systemic and topical corticosteroid. Her corrected visual acuity was 0.8 right and 0.5 left. Systemic studies, including magnetic resonance imaging and gadolinium scintigraphy, were negative. Vitreous biopsy led to the diagnosis of malignant lymphoma originating from the eye. Seven days after initiation of radiation at the daily doses of 2 Gy, massive subretinal infiltration developed in her right eye forming a niveau. Systemic prednisolone induced resolution of exudate with improved visual acuity to 1.0 13 days later. This cases illustrates that radiation may induce temporary aggravation of intraocular malignant lymphoma and that it may undergo resolution following systemic corticosteroid. (author)

  11. Gains following perceptual learning are closely linked to the initial visual acuity.

    Science.gov (United States)

    Yehezkel, Oren; Sterkin, Anna; Lev, Maria; Levi, Dennis M; Polat, Uri

    2016-04-28

    The goal of the present study was to evaluate the dependence of perceptual learning gains on initial visual acuity (VA), in a large sample of subjects with a wide range of VAs. A large sample of normally sighted and presbyopic subjects (N = 119; aged 40 to 63) with a wide range of uncorrected near visual acuities (VA, -0.12 to 0.8 LogMAR), underwent perceptual learning. Training consisted of detecting briefly presented Gabor stimuli under spatial and temporal masking conditions. Consistent with previous findings, perceptual learning induced a significant improvement in near VA and reading speed under conditions of limited exposure duration. Our results show that the improvements in VA and reading speed observed following perceptual learning are closely linked to the initial VA, with only a minor fraction of the observed improvement that may be attributed to the additional sessions performed by those with the worse VA.

  12. Visual acuity testing of radiographic inspectors in nondestructive inspection. Final report

    International Nuclear Information System (INIS)

    Yonemura, G.T.

    1981-06-01

    Visual acuity tests for radiographic inspectors should be correlated with the type of tasks encountered in real world radiography. The testing procedures should be capable of assessing differences in day to day performance of a given inspector as well as the performance of one inspector relative to other inspectors. Single line targets with specific parametric values for contrast, width, and blur are recommended to provide a means for testing a radiographic inspector for visual acuity. These targets may be used for periodic tests by the employing organization or for more frequent self testing by the inspector. Statistics from the National Health Survey, procedures recommended by the NAS-NRC Committee on Vision and real world radiographs have been utilized in arriving at recommended test configurations

  13. Vision-guided ocular growth in a mutant chicken model with diminished visual acuity.

    Science.gov (United States)

    Ritchey, Eric R; Zelinka, Christopher; Tang, Junhua; Liu, Jun; Code, Kimberly A; Petersen-Jones, Simon; Fischer, Andy J

    2012-09-01

    Visual experience is known to guide ocular growth. We tested the hypothesis that vision-guided ocular growth is disrupted in a model system with diminished visual acuity. We examine whether ocular elongation is influenced by form-deprivation (FD) and lens-imposed defocus in the Retinopathy, Globe Enlarged (RGE) chicken. Young RGE chicks have poor visual acuity, without significant retinal pathology, resulting from a mutation in guanine nucleotide-binding protein β3 (GNB3), also known as transducin β3 or Gβ3. The mutation in GNB3 destabilizes the protein and causes a loss of Gβ3 from photoreceptors and ON-bipolar cells (Ritchey et al., 2010). FD increased ocular elongation in RGE eyes in a manner similar to that seen in wild-type (WT) eyes. By comparison, the excessive ocular elongation that results from hyperopic defocus was increased, whereas myopic defocus failed to significantly decrease ocular elongation in RGE eyes. Brief daily periods of unrestricted vision interrupting FD prevented ocular elongation in RGE chicks in a manner similar to that seen in WT chicks. Glucagonergic amacrine cells differentially expressed the immediate early gene Egr1 in response to growth-guiding stimuli in RGE retinas, but the defocus-dependent up-regulation of Egr1 was lesser in RGE retinas compared to that of WT retinas. We conclude that high visual acuity, and the retinal signaling mediated by Gβ3, is not required for emmetropization and the excessive ocular elongation caused by FD and hyperopic defocus. However, the loss of acuity and Gβ3 from RGE retinas causes enhanced responses to hyperopic defocus and diminished responses to myopic defocus. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Visual acuity, self-reported vision and falls in the EPIC-Norfolk Eye study

    OpenAIRE

    Yip, Jennifer L Y; Khawaja, Anthony P; Broadway, David; Luben, Robert; Hayat, Shabina; Dalzell, Nichola; Bhaniani, Amit; Wareham, Nicholas; Khaw, Kay-Tee; Foster, Paul J

    2013-01-01

    Purpose To examine the relationship between visual acuity (VA) and self-reported vision (SRV) in relation to falls in 8317 participants of the European Prospective Investigation into Cancer-Norfolk Eye study. Methods All participants completed a health questionnaire that included a question regarding SRV and questions regarding the number of falls in the past year. Distance VA was measured using a logMAR chart for each eye. Poor SRV was defined as those reporting fair or poor distance vision....

  15. Macular Structures, Optical Components, and Visual Acuity in Preschool Children after Intravitreal Bevacizumab or Laser Treatment.

    Science.gov (United States)

    Lee, Yung-Sung; See, Lai-Chu; Chang, Shu-Hao; Wang, Nan-Kai; Hwang, Yih-Shiou; Lai, Chi-Chun; Chen, Kuan-Jen; Wu, Wei-Chi

    2018-05-10

    To investigate the macular structures, optical components, and visual acuity in preschool-aged children with a history of type I retinopathy of prematurity who underwent either intravitreal bevacizumab (IVB), laser, or a combination of treatments. Comparative interventional case series. A referred medical center in Taiwan. 80 eyes from 42 patients (33 IVB-treated eyes from 17 children, 24 laser-treated eyes from 13 children, and 23 laser + IVB-treated eyes from 12 children). Spectral-domain optical coherence tomography. The retinal thickness in the foveal area and the associated morphologic changes in foveal depression. Compared with the laser-treated and laser + IVB-treated eyes, the IVB-treated eyes had less myopia and deeper anterior chamber depths but presented similar axial lengths and corneal curvatures (P = .001, .002, .95 and .16, respectively). The IVB-treated eyes had significantly thinner foveal, parafoveal, and perifoveal retinal thicknesses (P < .01 for all) and a higher incidence of foveal depression than the laser- or laser + IVB-treated eyes. The macular and subfoveal choroidal thicknesses did not differ among the groups (P = .21 and .63, respectively). Moreover, compared with the eyes treated with laser or laser + IVB, the IVB-treated eyes had better uncorrected visual acuity, although a significant difference was not observed in best-corrected visual acuity (P = .008 and .29, respectively). Compared with laser therapy, IVB-treated eyes were associated with deeper anterior chamber depths and thinner foveal, parafoveal and perifoveal thicknesses. Moreover, these IVB-treated eyes had less refractive errors and better uncorrected visual acuity. Copyright © 2018. Published by Elsevier Inc.

  16. The advanced glaucoma intervention study, 6: effect of cataract on visual field and visual acuity. The AGIS Investigators.

    Science.gov (United States)

    2000-12-01

    To investigate the effect of cataract on visual function and the role of cataract in explaining a race-treatment interaction in outcomes of glaucoma surgery. The Advanced Glaucoma Intervention Study (AGIS) enrolled 332 black patients (451 eyes) and 249 white patients (325 eyes) with advanced glaucoma. Eyes were randomly assigned to an argon laser trabeculoplasty (ALT)-trabeculectomy-trabeculectomy sequence or a trabeculectomy-ALT-trabeculectomy sequence. From the AGIS experience with cataract surgery during follow-up, we estimated the expected change in visual function scores from before cataract surgery to after cataract surgery. Then, for eyes with cataract not removed, we used these estimates of expected change to adjust visual function scores for the presumed effects of cataract. In turn, we used the adjusted scores to obtain cataract-adjusted main outcome measures. Average percent of eyes with decrease of visual field (APDVF) and average percent of eyes with decrease of visual acuity (APDVA). Within the 2 months before cataract surgery, visual acuity was better in eyes of white patients than of black patients by an average of approximately 2 lines on the visual acuity test chart. Cataract surgery improved visual acuity and visual field defect scores, with the amounts of improvement greater when preoperative visual acuity was lower. Adjustments for cataract brought about the following relative reductions: for APDVF, a relative reduction of 5% to 11% in black patients and 9% to 11% in white patients; for APDVA, a relative reduction of 45% to 49% in black patients and 31% to 38% in white patients; and for the APDVF and APDVA race-treatment interactions, relative reductions of 25% and 45%, respectively. On average, visual function scores improved after cataract surgery. The findings of reduced race-treatment interactions after adjustment for cataract do not alter our earlier conclusion that the AGIS 7-year results support use of the ALT

  17. Wavefront coherence area for predicting visual acuity of post-PRK and post-PARK refractive surgery patients

    Science.gov (United States)

    Garcia, Daniel D.; van de Pol, Corina; Barsky, Brian A.; Klein, Stanley A.

    1999-06-01

    Many current corneal topography instruments (called videokeratographs) provide an `acuity index' based on corneal smoothness to analyze expected visual acuity. However, post-refractive surgery patients often exhibit better acuity than is predicted by such indices. One reason for this is that visual acuity may not necessarily be determined by overall corneal smoothness but rather by having some part of the cornea able to focus light coherently onto the fovea. We present a new method of representing visual acuity by measuring the wavefront aberration, using principles from both ray and wave optics. For each point P on the cornea, we measure the size of the associated coherence area whose optical path length (OPL), from a reference plane to P's focus, is within a certain tolerance of the OPL for P. We measured the topographies and vision of 62 eyes of patients who had undergone the corneal refractive surgery procedures of photorefractive keratectomy (PRK) and photorefractive astigmatic keratectomy (PARK). In addition to high contrast visual acuity, our vision tests included low contrast and low luminance to test the contribution of the PRK transition zone. We found our metric for visual acuity to be better than all other metrics at predicting the acuity of low contrast and low luminance. However, high contrast visual acuity was poorly predicted by all of the indices we studied, including our own. The indices provided by current videokeratographs sometimes fail for corneas whose shape differs from simple ellipsoidal models. This is the case with post-PRK and post-PARK refractive surgery patients. Our alternative representation that displays the coherence area of the wavefront has considerable advantages, and promises to be a better predictor of low contrast and low luminance visual acuity than current shape measures.

  18. Effect of pupil size on visual acuity in a laboratory model of pseudophakic monovision.

    Science.gov (United States)

    Kawamorita, Takushi; Uozato, Hiroshi; Handa, Tomoya; Ito, Misae; Shimizu, Kimiya

    2010-05-01

    To investigate the effect of pupil size on visual acuity in pseudophakic monovision. For the simulation, a modified Liou-Brennan model eye was used. The model eye was designed to include a centered optical system, corneal asphericity, an iris pupil, a Stiles-Crawford effect, an intraocular lens, and chromatic aberration. Calculation of the modulation transfer function (MTF) was performed with ZEMAX software. Visual acuity was estimated from the MTF and the retinal threshold curve. The sizes of the entrance pupil were 2.0, 2.5, 3.0, and 4.0 mm. Decreasing pupil diameter and increasing myopia progressively improved near visual acuity. For an entrance pupil size of 2.5 mm and a refractive error of -1.50 diopters, the logMAR value (Snellen; metric) in the non-dominant eye at 40 cm was 0.06 (20/23; 6/6.9). Knowledge of the patient's pupil diameter at near fixation can assist surgeons in determining the optimum degree of myopia for successful monovision.

  19. A new dynamic visual acuity test to assess peripheral vestibular function.

    Science.gov (United States)

    Vital, Domenic; Hegemann, Stefan C A; Straumann, Dominik; Bergamin, Oliver; Bockisch, Christopher J; Angehrn, Dominik; Schmitt, Kai-Uwe; Probst, Rudolf

    2010-07-01

    To evaluate a novel test for dynamic visual acuity (DVA) that uses an adaptive algorithm for changing the size of Landolt rings presented during active or passive head impulses, and to compare the results with search-coil head impulse testing. Prospective study in healthy individuals and patients with peripheral vestibular deficits. Tertiary academic center. One hundred neuro-otologically healthy individuals (age range, 19-80 years) and 15 patients with bilateral (n = 5) or unilateral (n = 10) peripheral vestibular loss (age range, 27-72 years). Testing of static visual acuity (SVA), DVA during active and passive horizontal head rotations (optotype presentation at head velocities >100 degrees/s and >150 degrees/s), and quantitative horizontal head impulse testing with scleral search coils. Difference between SVA and DVA, that is, visual acuity loss (VA loss), gain of the high-acceleration vestibulo-ocular reflex. Passive head impulses and higher velocities were more effective than active impulses and lower velocities. Using passive head impulses and velocities higher than 150 degrees/s, the DVA test discriminated significantly (P test sensitivity was 100%, specificity was 94%, and accuracy was 95%, with search-coil head impulse testing used as a reference. In healthy individuals, VA loss increased significantly with age (P testing with Landolt rings that are adaptively changed in size enables detection of peripheral vestibular dysfunction in a fast and simple way.

  20. Correlation between contrast sensitivity and visual acuity in retinitis pigmentosa patients.

    Science.gov (United States)

    Akeo, Kiyoshi; Hiida, Yoshiki; Saga, Masamichi; Inoue, Rikako; Oguchi, Yoshihisa

    2002-01-01

    High-contrast figures such as Landolt rings are insufficient to evaluate the function of the foveal cones of retinitis pigmentosa (RP) patients. We investigated the correlation between visual function as determined with Landolt rings and with the Vistech Contrast Sensitivity Function Test (VCTS) at various spatial frequencies, in addition to the Cambridge Low Contrast Grating (CLCG). The study included 30 retinitis pigmentosa patients (53 eyes). All patients were assessed with Landolt rings, the Vistech method, and the CLCG. We estimated the relative contribution of contrast sensitivity to visual acuity by VCTS at each spatial frequency and by CLCG by simple linear regression analysis. The results of the regression analysis of VCTS at 1.5, 3.0, and 6.0 cycles/degree showed a significant correlation between Landolt rings and VCTS and between CLCG and VCTS that was strongest at 6.0 cycles/degree. There was no significant correlation between Landolt rings and VCTS or between CLCG and VCTS at 12.0 and 18.0 cycles/degree. Patients with a visual acuity of 20/25 and CLCG greater than 100 were divided into two groups according to their contrast sensitivity at 18.0 cycles/degree on VCTS. The VCTS at the highest frequency was useful for evaluating the foveal visual function in RP patients having good visual acuity with the Landolt rings. Thus, contrast sensitivity should be useful in detecting minute impairment or improvement of visual function in RP. Copyright 2002 S. Karger AG, Basel

  1. Visual acuity measures do not reliably detect childhood refractive error--an epidemiological study.

    Directory of Open Access Journals (Sweden)

    Lisa O'Donoghue

    Full Text Available PURPOSE: To investigate the utility of uncorrected visual acuity measures in screening for refractive error in white school children aged 6-7-years and 12-13-years. METHODS: The Northern Ireland Childhood Errors of Refraction (NICER study used a stratified random cluster design to recruit children from schools in Northern Ireland. Detailed eye examinations included assessment of logMAR visual acuity and cycloplegic autorefraction. Spherical equivalent refractive data from the right eye were used to classify significant refractive error as myopia of at least 1DS, hyperopia as greater than +3.50DS and astigmatism as greater than 1.50DC, whether it occurred in isolation or in association with myopia or hyperopia. RESULTS: Results are presented from 661 white 12-13-year-old and 392 white 6-7-year-old school-children. Using a cut-off of uncorrected visual acuity poorer than 0.20 logMAR to detect significant refractive error gave a sensitivity of 50% and specificity of 92% in 6-7-year-olds and 73% and 93% respectively in 12-13-year-olds. In 12-13-year-old children a cut-off of poorer than 0.20 logMAR had a sensitivity of 92% and a specificity of 91% in detecting myopia and a sensitivity of 41% and a specificity of 84% in detecting hyperopia. CONCLUSIONS: Vision screening using logMAR acuity can reliably detect myopia, but not hyperopia or astigmatism in school-age children. Providers of vision screening programs should be cognisant that where detection of uncorrected hyperopic and/or astigmatic refractive error is an aspiration, current UK protocols will not effectively deliver.

  2. Contrast visual acuity after multifocal intraocular lens implantation:aspheric versus spherical design

    Directory of Open Access Journals (Sweden)

    Jun-Hua Li

    2014-02-01

    Full Text Available AIM: To evaluate contrast visual acuity (CVA after implantation of an aspheric apodized diffractive intraocular lens (IOL or a spherical apodized diffractive IOL in cataract surgery.METHOD: This prospective randomized controlled study with a 12-month follow-up compared the results of cataract surgery with implantation of an aspheric AcrySof ReSTOR SN6AD3 IOL (30 eyes and a spherical AcrySof ReSTOR SN60D3 IOL (30 eyes. CVA with best distance correction was measured at 4 contrast levels (100%, 25%, 10% and 5% under 3 levels of chart luminance [250, 85 and 25 candelas per square meter (cd/m2] using a multi-functional visual acuity tester (MFVA-100.RESULTS:At 12 months after surgery, there were no statistically significant differences in 100% CVA and 25% CVA under 250cd/m2 (P100%=0.875 and P25%=0.057 and 85cd/m2 (P100%=0.198 and P25%=0.193 between the aspheric group and the spherical group. However, the 10% CVA and 5% CVA were significant better in aspheric group than spherical group under 250cd/m2 (P10%=0.042 and P5%=0.007 and 85cd/m2 (P10%=0.002 and P5%=0.039. Under the luminance level of 25cd/m2, no significant differences was found in the 100% CVA between the 2 group (P100%=0.245, while aspheric group had better visual acuity in the remaining 3 contracts (P25%=0.023, P10%=0.026 and P5%=0.002, respectively.CONCULSION:The aspheric AcrySof ReSTOR SN6AD3 IOL provided patients with better low-contrast visual acuity than the spherical AcrySof ReSTOR SN60D3 IOL.Keyword:cataract surgery; intraocular lens; contrast sensitivity; visual acuity

  3. Avaliação da acuidade visual Snellen Snellen visual acuity evaluation

    Directory of Open Access Journals (Sweden)

    Marcio Zapparoli

    2009-12-01

    âncias diversas, mantém a razão de proporcionalidade dos optotipos baseada no ângulo visual e se aproxima em muito ao padrão teórico preconizado por Herman Snellen em 1862.PURPOSE: To evaluate the visual acuity (VA measurement by Snellen chart at three main Ophthalmology centers in Curitiba, compare these measurements with a computerized method for calibrating VA and also with the standard theory developed by Hermann Snellen. METHODS: Descriptive study including 15 Ophthalmology clinics and a computerized method to measure the VA. Using a tape measure and a caliper, measurement of the distance was obtained from the sitting patients' eye to VA optotypes projection on the wall. At the same time, measurement of the size of the letters of 4 lines of the VA projection on the wall was performed. RESULTS: To analyze the results, it was opted to compare the angles presented by each clinic for each measurement. It was not surprising that no clinic presented an exact angle of 5 arch minutes. Comparing clinics results with computerized method, we observed that only 2 clinics obtained better results if compared with the angles obtained from optotypes projection, but the data is very similar and with no statistical significance. In relation to the other clinics, the superiority of the computerized method is very relevant. All had differences in comparison to the gold standard. Individually, comparing computerized method to standard Snellen theory, it was observed that a condition very close to the ideal was obtained, in other words, results very similar to 5 arch minutes were noted in all the visual acuities analyzed. CONCLUSIONS: It can be concluded that there is a great heterogeneity in the evaluation of VA in different Ophthalmology centers. Also, the same patient, evaluated in different clinics, can obtain different VA measurements. The computerized method is practical, portable, adjustable for different distances, and maintains optotypes proportionality ratio based on visual angle

  4. Short-term visual deprivation does not enhance passive tactile spatial acuity.

    Directory of Open Access Journals (Sweden)

    Michael Wong

    Full Text Available An important unresolved question in sensory neuroscience is whether, and if so with what time course, tactile perception is enhanced by visual deprivation. In three experiments involving 158 normally sighted human participants, we assessed whether tactile spatial acuity improves with short-term visual deprivation over periods ranging from under 10 to over 110 minutes. We used an automated, precisely controlled two-interval forced-choice grating orientation task to assess each participant's ability to discern the orientation of square-wave gratings pressed against the stationary index finger pad of the dominant hand. A two-down one-up staircase (Experiment 1 or a Bayesian adaptive procedure (Experiments 2 and 3 was used to determine the groove width of the grating whose orientation each participant could reliably discriminate. The experiments consistently showed that tactile grating orientation discrimination does not improve with short-term visual deprivation. In fact, we found that tactile performance degraded slightly but significantly upon a brief period of visual deprivation (Experiment 1 and did not improve over periods of up to 110 minutes of deprivation (Experiments 2 and 3. The results additionally showed that grating orientation discrimination tends to improve upon repeated testing, and confirmed that women significantly outperform men on the grating orientation task. We conclude that, contrary to two recent reports but consistent with an earlier literature, passive tactile spatial acuity is not enhanced by short-term visual deprivation. Our findings have important theoretical and practical implications. On the theoretical side, the findings set limits on the time course over which neural mechanisms such as crossmodal plasticity may operate to drive sensory changes; on the practical side, the findings suggest that researchers who compare tactile acuity of blind and sighted participants should not blindfold the sighted participants.

  5. Near-field visual acuity of pigeons: effects of head location and stimulus luminance.

    Science.gov (United States)

    Hodos, W; Leibowitz, R W; Bonbright, J C

    1976-03-01

    Two pigeons were trained to discriminate a grating stimulus from a blank stimulus of equivalent luminance in a three-key chamber. The stimuli and blanks were presented behind a transparent center key. The procedure was a conditional discrimination in which pecks on the left key were reinforced if the blank had been present behind the center key and pecks on the right key were reinforced if the grating had been present behind the center key. The spatial frequency of the stimuli was varied in each session from four to 29.5 lines per millimeter in accordance with a variation of the method of constant stimuli. The number of lines per millimeter that the subjects could discriminate at threshold was determined from psychometric functions. Data were collected at five values of stimulus luminance ranging from--0.07 to 3.29 log cd/m2. The distance from the stimulus to the anterior nodal point of the eye, which was determined from measurements taken from high-speed motion-picture photographs of three additional pigeons and published intraocular measurements, was 62.0 mm. This distance and the grating detection thresholds were used to calculate the visual acuity of the birds at each level of luminance. Acuity improved with increasing luminance to a peak value of 0.52, which corresponds to a visual angle of 1.92 min, at a luminance of 2.33 log cd/m2. Further increase in luminance produced a small decline in acuity.

  6. A study of static, kinetic, and dynamic visual acuity in 102 Japanese professional baseball players

    Directory of Open Access Journals (Sweden)

    Hoshina K

    2013-03-01

    Full Text Available Kohji Hoshina,1 Yuichi Tagami,2 Osamu Mimura,3 Hiroshi Edagawa,4 Masao Matsubara,5 Teiichi Nakayama6 1Hoshina Eye Clinic, Nishinomiya, Japan; 2Department of Ophthalmology, Kobe Century Memorial Hospital, Kobe, Japan; 3Department of Ophthalmology, Hyogo College of Medicine, Nishinomiya, Japan; 4Edagawa Eye Clinic, Tokyo, Japan; 5Department of Ophthalmology, Tokyo Women's Medical University Medical Center East, Tokyo, Japan; 6Ritsumeikan University, Kyoto, Japan Background: It seemed that visual functions might have some effects on the performance of baseball players. We measured static, kinetic, and dynamic visual acuity (SVA, KVA, and DVA, respectively of Japanese professional baseball players to ascertain whether there would be any difference in SVA, KVA, and DVA among player groups stratified according to their performance level. Methods: The subjects were 102 male professional baseball players with a mean age of 26 years who were members of a Japanese professional baseball club from 2000 to 2009. They were stratified into three groups according to their performance level: A (players who were on the roster of the top-level team all the time throughout the study period, B (players who were on the roster of the top-level team sometimes but not all the time, and C (players who were never on the roster of the top-level team. They were interviewed for the use of corrective visual aids, and examined for SVA, KVA, and DVA. The measurements of these parameters were compared among groups A, B, and C. We also investigated and analyzed the association of KVA or DVA with player position (pitchers or fielders and with hand dominance for batting. KVA was compared between the pitchers and the fielders because they each require different playing skills. DVA was compared between the right-handed and the left-handed batters. Results: There was no statistically significant difference among groups A, B, and C. There was a statistically significant difference in

  7. A New Visual Stimulation Program for Improving Visual Acuity in Children with Visual Impairment: A Pilot Study

    Science.gov (United States)

    Tsai, Li-Ting; Hsu, Jung-Lung; Wu, Chien-Te; Chen, Chia-Ching; Su, Yu-Chin

    2016-01-01

    The purpose of this study was to investigate the effectiveness of visual rehabilitation of a computer-based visual stimulation (VS) program combining checkerboard pattern reversal (passive stimulation) with oddball stimuli (attentional modulation) for improving the visual acuity (VA) of visually impaired (VI) children and children with amblyopia and additional developmental problems. Six children (three females, three males; mean age = 3.9 ± 2.3 years) with impaired VA caused by deficits along the anterior and/or posterior visual pathways were recruited. Participants received eight rounds of VS training (two rounds per week) of at least eight sessions per round. Each session consisted of stimulation with 200 or 300 pattern reversals. Assessments of VA (assessed with the Lea symbol VA test or Teller VA cards), visual evoked potential (VEP), and functional vision (assessed with the Chinese-version Functional Vision Questionnaire, FVQ) were carried out before and after the VS program. Significant gains in VA were found after the VS training [VA = 1.05 logMAR ± 0.80 to 0.61 logMAR ± 0.53, Z = –2.20, asymptotic significance (2-tailed) = 0.028]. No significant changes were observed in the FVQ assessment [92.8 ± 12.6 to 100.8 ±SD = 15.4, Z = –1.46, asymptotic significance (2-tailed) = 0.144]. VEP measurement showed improvement in P100 latency and amplitude or integration of the waveform in two participants. Our results indicate that a computer-based VS program with passive checkerboard stimulation, oddball stimulus design, and interesting auditory feedback could be considered as a potential intervention option to improve the VA of a wide age range of VI children and children with impaired VA combined with other neurological disorders. PMID:27148014

  8. A New Visual Stimulation Program for Improving Visual Acuity in Children with Visual Impairment: A Pilot Study.

    Science.gov (United States)

    Tsai, Li-Ting; Hsu, Jung-Lung; Wu, Chien-Te; Chen, Chia-Ching; Su, Yu-Chin

    2016-01-01

    The purpose of this study was to investigate the effectiveness of visual rehabilitation of a computer-based visual stimulation (VS) program combining checkerboard pattern reversal (passive stimulation) with oddball stimuli (attentional modulation) for improving the visual acuity (VA) of visually impaired (VI) children and children with amblyopia and additional developmental problems. Six children (three females, three males; mean age = 3.9 ± 2.3 years) with impaired VA caused by deficits along the anterior and/or posterior visual pathways were recruited. Participants received eight rounds of VS training (two rounds per week) of at least eight sessions per round. Each session consisted of stimulation with 200 or 300 pattern reversals. Assessments of VA (assessed with the Lea symbol VA test or Teller VA cards), visual evoked potential (VEP), and functional vision (assessed with the Chinese-version Functional Vision Questionnaire, FVQ) were carried out before and after the VS program. Significant gains in VA were found after the VS training [VA = 1.05 logMAR ± 0.80 to 0.61 logMAR ± 0.53, Z = -2.20, asymptotic significance (2-tailed) = 0.028]. No significant changes were observed in the FVQ assessment [92.8 ± 12.6 to 100.8 ±SD = 15.4, Z = -1.46, asymptotic significance (2-tailed) = 0.144]. VEP measurement showed improvement in P100 latency and amplitude or integration of the waveform in two participants. Our results indicate that a computer-based VS program with passive checkerboard stimulation, oddball stimulus design, and interesting auditory feedback could be considered as a potential intervention option to improve the VA of a wide age range of VI children and children with impaired VA combined with other neurological disorders.

  9. A new visual stimulation program for improving visual acuity in children with visual impairment: a pilot study

    Directory of Open Access Journals (Sweden)

    Li-Ting eTsai

    2016-04-01

    Full Text Available The purpose of this study was to investigate the effectiveness of visual rehabilitation of a computer-based visual stimulation (VS program combining checkerboard pattern reversal (passive stimulation with oddball stimuli (attentional modulation for improving the visual acuity (VA of visually impaired (VI children and children with amblyopia and additional developmental problems. Six children (3 females, 3 males; mean age = 3.9 ± 2.3 years with impaired VA caused by deficits along the anterior and/or posterior visual pathways were recruited. Participants received eight rounds of VS training (two rounds per week of at least 8 sessions per round. Each session consisted of stimulation with 200 or 300 pattern reversals. Assessments of VA (assessed with the Lea symbol VA test or Teller VA cards, visual evoked potential (VEP, and functional vision (assessed with the Chinese-version Functional Vision Questionnaire, FVQ were carried out before and after the VS program. Significant gains in VA were found after the VS training (VA=1.05 logMAR ± 0.80 to 0.61 logMAR ± 0.53, Z=-2.20, asymptotic significance (2-tailed =0.028. No significant changes were observed in the FVQ assessment (92.8 ± 12.6 to 100.8 ± SD=15.4, Z=-1.46, asymptotic significance (2-tailed = 0.144. VEP measurement showed improvement in P100 latency and amplitude or integration of the waveform in two participants. Our results indicate that a computer-based VS program with passive checkerboard stimulation, oddball stimulus design, and interesting auditory feedback could be considered as a potential intervention option to improve the VA of a wide age range of VI children and children with impaired VA combined with other neurological disorders.

  10. Evaluation of a Public Child Eye Health Tertiary Facility for Pediatric Cataract in Southern Nigeria I: Visual Acuity Outcome

    Science.gov (United States)

    Duke, Roseline E.; Adio, Adedayo; Oparah, Sidney K.; Odey, Friday; Eyo, Okon A.

    2016-01-01

    Purpose: A retrospective study of the outcome of congenital and developmental cataract surgery was conducted in a public child eye health tertiary facility in children <16 years of age in Southern Nigeria, as part of an evaluation. Materials and Method: Manual Small Incision Cataract Surgery with or without anterior vitrectomy was performed. The outcome measures were visual acuity (VA) and change (gain) in visual acuity. The age of the child at onset, duration of delay in presentation, ocular co-morbidity, non ocular co-morbidity, gender, and pre operative visual acuity were matched with postoperative visual acuity. A total of 66 children were studied for a period of six weeks following surgery. Results: Forty eight (72.7%) children had bilateral congenital cataracts and 18 (27.3%) children had bilateral developmental cataracts. There were 38(57.6%) males and 28 (42.4%) females in the study. Thirty Five (53%) children had good visual outcome (normal vision range 6/6/ -6/18) post-operatively. The number of children with blindness (vision <3/60) decreased from 61 (92.4%) pre-operatively to 4 (6.1%) post-operatively. Post operative complication occurred in 6.8% of cases six week after surgery. Delayed presentation had an inverse relationship with change (gain) in visual acuity (r = - 0.342; p-value = 0.005). Pre-operative visual acuity had a positive relationship with post operative change (gain) in visual acuity (r = 0.618; p-value = 0.000). Conclusion: Predictors of change in visual acuity in our study were; delayed presentation and pre-operative VA. Cataract surgery in children showed clinical benefit. PMID:27347247

  11. An assessment of the iPad as a testing platform for distance visual acuity in adults

    Science.gov (United States)

    Black, J M; Jacobs, R J; Phillips, G; Chen, L; Tan, E; Tran, A; Thompson, B

    2013-01-01

    Objectives Visual acuity is a common measurement in general practice, and the advent of new technology such as tablet computers offers a change in the way in which these tests are delivered. The aim of this study was to assess whether measurements of distance visual acuity using LogMAR letter charts displayed on an iPad tablet computer were in agreement with standard clinical tests of visual acuity in adults with normal vision. Design Blinded, diagnostic test study. Setting Single centre (University) in Auckland, New Zealand. Participants University staff and students (n=85). Participants were required to have visual acuity better than 6/60 and wear habitual refractive correction during testing. Participants were excluded if there was any history of ocular pathology. Primary and secondary outcome measures Visual acuity measured under a number of conditions. Results The iPad tablet with its glossy screen was highly susceptible to glare resulting in acuity measurements that were significantly poorer (approximately 2 LogMAR lines) than those made using an ETDRS chart and a standard computerised testing system (n=56). However, fitting the iPad with an antiglare screen and positioning the device away from sources creating reflected (veiling) glare resulted in acuity measurements that were equivalent those made using gold standard charts (n=29). Conclusions Tablet computers are an attractive option for visual acuity measurement due to portability, the ability to randomise letters, automated scoring of acuity and the ability to select from a range of charts. However, these devices are only suitable for use in situations where sources of glare can be eliminated. PMID:23794568

  12. Visual acuity after trans-scleral sutured posterior chamber intraocular lens

    International Nuclear Information System (INIS)

    Mahmood, S.A.; Zafar, S.

    2014-01-01

    To determine the changes in visual acuity in patients undergoing Trans-Scleral Sutured Posterior Chamber Intra-Ocular Lens (TSSPCIOL) implantation at a tertiary care hospital in Karachi, Pakistan. Study Design: Case series. Place and Duration of Study: LRBT Tertiary Eye Hospital, Karachi, from January 2006 to December 2010. Methodology: Records of all patients undergoing implantation of TSSPCIOL were reviewed. Patients with diagnosed glaucoma, diabetic retinopathy, macular degeneration, history of recurrent uveitis, corneal haze or central corneal scars were excluded. For the final analysis, 70 eyes out of a total of 75 were selected. Main outcomes of interest were pre and postoperative visual acuities and surgical complications. SPSS 21 was used for data analysis. Results: Pre-operatively, the average Best Spectacle-Corrected Visual Acuity (BSCVA) was 6/36 on the Snellen chart. This improved to 6/12 postoperatively. The mean improvement seen was 2.4 lines on the Snellen chart (p < 0.05). Complications include transient intraocular pressure elevation in 25 eyes (36%), IOL tilt in 4 eyes (7.1%), Cystoid Macular Edema (CME) in 4 eyes (5.7%), vitreous haemorrhage in 2 eyes (2.9%), hyphema in 2 eyes (2.9%), uveitis in 1 eye (1.4%), and retinal detachment 1 eye (1.4%). No IOL subluxation, suture erosion, iris capture, choroidal effusion or endophthalmitis was encountered and no re-operations were needed. Conclusion: TSSPCIOLs are a good management option for patients with aphakia in whom PC IOLs cannot be placed. (author)

  13. Evaluation of a visual acuity test using closed Landolt-Cs to determine malingering.

    Science.gov (United States)

    Kröger, Nils; Jürgens, Clemens; Kohlmann, Thomas; Tost, Frank

    2017-12-01

    To evaluate a visual acuity test (VAT) with unexpected optotypes to detect malingering. We tested two groups. Group 1 consisted of 20 individuals with normal best corrected visual acuity (BCVA). Group 2 included participants with ocular diseases and reduced BCVA. All subjects underwent a VAT proposed by Gräf and Roesen to assess suspected malingering. This test used 36 charts with one Landolt-C per page. The first 20 optotypes were Landolt-Cs, while at positions 21, 26, 30, and 34 closed rings were presented. The testing distance was adapted to 50% of the test person's visual acuity. The test person was requested to name the gap direction of the Landolt-C within 3 s. The complete testing conversation was recorded digitally to determine response latency for each optotype from the audio tracks. The average response time was 0.46 s in group 1 and 0.45 s in group 2 for the first 20 Landolt-Cs. In both groups the response time was significantly extended (p ring compared to the mean of the first 20 Landolt-Cs, (group 1: 2.9 s; group 2: 2.3 s). The following three closed rings had also longer response times. However, these differences were not significant. Our results suggest that the proposed test may be helpful to evaluate ocular malingering. The testing procedure appeared to be feasible and showed good repeatability. The fast training effect may be a limitation for malingering detection.

  14. Parafoveal magnification: visual acuity does not modulate the perceptual span in reading.

    Science.gov (United States)

    Miellet, Sébastien; O'Donnell, Patrick J; Sereno, Sara C

    2009-06-01

    Models of eye guidance in reading rely on the concept of the perceptual span-the amount of information perceived during a single eye fixation, which is considered to be a consequence of visual and attentional constraints. To directly investigate attentional mechanisms underlying the perceptual span, we implemented a new reading paradigm-parafoveal magnification (PM)-that compensates for how visual acuity drops off as a function of retinal eccentricity. On each fixation and in real time, parafoveal text is magnified to equalize its perceptual impact with that of concurrent foveal text. Experiment 1 demonstrated that PM does not increase the amount of text that is processed, supporting an attentional-based account of eye movements in reading. Experiment 2 explored a contentious issue that differentiates competing models of eye movement control and showed that, even when parafoveal information is enlarged, visual attention in reading is allocated in a serial fashion from word to word.

  15. The role of visual acuity and segmentation cues in compound word identification

    Directory of Open Access Journals (Sweden)

    Jukka eHyönä

    2012-06-01

    Full Text Available Studies are reviewed that demonstrate how the foveal area of the eye constrains how compound words are identified during reading. When compound words are short, their letters can be identified during a single fixation, leading to the whole-word route dominating word recognition from early on. Hence, visually marking morpheme boundaries by hyphens slows down processing by encouraging morphological decomposition when holistic processing is a feasible option. In contrast, the decomposition route dominates the early stages of identifying long compound words. Thus, visual marking of morpheme boundaries facilitates processing of long compound words, unless the initial fixation made on the word lands very close to the morpheme boundary. The reviewed pattern of results is explained by the visual acuity principle (Bertram & Hyönä, 2003 and the dual-route framework of morphological processing.

  16. The Joint Effects of Spatial Cueing and Transcranial Direct Current Stimulation on Visual Acuity

    Directory of Open Access Journals (Sweden)

    Taly Bonder

    2018-02-01

    Full Text Available The present study examined the mutual influence of cortical neuroenhancement and allocation of spatial attention on perception. Specifically, it explored the effects of transcranial Direct Current Stimulation (tDCS on visual acuity measured with a Landolt gap task and attentional precues. The exogenous cues were used to draw attention either to the location of the target or away from it, generating significant performance benefits and costs. Anodal tDCS applied to posterior occipital area for 15 min improved performance during stimulation, reflecting heightened visual acuity. Reaction times were lower, and accuracy was higher in the tDCS group, compared to a sham control group. Additionally, in post-stimulation trials tDCS significantly interacted with the effect of precuing. Reaction times were lower in valid cued trials (benefit and higher in invalid trials (cost compared to neutrally cued trials, the effect which was pronounced stronger in tDCS group than in sham control group. The increase of cost and benefit effects in the tDCS group was of a similar magnitude, suggesting that anodal tDCS influenced the overall process of attention orienting. The observed interaction between the stimulation of the visual cortex and precueing indicates a magnification of attention modulation.

  17. Visual Acuity Improvement of Amblyopia in an Adult With Levodopa/Carbidopa Treatment.

    Science.gov (United States)

    Orge, Faruk H; Dar, Suhail A

    2015-09-09

    Amblyopia is the leading cause of visual loss in children, affecting 2% to 3% of the population. Occlusion of the dominant eye is the primary and best treatment, although efficacy decreases after 6 years of age. As a result, levodopa/carbidopa has been explored as an adjunct to conventional therapy and has been shown to have an immediate impact on visual acuity. Several studies to date have shown mixed results on the benefit of supplementing occlusion therapy with levodopa/carbidopa, although they have primarily studied children. The authors describe the oldest patient (46 years old) documented in the literature to have shown improvement in visual acuity using levodopa/carbidopa. He was given a 16-week course at a dose in line with previous studies while being effectively occluded full time due to a glaucomatous right eye with no light perception. On 3-month follow-up, his left eye improved two lines and stabilized at 6 months. Copyright 2015, SLACK Incorporated.

  18. Origins of Superior Dynamic Visual Acuity in Baseball Players: Superior Eye Movements or Superior Image Processing

    OpenAIRE

    Uchida, Yusuke; Kudoh, Daisuke; Murakami, Akira; Honda, Masaaki; Kitazawa, Shigeru

    2012-01-01

    Dynamic visual acuity (DVA) is defined as the ability to discriminate the fine parts of a moving object. DVA is generally better in athletes than in non-athletes, and the better DVA of athletes has been attributed to a better ability to track moving objects. In the present study, we hypothesized that the better DVA of athletes is partly derived from better perception of moving images on the retina through some kind of perceptual learning. To test this hypothesis, we quantitatively measured DV...

  19. Using the Freiburg Acuity and Contrast Test to measure visual performance in USAF personnel after PRK.

    Science.gov (United States)

    Dennis, Richard J; Beer, Jeremy M A; Baldwin, J Bruce; Ivan, Douglas J; Lorusso, Frank J; Thompson, William T

    2004-07-01

    Photorefractive keratectomy (PRK) may be an alternative to spectacle and contact lens wear for United States Air Force (USAF) aircrew and may offer some distinct advantages in operational situations. However, any residual corneal haze or scar formation from PRK could exacerbate the disabling effects of a bright glare source on a complex visual task. The USAF recently completed a longitudinal clinical evaluation of the long-term effects of PRK on visual performance, including the experiment described herein. After baseline data were collected, 20 nonflying active duty USAF personnel underwent PRK. Visual performance was then measured at 6, 12, and 24 months after PRK. Visual acuity (VA) and contrast sensitivity (CS) data were collected by using the Freiburg Acuity and Contrast Test (FrACT), with the subject viewing half of the runs through a polycarbonate windscreen. Experimental runs were completed under 3 glare conditions: no glare source and with either a broadband or a green laser (532-nm) glare annulus (luminance approximately 6090 cd/m) surrounding the Landolt C stimulus. Systematic effects of PRK on VA relative to baseline were not identified. However, VA was almost 2 full Snellen lines worse with the laser glare source in place versus the broadband glare source. A significant drop-off was observed in CS performance after PRK under conditions of no glare and broadband glare; this was the case both with and without the windscreen. As with VA, laser glare disrupted CS performance significantly and more than broadband glare did. PRK does not appear to have affected VA, but the changes in CS might represent a true decline in visual performance. The greater disruptive effects from laser versus broadband glare may be a result of increased masking from coherent spatial noise (speckle) surrounding the laser stimulus.

  20. Vision in avian emberizid foragers: maximizing both binocular vision and fronto-lateral visual acuity.

    Science.gov (United States)

    Moore, Bret A; Pita, Diana; Tyrrell, Luke P; Fernández-Juricic, Esteban

    2015-05-01

    Avian species vary in their visual system configuration, but previous studies have often compared single visual traits between two to three distantly related species. However, birds use different visual dimensions that cannot be maximized simultaneously to meet different perceptual demands, potentially leading to trade-offs between visual traits. We studied the degree of inter-specific variation in multiple visual traits related to foraging and anti-predator behaviors in nine species of closely related emberizid sparrows, controlling for phylogenetic effects. Emberizid sparrows maximize binocular vision, even seeing their bill tips in some eye positions, which may enhance the detection of prey and facilitate food handling. Sparrows have a single retinal center of acute vision (i.e. fovea) projecting fronto-laterally (but not into the binocular field). The foveal projection close to the edge of the binocular field may shorten the time to gather and process both monocular and binocular visual information from the foraging substrate. Contrary to previous work, we found that species with larger visual fields had higher visual acuity, which may compensate for larger blind spots (i.e. pectens) above the center of acute vision, enhancing predator detection. Finally, species with a steeper change in ganglion cell density across the retina had higher eye movement amplitude, probably due to a more pronounced reduction in visual resolution away from the fovea, which would need to be moved around more frequently. The visual configuration of emberizid passive prey foragers is substantially different from that of previously studied avian groups (e.g. sit-and-wait and tactile foragers). © 2015. Published by The Company of Biologists Ltd.

  1. Normative monocular visual acuity for early treatment diabetic retinopathy study charts in emmetropic children 5 to 12 years of age.

    Science.gov (United States)

    Dobson, Velma; Clifford-Donaldson, Candice E; Green, Tina K; Miller, Joseph M; Harvey, Erin M

    2009-07-01

    To provide normative data for children tested with Early Treatment Diabetic Retinopathy Study (ETDRS) charts. Cross-sectional study. A total of 252 Native American (Tohono O'odham) children aged 5 to 12 years. On the basis of cycloplegic refraction conducted on the day of testing, all were emmetropic (myopia < or =0.25 diopter [D] spherical equivalent, hyperopia < or =1.00 D spherical equivalent, and astigmatism < or =0.50 D in both eyes). Monocular visual acuity was tested at 4 m, using 1 ETDRS chart for the right eye (RE) and another for the left eye (LE). Visual acuity was scored as the total number of letters correctly identified, by naming or matching to letters on a lap card, and as the smallest letter size for which the child identified 3 of 5 letters correctly. Visual acuity results did not differ for the RE versus the LE, so data are reported for the RE only. Mean visual acuity for 5-year-olds (0.16 logarithm of the minimum angle of resolution [logMAR] [20/29]) was significantly worse than for 8-, 9-, 10-, 11-, and 12-year-olds (0.05 logMAR [20/22] or better at each age). The lower 95% prediction limit for determining whether a child has visual acuity within the normal range was 0.38 (20/48) for 5-year-olds and 0.30 (20/40) for 6- to 12-year-olds, which was reduced to 0.32 (20/42) for 5-year-olds and 0.21 (20/32) for 6- to 12-year-olds when recalculated with outlying data points removed. Mean interocular acuity difference did not vary by age, averaging less than 1 logMAR line at each age, with a lower 95% prediction limit of 0.17 log unit (1.7 logMAR lines) across all ages. For monocular visual acuity based on ETDRS charts to be in the normal range, it must be better than 20/50 for 5-year-olds and better than 20/40 for 6- to 12-year-olds. Normal interocular acuity difference includes values of less than 2 logMAR lines. Normative ETDRS visual acuity values are not as good as norms reported for adults, suggesting that a child's visual acuity results should

  2. Quality of life and visual acuity outcomes in the Registry in Glaucoma Outcomes Research study.

    Science.gov (United States)

    Coleman, Anne L; Lum, Flora C; Gliklich, Richard E; Velentgas, Priscilla; Su, Zhaohui

    2016-01-01

    The RiGOR study evaluated the association of treatment and patient-reported outcomes for open-angle glaucoma patients. The Glaucoma Symptom Scale (National Eye Institute-Visual Function Questionnaire (NEI-VFQ) and visual acuity (VA) were collected as quality of life measures. The proportion of patients with improvement of at least two lines of vision was highest in the incisional surgery group (14.2% compared with 9.9% for laser surgery and 10.9% for additional medication). No clinically relevant differences were seen in benefit for the laser surgery or incisional surgery groups compared with additional medications for the Glaucoma Symptom Scale or NEI-VFQ measures or subscales. Differences in quality of life by race need to be explored in further studies.

  3. The Use of Dynamic Visual Acuity as a Functional Test of Gaze Stabilization Following Space Flight

    Science.gov (United States)

    Peters, B. T.; Mulavara, A. P.; Brady, R.; Miller, C. A.; Richards, J. T.; Warren, L. E.; Cohen, H. S.; Bloomberg, J. J.

    2006-01-01

    After prolonged exposure to a given gravitational environment the transition to another is accompanied by adaptations in the sensorimotor subsystems, including the vestibular system. Variation in the adaptation time course of these subsystems, and the functional redundancies that exist between them make it difficult to accurately assess the functional capacity and physical limitations of astro/cosmonauts using tests on individual subsystems. While isolated tests of subsystem performance may be the only means to address where interventions are required, direct measures of performance may be more suitable for assessing the operational consequences of incomplete adaptation to changes in the gravitational environment. A test of dynamic visual acuity (DVA) is currently being used in the JSC Neurosciences Laboratory as part of a series of measures to assess the efficacy of a countermeasure to mitigate postflight locomotor dysfunction. In the current protocol, subjects visual acuity is determined using Landolt ring optotypes presented sequentially on a computer display. Visual acuity assessments are made both while standing and while walking at 1.8 m/s on a motorized treadmill. The use of a psychophysical threshold detection algorithm reduces the required number of optotype presentations and the results can be presented immediately after the test. The difference between the walking and standing acuity measures provides a metric of the change in the subject s ability to maintain gaze fixation on the visual target while walking. This functional consequence is observable regardless of the underlying subsystem most responsible for the change. Data from 15 cosmo/astronauts have been collected following long-duration (approx. 6 months) stays in space using a visual target viewing distance of 4.0 meters. An investigation of the group mean shows a change in DVA soon after the flight that asymptotes back to baseline approximately one week following their return to earth. The

  4. A comparison of Lea Symbol vs ETDRS letter distance visual acuity in a population of young children with a high prevalence of astigmatism.

    Science.gov (United States)

    Dobson, Velma; Clifford-Donaldson, Candice E; Miller, Joseph M; Garvey, Katherine A; Harvey, Erin M

    2009-06-01

    To compare visual acuity results obtained by use of the Lea Symbols chart with results obtained with Early Treatment Diabetic Retinopathy Study (ETDRS) charts in young children who are members of a population with a high prevalence of astigmatism. Subjects were 438 children ages 5 through 7 years who were enrolled in kindergarten or first grade on the Tohono O'odham Reservation: 241 (55%) had astigmatism >or=1.00 D in one or both eyes (range, 0.00-6.75 D). While wearing best correction, each child had right eye visual acuity tested with the 62 cm by 65 cm Lea Symbols chart at 3 m and with the 62 cm by 65 cm ETDRS chart at 4 m. Visual acuity was scored as the smallest optotype size at which the child correctly identified 3 of a maximum of 5 optotypes. ETDRS visual acuity also was scored based on the total number of letters that the child correctly identified. Correlation between Lea Symbols visual acuity and ETDRS visual acuity was 0.78 (p < 0.001). Mean Lea Symbols visual acuity was one-half line (0.04-0.06 logMAR) better than mean ETDRS visual acuity (p < 0.001). The difference between Lea Symbols and ETDRS visual acuity was not correlated with the mean of the Lea Symbols and ETDRS visual acuity scores, which ranged from -0.3 logMAR (20/10) to 0.74 logMAR (20/110). In this population of young children, in whom the primary source of reduced visual acuity is astigmatism-related amblyopia, the Lea Symbols chart produced visual acuity scores that were about 0.5 line better than visual acuity scores obtained with ETDRS charts.

  5. The correlation between variation of visual acuity and the anterior chamber depth in the early period after phacoemulsification

    Directory of Open Access Journals (Sweden)

    Kai-jian CHEN

    2011-04-01

    Full Text Available Objective To investigate the correlation between the visual acuity variation and the anterior chamber depth in the early period after phacoemulsification.Methods Thirty-six eyes of 32 patients with age-related cataract underwent 3.2mm clear corneal incision phacoemulsification and intraocular lens(IOL implantation.The visual acuity was examined and horizontal curvature(K1,vertical curvature(K2,corneal astigmatism,and anterior chamber depth were measured with IOL-master preoperatively and also on 1,3,7 and 15 postoperative days.The changes in parameters were compared,and the correlations among visual acuity,corneal astigmatism and anterior chamber depth were analyzed.Results Before operation and 1d,3d,7d and 15d after operation,the corneal astigmatism was-0.87±0.40D,-1.92±1.38D,-1.69±1.13D,-1.45±0.79D and-1.36±0.74D;the anterior chamber depth was 3.08±0.35mm,4.04±0.38mm,4.28±0.29mm,4.22±0.17mm and 4.22±0.16mm;the visual acuity was 0.18±0.10,0.44±0.14,0.59±0.12,0.61±0.11 and 0.62±0.14.Significant difference was found between pre-operative and postoperative visual acuity,corneal astigmatism and anterior chamber depth,and it was also found in corneal astigmatism between 1d and 15d post operation(P < 0.05,as well as in anterior chamber depth and visual acuity between 1d and 3d post operation(P < 0.05.A positive correlation was found between visual acuity and corneal astigmatism on 1d(r=0.42,P < 0.05,3d(r=0.35,P < 0.05 and 7d(r=0.35,P < 0.05 post operation;and a negative correlation was found between visual acuity and anterior chamber depth on 3d(r=-0.29,P < 0.05,7d(r=-0.43,P < 0.01 and 15d(r=-0.37,P < 0.05 post operation.Conclusion Both the corneal astigmatism and the anterior chamber depth are correlated with the visual acuity variation in the early period after phacoemulsification.

  6. Effect of ruboxistaurin (RBX) On visual acuity decline over a 6-year period with cessation and reinstitution of therapy

    DEFF Research Database (Denmark)

    Sheetz, Matthew J; Aiello, Lloyd Paul; Shahri, Nazila

    2011-01-01

    reduced the occurrence of sustained moderate visual loss (SMVL; ≥15-letter decline in visual acuity sustained for the last 6 months of study participation) from 9.1% in the PBO group (N = 340) to 5.5% in the RBX group (N = 345, P = 0.034). This study evaluates the primary end point of SMVL in a 2-year...

  7. Effect of magnetic resonance imaging on near visual acuity Efecto de la resonancia magnética sobre la agudeza visual cercana

    OpenAIRE

    José David Paulo Trujillo; Juan Carlos Vergara; Jorge Hernando Donado Gómez; Luz Marina Agudelo; Mercedes Cecilia Molina Betancur; Andrés Ignacio Arbeláez Medina; Carlos Andrés Molina Betancur

    2007-01-01

    Purpose: To determine the variation of near visual acuity, in patients exposed during short periods to intense magnetic fields in studies of magnetic resonance imaging. Methods: Descriptive study of a case series that included 40 healthy and literate individuals older than 40 years, nine of them men, submitted to a procedure of head and neck magnetic resonance imaging; all of them had near visual acuity better than 20/200 without glasses, and were not under the effects of ansiolytic medicatio...

  8. Comparison on testability of visual acuity, stereo acuity and colour vision tests between children with learning disabilities and children without learning disabilities in government primary schools.

    Science.gov (United States)

    Abu Bakar, Nurul Farhana; Chen, Ai-Hong

    2014-02-01

    Children with learning disabilities might have difficulties to communicate effectively and give reliable responses as required in various visual function testing procedures. The purpose of this study was to compare the testability of visual acuity using the modified Early Treatment Diabetic Retinopathy Study (ETDRS) and Cambridge Crowding Cards, stereo acuity using Lang Stereo test II and Butterfly stereo tests and colour perception using Colour Vision Test Made Easy (CVTME) and Ishihara's Test for Colour Deficiency (Ishihara Test) between children in mainstream classes and children with learning disabilities in special education classes in government primary schools. A total of 100 primary school children (50 children from mainstream classes and 50 children from special education classes) matched in age were recruited in this cross-sectional comparative study. The testability was determined by the percentage of children who were able to give reliable respond as required by the respective tests. 'Unable to test' was defined as inappropriate response or uncooperative despite best efforts of the screener. The testability of the modified ETDRS, Butterfly stereo test and Ishihara test for respective visual function tests were found lower among children in special education classes ( P learning disabilities. Modifications of vision testing procedures are essential for children with learning disabilities.

  9. Contrast sensitivity measured by two different test methods in healthy, young adults with normal visual acuity.

    Science.gov (United States)

    Koefoed, Vilhelm F; Baste, Valborg; Roumes, Corinne; Høvding, Gunnar

    2015-03-01

    This study reports contrast sensitivity (CS) reference values obtained by two different test methods in a strictly selected population of healthy, young adults with normal uncorrected visual acuity. Based on these results, the index of contrast sensitivity (ICS) is calculated, aiming to establish ICS reference values for this population and to evaluate the possible usefulness of ICS as a tool to compare the degree of agreement between different CS test methods. Military recruits with best eye uncorrected visual acuity 0.00 LogMAR or better, normal colour vision and age 18-25 years were included in a study to record contrast sensitivity using Optec 6500 (FACT) at spatial frequencies of 1.5, 3, 6, 12 and 18 cpd in photopic and mesopic light and CSV-1000E at spatial frequencies of 3, 6, 12 and 18 cpd in photopic light. Index of contrast sensitivity was calculated based on data from the three tests, and the Bland-Altman technique was used to analyse the agreement between ICS obtained by the different test methods. A total of 180 recruits were included. Contrast sensitivity frequency data for all tests were highly skewed with a marked ceiling effect for the photopic tests. The median ICS for Optec 6500 at 85 cd/m2 was -0.15 (95% percentile 0.45), compared with -0.00 (95% percentile 1.62) for Optec at 3 cd/m2 and 0.30 (95% percentile 1.20) FOR CSV-1000E. The mean difference between ICSFACT 85 and ICSCSV was -0.43 (95% CI -0.56 to -0.30, p<0.00) with limits of agreement (LoA) within -2.10 and 1.22. The regression line on the difference of average was near to zero (R2=0.03). The results provide reference CS and ICS values in a young, adult population with normal visual acuity. The agreement between the photopic tests indicated that they may be used interchangeably. There was little agreement between the mesopic and photopic tests. The mesopic test seemed best suited to differentiate between candidates and may therefore possibly be useful for medical selection purposes.

  10. Individual Differences in Scotopic Visual Acuity and Contrast Sensitivity: Genetic and Non-Genetic Influences.

    Directory of Open Access Journals (Sweden)

    Alex J Bartholomew

    Full Text Available Despite the large amount of variation found in the night (scotopic vision capabilities of healthy volunteers, little effort has been made to characterize this variation and factors, genetic and non-genetic, that influence it. In the largest population of healthy observers measured for scotopic visual acuity (VA and contrast sensitivity (CS to date, we quantified the effect of a range of variables on visual performance. We found that young volunteers with excellent photopic vision exhibit great variation in their scotopic VA and CS, and this variation is reliable from one testing session to the next. We additionally identified that factors such as Circadian preference, iris color, astigmatism, depression, sex and education have no significant impact on scotopic visual function. We confirmed previous work showing that the amount of time spent on the vision test influences performance and that laser eye surgery results in worse scotopic vision. We also showed a significant effect of intelligence and photopic visual performance on scotopic VA and CS, but all of these variables collectively explain <30% of the variation in scotopic vision. The wide variation seen in young healthy volunteers with excellent photopic vision, the high test-retest agreement, and the vast majority of the variation in scotopic vision remaining unexplained by obvious non-genetic factors suggests a strong genetic component. Our preliminary genome-wide association study (GWAS of 106 participants ruled out any common genetic variants of very large effect and paves the way for future, larger genetic studies of scotopic vision.

  11. [Amblyopia: reading speed in comparison with visual acuity for gratings, single Landolt Cs and series Landolt Cs].

    Science.gov (United States)

    Bach, M; Strahl, P; Waltenspiel, S; Kommerell, G

    1990-01-01

    In the treatment of amblyopia in preschool children, a means of predicting later reading ability would be helpful. This prediction might be possible using a test for visual acuity where the results correlate with reading ability in adult patients with amblyopia. We measured the following four parameters in 18 experienced readers with strabismic amblyopia: (1) time spent reading ten lines of a standard text in one of three magnifications, (2) visual acuity for gratings, (3) visual acuity for single Landolt Cs, and (4) visual acuity for crowded Landolt Cs (one Landolt C flanked by two full rings on each side each at a distance of 2.6 min of arc). The reading text was presented on paper at a distance of 40 cm; the subject had a choice of three magnifications. The acuity tests were generated by a computer on a VDU at 4.6 m. The relative impairment of the amblyopic eye was defined as the quotient between the performance of the amblyopic and the good eye. In addition, the difference between the times spent reading the ten lines with the amblyopic and with the good eye was calculated.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Impact of colour in the assessment of potential visual acuity in patients with age-related macular degeneration.

    Science.gov (United States)

    Dorrepaal, Stephen J; Markowitz, Samuel N

    2013-06-01

    To compare chromatic and achromatic potential visual acuity (PVA) in patients with bilateral low vision caused by age-related macular degeneration (AMD). Prospective, nonrandomized, observational case series. Fifty-five patients, representing a consecutive series of patients all presenting with bilateral AMD. Best-corrected visual acuity of each eye was measured using an Early Treatment in Diabetic Retinopathy Study (ETDRS) chart with appropriate near correction. Included were cases with visual acuity of 0.4 logMAR (20/50) or worse in both eyes. Achromatic and chromatic PVA were measured in each eye using white on black and red on yellow flooding E charts at 50 cm in controlled lighting conditions. One hundred and seven eyes from 55 patients were included in the analysis. Mean achromatic and chromatic PVA were 0.69 ± 0.26 and 0.65 ± 0.22 logMAR, respectively. Overall, patients had a significantly higher chromatic than achromatic PVA, with a median difference of 0.1 logMAR (p<0.05). Patients with ETDRS visual acuity worse than 0.9 logMAR also had a significantly higher chromatic than achromatic PVA, with a median difference of 0.1 logMAR (p<0.05). Patients with ETDRS visual acuity between 0.4 and 0.9 logMAR had a trend toward a higher chromatic than achromatic visual acuity that was not significant, with a median difference of 0.1 logMAR (p = 0.8539). Patients with low vision caused by AMD can discern smaller targets when a red on yellow colour scheme is used than when using achromatic white on black charts. Copyright © 2013 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

  13. Comparison of monochromatic aberrations in young adults with different visual acuity and refractive errors.

    Science.gov (United States)

    Yazar, Seyhan; Hewitt, Alex W; Forward, Hannah; McKnight, Charlotte M; Tan, Alex; Mountain, Jenny A; Mackey, David A

    2014-03-01

    To compare the monochromatic aberrations in a large cohort of 20-year-old Australians with differing levels of visual acuity and explore the relationship between these aberrations and refractive error. Lions Eye Institute, Perth, Western Australia, Australia. Cross-sectional analysis of a population-based cohort. Monochromatic aberrations were measured using a Zywave II wavefront aberrometer with natural pupils in a dark room. The logMAR corrected distance visual acuity (CDVA) was measured monocularly under normal illumination. Cycloplegic autorefraction was also performed. The study enrolled 2039 eyes of 1040 participants. Data from 1007 right eyes were analyzed. The median CDVA and spherical equivalent were -0.06 logMAR (interquartile range [IQR], -0.10 to 0.00) and +0.25 diopters (D) (IQR, -0.38 to 0.63), respectively. The median 6.0 mm higher-order aberration (HOA) was 0.58 μm (IQR, 0.44 to 0.79). Coma-like aberrations and 3rd-, 4th-, and 5th-order HOAs were significantly different between subjects with a CDVA of -0.10 logMAR or better and those with a CDVA worse than -0.10 logMAR. Fourth-order aberrations Z(4,-4) (P=.024) and Z(4,-2) (P=.029) and 2nd-order aberration Z(2,0) (Peyes, emmetropic eyes, and hyperopic eyes. Subjects with higher myopia had slightly higher total HOAs. The HOAs in this population were marginally higher than previously reported values. The findings confirm there is a difference in monochromatic aberrations between different vision and refractive groups. Results in this study will benefit decision-making processes in the clinical setting. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  14. A cross-sectional examination of visual acuity by specific type of albinism.

    Science.gov (United States)

    Winsor, Caitlin Nosanov; Holleschau, Ann M; Connett, John E; Summers, C Gail

    2016-10-01

    Reports of best-corrected visual acuity (BCVA) in albinism are often based on overlapping clinical phenotypes. BCVA in albinism has been shown to improve with age. This study reports a large cross-sectional investigation to determine whether BCVA differs by specific type of albinism when age-corrected. This retrospective review identified 170 individuals with a specific type of albinism identified by mutation(s) in a gene known to cause albinism (for OCA1, OCA2, and Hermansky-Pudlak syndrome ([HPS]) or a specific phenotype (white hair and no melanin pigment in OCA1A; pigmentary mosaicism in the obligate carriers for males with OA1). We recorded optotype binocular BCVA at final follow-up. Patients were age-grouped (2-5 years, 6-14 years, and ≥15 years) for comparison. The greatest visual acuity deficit was found for OCA1A in all age groups. At age ≥15 years (n = 79), mean BCVA was 20/128 for OCA1A, 20/37 for OCA1B, 20/59 for OCA2, 20/63 for OA1, and 20/121 for HPS. Significant differences between BCVA at ≥15 years were found in the following: OCA1A vs OCA1B, OCA1A vs OCA2, OCA1A vs OA1, OCA1B vs HPS, OCA2 vs HPS, and OA1 vs HPS (P ≤ 0.02). This study provides a large sample size and includes only those with a specific type of albinism. BCVA varies by albinism type, and there is overlap in BCVA, particularly in the younger age groups. For ages ≥15 years, there are significant differences in BCVA between several types of albinism. Copyright © 2016 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

  15. Visual acuity and refraction by age for children of three different ethnic groups in Paraguay

    Directory of Open Access Journals (Sweden)

    Marissa Janine Carter

    2013-04-01

    Full Text Available PURPOSE: To characterize refractive errors in Paraguayan children aged 5-16 years and investigate effect of age, gender, and ethnicity. METHODS:The study was conducted at 3 schools that catered to Mennonite, indigenous, and mixed race children. Children were examined for presenting visual acuity, autorefraction with and without cycloplegia, and retinoscopy. Data were analyzed for myopia and hyperopia (SE ≤-1 D or -0.5 D and ≥2 D or ≥3 D and astigmatism (cylinder ≥1 D. Spherical equivalent (SE values were calculated from right eye cycloplegic autorefraction data and analyzed using general linear modelling. RESULTS: There were 190, 118, and 168 children of Mennonite, indigenous and mixed race ethnicity, respectively. SE values between right/left eyes were nonsignificant. Mean visual acuity (VA without correction was better for Mennonites compared to indigenous or mixed race children (right eyes: 0.031, 0.090, and 0.102 logMAR units, respectively; P<0.000001. There were 2 cases of myopia in the Mennonite group (1.2% and 2 cases in the mixed race group (1.4% (SE ≤-0.5 D. The prevalence of hyperopia (SE ≥2 D was 40.6%, 34.2%, and 46.3% for Mennonite, indigenous and mixed race children. Corresponding astigmatism rates were 3.2%, 9.5%, and 12.7%. Females were slightly more hyperopic than males, and the 9-11 years age group was the most hyperopic. Mennonite and mixed race children were more hyperopic than indigenous children. CONCLUSIONS: Paraguayan children were remarkably hyperopic and relatively free of myopia. Differences with regard to gender, age, and ethnicity were small.

  16. Visual acuity loss associated with excessive “dry macula” in exudative age-related macular degeneration

    Directory of Open Access Journals (Sweden)

    Takahashi H

    2018-02-01

    Full Text Available Hidenori Takahashi,1–3 Yuji Inoue,1,2 Xue Tan,2,3 Satoru Inoda,1 Shinichi Sakamoto,1 Yusuke Arai,1 Yasuo Yanagi,4–6 Yujiro Fujino,2,3 Hidetoshi Kawashima1 1Department of Ophthalmology, Jichi Medical University, Shimotsuke, 2Department of Ophthalmology, The University of Tokyo, Bunkyo, 3Department of Ophthalmology, Japan Community Health Care Organization Tokyo Shinjuku Medical Center, Shinjuku, Japan; 4Medical Retina, Singapore National Eye Centre, 5Medical Retina, Singapore Eye Research Institute, 6Eye-ACP, Duke NUS Medical School, National University of Singapore, Singapore Purpose: To investigate the correlation between visual acuity and central macular thickness (CMT and choroidal thickness (CCT in patients with wet age-related macular degeneration (AMD. Methods: In this retrospective analysis, 14 eyes that received >10 ranibizumab injections (based on pro re nata [PRN] regimen and maintained initial visual acuity gain were analyzed. The following 5 parameters were measured at the foveal center: CMT (distance from the inner limiting membrane [ILM] to Bruch’s membrane; central retinal thickness (CRT; distance from the ILM to the inner limit of the retinal pigment epithelium or subretinal fluid [SRF]; SRF thickness (SRFT; pigment epithelium detachment thickness (PEDT; and CCT. The correlation between the logarithm of the minimum angle of resolution (logMAR best-corrected visual acuity (BCVA and the 5 parameters was examined with generalized estimating equations. Results: CMT, CRT, and CCT were negatively correlated with logMAR BCVA (P=0.031, 0.023, and 0.036, respectively when only CMT values less than the thickness that maximized visual acuity for each eye were used for the analysis. Each 100-µm reduction in CMT, CRT, or CCT improved logMAR BCVA by -0.1, -0.08, or -0.07, respectively. SRFT and PEDT were not correlated with BCVA. The median CMT that maximized the visual acuity was 230 µm. Conclusion: Dry macula with CMT <230 µm was

  17. Comparison of visual acuity in reduced lumination and facility of ocular accommodation in table tennis champions and non- players.

    Science.gov (United States)

    Jafarzadehpur, Ebrahim; Yarigholi, Mohammad R

    2004-03-01

    A table tennis player should fixate at different distances; track the objects with different speed, and in different visual environment. Their visual skills must be well developed for these capabilities. Therefore, visual acuity in reduced lumination and facility of ocular accommodation those are two criteria for visual skills have been compared in table tennis players and normal non-players. Twenty-nine young table tennis champions and 29 normal matched non-players (did not take part in any racket sports game) were evaluated. Basic visual and eye examinations were done for both of them. Normal results in basic examination were fundamental requirement for all the subjects. +/-2.00 sphere lenses for accommodation facility are used. An electrical current regulator changed the output light intensity of a conventional chart projector (Topcon). Light intensity decreased to 10 cd·m(-2) and visual acuity tested. In comparison of visual acuity in reduced lumination and facility of ocular accommodation in table tennis champions and non-players there are significant differences (p reflecting a better perceptual system of experts to the constraints encountered during table tennis and its use in practical settings for evaluating athletes or detecting sport talents. However some visual and perceptual training that usually used in orthoptics can be used for novice table tennis player to improve their abilities. Key PointsThat the ability of a champion depends on many sensory, motor and perceptual factors.Visual factors such as facility of accommodation and visual acuity in reduced lumination should be considered in table tennis players.Visual training may be useful for novice and also for experts.

  18. Revealing Detail along the Visual Hierarchy: Neural Clustering Preserves Acuity from V1 to V4.

    Science.gov (United States)

    Lu, Yiliang; Yin, Jiapeng; Chen, Zheyuan; Gong, Hongliang; Liu, Ye; Qian, Liling; Li, Xiaohong; Liu, Rui; Andolina, Ian Max; Wang, Wei

    2018-04-18

    How primates perceive objects along with their detailed features remains a mystery. This ability to make fine visual discriminations depends upon a high-acuity analysis of spatial frequency (SF) along the visual hierarchy from V1 to inferotemporal cortex. By studying the transformation of SF across macaque parafoveal V1, V2, and V4, we discovered SF-selective functional domains in V4 encoding higher SFs up to 12 cycles/°. These intermittent higher-SF-selective domains, surrounded by domains encoding lower SFs, violate the inverse relationship between SF preference and retinal eccentricity. The neural activities of higher- and lower-SF domains correspond to local and global features, respectively, of the same stimuli. Neural response latencies in high-SF domains are around 10 ms later than in low-SF domains, consistent with the coarse-to-fine nature of perception. Thus, our finding of preserved resolution from V1 into V4, separated both spatially and temporally, may serve as a connecting link for detailed object representation. Copyright © 2018 Elsevier Inc. All rights reserved.

  19. The (lack of) relation between straylight and visual acuity. Two domains of the point-spread-function

    NARCIS (Netherlands)

    van den Berg, Thomas J T P

    2017-01-01

    PURPOSE: The effect of cataract and other media opacities on functional vision is typically assessed clinically using visual acuity. In both clinical and basic research, straylight (the functional result of light scattering in the eye) is commonly measured. The purpose of the present study was to

  20. The Prevalence of Visual Acuity Impairment among School Children at Arada Subcity Primary Schools in Addis Ababa, Ethiopia

    Directory of Open Access Journals (Sweden)

    Haile Fentahun Darge

    2017-01-01

    Full Text Available Background. Visual impairment and blindness are major public health problems in developing countries where there is no enough health-care service. Objective. To determine the prevalence of visual impairment among school children. Materials and Methods. A school-based cross-sectional study was conducted between 15 June 2015 and 30 November 2015 at Arada subcity primary schools, Addis Ababa, Ethiopia. Two schools were selected randomly, and 378 students were screened from grades 1 to 8 using systematic random sampling method. Snellen chart was used for visual acuity test. Students who had visual acuity of ≤6/12 were further examined by an ophthalmologist to diagnose the reason for low vision. Data was analyzed using SPSS version 20. Results. A total of 378 students were screened, and 192 (50.8% were females and the remaining 186 (49.2% were males. The prevalence of visual impairment (VA of ≤6/12 on either eye was 5.8%, VA < 6/18 on either eye was 1.1%, and VA < 6/18 on the better eye was 0.53%. In this study, color blindness [OR: 19.65, 95% CI (6.01–64.33] was significantly associated with visual acuity impairment. Conclusion. The prevalence of visual impairment among school children in the study area was 5.8% and school screening is recommended.

  1. The Prevalence of Visual Acuity Impairment among School Children at Arada Subcity Primary Schools in Addis Ababa, Ethiopia.

    Science.gov (United States)

    Darge, Haile Fentahun; Shibru, Getahun; Mulugeta, Abiy; Dagnachew, Yinebeb Mezgebu

    2017-01-01

    Visual impairment and blindness are major public health problems in developing countries where there is no enough health-care service. To determine the prevalence of visual impairment among school children. A school-based cross-sectional study was conducted between 15 June 2015 and 30 November 2015 at Arada subcity primary schools, Addis Ababa, Ethiopia. Two schools were selected randomly, and 378 students were screened from grades 1 to 8 using systematic random sampling method. Snellen chart was used for visual acuity test. Students who had visual acuity of ≤6/12 were further examined by an ophthalmologist to diagnose the reason for low vision. Data was analyzed using SPSS version 20. A total of 378 students were screened, and 192 (50.8%) were females and the remaining 186 (49.2%) were males. The prevalence of visual impairment (VA) of ≤6/12 on either eye was 5.8%, VA visual acuity impairment. The prevalence of visual impairment among school children in the study area was 5.8% and school screening is recommended.

  2. Efficacy of perceptual vision therapy in enhancing visual acuity and contrast sensitivity function in adult hypermetropic anisometropic amblyopia

    Directory of Open Access Journals (Sweden)

    Yalcin E

    2013-12-01

    Full Text Available Elvan Yalcin, Ozlem BalciWorld Eye Hospital, Department of Pediatric Ophthalmology, Istanbul, TurkeyBackground: The purpose of this study was to evaluate the efficacy of neural vision therapy, also termed perceptual vision therapy, in enhancing best corrected visual acuity (BCVA and contrast sensitivity function in amblyopic patients.Methods: This prospective study enrolled 99 subjects previously diagnosed with unilateral hypermetropic amblyopia aged 9–50 years. The subjects were divided into two groups, with 53 subjects (53 eyes in the perceptual vision therapy group and 46 subjects (46 eyes in the control group. Because the nature of the treatment demands hard work and strict compliance, we enrolled the minimal number of subjects required to achieve statistically significant results. Informed consent was obtained from all subjects. Study phases included a baseline screening, a series of 45 training sessions with perceptual vision therapy, and an end-of-treatment examination. BCVA and contrast sensitivity function at 1.5, 3, 6, 12, and 18 cycles per degree spatial frequencies were obtained for statistical analysis in both groups. All subjects had follow-up examinations within 4–8 months. With the exception of one subject from the study group and two subjects from the control group, all subjects had occlusion during childhood. The study was not masked.Results: The results for the study group demonstrated a mean improvement of 2.6 logarithm of the minimum angle of resolution (logMAR lines in visual acuity (from 0.42 to 0.16 logMAR. Contrast sensitivity function improved at 1.5, 3, 6, 12, and 18 cycles per degree spatial frequencies. The control group did not show any significant change in visual acuity or contrast sensitivity function. None of the treated eyes showed a drop in visual acuity. Manifest refractions remained unchanged during the study.Conclusion: The results of our study demonstrate the efficacy of perceptual vision therapy in

  3. An Audit of Visual Acuity using a Snellen chart for Residents in a Care home, aged 65years or over

    OpenAIRE

    Ward, Hannah

    2012-01-01

    Background: Visual impairment (VI) is highly prevalent, but currently remains untreated and preventable in Britain‟s older population (Evans, Fletcher, Wormald et al. 2002). Eighty percent of all VI can be avoided or treated (WHO, 2011). People in residential or nursing homes are at a higher risk of having their eye problems overlooked (Pols, Bates, McGraw et al. 2000). Aim: To conduct an audit of visual acuity (VA), a measure of VI against a national standard, the British Geriatric Societ...

  4. Correlation of visual acuity and central macular morphology in different types of diabetic macular edema

    Directory of Open Access Journals (Sweden)

    Qiu-Ju Wu

    2016-02-01

    Full Text Available AIM:To observe the correlation of visual acuity and central macular morphology in patients with different types of diabetic macular edema(DME. METHODS: Presented study was single-center, uncontrolled retrospective clinical study. Sixty-two patients(103 eyeswith DME were included. Best corrected visual acuity(BCVAwas evaluated using early treatment diabetic retinopathy study(ETDRSvision test chart. All patients were examined by non-contact tonometer, slit lamp, indirect ophthalmoscope, and fundus fluorescein angiography(FFA. Central subfield mean thickness(CSMTin the macular area of diameter 1mm was measured by optical coherence tomography(OCT.And in the same time the integrity of inner segments/ outer segments(IS/OSand external limiting membrane(ELMreflecting light strip of 350μm center horizontal scanning line was investigated by OCT. BCVA and CSMT in different types of DME patients were analyzed using Kruskal- Wallis test. BCVA and CSMT between the two-two groups in different types of DME patients were analyzed using Nemenyi test, and multiple regression analysis was used to analyze the relative factors of BCVA. RESULTS: In the 103 eyes, 47 eyes(45.6%were focal DME, 35 eyes(34.0%were diffuse DME, 6 eyes(5.8%were ischemic DME and 15 eyes(14.6%were proliferative DME. The difference of mean BCVA(H=69.167, PH=57.113, Pχ2=14.982,Pχ2=14.537,Pχ2=15.596,Pχ2=15.393,Pχ2=16.567,Pχ2=15.687,Pχ2=12.974、P=0.008; CSMT:χ2=13.999,Pr=-0.064,-0.207,-0.082 and -0.160, respectively, Pr=-0.885, -2.522, -1.504, and-0.595, respectively, P>0.05. CONCLUSION: There are statistically significant differences on macular morphology and vision function among different types of DME patients.

  5. Influence of visual acuity on suicidal ideation, suicide attempts and depression in South Korea.

    Science.gov (United States)

    Rim, Tyler Hyungtaek; Lee, Christopher Seungkyu; Lee, Sung Chul; Chung, Byunghoon; Kim, Sung Soo

    2015-08-01

    To assess the influence of visual acuity (VA) on suicidal ideation, suicide attempts and depression. From 2008 to 2012, a total of 28 919 nationally representative participants aged 19 years or older in the Korea National Health and Nutrition Examination Survey underwent additional ophthalmological examinations by the Korean Ophthalmologic Society. Associations between best corrected VA in the better-seeing eye based on decimal fraction and mental health were identified using multivariable logistic regression analysis after adjusting for possible biopsychosocial confounders. Self-reported mental health (suicidal ideation, suicide attempt and depression), Euro Quality of Life-Visual Analog Scale and counselling experience were evaluated by direct interviews. A nomogram for risk of suicidal ideation was generated. By multivariable logistic regression analysis, low VA was significantly associated with suicidal ideation and suicide attempt but not depression. Participants with a VA of no light perception to 0.2 had a nearly twofold and threefold increased risk of suicidal ideation (adjusted OR, 1.85; 95% CI 1.04 to 3.27) and suicidal attempt (adjusted OR, 3.44; 95% CI 0.92 to 12.79), compared with participants with a VA of 1.0. Sociodemographic disparities, including age and socioeconomic status, existed for suicidal ideation, suicidal attempt and depression. Euro Quality of Life-Visual Analog Scale significantly decreased as VA decreased and was lower in participants who attempted suicide. Low VA was associated with the occurrence of suicidal ideation or a suicide attempt. Ophthalmologists should embrace their responsibility to help reduce suicidality and prevent suicides in patients with low VA by encouraging them to seek psychiatric care. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  6. Refraction and visual acuity in a national Danish cohort of 4-year-old children of extremely preterm delivery

    DEFF Research Database (Denmark)

    Fledelius, Hans C; Bangsgaard, Regitze; Slidsborg, Carina

    2015-01-01

    PURPOSE: A recent threefold increase in laser treatment for advanced retinopathy of prematurity (ROP) triggered a nationwide preschool ophthalmic and developmental status among extremely preterm survivors. Here, we discuss refraction and visual acuity. METHODS: Survivors (n = 178) from a national...... was 0.1 in FT and 0.2 in PT, in Snellen equivalents 0.8 and 0.63. Snellen acuity ≤0.5 occurred across the ROP subgroups, but mainly in those with at least ROP stage 3. Two children had low vision. CONCLUSIONS: The overall fair outcome for refraction and function is in accordance with other recent...

  7. RISK FOR LOW VISUAL ACUITY AFTER 1 AND 2 YEARS OF TREATMENT WITH RANIBIZUMAB OR BEVACIZUMAB FOR PATIENTS WITH NEOVASCULAR AGE-RELATED MACULAR DEGENERATION.

    Science.gov (United States)

    Westborg, Inger; Albrecht, Susanne; Rosso, Aldana

    2017-11-01

    To investigate how patients with neovascular age-related macular degeneration treated with ranibizumab or bevacizumab respond to treatment in daily clinical practice. Data from the Swedish Macula Register on the treatment received by 3,912 patients during 2011 to 2014 is reported. Patients' characteristics at the first visit, visual acuity, number of injections, and reason for terminating the treatment if applicable are discussed. Furthermore, the risk of having poor vision (visual acuity under 60 Early Treatment Diabetes Retinopathy Study letters or approximately 20/60 Snellen) is calculated for the treated eye after 1 year and 2 years. The treatment outcome depends on the visual acuity at the first visit. For patients with visual acuity more than 60 letters, the risk of having a visual acuity lower than 60 letters after 1 year or 2 years of treatment is approximately 20%. However, for patients with low visual acuity at diagnosis (fewer than 60 letters), the risk is approximately 60%. The risk of having a visual acuity lower than 60 letters does not depend on the choice of treatment drug. Treatment with anti-vascular endothelial growth factor intravitreal injections mainly maintains the visual acuity level, and only approximately 20% and 40% of the patients required vision rehabilitation after 1 year and 2 years, respectively.

  8. Post-treatment visual acuity in patients treated with episcleral plaque therapy for choroidal melanoma: Dose and dose rate effects

    International Nuclear Information System (INIS)

    Jones, Robert; Gore, Elizabeth; Mieler, William; Gillin, Michael; Albano, Katherine; Erickson, Beth

    1996-01-01

    Purpose: To determine the relationship between the long-term visual function and the dose and dose rates delivered to critical ocular structures in patients with choroidal melanoma treated with 125 I episcleral plaque radiotherapy. Methods and Materials: From 1987 to 1993, 63 patients underwent 125 I episcleral plaque application for the treatment of choroidal melanoma. Mean tumor height was 4.6 mm (range 1.7-8.3 mm). Plaques utilized were of COMS design. Doses and dose rates at the tumor apex, macula, and optic disc were obtained. Visual acuity data prior to and after plaque application was available for 52 patients. 9 patients were excluded from analysis secondary to co-morbidities or disease progression. 43 records were scored to assess if a decrease in visual acuity of ≥ 2 lines on a standard Snellen eye chart had occurred. Statistical analysis was performed using chi-square tests of significance. Results: Of the 63 total patients, 59 (93.7%) were alive at a median follow-up of 36 months. Local progression occurred in (7(63)) (11.1%). Median dose and dose rate to the tumor apex were 90 Gy and 97.2 cGy/hr, respectively. Of the 43 patients with post-treatment visual acuity analysis, 28 (65.1%) experienced visual loss of ≥ 2 lines on a standard eye chart. Median time to altered visual acuity was 20 months. Median dose and dose rates to the macula in patients with a significant visual loss were 123.3 Gy and 122.5 cGy/hr, respectively, compared with 38 Gy and 51.9 cGy/hr in those without notable visual change. These differences reached statistical significance at a dose and dose rate to the macula of 82.0 Gy (p 125 I plaque brachytherapy for choroidal melanoma experienced favorable tumor control, but with a measurable incidence of decreased visual acuity. Both total dose and dose rates to the macula and optic disc correlated strongly with post-treatment visual outcome. This information may be valuable in decisions about the dose and dose rates used to treat

  9. Post-treatment visual acuity in patients treated with episcleral plaque therapy for choroidal melanoma: dose and dose rate effects

    International Nuclear Information System (INIS)

    Jones, Robert; Gore, Elizabeth; Mieler, William; Murray, Kevin; Gillin, Michael; Albano, Katherine; Erickson, Beth

    1996-01-01

    Purpose: To determine the relationship between the long-term visual function and the dose and dose rates delivered to critical ocular structures in patients with choroidal melanoma treated with 125 I episcleral plaque radiotherapy. Methods and Materials: From 1987 to 1994, 63 patients underwent 125 I episcleral plaque application for the treatment of choroidal melanoma. Mean tumor height was 4.6 mm (range 1.7-8.3 mm). Plaques utilized were of COMS design. Doses and dose rates at the tumor apex, macula, and optic disc were obtained. Visual acuity data prior to and after plaque application was available for 52 patients. Nine patients were excluded from analysis secondary to co-morbidities or disease progression. Forty-three records were scored to assess if a decrease in visual acuity of ≥ 2 lines on a standard Snellen eye chart had occurred. Statistical analysis was performed using chi-square tests of significance. Results: Of the 63 total patients, 59 (93.7%) were alive at a median follow-up of 36 months. Local progression occurred in 7/63 (11.1%). Median dose and dose rate to the tumor apex were 90 Gy and 97.2 cGy/hr, respectively. Of the 43 patients with post-treatment visual acuity analysis, 28 (65.1%) experienced visual loss of ≥ 2 lines on a standard eye chart. Median time to altered visual acuity was 20 months. Median dose and dose rates to the macula in patients with a significant visual loss were 123.3 Gy and 122.5 cGy/hr, respectively, compared with 38 Gy and 51.9 cGy/hr in those without notable visual change. These differences reached statistical significance at a dose and dose rate to the macula of 82.0 Gy (p 125 I plaque brachytherapy for choroidal melanoma experienced favorable tumor control, but with a measurable incidence of decreased visual acuity. Both total dose and dose rates to the macula and optic disc correlated strongly with post-treatment visual outcome. This information may be valuable in decisions about the dose and dose rates used to

  10. A randomised comparison between an inexpensive, general-purpose headlight and a purpose-built surgical headlight on users' visual acuity and colour vision.

    Science.gov (United States)

    Street, I; Sayles, M; Nistor, M; McRae, A R

    2014-02-01

    To determine if there are any differences in near visual acuity and colour vision between an inexpensive general-purpose light emitting diode (LED) headlight and a purpose-built surgical LED headlight. A prospective study was conducted sequentially comparing near visual acuity and colour vision, the headlights being tested in random order, in a testing room with a constant minimal amount of background light. The participants were NHS employee volunteers, with self-declared normal (or corrected) vision, working in occupations requiring full literacy. For visual acuity, outcome was measured by recording the smallest font legible when using each headlight when the subject read a near visual acuity test card. For colour vision, the outcome was passing or failing the Ishihara test. There was no statistically significant difference between the general-purpose and the purpose-built headlights in users' near visual acuity or colour vision.

  11. Recognition versus Resolution: a Comparison of Visual Acuity Results Using Two Alternative Test Chart Optotype

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    Jonathan S. Pointer

    2008-01-01

    Conclusions: For normally sighted subjects wearing an optimal refractive correction, a bias was recorded in favour of recognition over resolution acuity: the clinical difference amounted to approximately 40% of one logMAR chart line, with similar high repeatability for either chart optotype. We conclude that the assumption of clinical equivalence between letter and Landolt acuity is reasonable under optimum test conditions.

  12. Medida da acuidade visual em um shopping center metropolitano Visual acuity measurement in a metropolitan shopping mall population

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    Giovanni M. Travi

    2000-04-01

    Full Text Available Objetivo: Determinar a prevalência de baixa acuidade visual (AV em uma amostra populacional, com um padrão socioeconômico diferenciado. Métodos: Realizou-se estudo de prevalência, sendo verificada a AV de 213 voluntários examinados em um posto no interior de um shopping center em Porto Alegre, por meio do aparelho Ortho-Rater, da Bausch & Lomb. Foi medida a AV para longe em todos os indivíduos e naqueles com 40 anos ou mais, a AV para perto, ambos sem e com correção. Determinou-se como baixa AV, aquela inferior a 10 (equivalente a 20/20 na Tabela de Snellen. Resultados: A idade variou de 6 a 75 anos, com uma média ± desvio-padrão de 27,8 ± 15,16 anos, pertencendo a maioria dos examinados à faixa entre 10 e 40 anos. Encontrou-se uma prevalência de 38,7% (IC 95%: 32,1-45,7 de baixa AV para longe nos dois olhos. 24,9% (IC 95%: 19,2-31,3 apresentavam déficit visual binocular e não faziam uso de correção. Para perto, observou-se que 70,8% (IC 95%: 55,9-83 dos indivíduos testados apresentaram déficit visual binocular sem correção e 41,7% (IC 95%: 27,6-56,8 apresentaram baixa AV independente do uso de correção. Conclusão: Este estudo demonstrou que existe considerável parcela da população com déficit visual, necessitando de avaliação e manejo adequados. Conclui-se que programas de medida da AV e orientação sobre saúde ocular são importantes em qualquer ambiente e atingindo diferentes classes socioeconômicas.Purpose: To determine the prevalence of low visual acuity (VA in a populational sample, with a differentiated social pattern. Methods: This was a prevalence study, in which the 213 volunteers' VA, examined in a shopping mall in Porto Alegre, was verified through the Ortho-Rater device, from Bausch & Lomb. Far sight VA was measured in all the individuals and in those who were 40 years old or older, near sight VA, both of them without and with correction. VA was considered low when it was less than 10 (equivalent

  13. [Epidemiological Study of Poor Visual Acuity among Schoolchildren in Bonin Islands].

    Science.gov (United States)

    Ito, Misae; Shimizu, Kimiya; Kawamorita, Takushi; Shoji, Nobuyuki

    2016-04-01

    To investigate the change in uncorrected visual acuity (UCVA) among schoolchildren in Bonin Islands. UCVA of schoolchildren aged 6 to 14 years, was collected from reports of School Health Examination Surveys conducted from 1981 to 2012. The proportion of schoolchildren with poor UCVA in the Bonin Islands was compared with those in metropolitan Tokyo. The results in Bonin Islands were also divided into two groups, before- and after-1996 when terrestrial television broadcasting service has been started, and the data of those two groups were compared. The proportion of schoolchildren with poor UCVA in Bonin Islands was lower than that in Tokyo. Among the residents of Bonin Islands, the proportion of schoolchildren with UCVA of < 1.0 was higher in the after-1996 group than in the before- 1996 group, with a clear increase in schoolchildren with poor UCVA after 1996 (p < 0.01, Fisher's exact test), examined among the 4th grade of elementary school or above. After 1996, 26.6% of first graders at a public junior high school had poor UCVA of < 0.7, whereas before 1996 no such case could be detected. The present study revealed that the proportions of schoolchildren with poor UCVA in Bonin Islands was lower than that in Tokyo; but in the residents of Bonin Islands after 1996, the proportion of the schoolchildren with poor UCVA increased.

  14. Relation between Visual Acuity and Slope of Psychometric Function in Young Adults

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    Tomoki Tokutake

    2011-05-01

    Full Text Available Mita et al. (2010 devised a technique of comparing a visual acuity (VA change in an individual with more accurate VA than conventional VA tests by significant difference examined logarithmic (Log VA ± standard deviation (SD. Using this technique, in this study, we examined a relation between VA and the slope of the psychometric function in normal young subjects. Six occlusion foil conditions were employed (1.0, 0.8, 0.6, 0.4, 0.1 and without the foil under a full refractive correction. Ten normal young adults (22.8 years old on average who have no ophthalmologic disease except ametropia participated in the measurement. The experiment was carried out with the constant method, a series of ten Landolt rings were used and each ring was presented 20 times randomly in a measurement. A 5.6-inch type of liquid crystal display driven by a computer, which has 1,280×800 pixels spatial resolution, was used to present the stimulus. In the normal young adults, the slope of the psychometric function did not change as the VA change systematically, and there was almost no correlation between them (r = −0.103.

  15. Baseline Predictors of Visual Acuity Outcome in Patients with Wet Age-Related Macular Degeneration

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    Xinyuan Zhang

    2018-01-01

    Full Text Available Age-related macular degeneration (AMD is one of the leading causes of severe vision loss in people over 60 years. Wet AMD (wAMD causes more severe visual acuity (VA loss compared with the dry form due to formation of choroidal neovascularization (CNV. Antivascular endothelial growth factor (anti-VEGF agents such as ranibizumab and aflibercept are now the standard of care treatment for wAMD. Unfortunately, up to a quarter of anti-VEGF-treated wAMD patients might not fully benefit from intravitreal injections and CNV activity may not respond to the treatment and these patients are called anti-VEGF nonresponders. This article aims to discuss the baseline factors associated with VA outcome such as age, initial VA, lesion types, disease duration, optical coherence tomography (OCT features, fundus autofluorescence findings, and the presence of particular genotype risk alleles in patients with wAMD. Recommendations are provided regarding when to consider discontinuation of therapy because of either success or futility. Understanding the predictive factors associated with VA outcome and treatment frequency response to anti-VEGF therapy may help retina specialists to manage patients’ expectations and guide treatment decisions from the beginning of treatment on the basis of “personalized medicine.”

  16. Unexpected Genetic Cause in Two Female Siblings with High Myopia and Reduced Visual Acuity

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    M. N. Preising

    2018-01-01

    Full Text Available In daily life, myopia is a frequent cause of reduced visual acuity (VA due to missing or incomplete optical correction. While the genetic cause of high myopia itself is not well understood, a significant number of cases are secondary to hereditary malfunctions or degenerations of the retina. The mechanism by which this occurs remains yet unclear. Two female siblings, 4 y and 2 y, respectively, from a consanguineous Pakistani family were referred to our department for reduced VA and strabismus. Both girls were highly myopic and hence were further examined using standard clinical tests and electroretinography (ERG. The latter confirmed confounded electrical coupling of photoreceptors and bipolar cells. Further inquiry and testing confirmed a similar condition for the father including impaired night vision, reduced VA, photophobia, and an equally characteristic ERG. Findings in the mother were unremarkable. Subsequent genetic analysis of autosomal recessive and X-linked genes for congenital stationary night blindness (CSNB revealed a novel homozygous splice site mutation in CACNA1F in the two girls transmitted from both the father and the mother. While in males the above clinical constellation is a frequent finding, this report, to the authors’ knowledge, is the first demonstrating biallelic mutations at the CACNA1F locus in females.

  17. Origins of superior dynamic visual acuity in baseball players: superior eye movements or superior image processing.

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    Yusuke Uchida

    Full Text Available Dynamic visual acuity (DVA is defined as the ability to discriminate the fine parts of a moving object. DVA is generally better in athletes than in non-athletes, and the better DVA of athletes has been attributed to a better ability to track moving objects. In the present study, we hypothesized that the better DVA of athletes is partly derived from better perception of moving images on the retina through some kind of perceptual learning. To test this hypothesis, we quantitatively measured DVA in baseball players and non-athletes using moving Landolt rings in two conditions. In the first experiment, the participants were allowed to move their eyes (free-eye-movement conditions, whereas in the second they were required to fixate on a fixation target (fixation conditions. The athletes displayed significantly better DVA than the non-athletes in the free-eye-movement conditions. However, there was no significant difference between the groups in the fixation conditions. These results suggest that the better DVA of athletes is primarily due to an improved ability to track moving targets with their eyes, rather than to improved perception of moving images on the retina.

  18. Origins of superior dynamic visual acuity in baseball players: superior eye movements or superior image processing.

    Science.gov (United States)

    Uchida, Yusuke; Kudoh, Daisuke; Murakami, Akira; Honda, Masaaki; Kitazawa, Shigeru

    2012-01-01

    Dynamic visual acuity (DVA) is defined as the ability to discriminate the fine parts of a moving object. DVA is generally better in athletes than in non-athletes, and the better DVA of athletes has been attributed to a better ability to track moving objects. In the present study, we hypothesized that the better DVA of athletes is partly derived from better perception of moving images on the retina through some kind of perceptual learning. To test this hypothesis, we quantitatively measured DVA in baseball players and non-athletes using moving Landolt rings in two conditions. In the first experiment, the participants were allowed to move their eyes (free-eye-movement conditions), whereas in the second they were required to fixate on a fixation target (fixation conditions). The athletes displayed significantly better DVA than the non-athletes in the free-eye-movement conditions. However, there was no significant difference between the groups in the fixation conditions. These results suggest that the better DVA of athletes is primarily due to an improved ability to track moving targets with their eyes, rather than to improved perception of moving images on the retina.

  19. Night-shift work and risk of compromised visual acuity among the workers in an electronics manufacturing company.

    Science.gov (United States)

    Lin, Yu-Cheng; Ho, Kuo-Jung

    2018-01-01

    To evaluate the association between night-shift work exposure and visual health, this cross-sectional study utilized visual acuity, a surrogate measure for visual function, as a parameter, and performed an analysis comparing visual acuity between daytime and nighttime employees in an electronics manufacturing company. Data of personal histories, occupational records, physical examinations and blood tests was obtained from the electronic health records of workers. The total of 8280 workers including 3098 women and 5182 men, wearing their own daily used eyeglasses, were included in the final analysis. The mean age of the sample population was 34.7 years old (standard deviation = 5.4 years). All workers were divided into 3 work categories - consistent daytime worker (CDW), day-shift worker (DSW) and night-shift worker (NSW). The check-up results of glasses-corrected visual acuity (c-VA) were utilized to classify individuals as good (≥ 1.2, both eyes) and inadequate (electronics manufacturing company. Int J Occup Med Environ Health 2018;31(1):71-79. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  20. Metformin Impairs Spatial Memory and Visual Acuity in Old Male Mice.

    Science.gov (United States)

    Thangthaeng, Nopporn; Rutledge, Margaret; Wong, Jessica M; Vann, Philip H; Forster, Michael J; Sumien, Nathalie

    2017-02-01

    Metformin is an oral anti-diabetic used as first-line therapy for type 2 diabetes. Because benefits of metformin extend beyond diabetes to other age-related pathology, and because its effect on gene expression profiles resembles that of caloric restriction, metformin has a potential as an anti-aging intervention and may soon be assessed as an intervention to extend healthspan. However, beneficial actions of metformin in the central nervous system have not been clearly established. The current study examined the effect of chronic oral metformin treatment on motor and cognitive function when initiated in young, middle-aged, or old male mice. C57BL/6 mice aged 4, 11, or 22 months were randomly assigned to either a metformin group (2 mg/ml in drinking water) or a control group. The mice were monitored weekly for body weight, as well as food and water intake and a battery of behavioral tests for motor, cognitive and visual function was initiated after the first month of treatment. Liver, hippocampus and cortex were collected at the end of the study to assess redox homeostasis. Overall, metformin supplementation in male mice failed to affect blood glucose, body weights and redox homeostasis at any age. It also had no beneficial effect on age-related declines in psychomotor, cognitive or sensory functions. However, metformin treatment had a deleterious effect on spatial memory and visual acuity, and reduced SOD activity in brain regions. These data confirm that metformin treatment may be associated with deleterious effect resulting from the action of metformin on the central nervous system.

  1. Dynamic visual acuity during transient and sinusoidal yaw rotation in normal and unilaterally vestibulopathic humans.

    Science.gov (United States)

    Tian, J R; Shubayev, I; Demer, J L

    2001-03-01

    The vestibulo-ocular reflex (VOR) stabilizes gaze to permit clear vision during head movements. It has been supposed that VOR function might be inferred from dynamic visual acuity (DVA), the acuity during imposed head motion. We sought to determine effectiveness of DVA for detection and lateralization of unilateral vestibulopathy, using rigorous psychophysical methods. Seventeen normal and 11 unilaterally vestibulopathic subjects underwent measurement of optically best corrected DVA during head motion. A variable size letter "E" 6 m distant was displayed in oblique random orientations to determine binocular DVA by a computer controlled, forced choice method. Three types of whole-body yaw rotation were delivered by a servo-controlled chair synchronized with optotype presentation. Two types of motion were predictable: (1) steady-state 2.0-Hz rotation at 10-130 degrees/s peak velocity with repetitive optotype presentation only during head velocity exceeding 80% of peak; and (2) directionally predictable transients at peak accelerations of 1000, 1600 and 2800 degrees/s2 with optotype presentation for 300 ms. For neither of these predictable motions did DVA in vestibulopathic subjects significantly differ from normal, with suggestions from search coil recordings that this was due to predictive slow and saccadic eye movements. Unilaterally vestibulopathic subjects experienced a significant decrease in DVA from the static condition during ipsilesional rotation for all three peak head accelerations. Only during directionally unpredictable transients with 75 ms or 300 ms optotype presentation was the sensitivity of DVA in unilaterally vestibulopathic subjects significantly abnormal during ipsilesional rotation. The ipsilesional decrease in DVA with head motion was greater for 75 ms than 300 ms optotype presentation. Search coil recordings confirmed hypometric compensatory eye movements during DVA testing with unpredictable, ipsilesional rotation. Receiver

  2. COMPARISON OF VISUAL ACUITY IN REDUCED LUMINATION AND FACILITY OF OCULAR ACCOMMODATION IN TABLE TENNIS CHAMPIONS AND NON- PLAYERS

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    Ebrahim Jafarzadehpur

    2004-03-01

    Full Text Available A table tennis player should fixate at different distances; track the objects with different speed, and in different visual environment. Their visual skills must be well developed for these capabilities. Therefore, visual acuity in reduced lumination and facility of ocular accommodation those are two criteria for visual skills have been compared in table tennis players and normal non-players. Twenty-nine young table tennis champions and 29 normal matched non-players (did not take part in any racket sports game were evaluated. Basic visual and eye examinations were done for both of them. Normal results in basic examination were fundamental requirement for all the subjects. +/-2.00 sphere lenses for accommodation facility are used. An electrical current regulator changed the output light intensity of a conventional chart projector (Topcon. Light intensity decreased to 10 cd·m-2 and visual acuity tested. In comparison of visual acuity in reduced lumination and facility of ocular accommodation in table tennis champions and non-players there are significant differences (p < 0.001. In the preliminary visual tests there was not any significant different in the two groups but the results in the top level table tennis player was very uniform and in every test and the standard deviation was lesser in tennis player group than non-players. These results show that motor and sensorial functions of expert players are well developed. That is consistent with other researchers. This result was interpreted as reflecting a better perceptual system of experts to the constraints encountered during table tennis and its use in practical settings for evaluating athletes or detecting sport talents. However some visual and perceptual training that usually used in orthoptics can be used for novice table tennis player to improve their abilities

  3. How well do you see what you hear? The acuity of visual-to-auditory sensory substitution

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    Alastair eHaigh

    2013-06-01

    Full Text Available Sensory substitution devices (SSDs aim to compensate for the loss of a sensory modality, typically vision, by converting information from the lost modality into stimuli in a remaining modality. The vOICe is a visual-to-auditory SSD which encodes images taken by a camera worn by the user into soundscapes such that an experienced user can extract information about their surroundings. Here we investigated how much detail was resolvable during the early induction stages by testing the acuity of blindfolded sighted, naïve vOICe users. Initial performance was well above chance. Participants who took the test twice as a form of minimal training showed a marked improvement on the second test. Acuity was slightly but not significantly impaired when participants wore a camera and judged letter orientations live. A positive correlation was found between participants’ musical training and their acuity. The relationship between auditory expertise via musical training and the lack of a relationship with visual imagery, suggests that early use of a sensory substitution device draws primarily on the mechanisms of the sensory modality being used rather than the one being substituted. If vision is lost, audition represents the sensory channel of highest bandwidth of those remaining. The level of acuity found here, and the fact it was achieved with very little experience in sensory substitution by naïve users is promising.

  4. Stable statistical representations facilitate visual search.

    Science.gov (United States)

    Corbett, Jennifer E; Melcher, David

    2014-10-01

    Observers represent the average properties of object ensembles even when they cannot identify individual elements. To investigate the functional role of ensemble statistics, we examined how modulating statistical stability affects visual search. We varied the mean and/or individual sizes of an array of Gabor patches while observers searched for a tilted target. In "stable" blocks, the mean and/or local sizes of the Gabors were constant over successive displays, whereas in "unstable" baseline blocks they changed from trial to trial. Although there was no relationship between the context and the spatial location of the target, observers found targets faster (as indexed by faster correct responses and fewer saccades) as the global mean size became stable over several displays. Building statistical stability also facilitated scanning the scene, as measured by larger saccadic amplitudes, faster saccadic reaction times, and shorter fixation durations. These findings suggest a central role for peripheral visual information, creating context to free resources for detailed processing of salient targets and maintaining the illusion of visual stability.

  5. Outcomes of visual acuity in carbon ion radiotherapy: Analysis of dose-volume histograms and prognostic factors

    International Nuclear Information System (INIS)

    Hasegawa, Azusa; Mizoe, Jun-etsu; Mizota, Atsushi; Tsujii, Hirohiko

    2006-01-01

    Purpose: To analyze the tolerance dose for retention of visual acuity in patients with head-and-neck tumors treated with carbon ion radiotherapy. Methods and Materials: From June 1994 to March 2000, 163 patients with tumors in the head and neck or skull base region were treated with carbon ion radiotherapy. Analysis was performed on 54 optic nerves (ONs) corresponding to 30 patients whose ONs had been included in the irradiated volume. These patients showed no evidence of visual impairment due to other factors and had a follow-up period of >4 years. All patients had been informed of the possibility of visual impairment before treatment. We evaluated the dose-complication probability and the prognostic factors for the retention of visual acuity in carbon ion radiotherapy, using dose-volume histograms and multivariate analysis. Results: The median age of 30 patients (14 men, 16 women) was 57.2 years. Median prescribed total dose was 56.0 gray equivalents (GyE) at 3.0-4.0 GyE per fraction per day (range, 48-64 GyE; 16-18 fractions; 4-6 weeks). Of 54 ONs that were analyzed, 35 had been irradiated with max ]) resulting in no visual loss. Conversely, 11 of the 19 ONs (58%) irradiated with >57 GyE (D max ) suffered a decrease of visual acuity. In all of these cases, the ONs had been involved in the tumor before carbon ion radiotherapy. In the multivariate analysis, a dose of 20% of the volume of the ON (D 2 ) was significantly associated with visual loss. Conclusions: The occurrence of visual loss seems to be correlated with a delivery of >60 GyE to 20% of the volume of the ON

  6. Visual Acuity in Orbital Floor Fractures: Does Surgical Subspecialty Management Matter?

    Science.gov (United States)

    Richards, Nikisha Q; Brown, Ninita H; Kidwell, Earl D R

    2015-07-01

    At the time of this writing, there is no consensus regarding orbital floor fracture (OFFx) management. Proper management of OFFxs is imperative to help prevent well known complications and the possibility of decreased visual acuity (VA). The VA outcomes have been largely underreported in the literature. The current study identifies the complications of the different subspecialty management including VA outcome. A retrospective chart review study was performed to identify patients who suffered an OFFx and were managed by ophthalmology alone or in conjunction with either ENT or oral maxillofacial surgery at a single hospital. The primary outcome included VA at injury and subsequent visits. Secondary outcomes included epiphora, diplopia, enophthalmos, infraorbital dysesthesia, and decreased motility. Data were analyzed using Microsoft Office Excel 2007 using the Student t-test to find a P value < 0.05. There were 54 patients with OFFx. The majority were Black (83.3%) and men (77.8%) with their average age at time of injury being 37.6 (SE = 17.02) years. The majority of OFFxs were secondary to assault (65%). The average follow-up was 2.84 (SE = 5.38) months. The 34 patients who did not undergo surgical correction had statistically significant improvement of their VA by 1 week after injury (P = 0.02). There was no statistically significant improvement in VA outcomes for surgical patients of ophthalmology (P = 0.45) or oral maxillofacial surgery (P = 0.12). Patients undergoing OFFx repair did not have improved VA. The VA of nonsurgical patients was statistically significantly improved by 1 week after injury (P = 0.02).

  7. Effects of Milk vs Dark Chocolate Consumption on Visual Acuity and Contrast Sensitivity Within 2 Hours: A Randomized Clinical Trial.

    Science.gov (United States)

    Rabin, Jeff C; Karunathilake, Nirmani; Patrizi, Korey

    2018-04-26

    Consumption of dark chocolate can improve blood flow, mood, and cognition in the short term, but little is known about the possible effects of dark chocolate on visual performance. To compare the short-term effects of consumption of dark chocolate with those of milk chocolate on visual acuity and large- and small-letter contrast sensitivity. A randomized, single-masked crossover design was used to assess short-term visual performance after consumption of a dark or a milk chocolate bar. Thirty participants without pathologic eye disease each consumed dark and milk chocolate in separate sessions, and within-participant paired comparisons were used to assess outcomes. Testing was conducted at the Rosenberg School of Optometry from June 25 to August 15, 2017. Visual acuity (in logMAR units) and large- and small-letter contrast sensitivity (in the log of the inverse of the minimum detectable contrast [logCS units]) were measured 1.75 hours after consumption of dark and milk chocolate bars. Among the 30 participants (9 men and 21 women; mean [SD] age, 26 [5] years), small-letter contrast sensitivity was significantly higher after consumption of dark chocolate (mean [SE], 1.45 [0.04] logCS) vs milk chocolate (mean [SE], 1.30 [0.05] logCS; mean improvement, 0.15 logCS [95% CI, 0.08-0.22 logCS]; P chocolate (mean [SE], 2.05 [0.02] logCS) vs milk chocolate (mean [SE], 2.00 [0.02] logCS; mean improvement, 0.05 logCS [95% CI, 0.00-0.10 logCS]; P = .07). Visual acuity improved slightly after consumption of dark chocolate (mean [SE], -0.22 [0.01] logMAR; visual acuity, approximately 20/12) and milk chocolate (mean [SE], -0.18 [0.01] logMAR; visual acuity, approximately 20/15; mean improvement, 0.04 logMAR [95% CI, 0.02-0.06 logMAR]; P = .05). Composite scores combining results from all tests showed significant improvement after consumption of dark compared with milk chocolate (mean improvement, 0.20 log U [95% CI, 0.10-0.30 log U]; P chocolate bar compared with a

  8. Possible role for fundus autofluorescence as a predictive factor for visual acuity recovery after epiretinal membrane surgery.

    Science.gov (United States)

    Brito, Pedro N; Gomes, Nuno L; Vieira, Marco P; Faria, Pedro A; Fernandes, Augusto V; Rocha-Sousa, Amândio; Falcão-Reis, Fernando

    2014-02-01

    To study the potential association between fundus autofluorescence, spectral-domain optical coherence tomography, and visual acuity in patients undergoing surgery because of epiretinal membranes. Prospective, interventional case series including 26 patients submitted to vitrectomy because of symptomatic epiretinal membranes. Preoperative evaluation consisted of a complete ophthalmologic examination, autofluorescence, and spectral-domain optical coherence tomography. Studied variables included foveal autofluorescence (fov.AF), photoreceptor inner segment/outer segment (IS/OS) junction line integrity, external limiting membrane integrity, central foveal thickness, and foveal morphology. All examinations were repeated at the first, third, and sixth postoperative months. The main outcome measures were logarithm of minimal angle resolution visual acuity, fov.AF integrity, and IS/OS integrity. All cases showing a continuous IS/OS line had an intact fov.AF, whereas patients with IS/OS disruption could have either an increased area of foveal hypoautofluorescence or an intact fov.AF, with the latter being associated with IS/OS integrity recovery in follow-up spectral-domain optical coherence tomography imaging. The only preoperative variables presenting a significant correlation with final visual acuity were baseline visual acuity (P = 0.047) and fov.AF grade (P = 0.023). Recovery of IS/OS line integrity after surgery, in patients with preoperative IS/OS disruption and normal fov.AF, can be explained by the presence of a functional retinal pigment epithelium-photoreceptor complex, supporting normal photoreceptor activity. Autofluorescence imaging provides a functional component to the study of epiretinal membranes, complementing the structural information obtained with optical coherence tomography.

  9. Effect of occlusion amblyopia after prescribed full-time occlusion on long-term visual acuity outcomes.

    Science.gov (United States)

    Longmuir, Susannah; Pfeifer, Wanda; Scott, William; Olson, Richard

    2013-01-01

    To investigate the incidence and characteristics of occlusion amblyopia with prescribed full-time patching and determine its effect on long-term visual acuity outcomes. The records of patients younger than 10 years diagnosed as having amblyopia between 1970 and 2000 were retrospectively reviewed. Patients were prescribed full-time occlusion and observed until completion of therapy. Of 597 patients treated for amblyopia by full-time patching, 115 were diagnosed as having occlusion amblyopia (19.3%). Seventy-five percent (86 of 115) developed occlusion amblyopia during the first episode of full-time patching. Occlusion amblyopia occurred more frequently in children prescribed full-time patching at an earlier age (P = .0002), with an odds ratio of 8.56 (95% confidence interval: 2.73, 26.84) in children younger than 36 months and 2.66 (95% confidence interval: 0.96, 7.37) in children between 36 and 59 months old. Seven of the patients with occlusion amblyopia did not reverse fixation and continued to fixate with the initially amblyopic eye after treatment. Final visual acuity in these eyes with occlusion amblyopia was 20/30 or better. After cessation of treatment, the final interocular difference in visual acuity was less in patients with a history of occlusion amblyopia (P = .003). Occlusion amblyopia occurred at all ages, but the incidence decreased with increasing age. Patients who developed occlusion amblyopia with prescribed full-time occlusion had less interocular visual acuity difference than patients who did not, suggesting that development of occlusion amblyopia can indicate the potential for the development of better vision in the originally amblyopic eye. Copyright 2013, SLACK Incorporated.

  10. Association Between Adherence to Glasses Wearing During Amblyopia Treatment and Improvement in Visual Acuity.

    Science.gov (United States)

    Maconachie, Gail D E; Farooq, Shegufta; Bush, Glen; Kempton, Julie; Proudlock, Frank A; Gottlob, Irene

    2016-12-01

    Occlusion dose monitors have helped establish that better adherence to occlusion is associated with improved visual outcomes in patients undergoing amblyopia treatment. However, the role of adherence to glasses wearing is unknown. To establish the feasibility and reliability of objectively monitoring adherence to glasses wearing using age-based norms, establish the association between adherence to glasses wearing and improvement in visual acuity (VA) after optical treatment and occlusion therapy, and analyze the effect of age, sex, refractive errors, type of amblyopia, and adherence to glasses wearing on improvement in VA. A prospective, observational, nonmasked, cohort study was conducted between June 8, 2008, and June 30, 2013, among patients at a pediatric ophthalmology clinic of a tertiary care hospital who were newly diagnosed with anisometropic and/or strabismic amblyopia and had not undergone previous treatment. The study consisted of a glasses phase (18 weeks) and a patching phase (glasses and occlusion for 10 hours per day for 12 weeks). Reliability of the glasses monitors was assessed by comparing diary entries and monitor recordings in adults. Objective monitoring of glasses wearing and occlusion. Adherence to glasses wearing (hours per day) and effect on VA. Among 20 children with anisometropia (mean [SD] age, 6.20 [2.16] years; 11 boys and 9 girls) and 20 with strabismic or mixed amblyopia (mean [SD] age, 4.90 [1.36] years; 10 boys and 10 girls), adherence to glasses wearing was successfully monitored in all but 1 patient. Agreement between diaries and monitored times wearing glasses in adults was high (intraclass correlation coefficient, 1.00; 95% CI, 0.999-1.00). Median (SD) adherence to glasses wearing was 70% (25.3%). A moderate correlation was observed between adherence to glasses wearing and percentage improvement in VA during the glasses phase (r = 0.462; P = .003). Multiple regression revealed that age (β = -0.535; P = .001

  11. [Evaluation of visual acuity in a historical cohort of 137 patients treated for amblyopia by occlusion 30-35 years ago].

    Science.gov (United States)

    Simonsz-Tóth, B; Loudon, S E; van Kempen-du Saar, H; van de Graaf, E S; Groenewoud, J H; Simonsz, H J

    2007-01-01

    Opinions differ on the course of the visual acuity in the amblyopic eye after cessation of occlusion therapy. This study evaluated visual acuity in a historical cohort treated for amblyopia with occlusion therapy 30-35 years ago. Between 1968 and 1975, 1250 patients had been treated by the orthoptist in the Waterland Hospital in Purmerend, The Netherlands. Of these, 471 received occlusion treatment for amblyopia (prevalence 5.0%, after comparison with the local birth rate). We were able to contact 203 of these patients, 137 were orthoptically re-examined in 2003. We correlated the current visual acuity with the cause of amblyopia, the age at start and end of treatment, the visual acuity at start and end of treatment, fixation, binocular vision and refractive errors. Mean age at the start of treatment was 5.4 +/- 1.9 years, 7.4 +/- 1.7 years at the end and 37 +/- 2.7 years at follow-up. Current visual acuity in the amblyopic eye was correlated with a low visual acuity at the start (p occlusion therapy, an eccentric fixation (p amblyopia (p = 0.005). At the end of the treatment, patients with a strabismic amblyopia (n = 98) had a visual acuity in the amblyopic eye of 0.29 logMAR +/- 0.3, and in 2003 0.27 +/- 0.3 logMAR. In patients with an anisometropic amblyopia (> 1 D, n = 16) visual acuity had decreased from 0.17 +/- 0.23 logMAR to 0.21 logMAR +/- 0.23. In patients with both strabismic and anisometropic amblyopia (n = 23), visual acuity had decreased from 0.52 logMAR +/- 0.54 to 0.65 logMAR +/- 0.54. Overall, acuity had decreased in 54 patients (39%) after cessation of treatment. Of these, 18 patients had an acuity decrease to less than 50% of their acuity at the end of treatment. In 15 of these 18 patients anisohypermetropia had increased. A decrease in visual acuity after cessation of occlusion therapy occurred in patients with a combined cause of amblyopia or with an increase in anisohypermetropia.

  12. Visual evoked potentials (VEP and visual acuity improvement after cytidine 52 -diphosphocholine (CDP-Choline therapy in amblyopic patient

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    Regina Halfeld Furtado de Mendonça

    2012-10-01

    Full Text Available Citicoline may be used in many neurological disorders. Combined treatment of citicoline with patching in amblyopia has previously been researched. The purpose of this paper is to illustrate the effect of citicoline in non-patching amblyopic patient. A 11-year-old amblyopic boy underwent complete ophthalmological examinations, including VEP with flash and pattern stimulus. Two averages of 100 sweep were performed for flash stimulus. Pattern reversal stimulus obtained with high contrast was performed with 60', 30' and 15' checks stimuli. The VEP was repeated 90 days later after a therapy with citicoline and vitamin and the results compared with the responses of the previous recording session. The visual acuity (VA was 0,7 in the RE and 1,0 in the LE. The VEP pattern amplitude was normal in both eyes. Delayed in latency was detected for all spatial frequency stimulus (SFS in the RE. Delay in latency was detected only for high SFS in the LE. After the treatment, the VA was 1,0 in both eyes. The latency was normalized with low SFS on the RE and with high SFS on the LE. The flash VEP was normal before and after the therapy. In conclusion, the citicoline demonstrated that it was effective in the treatment of amblyopic eye without patching. The VA and the VEP latency improvement demonstrated that the citicoline enhance the transmission of the electric impulse from retina to visual cortex. Further research is required to understand the immediate and long-term effect of coline treatment in amblyopic patients.

  13. Visual acuity at 10 years in Cryotherapy for Retinopathy of Prematurity (CRYO-ROP) study eyes: effect of retinal residua of retinopathy of prematurity.

    Science.gov (United States)

    Dobson, Velma; Quinn, Graham E; Summers, C Gail; Hardy, Robert J; Tung, Betty

    2006-02-01

    To describe recognition (letter) acuity at age 10 years in eyes with and without retinal residua of retinopathy of prematurity (ROP). Presence and severity of ROP residua were documented by a study ophthalmologist. Masked testers measured monocular recognition visual acuity (Early Treatment of Diabetic Retinopathy Study) when the children were 10 years old. Two hundred forty-seven of 255 surviving Cryotherapy for Retinopathy of Prematurity (CRYO-ROP) randomized trial patients participated. A reference group of 102 of 104 Philadelphia-based CRYO-ROP study participants who did not develop ROP was also tested. More severe retinal residua were associated with worse visual acuity, regardless of whether retinal ablation was performed to treat the severe acute-phase ROP. However, within each ROP residua category, there was a wide range of visual acuity results. This is the first report of the relation between visual acuity (Early Treatment of Diabetic Retinopathy Study charts) and structural abnormalities related to ROP in a large group of eyes that developed threshold ROP in the perinatal period. Visual deficits are greater in eyes with more severe retinal residua than in eyes with mild or no residua. However, severity of ROP residua does not predict the visual acuity of an individual eye because within a single residua category, acuity may range from near normal to blind.

  14. A contralateral eye study comparing apodized diffrative and full diffrative lenses: wavefront analysis and distance and near uncorrected visual acuity

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    Marcony Rodrigues de Santhiago

    2009-01-01

    Full Text Available PURPOSE: To evaluate intraindividual visual acuity, wavefront errors and modulation transfer functions in patients implanted with two diffractive multifocal intraocular lenses. METHODS: This prospective study examined 40 eyes of 20 cataract patients who underwent phacoemulsification and implantation of a spherical multifocal ReSTOR intraocular lens in one eye and an aspheric Tecnis ZM900 multifocal intraocular lens in the other eye. The main outcome measures, over a 3-month follow-up period, were the uncorrected photopic distance and near visual acuity and the defocus curve. The visual acuity was converted to logMAR for statistical analysis and is presented in decimal scale. The wavefront error and modulation transfer function were also evaluated in both groups. RESULTS: At the 3-month postoperative visit, the mean photopic distance uncorrected visual acuity (UCVA was 0.74 ± 0.20 in the ReSTOR group and 0.76 ± 0.22 in the Tecnis group (p=0.286. The mean near UCVA was 0.96 ± 0.10 in the ReSTOR group and 0.93 ± 0.14 in the Tecnis group (p=0.963. The binocular defocus curve showed measurements between the peaks better than 0.2 logMAR. The total aberration, higher-order aberration and coma aberration were not significantly different between the groups. The spherical aberration was significantly lower in the Tecnis group than in the ReSTOR group. (p=0.004. Both groups performed similarly for the modulation transfer function. CONCLUSION: The ReSTOR SN60D3 and Tecnis ZM 900 intraocular lenses provided similar photopic visual acuity at distance and near. The diffractive intraocular lenses studied provided a low value of coma and spherical aberrations, with the Tecnis intraocular lens having a statistically lower spherical aberration compared to the ReSTOR intraocular lens. In the 5 mm pupil diameter analyses, both intraocular lens groups showed similar modulation transfer functions.

  15. A comparison of two methods of logMAR visual acuity data scoring for statistical analysis

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    O. A. Oduntan

    2009-12-01

    Full Text Available The purpose of this study was to compare two methods of logMAR visual acuity (VA scoring. The two methods are referred to as letter scoring (method 1 and line scoring (method 2. The two methods were applied to VA data obtained from one hundred and forty (N=140 children with oculocutaneous albinism. Descriptive, correlation andregression statistics were then used to analyze the data.  Also, where applicable, the Bland and Altman analysis was used to compare sets of data from the two methods.  The right and left eyes data were included in the study, but because the findings were similar in both eyes, only the results for the right eyes are presented in this paper.  For method 1, the mean unaided VA (mean UAOD1 = 0.39 ±0.15 logMAR. The mean aided (mean ADOD1 VA = 0.50 ± 0.16 logMAR.  For method 2, the mean unaided (mean UAOD2 VA = 0.71 ± 0.15 logMAR, while the mean aided VA (mean ADOD2 = 0.60 ± 0.16 logMAR. The range and mean values of the improvement in VA for both methods were the same. The unaided VAs (UAOD1, UAOD2 and aided (ADOD1, ADOD2 for methods 1 and 2 correlated negatively (Unaided, r = –1, p<0.05, (Aided, r = –1, p<0.05.  The improvement in VA (differences between the unaided and aided VA values (DOD1 and DOD2 were positively correlated (r = +1, p <0.05. The Bland and Altman analyses showed that the VA improvement (unaided – aided VA values (DOD1 and DOD2 were similar for the two methods. Findings indicated that only the improvement in VA could be compared when different scoring methods are used. Therefore the scoring method used in any VA research project should be stated in the publication so that appropriate comparisons could be made by other researchers.

  16. Analysis of laser photocoagulation with cataract surgery for improvement of visual acuity and macular edema in patients with cataract and diabetic macular edema

    Directory of Open Access Journals (Sweden)

    Chao-Yu Wang

    2016-02-01

    Full Text Available AIM:To explore laser photocoagulation with cataract surgery for improvement of visual acuity and macular edema in patients with cataract and diabetic macular edema.METHODS:A total of 60 patients(72 eyesfrom January 2014 to July 2015 in our hospital were selected, which all were diagnosed as cataract with diabetic macular edema. According to a random number table method, the patients were divided into observation group and control group, 30 cases(36 eyesin each group. The observation group was treated with combination therapy of laser photocoagulation before cataract surgeries, while the control group with the combination therapy of laser photocoagulation after cataract surgeries. At 2mo after surgeries, some routine examination, such as visual acuity, fundus examination after mydriasis, slit lamp examination, optical coherence tomography(OCTexamination, fluorescence angiography examination(FFAfor retinal blood vessels were applied in all the patients. RESULTS:The visual acuity of the observation group and the control group before treatments was not significantly different(P>0.05. At 2mo after treatments, the visual inspection showed that compared with the visual acuity before treatment, the visual acuity of the two groups were both significantly improved(PPP>0.05. At 2mo after treatments, compared with those before treatments, the macular thickness of two groups were both significantly improved(PPCONCLUSION:The laser photocoagulation before cataract surgery for patients with cataract and diabetic macular edema can significantly improve their visual acuity and macular thickness.

  17. Examining Effects of Physical Exertion on the Dynamic Visual Acuity Test in Collegiate Athletes.

    Science.gov (United States)

    Patterson, Jessie N; Murphy, Anna M; Honaker, Julie A

    2017-01-01

    Acute symptoms of dizziness and/or imbalance commonly experienced in athletes postconcussion are speculated to arise from dysfunction at multiple levels (i.e., inner ear or central vestibular system) to appropriately integrate afferent sensory information. Disruption along any pathway of the balance system can result in symptoms of dizziness, decreased postural control function (vestibulospinal reflex), and reduced vestibulo-ocular reflex function. This may also lead to decreased gaze stability with movements of the head and may account for symptoms of blurred vision or diplopia reported in almost half of athletes sustaining a concussion. Current concussion position statements include measures of postural control to examine changes to the balance system postconcussion. The Balance Error Scoring System (BESS) is a commonly used low-cost postural control measure for concussion assessment. Although this is a widely used measure for documenting balance function on both immediate (sideline) and recovery monitoring, the BESS has been shown to be affected by physical exertion. Therefore, the BESS may not be the most efficient means of examining functional changes to the balance system immediately after head injury. Dynamic Visual Acuity Test (DVAT) has been found to effectively evaluate and monitor changes to the gaze stability system postinjury. Thus, DVAT may be an additional measure in the concussion assessment battery, as well as an alternative for more immediate sideline assessment to help make objective return-to-play decisions. The aim of the study was to determine the effects of physical exertion on a clinical vestibular assessment, the DVAT, in collegiate athletes, as a first step in defining the role of this measure in the concussion assessment battery. Cross-sectional, repeated-measures design. Twenty-eight healthy collegiate athletes (20 males, 8 females; age = 20.25 ± 1.46 yr, range = 18-25 yr) volunteered to participate in the study. Participants were

  18. THAI-SPICE: Testbed for High-Acuity Imaging – Stable Photometry and ImageMotion Compensation Experiment

    Science.gov (United States)

    Young, Eliot

    THAI-SPICE is the Testbed for High-Acuity Imaging - Stable Photometry and ImageMotion Compensation Experiment - It is a lead proposal, accompanied by a coInstitutional proposal from MIT LL. The overarching goal of THAI-SPICE is to advance balloonborne telescopes to the point where they can surpass HST in terms of spatial resolution in visible wavelengths and surpass the Kepler mission in terms of observing exoplanet transits. Balloon-borne telescopes are becoming an important part of NASA's observing programs - each 100-day super-pressure balloon flight will provide 1000 hours of dark time observing, equivalent to about 1/3 of the total on-target time allocated in an HST cycle across its entire portfolio of science programs. However, balloon-borne telescopes face unique challenges from the stratospheric thermal environment and the pointing stability of a suspended platform. This proposal will study and test three areas of development that will enable high-acuity image quality and stable photometry from balloon-borne telescopes. - Passive thermal control and stabilization of balloon-borne OTAs (Optical Tube Assemblies). Recent modeling suggests that an appropriate arrangement of sunshields, earth-shields and telescope insulation can reduce diurnal temperature excursions from more than 40°C to less than 2°C. Furthermore, modeling also suggests that the steadystate temperature of an OTA can be reduced to temperatures near 180 K, an advantage for infrared observing programs. However, most modeling packages (e.g., Thermal Desktop) do not accurately account for convection in the 3 torr or 8 torr environment of zeropressure or super-pressure balloons. In fact, it is hard to tell whether radiation or convection is a more significant cooling mechanism at super-pressure balloon altitudes. We propose to verify or update Thermal Desktop results with a series of experiments using an instrumented OTA and sun- and earth-shields. The payoff from this experiment will be balloon

  19. Lrit1, a Retinal Transmembrane Protein, Regulates Selective Synapse Formation in Cone Photoreceptor Cells and Visual Acuity

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    Akiko Ueno

    2018-03-01

    Full Text Available Summary: In the vertebrate retina, cone photoreceptors play crucial roles in photopic vision by transmitting light-evoked signals to ON- and/or OFF-bipolar cells. However, the mechanisms underlying selective synapse formation in the cone photoreceptor pathway remain poorly understood. Here, we found that Lrit1, a leucine-rich transmembrane protein, localizes to the photoreceptor synaptic terminal and regulates the synaptic connection between cone photoreceptors and cone ON-bipolar cells. Lrit1-deficient retinas exhibit an aberrant morphology of cone photoreceptor pedicles, as well as an impairment of signal transmission from cone photoreceptors to cone ON-bipolar cells. Furthermore, we demonstrated that Lrit1 interacts with Frmpd2, a photoreceptor scaffold protein, and with mGluR6, an ON-bipolar cell-specific glutamate receptor. Additionally, Lrit1-null mice showed visual acuity impairments in their optokinetic responses. These results suggest that the Frmpd2-Lrit1-mGluR6 axis regulates selective synapse formation in cone photoreceptors and is essential for normal visual function. : Ueno et al. finds that Lrit1 plays an important role in regulating the synaptic connection between cone photoreceptors and cone ON-bipolar cells. The Frmpd2-Lrit1-mGluR6 axis is crucial for selective synapse formation in cone photoreceptors and for development of normal visual function. Keywords: retina, circuit, synapse formation, cone photoreceptor cell, ON-bipolar cell, visual acuity

  20. A new specialized visual acuity chart for amblyopic children aged 3-5 years old:development and its clinical applications

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    Yang-Qing Huang

    2013-12-01

    Full Text Available AIM: To introduce a new specialized visual acuity chart for amblyopic children aged 3-5 years old and its clinical applications.METHODS:The new visual acuity chart and notations were designed based on Weber-Fechner law. The optotypes were red against a white background and were specially shaped four basic geometric symbols:circle, square, triangle,and cross. A regular geometric progression of the optotype sizes and distribution was employed to arrange in 14 lines. The progression rate of the optotype size between two lines was 1.2589 and the testing distance was 3m. Visual acuity score could be recorded as logMAR notation or decimal notation. Age-stratified diagnostic criteria for amblyopia established by consensus statement on diagnosis of amblyopia (2011 among members of the Strabismus and Pediatric Ophthalmology Group, Ophthalmology Society, Chinese Medical Association (SPOGOSCMA were illustrated in the new visual acuity chart.RESULTS: When assessing visual acuity in children aged 3-5 years old, this new visual acuity chart that consists of four symmetrical shapes (triangle, square, cross, and circle overcame an inability to recognize the letters of the alphabet and difficulties in designating the direction of black abstract symbols such as the tumbling ‘E’ or Landolt ‘C’, which the subjects were prone to lose interest in. The visual acuity score may be recorded in different notations:decimal acuity and logMAR. These two notations can be easily converted each other in the new eye chart. The measurements of this new chart not only showed a significant correlation and a good consistency with the international standard logarithmic visual acuity chart (r=0.932, P<0.01, but also indicated a high test-retest reliability (89% of retest scores were within 0.1logMAR units of the initial test score.CONCLUSION: The results of this study support the validity and reliability of distance visual acuity measurements using the new eye chart in

  1. Correlation between observation task performance and visual acuity, contrast sensitivity and environmental light in a simulated maritime study.

    Science.gov (United States)

    Koefoed, Vilhelm F; Assmuss, Jörg; Høvding, Gunnar

    2018-03-25

    To examine the relevance of visual acuity (VA) and index of contrast sensitivity (ICS) as predictors for visual observation task performance in a maritime environment. Sixty naval cadets were recruited to a study on observation tasks in a simulated maritime environment under three different light settings. Their ICS were computed based on contrast sensitivity (CS) data recorded by Optec 6500 and CSV-1000E CS tests. The correlation between object identification distance and VA/ICS was examined by stepwise linear regression. The object detection distance was significantly correlated to the level of environmental light (p maritime environment may presumably be ascribed to the normal and uniform visual capacity in all our study subjects. © 2018 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  2. CLINICAL PRESENTATION OF LENS INDUCED GLAUCOMA: STUDY OF EPIDEMIOLOGY, DURATION OF SYMPTOMS, INTRAOCULAR PRESSURE AND VISUAL ACUITY

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    Venkataratnam

    2015-10-01

    Full Text Available BACKGROUND: Lens Induced Glaucoma is a common cause of ocular morbidity. OBJECTIVES: Our study was to know the Epidemiological factors, Duration of Symptoms, Visual Acuity and Intraocular Pressure in the clinical Presentation of Lens Induced Glaucoma. MATERIALS AND METHODS : This w as a tertiary hospital based prospective study in the department of Glaucoma, Sarojini Devi Eye Hospital and Regional Institute of Ophthalmology (RIO, Osmania Medical College, Hyderabad over a period from March 2015 to August 2015. 50 Patients clinically diagnosed as Lens Induced Glaucoma (LIG were studied with the data of Age, Sex, literacy, Laterality and Rural / Urban status with the duration of symptoms, Intraocular pressure and Visual Acuity. The data was analyzed by simple statistical methods. RESULT S: 50 patients, clinically diagnosed as Lens Induced Glaucoma (LIG were studied. Age group distribution was 1(2.0% in 40 - 50yrs, 13 ( 26.0% in >50 - 60yrs, 26(52.0% in >60 - 70yrs and 10(20.0% in > 70 yrs. Sex distribution was 23(46.0% of Males and 27(54.0% of Females. Urban / Rural status was 15(30.0% of Urban and 35(70.0% of Rural. Literacy status was 7(14.0% of Literate and 43(86.0% of Illiterate. Laterality was RE in 24(48.0% and LE in 26(52.0%. Duration of the presenting symptoms before re porting to the Hospital was 12.0% in 2wks. Intraocular pressure (IOP in mm of Hg showed no case (0.0% in 20 – 40, 27(54.0% in >40 - 60 and 5(10.0% >60 wit h the Mean IOP of 42.12 mm of Hg. Visual Acuity (VA was PL +ve in 24(48.0 and HM - 3/60. CONCLUSIONS: Increasing age, female gender, rural, illiterate, and delayed reporting to the hospital after the pre senting symptoms were the common risk factors with increased Intraocular pressure and poor visual acuity in the clinical presentation of Lens induced Glaucoma.

  3. To Further the Near-Vision Visual Acuity Tests (3): For a Test Which Saves Time, Labor, and Expenses

    OpenAIRE

    高橋, ひとみ; 川端, 秀仁; 衞藤, 隆

    2014-01-01

    The Ministry of Education, Culture, Sports, Science and Technology of Japan has its advisory board to review the list of medical checkup for school children every ten years. In August 2013 the board found that there was a considerable number of school children who had poor near vision and thus learn in the class less efficiently. The board recommended that the Ministry consider whether to include a near-vision visual acuity test in a regular medical examination at school. It may not be known ...

  4. Acuidade visual em implantes bilaterais de lentes intra-oculares monofocais e multifocais Visual acuity of bilateral implants of monofocal and multifocal intraocular lenses

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    Leonardo Akaishi

    2003-01-01

    Full Text Available OBJETIVO: Comparar a acuidade visual de longe e perto de pacientes submetidos à facoemulsificação binocular não simultânea com implante de lentes multifocais ou monofocais. MÉTODOS: Foram selecionados 20 pacientes com lentes multifocais bilaterais e outros 20 pacientes com lentes monofocais também bilaterais, com acuidade visual sem correção melhor ou igual a 0,63 (20/30, medidos separadamente, nos três primeiros meses de pós-operatório. Foi medida a acuidade visual para longe e perto com e sem correção e testes de sensibilidade ao contraste e ofuscamento. RESULTADOS: A acuidade visual sem correção para longe no grupo das monofocais teve média de 0,82 (DP± 0,16 e no grupo das multifocais, 0,94 (DP±0,12, valor de p 0,001. Os dois grupos de lentes tiveram visão com correção para longe igual a 1. No grupo das multifocais, 75% tiveram J1 e 100% tiveram J3 ou melhor sem correção. No grupo das lentes monofocais, 10% tiveram J1 e 70% tiveram J3 ou melhor sem correção. Não houve diferença significante na avaliação com o teste de sensibilidade ao contraste entre os grupos pesquisados. No teste de ofuscamento, os dois grupos tiveram redução da visão, que foi mais acentuada no grupo dos pacientes com lentes multifocais. CONCLUSÃO: A acuidade visual para longe com correção nos pacientes com implante multifocal foi semelhante a dos pacientes com implantes monofocais, embora a acuidade visual para perto no grupo em que foi implantado lente multifocal foi bastante superior ao grupo da lente monofocal. A sensibilidade ao contraste manteve-se semelhante nos dois grupos, já o ofuscamento ("glare test" no grupo multifocal foi maior que no grupo monofocal.PURPOSE: To compare distant and near visual acuity between patients submitted to bilateral nonsimultaneous facoemulsification and implantation of multifocal or monofocal intraocular lenses (IOL. METHODS: Twenty patients with bilateral multifocal IOL and 20 patients with

  5. Visual stimulus parameters seriously compromise the measurement of approximate number system acuity and comparative effects between adults and children

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    Denes eSzucs

    2013-07-01

    Full Text Available It has been suggested that a simple non-symbolic magnitude comparison task is sufficient to measure the acuity of a putative Approximate Number System (ANS. A proposed measure of the ANS, the so-called 'internal Weber fraction' (w, would provide a clear measure of ANS acuity. However, ANS studies have never presented adequate evidence that the visual stimulus parameters did not compromise measurements of w to such extent that w is actually driven by visual instead of numerical processes. We therefore investigated this question by testing non-symbolic magnitude discrimination in seven-year-old children and adults. We controlled for visual parameters in a more stringent manner than usual. As a consequence of these controls, in some trials numerical cues correlated positively with number while in others they correlated negatively with number. This congruency effect strongly correlated with w, which means that congruency effects were probably driving effects in w. Consequently, in both adults and children congruency had a major impact on the fit of the model underlying the computation of w. Furthermore, children showed larger congruency effects than adults. This suggests that ANS tasks are seriously compromised by the visual stimulus parameters, which cannot be controlled. Hence, they are not pure measures of the ANS and some putative w or ratio effect differences between children and adults in previous ANS studies may be due to the differential influence of the visual stimulus parameters in children and adults. In addition, because the resolution of congruency effects relies on inhibitory (interference suppression function, some previous ANS findings were probably influenced by the developmental state of inhibitory processes especially when comparing children with developmental dyscalculia and typically developing children.

  6. Higher-order aberrations and best-corrected visual acuity in Native American children with a high prevalence of astigmatism.

    Science.gov (United States)

    Miller, Joseph M; Harvey, Erin M; Schwiegerling, Jim

    2015-08-01

    To determine whether higher-order aberrations (HOAs) in children from a highly astigmatic population differ from population norms and whether HOAs are associated with astigmatism and reduced best-corrected visual acuity. Subjects were 218 Tohono O'odham Native American children 5-9 years of age. Noncycloplegic HOA measurements were obtained with a handheld Shack-Hartmann sensor (SHS). Signed (z06s to z14s) and unsigned (z06u to z14u) wavefront aberration Zernike coefficients Z(3,-3) to Z(4,4) were rescaled for a 4 mm diameter pupil and compared to adult population norms. Cycloplegic refraction and best-corrected logMAR letter visual acuity (BCVA) were also measured. Regression analyses assessed the contribution of astigmatism (J0) and HOAs to BCVA. The mean root-mean-square (RMS) HOA of 0.191 ± 0.072 μm was significantly greater than population norms (0.100 ± 0.044 μm). All unsigned HOA coefficients (z06u to z14u) and all signed coefficients except z09s, z10s, and z11s were significantly larger than population norms. Decreased BCVA was associated with astigmatism (J0) and spherical aberration (z12u) but not RMS coma, with the effect of J0 about 4 times as great as z12u. Tohono O'odham children show elevated HOAs compared to population norms. Astigmatism and unsigned spherical aberration are associated with decreased acuity, but the effects of spherical aberration are minimal and not clinically significant. Copyright © 2015 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

  7. Interocular Shift of Visual Attention Enhances Stereopsis and Visual Acuities of Anisometropic Amblyopes beyond the Critical Period of Visual Development: A Novel Approach

    Directory of Open Access Journals (Sweden)

    Liwen Huang

    2014-01-01

    Full Text Available Aims. Increasing evidence shows that imbalanced suppressive drive prior to binocular combination may be the key factor in amblyopia. We described a novel binocular approach, interocular shift of visual attention (ISVA, for treatment of amblyopia in adult patients. Methods. Visual stimuli were presented anaglyphically on a computer screen. A square target resembling Landolt C had 2 openings, one in red and one in cyan color. Through blue-red goggles, each eye could only see one of the two openings. The patient was required to report the location of the opening presented to the amblyopic eye. It started at an opening size of 800 sec of arc, went up and down in 160 sec of arc step, and stopped when reaching the 5th reversals. Ten patients with anisometropic amblyopia older than age 14 (average age: 26.7 were recruited and received ISVA treatment for 6 weeks, with 2 training sessions per day. Results. Both Titmus stereopsis (z=-2.809, P=0.005 and Random-dot stereopsis (z=-2.317, P=0.018 were significantly improved. Average improvement in best corrected visual acuity (BCVA was 0.74 line (t=5.842, P<0.001. Conclusions. The ISVA treatment may be effective in treating amblyopia and restoring stereoscopic function.

  8. Posttreatment visual acuity in patients treated with episcleral plaque therapy for choroidal melanomas: dose and dose rate effects

    International Nuclear Information System (INIS)

    Jones, Robert; Gore, Elizabeth; Mieler, William; Murray, Kevin; Gillin, Michael; Albano, Katherine; Erickson, Beth

    2002-01-01

    Purpose: To determine the relationship between the long-term visual function and the dose and dose rates delivered to critical ocular structures in patients with choroidal melanoma treated with 125 I episcleral plaque radiotherapy. Methods and Materials: From 1987 to 1994, 63 patients underwent 125 I episcleral plaque (Collaborative Ocular Melanoma Study [COMS] design) application for the treatment of choroidal melanoma. The mean tumor height was 4.5 mm (range 1.7-8.3). Doses and dose rates at the tumor apex, macula, and optic disc were calculated. Forty-three records were scored to assess whether a decrease in visual acuity of >2 lines on a standard Snellen eye chart had occurred. Patient age and the presence of hypertension or diabetes were noted. Statistical analysis was performed to assess both the rate at which visual decline had occurred and the presence of significant factors that had contributed to this decline. Results: With a median follow-up of 36 months, the 3-year actuarial survival rate was 93.6%. The 3-year actuarial local control rate was 86.9%. The median time to visual loss after therapy was 18.7 months. The 3-year actuarial rate of visual preservation was 40.5%. Multivariate analysis demonstrated higher macula dose rates (p=0.003) to forecast visual decline. Macula dose rates of 111±11.1 cGy/h were associated with a 50% risk of significant visual loss. Conclusion: Patients in our series treated with 125 I plaque brachytherapy for choroidal melanoma experienced favorable tumor control, but with a measurable incidence of visual decline. Higher dose rates to the macula correlated strongly with poorer posttreatment visual outcome. This information may be valuable in selecting the optimal dose rates to treat choroidal melanomas and to predict the risk of visual decline

  9. A pilot trial of the iPad tablet computer as a portable device for visual acuity testing.

    Science.gov (United States)

    Zhang, Zhao-tian; Zhang, Shao-chong; Huang, Xiong-gao; Liang, Ling-yi

    2013-01-01

    We evaluated the accuracy of an app for the iPad tablet computer (Eye Chart Pro) as a portable method of visual acuity (VA) testing. A total of 120 consecutive patients (240 eyes) underwent visual acuity test with an iPad 2 and a conventional light-box chart. The logMAR VA results from the iPad were significantly higher than those from the light-box (P iPad chart and the light-box chart, with 95% limits of agreement of -0.14 to 0.19. Two groups of patients were defined: in Group 1 there were 182 eyes with VA better than 0.1 according to the light-box VA test. The median logMAR VA by the iPad was 0.54 and by the light-box chart it was 0.52; there was no significant difference between them (P = 0.69). In Group 2 there were 58 eyes with VA equal to or worse than 0.1 according to the light-box VA test. The median logMAR VA by the iPad was 1.26 and was 1.10 by the light box; the result from the iPad was significantly lower (P iPad is reliable for VA testing only when the Snellen VA is better than 0.1 (20/200).

  10. Femtosecond-Assisted LASIK Versus PRK: Comparison of 6-Month Visual Acuity and Quality Outcome for High Myopia.

    Science.gov (United States)

    Hashemi, Hassan; Miraftab, Mohammad; Ghaffari, Reza; Asgari, Soheila

    2016-11-01

    To compare the results of femtosecond-assisted laser in situ keratomileusis (femto-LASIK) and photorefractive keratectomy with mitomycin C (PRK-MMC) for the correction of myopia more than 7.0 diopters (D). In this comparative nonrandomized trial, 60 eyes (30 eyes in each group) were enrolled. Patients were tested for uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction spherical equivalent, ocular and corneal aberrations, and contrast sensitivity (CS) before surgery and at 3 and 6 months postoperatively. Mean preoperative myopia was -8.65±1.51 and -8.04±1.70 D in the femto-LASIK and PRK-MMC groups, respectively (P=0.149). Intergroup differences in baseline indices were not statistically significant. At 6 months after surgery, UDVA showed an improving trend, but it was better in the femto-LASIK group (P=0.026). CDVA in the two groups remained similarly unchanged (P=0.170). For the femto-LASIK and PRK-MMC groups, the safety indices were 1.01±0.05 and 1.01±0.14 (P=0.949), respectively, and the efficacy indices were 0.99±0.07 and 0.93±0.22 (P=0.192), respectively. Comparing CS, only CS18 showed a significantly greater decrease in the femto-LASIK group compared with the PRK-MMC group (P=0.016). Intergroup differences were not statistically significant in other spatial frequencies. Changes in the ocular and corneal higher order aberrations were not statistically different between the two groups except ocular coma, which increased in the femto-LASIK group (P=0.041). Femto-LASIK improves UDVA better than PRK-MMC in high myopia. However, because of increased coma, the quality of vision is reduced. In other words, visual acuity outcome is better with femto-LASIK and visual quality outcome is better with PRK-MMC.

  11. Oregon State University Softball: Dynamic Visual Acuity Training for Improving Performance

    OpenAIRE

    Madsen, Bruce; Blair, Kyle

    2017-01-01

    Sports vision training involves eye focusing and movement workouts that center on the visual tracking of objects. The purpose of sports vision training is to improve performance in various sports by improving visual responses and processing, such as by lowering reaction times. In 2015, the Athletic Eye Institute started a sports vision-training program study with the Oregon State University Softball Team in the hopes of increasing the dynamic visual skills of their players. There were two aim...

  12. Uncorrected visual acuity in the immediate postoperative period following uncomplicated cataract surgery: bimanual microincision cataract surgery versus standard coaxial phacoemulsification.

    LENUS (Irish Health Repository)

    Saeed, Ayman

    2012-02-01

    AIM: We compared bimanual microincision cataract surgery (MICS) and standard coaxial phacoemulsification (CAP) in terms of uncorrected visual acuity (UCVA) recorded 1 h and 2 weeks postoperatively. METHODS: This was a prospective, nonrandomised comparative study. All MICS procedures were performed by one surgeon (MGM), and all CAP procedures were performed by another surgeon (SB). Eyes with visually consequential ocular morbidity were excluded. The primary outcome measure was UCVA recorded 1 h postoperatively. RESULTS: One hundred eyes underwent MICS and CAP (50 eyes in each group). The treatment groups did not differ significantly in terms of preoperative mean best corrected visual acuity (6\\/24 +\\/- 4.3 lines and 6\\/20 +\\/- 4.4 lines in the MICS and the CAP groups, respectively; P = 0.65). Also, there was no significant difference in terms of postoperative UCVA at 1 h or at 2 weeks (mean +\\/- standard deviation UCVA 1 h postoperatively: MICS: 6\\/36 +\\/- 5.7 lines; CAP: 6\\/30 +\\/- 4.7 lines; P = 0.80; UCVA 2 weeks postoperatively: MICS: 6\\/10 +\\/- 1.9 lines; CAP: 6\\/10 +\\/- 2.2 lines; P = 0.90). However, nine eyes (18%) and one eye (2%) achieved a UCVA of C6\\/12 at 1 h following MICS and CAP, respectively, and this difference was statistically significant (P = 0.02). CONCLUSION: Mean UCVA at 1 h and at 2 weeks following cataract surgery was not significantly different between eyes undergoing MICS and CAP. However, a greater proportion of patients achieved a UCVA of C6\\/12 following MICS when compared with CAP.

  13. Switching from pro re nata to treat-and-extend regimen improves visual acuity in patients with neovascular age-related macular degeneration.

    Science.gov (United States)

    Kvannli, Line; Krohn, Jørgen

    2017-11-01

    To evaluate the visual outcome after transitioning from a pro re nata (PRN) intravitreal injection regimen to a treat-and-extend (TAE) regimen for patients with neovascular age-related macular degeneration (AMD). A retrospective review of patients who were switched from a PRN regimen with intravitreal injections of bevacizumab, ranibizumab or aflibercept to a TAE regimen. The best corrected visual acuity (BCVA), central retinal thickness (CRT) and type of medication used at baseline, at the time of changing treatment regimen and at the end of the study were analysed. Twenty-one eyes of 21 patients met the inclusion criteria. Prior to the switch, the patients received a mean of 13.8 injections (median, 10; range, 3-39 injections) with the PRN regimen for 44 months (range, 3-100 months), which improved the visual acuity in five patients (24%). After a mean of 6.1 injections (median, 5; range, 3-14 injections) with the TAE regimen over 8 months (range, 2-16 months), the visual acuity improved in 12 patients (57%). The improvement in visual acuity during treatment with the TAE regimen was statistically significant (p = 0.005). The proportion of patients with a visual acuity of 0.2 or better was significantly higher after treatment with the TAE regimen than after treatment with the PRN regimen (p = 0.048). No significant differences in CRT were found between the two treatment regimens. Even after prolonged treatment and a high number of intravitreal injections, switching AMD patients from a PRN regimen to a strict TAE regimen significantly improves visual acuity. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  14. Femtosecond laser-assisted LASIK versus PRK for high myopia: comparison of 18-month visual acuity and quality.

    Science.gov (United States)

    Hashemi, Hassan; Ghaffari, Reza; Miraftab, Mohammad; Asgari, Soheila

    2017-08-01

    To compare 18-month outcomes between femtosecond laser-assisted LASIK (femto-LASIK) and photorefractive keratectomy with mitomycin-C (PRK-MMC) for myopia of more than 7.0 D in terms of visual acuity and quality. In this comparative nonrandomized clinical trial, 60 eyes from 30 patients (30 eyes in each group) were enrolled. The two procedures were compared in terms of 18-month changes in uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction spherical equivalent, ocular and corneal higher order aberrations (HOAs), and contrast sensitivity (CS). Mean myopia was -8.65 ± 1.51 and -8.04 ± 1.70 D (P = 0.149) and mean ablation depth was 109.37 ± 9.07 and 105.09 ± 12.59 µm (P = 0.138), in the femto-LASIK and PRK-MMC groups, respectively. Baseline parameters were not significantly different between the two groups (all P > 0.05). At 18 months postoperatively, 75 % in the femto-LASIK, versus 57.1 % in the PRK-MMC group, had 20/20 UDVA (P = 0.017). CDVA remained similarly unchanged in both groups (P = 0.616). No case had residual refractive error more than 1.0 D in the femto-LASIK group, while 33.5 % in the other group had more than 1.0 D residual error (P = 0.390). Changes in corneal HOA were not significantly different between the two groups (P = 0.260). Cases in the femto-LASIK group showed more increase in ocular HOA (P = 0.032) and coma (P = 0.083, power = 72 %). CS remained similarly unchanged in all spatial frequencies in both groups (all P > 0.05). Although femto-LASIK induces more HOA compared to PRK-MMC, considering outcomes in terms of 20/20 UDVA, residual refractive error, and CS stability, femto-LASIK provides more favorable results than PRK-MMC in high myopia.

  15. PROSPECTIVE EVALUATION OF VISUAL ACUITY AGREEMENT BETWEEN STANDARD EARLY TREATMENT DIABETIC RETINOPATHY STUDY CHART AND A HANDHELD EQUIVALENT IN EYES WITH RETINAL PATHOLOGY.

    Science.gov (United States)

    Rahimy, Ehsan; Reddy, Sahitya; DeCroos, Francis Char; Khan, M Ali; Boyer, David S; Gupta, Omesh P; Regillo, Carl D; Haller, Julia A

    2015-08-01

    To evaluate the visual acuity agreement between a standard back-illuminated Early Treatment Diabetic Retinopathy Study (ETDRS) chart and a handheld internally illuminated ETDRS chart. Two-center prospective study. Seventy patients (134 eyes) with retinal pathology were enrolled between October 2012 and August 2013. Visual acuity was measured using both the ETDRS chart and the handheld device by masked independent examiners after best protocol refraction. Examination was performed in the same room under identical illumination and testing conditions. The mean number of letters seen was 63.0 (standard deviation: 19.8 letters) and 61.2 letters (standard deviation: 19.1 letters) for the ETDRS chart and handheld device, respectively. Mean difference per eye between the ETDRS and handheld device was 1.8 letters. A correlation coefficient (r) of 0.95 demonstrated a positive linear correlation between ETDRS chart and handheld device measured acuities. Intraclass correlation coefficient was performed to assess the reproducibility of the measurements made by different observers measuring the same quantity and was calculated to be 0.95 (95% confidence interval: 0.93-0.96). Agreement was independent of retinal disease. The strong correlation between measured visual acuity using the ETDRS and handheld equivalent suggests that they may be used interchangeably, with accurate measurements. Potential benefits of this device include convenience and portability, as well as the ability to assess ETDRS visual acuity without a dedicated testing lane.

  16. The Advanced Glaucoma Intervention Study (AGIS): 12. Baseline risk factors for sustained loss of visual field and visual acuity in patients with advanced glaucoma.

    Science.gov (United States)

    2002-10-01

    To examine the relationships between baseline risk factors and sustained decrease of visual field (SDVF) and sustained decrease of visual acuity (SDVA). Cohort study of participants in the Advanced Glaucoma Intervention Study (AGIS). This multicenter study enrolled patients between 1988 and 1992 and followed them until 2001; 789 eyes of 591 patients with advanced glaucoma were randomly assigned to one of two surgical sequences, argon laser trabeculoplasty (ALT)-trabeculectomy-trabeculectomy (ATT) or trabeculectomy-ALT-trabeculectomy (TAT). This report is based on data from 747 eyes. Eyes were offered the next intervention in the sequence upon failure of the previous intervention. Failure was based on recurrent intraocular pressure elevation, visual field defect, and disk rim criteria. Study visits occurred every 6 months; potential follow-up ranged from 8 to 13 years. For each intervention sequence, Cox multiple regression analyses were used to examine the baseline characteristics for association with two vision outcomes: SDVF and SDVA. The magnitude of the association is measured by the hazard ratio (HR), where HR for binary variables is the relative change in the hazard (or risk) of the outcome in eyes with the factor divided by the hazard in eyes without the factor, and HR for continuous variables is the relative change in the hazard (or risk) of the outcome in eyes with a unit increase in the factor. Characteristics associated with increased SDVF risk in the ATT sequence are: less baseline visual field defect (hazard ratio [HR] = 0.86, P <.001, 95% CI = 0.82-0.90), male gender (HR = 2.23, P <.001, 1.54-3.23), and worse baseline visual acuity (HR = 0.96, P =.001, 0.94-0.98); in the TAT sequence: less baseline visual field defect (HR = 0.93, P =.001, 0.89-0.97) and diabetes (HR = 1.87, P =.007, 1.18-2.97). Characteristics associated with increased SDVA risk in both treatment sequences are better baseline acuity (ATT: HR = 1.05, P <.001, 1.02-1.09; TAT: HR = 1

  17. Changes in visual acuity in patients with malignant melanoma of the uvea treated with stereotactic radiosurgery (presentation)

    International Nuclear Information System (INIS)

    Mackova, K.; Waczultkova, I.; Furdova, Ad.; Furdova, Al.

    2013-01-01

    The goal was to assess the changes in visual acuity before and after 6 months of treatment, depending on the dose in risk structures (lens, optic nerve). This is a retrospective study of 19 patients group treated in 2011. The average age of the group was (57.3 ± 12.4) years (31-73 years). The analysis of the studied group did not demonstrate dependence of the tumour presence on gender. Higher prevalence of tumours was observed in the elderly population. Considered relationship of worse diagnosis with higher age (r = 0.39; p = 0.13) we could not prove to be significant due to the small group of patients. The median of melanoma volume was 0.77 cm 3 (0.11 to 1.76 cubic centimetres). The mean dose applied to melanoma was 37.34 Gy (Gy 36.74 to 44.65).

  18. The Effects of Ramadan Fasting on Anterior Segment Parameters, Visual Acuity and Intraocular Pressures of the Eye.

    Science.gov (United States)

    Selver, Ozlem Barut; Palamar, Melis; Gerceker, Kevser; Egrilmez, Sait; Yagci, Ayse

    2017-01-01

    It is aimed to determine whether fasting during Ramadan has any significant effect on anterior chamber parameters, visual acuity and intraocular pressures. 31 fasting (Group 1) and 30 non-fasting healthy volunteers (Group 2) were enrolled. All cases underwent an ophthalmological examination and anterior segment parameter evaluation (central corneal thickness (CCT), anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA), pupil size) with Pentacam before and after the breaking of the Ramadan fast in Group 1, before and after dinner in Group 2. The mean age was 43.35 ± 13.20 in Group 1, 43.17 ± 12.90 in Group 2 (p= 0.955). No significant difference was detected in any of the parameters in both groups. There is a need for more detailed and associated studies to understand better about the influence of Ramadan fast on various ocular parameters.

  19. Visual acuity and microperimetric mapping of lesion area in eyes with inflammatory cystoid macular oedema

    DEFF Research Database (Denmark)

    Munk, Marion R; Kiss, Christopher G; Huf, Wolfgang

    2014-01-01

    PURPOSE:   To evaluate the effect of fluid accumulation on local visual function in inflammatory cystoid-macular-edema (ICME). METHODS:   This cross-sectional study applied optical-coherence-tomography over a 12×12 fovea-centered field in 50 patients with ICME and mapped the extent of fluid-fille...... retinal layers also had major impact on both of these two functional parameters. Visual-impairment seems to differ depending on the layers involved, thus different types of fluid accumulation may potentially be given varying treatment priorities....

  20. Visual acuity and full-field electroretinography in patients with Usher's syndrome

    OpenAIRE

    Mendieta, Luana; Berezovsky, Adriana; Salomão, Solange Rios; Sacai, Paula Yuri; Pereira, Josenilson Martins; Fantini, Sérgio Costa

    2005-01-01

    A síndrome de Usher (SU) é doença autossômica recessiva caracterizada por perda auditiva neuro-sensorial acompanhada de retinose pigmentária (RP). OBJETIVO: Analisar a eletrorretinografia de campo total (ERG) e a acuidade visual (AV) em pacientes com síndrome de Usher tipos I e II. MÉTODOS: Foram estudadas as respostas da eletrorretinografia de campo total e a acuidade visual de 22 pacientes (idade média = 26,8±16,8 anos). Destes, 17 tinham síndrome de Usher tipo I e 5 tinham síndrome ...

  1. Association between changes in visual acuity and vision-related quality of life in Japanese patients with low vision.

    Science.gov (United States)

    Yanagisawa, Mieko; Kato, Satoshi; Kunimatsu, Shiho; Kobayashi, Megumi; Ochiai, Makiko

    2011-01-01

    To investigate the association between vision-related quality of life (VRQOL) and changes in visual acuity (VA). We examined the VA in 100 patients for > 1 year and evaluated the degree of its impact on VRQOL using the National Eye Institute Visual Function (VF) Questionnaire (VFQ-25; Japanese version). Before determining VFQ-25, we monitored the changes in VA in these patients for 1 year and classified them into the following two groups depending on VA changes. Patients exhibiting a decline of > 3 steps in VA, as assessed by the logarithm of the minimum angle of resolution scale, were placed in the 'decline' group (47.0%) and patients exhibiting no change in VA were placed in the 'no change' group (53.0%). We compared the VFQ-25 scores between both groups in all patients with glaucoma (GLA) and macular degeneration (MD). The total score of the decline was 34.9 ± 13.6 and that of the no change group was 44.6 ± 13.9: the difference in the scores between both groups was statistically significant (p = 0.006). Similar results were obtained for patients with GLA and MD (p = 0.007 and 0.003, respectively). VRQOL differed between patients with constant VA and those with reduced VA, even though VA values were equal at a certain time point. Copyright © 2010 S. Karger AG, Basel.

  2. Maternal fish oil supplementation in lactation: Effect on visual acuity and n-3 fatty acid content of infant erythrocytes

    DEFF Research Database (Denmark)

    Lauritzen, L.; Jørgensen, M.H.; Mikkelsen, T.B.

    2004-01-01

    of fish oil (FO) supplements in lactating mothers. In this double-blinded randomized trial, Danish mothers with habitual fish intake below the 50th percentile of the Danish National Birth Cohort were randomized to microencapsulated FO [1.3 g/d long-chain n-3 FA (n-3 LCPUFA)] or olive oil (00......). The intervention started within a week after delivery and lasted 4 mon. Mothers with habitual high fish intake and their infants were included as a reference group. Ninety-seven infants completed the trial (44 OO-group, 53 FO-group) and 47 reference infants were followed up. The primary outcome measures were: DHA...... content of milk samples (0, 2, and 4 mon postnatal) and of infant red blood cell (RBC) membranes (4 mon postnatal), and infant visual acuity (measured by swept visual evoked potential at 2 and 4 mon of age). FO supplementation gave rise to a threefold increase in the DHA content of the 4-mon milk samples...

  3. Lrit1, a Retinal Transmembrane Protein, Regulates Selective Synapse Formation in Cone Photoreceptor Cells and Visual Acuity.

    Science.gov (United States)

    Ueno, Akiko; Omori, Yoshihiro; Sugita, Yuko; Watanabe, Satoshi; Chaya, Taro; Kozuka, Takashi; Kon, Tetsuo; Yoshida, Satoyo; Matsushita, Kenji; Kuwahara, Ryusuke; Kajimura, Naoko; Okada, Yasushi; Furukawa, Takahisa

    2018-03-27

    In the vertebrate retina, cone photoreceptors play crucial roles in photopic vision by transmitting light-evoked signals to ON- and/or OFF-bipolar cells. However, the mechanisms underlying selective synapse formation in the cone photoreceptor pathway remain poorly understood. Here, we found that Lrit1, a leucine-rich transmembrane protein, localizes to the photoreceptor synaptic terminal and regulates the synaptic connection between cone photoreceptors and cone ON-bipolar cells. Lrit1-deficient retinas exhibit an aberrant morphology of cone photoreceptor pedicles, as well as an impairment of signal transmission from cone photoreceptors to cone ON-bipolar cells. Furthermore, we demonstrated that Lrit1 interacts with Frmpd2, a photoreceptor scaffold protein, and with mGluR6, an ON-bipolar cell-specific glutamate receptor. Additionally, Lrit1-null mice showed visual acuity impairments in their optokinetic responses. These results suggest that the Frmpd2-Lrit1-mGluR6 axis regulates selective synapse formation in cone photoreceptors and is essential for normal visual function. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  4. Examination of factors affecting gait properties in healthy older adults: focusing on knee extension strength, visual acuity, and knee joint pain.

    Science.gov (United States)

    Demura, Tomohiro; Demura, Shin-ichi; Uchiyama, Masanobu; Sugiura, Hiroki

    2014-01-01

    Gait properties change with age because of a decrease in lower limb strength and visual acuity or knee joint disorders. Gait changes commonly result from these combined factors. This study aimed to examine the effects of knee extension strength, visual acuity, and knee joint pain on gait properties of for 181 healthy female older adults (age: 76.1 (5.7) years). Walking speed, cadence, stance time, swing time, double support time, step length, step width, walking angle, and toe angle were selected as gait parameters. Knee extension strength was measured by isometric dynamometry; and decreased visual acuity and knee joint pain were evaluated by subjective judgment whether or not such factors created a hindrance during walking. Among older adults without vision problems and knee joint pain that affected walking, those with superior knee extension strength had significantly greater walking speed and step length than those with inferior knee extension strength (P pain in both knees showed slower walking speed and longer stance time and double support time. A decrease of knee extension strength and visual acuity and knee joint pain are factors affecting gait in the female older adults. Decreased knee extension strength and knee joint pain mainly affect respective distance and time parameters of the gait.

  5. Improvement in distance and near visual acuities using low vision devices in diabetic retinopathy

    Directory of Open Access Journals (Sweden)

    Sarika Gopalakrishnan

    2017-01-01

    Full Text Available Purpose: The aim of this study is to elucidate the causes and level of visual impairment (VI in patients with different pathologies of diabetic retinopathy (DR who presented to a low vision care (LVC clinic, to analyze the type of distant and near devices prescribed to them and the visual benefits thereof. Methods: A retrospective chart review was done for 100 consecutive patients with DR who were referred to the LVC clinic from June 2015 to June 2016. The reason for referral was assessed from the electronic medical records and available fundus photographs, fundus fluorescein angiograms, and optical coherence tomography images by a retina specialist. The details of low-vision devices and subsequent improvements were noted. Results: Of the 100 patients, 52% had moderate VI, 19% mild VI, 16% severe VI, and 13% had profound VI or blindness. The most commonly prescribed low vision device was half-eye spectacles (38.4%. The pathologies which had statistically significant improvement (P < 0.05 in distance vision with low vision devices were DR with disc pallor (4.4% improvement, ischemic maculopathy (11.9% improvement, and plaque of hard exudate (10.1% improvement. However, in all pathologies, there was statistically significant improvement (P < 0.05 in near vision. Conclusion: Usually, the patients with DR presented to the LVC clinic with moderate VI. The use of low vision devices can help these patients in cases where medical and surgical treatment have no or a limited role in restoring useful vision.

  6. Macular morphology and visual acuity after macular hole surgery with or without internal limiting membrane peeling

    DEFF Research Database (Denmark)

    Christensen, U.C.; Kroyer, K.; Sander, B.

    2010-01-01

    Aim: To examine postoperative macular morphology and visual outcome after 12 months in relation to internal limiting membrane (ILM) peeling versus no peeling, indocyanine green (ICG) staining and re-operation in eyes that achieved macular hole closure after surgery. Methods: Seventy-four eyes...... with closed stage 2 or 3 macular holes were recruited from a randomised clinical trial comparing: (1) vitrectomy without ILM peeling; (2) vitrectomy with 0.05% isotonic ICG-assisted ILM peeling; and (3) vitrectomy with 0.15% trypan blue-assisted ILM peeling. Contrast-enhanced Stratus optical coherence...... between subgroups. Conclusions: Poor vision after 12 months despite macular hole closure was associated with attenuation and disruption of the foveolar photoreceptor matrix. The extent of attenuation and disruption was independent of peeling and staining....

  7. The Cost-effectiveness of Welcome to Medicare Visual Acuity Screening and a Possible Alternative Welcome to Medicare Eye Evaluation Among Persons Without Diagnosed Diabetes Mellitus

    Science.gov (United States)

    Rein, David B.; Wittenborn, John S.; Zhang, Xinzhi; Hoerger, Thomas J.; Zhang, Ping; Klein, Barbara Eden Kobrin; Lee, Kris E.; Klein, Ronald; Saaddine, Jinan B.

    2013-01-01

    Objective To estimate the cost-effectiveness of visual acuity screening performed in primary care settings and of dilated eye evaluations performed by an eye care professional among new Medicare enrollees with no diagnosed eye disorders. Medicare currently reimburses visual acuity screening for new enrollees during their initial preventive primary care health check, but dilated eye evaluations may be a more cost-effective policy. Design Monte Carlo cost-effectiveness simulation model with a total of 50 000 simulated patients with demographic characteristics matched to persons 65 years of age in the US population. Results Compared with no screening policy, dilated eye evaluations increased quality-adjusted life-years (QALYs) by 0.008 (95% credible interval [CrI], 0.005–0.011) and increased costs by $94 (95% CrI, −$35 to $222). A visual acuity screening increased QALYs in less than 95% of the simulations (0.001 [95% CrI, −0.002 to 0.004) and increased total costs by $32 (95% CrI, −$97 to $159) per person. The incremental cost-effectiveness ratio of a visual acuity screening and an eye examination compared with no screening were $29 000 and $12 000 per QALY gained, respectively. At a willingness-to-pay value of $15 000 or more per QALY gained, a dilated eye evaluation was the policy option most likely to be cost-effective. Conclusions The currently recommended visual acuity screening showed limited efficacy and cost-effectiveness compared with no screening. In contrast, a new policy of reimbursement for Welcome to Medicare dilated eye evaluations was highly cost-effective. PMID:22232367

  8. Macular edema in Asian Indian premature infants with retinopathy of prematurity: Impact on visual acuity and refractive status after 1-year

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    Anand Vinekar

    2015-01-01

    Full Text Available Purpose: To report the impact of transient, self-resolving, untreated "macular edema" detected on spectral domain optical coherence tomography in Asian Indian premature infants with retinopathy of prematurity (ROP on visual acuity (VA and refraction at 1-year of corrected age. Materials and Methods: Visual acuity and refraction of 11 infants with bilateral macular edema (Group A was compared with gestational age-matched 16 infants with ROP without edema (Group B and 17 preterms infants without ROP and without edema (Group C at 3, 6, 9 and 12 months of corrected age using Teller Acuity Cards and cycloplegic retinoscopy. Sub-group analysis of the previously described pattern A and B macular edema was performed. Results: Visual acuity was lower in infants with macular edema compared with the other two control groups throughout the study period, but statistically significant only at 3 months. Visual improvement in these infants was highest between the 3 rd and 6 th month and plateaued by the end of the 1 st year with acuity comparable to the other two groups. The edema cohort was more hyperopic compared to the other two groups between 3 and 12 months of age. Pattern A edema had worse VA compared to pattern B, although not statistically significant. Conclusion: Macular edema, although transient, caused reduced VA as early as 3 months of corrected age in Asian Indian premature infants weighing <2000 g at birth. The higher hyperopia in these infants is possibly due to visual disturbances caused at a critical time of fovealization. We hypothesize a recovery and feedback mechanism based on the principles of active emmetropization to explain our findings.

  9. Visual Acuity Is Correlated with the Area of the Foveal Avascular Zone in Diabetic Retinopathy and Retinal Vein Occlusion.

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    Balaratnasingam, Chandrakumar; Inoue, Maiko; Ahn, Seungjun; McCann, Jesse; Dhrami-Gavazi, Elona; Yannuzzi, Lawrence A; Freund, K Bailey

    2016-11-01

    To determine if the area of the foveal avascular zone (FAZ) is correlated with visual acuity (VA) in diabetic retinopathy (DR) and retinal vein occlusion (RVO). Cross-sectional study. Ninety-five eyes of 66 subjects with DR (65 eyes), branch retinal vein occlusion (19 eyes), and central retinal vein occlusion (11 eyes). Structural optical coherence tomography (OCT; Spectralis, Heidelberg Engineering) and OCT angiography (OCTA; Avanti, Optovue RTVue XR) data from a single visit were analyzed. FAZ area, point thickness of central fovea, central 1-mm subfield thickness, the occurrence of intraretinal cysts, ellipsoid zone disruption, and disorganization of retinal inner layers (DRIL) length were measured. VA was also recorded. Correlations between FAZ area and VA were explored using regression models. Main outcome measure was VA. Mean age was 62.9±13.2 years. There was no difference in demographic and OCT-derived anatomic measurements between branch retinal vein occlusion and central retinal vein occlusion groups (all P ≥ 0.058); therefore, data from the 2 groups were pooled together to a single RVO group for further statistical comparisons. Univariate and multiple regression analysis showed that the area of the FAZ was significantly correlated with VA in DR and RVO (all P ≤ 0.003). The relationship between FAZ area and VA varied with age (P = 0.026) such that for a constant FAZ area, an increase in patient age was associated with poorer vision (rise in logarithm of the minimum angle of resolution visual acuity). Disruption of the ellipsoid zone was significantly correlated with VA in univariate and multiple regression analysis (both P < 0.001). Occurrence of intraretinal cysts, DRIL length, and lens status were significantly correlated with VA in the univariate regression analysis (P ≤ 0.018) but not the multiple regression analysis (P ≥ 0.210). Remaining variables evaluated in this study were not predictive of VA (all P ≥ 0.225). The area of the FAZ is

  10. Long-term outcomes of penetrating keratoplasty in keratoconus:analysis of the factors associated with final visual acuities

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    Jin A Choi

    2014-06-01

    Full Text Available AIM: To investigate the long-term results of penetrating keratoplasty (PK in patients with keratoconus (KC and to evaluate factors that might influence the final visual outcome.METHODS:We retrospectively reviewed the data of all patients with clinical KC who had undergone PK by a single corneal surgeon in a single center from May 1980 to December 2005. The age of the patients, preoperative best-corrected visual acuity (BCVA, corneal thickness, death to preservation time, and preservation to transplantation time were recorded. Additionally, postoperative complications such as graft rejection, development of glaucoma and specular microscopy were checked during the follow-up.RESULTS:Sixty-nine eyes from 69 patients were finally included. The follow-up period was 8.64±6.13y. Graft rejection occurred in 4 eyes of 69 cases (5.8%, and the time to graft rejection was 2.1±1.3y. A Kaplan–Meier survival analysis showed that the estimated cumulative probability of graft rejection at 6, 13, and 17y after PK were 95.6%, 90.0%, and 78.8%, respectively. When we evaluated factors that might influence final BCVA in eyes, no disparity donor-host trephine size (same graft size as well as higher spherical equivalent, and average K-value were associated with higher final BCVA. (P=0.006, 0.051, 0.092, and 0.021 in eyes with follow-up <8y; P=0.068, 0.065, and 0.030 in eyes with follow-up ≥8y, respectively.CONCLUSION: The long-term results of PK in patients with KC were favorable with a high percentage of good BCVA. Less myopic change and low average K-reading, as well as a surgical technique using the same size donor-recipient button may provide better visual outcomes particularly in patients with KC.

  11. Validity and Reliability of Dynamic Visual Acuity (DVA) Measurement During Walking

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    Deshpande, Nandini; Peters, Brian T.; Bloomberg, Jacob J.

    2014-01-01

    DVA is primarily subserved by the vestibulo-ocular reflex mechanism. Individuals with vestibular hypofunction commonly experience highly debilitating illusory movement or blurring of visual images during daily activities possibly, due to impaired DVA. Even without pathologies, gradual age-related morphological deterioration is evident in all components of the vestibular system. We examined the construct validity to detect age-related differences and test-retest reliability of DVA measurements performed during walking. METHODS: Healthy adults were recruited into 3 groups: 1. young (20-39years, n=18), 2. middle-aged (40-59years, n=14), and 3. older adults (60-80years, n=15). Randomly selected seven participants from each group (n=21) participated in retesting. Participants were excluded if they had a history of vestibular or neuromuscular pathologies, dizziness/vertigo or >1 falls in the past year. Older persons with MMSE scores reliability. RESULTS: The three age groups were not different in their height, weight and normal walking speed (p>0.05). The post hoc analyses for DVA measurements demonstrated that each group was significantly different from the other two groups for Near as well as FarDVA (preliability. FarDVA at 0.8 m/s and 1.0 m/s demonstrated good test-retest reliability (ICCs 0.71 and 0.77, respectively).

  12. Zagreb Amblyopia Preschool Screening Study: near and distance visual acuity testing increase the diagnostic accuracy of screening for amblyopia.

    Science.gov (United States)

    Bušić, Mladen; Bjeloš, Mirjana; Petrovečki, Mladen; Kuzmanović Elabjer, Biljana; Bosnar, Damir; Ramić, Senad; Miletić, Daliborka; Andrijašević, Lidija; Kondža Krstonijević, Edita; Jakovljević, Vid; Bišćan Tvrdi, Ana; Predović, Jurica; Kokot, Antonio; Bišćan, Filip; Kovačević Ljubić, Mirna; Motušić Aras, Ranka

    2016-02-01

    To present and evaluate a new screening protocol for amblyopia in preschool children. Zagreb Amblyopia Preschool Screening (ZAPS) study protocol performed screening for amblyopia by near and distance visual acuity (VA) testing of 15 648 children aged 48-54 months attending kindergartens in the City of Zagreb County between September 2011 and June 2014 using Lea Symbols in lines test. If VA in either eye was >0.1 logMAR, the child was re-tested, if failed at re-test, the child was referred to comprehensive eye examination at the Eye Clinic. 78.04% of children passed the screening test. Estimated prevalence of amblyopia was 8.08%. Testability, sensitivity, and specificity of the ZAPS study protocol were 99.19%, 100.00%, and 96.68% respectively. The ZAPS study used the most discriminative VA test with optotypes in line as they do not underestimate amblyopia. The estimated prevalence of amblyopia was considerably higher than reported elsewhere. To the best of our knowledge, the ZAPS study protocol reached the highest sensitivity and specificity when evaluating diagnostic accuracy of VA tests for screening. The pass level defined at ≤0.1 logMAR for 4-year-old children, using Lea Symbols in lines missed no amblyopia cases, advocating that both near and distance VA testing should be performed when screening for amblyopia.

  13. Sports can protect dynamic visual acuity from aging: A study with young and older judo and karate martial arts athletes.

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    Muiños, Mónica; Ballesteros, Soledad

    2015-08-01

    A major topic of current research in aging has been to investigate ways to promote healthy aging and neuroplasticity in order to counteract perceptual and cognitive declines. The aim of the present study was to investigate the benefits of intensive, sustained judo and karate martial arts training in young and older athletes and nonathletes of the same age for attenuating age-related dynamic visual acuity (DVA) decline. As a target, we used a moving stimulus similar to a Landolt ring that moved horizontally, vertically, or obliquely across the screen at three possible contrasts and three different speeds. The results indicated that (1) athletes had better DVA than nonathletes; (2) the older adult groups showed a larger oblique effect than the younger groups, regardless of whether or not they practiced a martial art; and (3) age modulated the results of sport under the high-speed condition: The DVA of young karate athletes was superior to that of nonathletes, while both judo and karate older athletes showed better DVA than did sedentary older adults. These findings suggest that in older adults, the practice of a martial art in general, rather than the practice of a particular type of martial art, is the crucial thing. We concluded that the sustained practice of a martial art such as judo or karate attenuates the decline of DVA, suggesting neuroplasticity in the aging human brain.

  14. CORRELATION OF CLINICAL AND STRUCTURAL PROGRESSION WITH VISUAL ACUITY LOSS IN MACULAR TELANGIECTASIA TYPE 2: MacTel Project Report No. 6-The MacTel Research Group.

    Science.gov (United States)

    Peto, Tunde; Heeren, Tjebo F C; Clemons, Traci E; Sallo, Ferenc B; Leung, Irene; Chew, Emily Y; Bird, Alan C

    2018-01-01

    To evaluate progression of macular telangiectasia Type 2 lesions and their correlation with visual acuity. An international multicenter prospective study with annual examinations including best-corrected visual acuity (BCVA), fundus photography, fluorescein angiography, and optical coherence tomography images graded centrally. Mixed models were used to estimate progression rates, and a generalized linear model to compute the relative risk of BCVA loss, loss of ellipsoid zone (EZ) reflectivity, development of pigment plaques, or neovascularization. One thousand and fourteen eyes of 507 participants were followed for 4.2 ± 1.6 years. Best-corrected visual acuity decreased 1.07 ± 0.05 letters (mean ± SE) per year. Of all eyes, 15% lost ≥15 letters after 5 years. Of the eyes without EZ loss, 76% developed a noncentral loss. Of the eyes with noncentral loss, 45% progressed to central EZ loss. The rate of BCVA loss in eyes with noncentral EZ loss at baseline was similar to eyes without EZ loss. The rate of BCVA loss was significantly higher in eyes with central EZ loss at baseline (-1.40 ± 0.14 letters, P structural component reflecting visual function. Its presence in the fovea significantly correlates with worse visual prognosis.

  15. Long-Term Visual Training Increases Visual Acuity and Long-Term Monocular Deprivation Promotes Ocular Dominance Plasticity in Adult Standard Cage-Raised Mice.

    Science.gov (United States)

    Hosang, Leon; Yusifov, Rashad; Löwel, Siegrid

    2018-01-01

    For routine behavioral tasks, mice predominantly rely on olfactory cues and tactile information. In contrast, their visual capabilities appear rather restricted, raising the question whether they can improve if vision gets more behaviorally relevant. We therefore performed long-term training using the visual water task (VWT): adult standard cage (SC)-raised mice were trained to swim toward a rewarded grating stimulus so that using visual information avoided excessive swimming toward nonrewarded stimuli. Indeed, and in contrast to old mice raised in a generally enriched environment (Greifzu et al., 2016), long-term VWT training increased visual acuity (VA) on average by more than 30% to 0.82 cycles per degree (cyc/deg). In an individual animal, VA even increased to 1.49 cyc/deg, i.e., beyond the rat range of VAs. Since visual experience enhances the spatial frequency threshold of the optomotor (OPT) reflex of the open eye after monocular deprivation (MD), we also quantified monocular vision after VWT training. Monocular VA did not increase reliably, and eye reopening did not initiate a decline to pre-MD values as observed by optomotry; VA values rather increased by continued VWT training. Thus, optomotry and VWT measure different parameters of mouse spatial vision. Finally, we tested whether long-term MD induced ocular dominance (OD) plasticity in the visual cortex of adult [postnatal day (P)162-P182] SC-raised mice. This was indeed the case: 40-50 days of MD induced OD shifts toward the open eye in both VWT-trained and, surprisingly, also in age-matched mice without VWT training. These data indicate that (1) long-term VWT training increases adult mouse VA, and (2) long-term MD induces OD shifts also in adult SC-raised mice.

  16. Acuidade visual e eletrorretinografia de campo total em pacientes com síndrome de Usher Visual acuity and full-field electroretinography in patients with Usher's syndrome

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    Luana Mendieta

    2005-04-01

    and visual acuity (VA among patients with type I and II Usher's syndrome. METHODS: Electroretinography responses and visual acuity were studied in 22 patients (mean age at test = 26.8±16.8 years. Seventeen patients had SU type I and 5 patients were diagnosed as Usher's syndrome type II. RESULTS: Mean visual acuity was 0.9 logMAR (20/160, Snellen equivalent for patients with Usher's syndrome type I and 0.4 logMAR (20/50, Snellen equivalent for patients with Usher's syndrome type II. Scotopic rod and maximal responses were non-detectable in both groups. Mean amplitude for oscillatory potentials was 14.5 µV ±6.1 in Usher's syndrome type I and 12.6 µV±5.2 in Usher's syndrome type II. Cone responses were non-detectable in 95% of the patients with Usher's syndrome I and in 100% of patients with Usher's syndrome II. Mean amplitude for 30 Hz flicker photopic cone response was 3.1 µV±4.1 for Usher's syndrome type I and 1.0 µV±0.6 for type II with mean implicit time of 34.0 ms±6.2 (US I and 35.8 ms±3.1 (type II. CONCLUSIONS: Visual acuity was relatively preserved in both groups, however Usher's syndrome II group showed better visual acuity results. Electroretinography findings were severely reduced in both groups, with most patients showing non-detectable rod and cone responses.

  17. Relationship Between Visual Acuity and Retinal Thickness During Anti-Vascular Endothelial Growth Factor Therapy for Retinal Diseases.

    Science.gov (United States)

    Ou, William C; Brown, David M; Payne, John F; Wykoff, Charles C

    2017-08-01

    To investigate the relationship between best-corrected visual acuity (BCVA) and central retinal thickness (CRT) in eyes receiving ranibizumab for 3 common retinal diseases. Retrospective analysis of clinical trial data. Early Treatment Diabetic Retinopathy Study BCVA and spectral-domain optical coherence tomography-measured CRT of 387 eyes of 345 patients enrolled in 6 prospective clinical trials for management of neovascular age-related macular degeneration (AMD), diabetic macular edema (DME), and retinal vein occlusion (RVO) were evaluated by Pearson correlation and linear regression. At baseline, there was a small correlation between BCVA and CRT in pooled AMD trial data (r = -0.24). A medium correlation was identified in pooled DME trial data (r = -0.42). No correlation was found in pooled RVO trial data. At month 12, no correlation was found between changes from baseline in BCVA and CRT in pooled AMD trial data. Medium correlations were identified in both pooled DME (r = -0.45) and pooled RVO (r = -0.35) trial data at month 12. Changes in BCVA and CRT associated with edema recurrence upon transition from monthly to pro re nata (PRN) dosing were correlated in AMD (r = -0.27) and RVO (r = -0.72) trials, but not in DME trial data. DME demonstrated a convincing relationship between BCVA and CRT. Correlations appear to be more complex in AMD and RVO. At the inflection point between monthly and PRN dosing, when recurrence of edema is anticipated in many patients, CRT appears strongly correlated with loss of BCVA in RVO. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Temporal Evolution and Dose-Volume Histogram Predictors of Visual Acuity After Proton Beam Radiation Therapy of Uveal Melanoma

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    Polishchuk, Alexei L. [Department of Radiation Oncology, University of California, San Francisco, San Francisco, California (United States); Mishra, Kavita K., E-mail: Kavita.Mishra@ucsf.edu [Department of Radiation Oncology, University of California, San Francisco, San Francisco, California (United States); Weinberg, Vivian; Daftari, Inder K. [Department of Radiation Oncology, University of California, San Francisco, San Francisco, California (United States); Nguyen, Jacqueline M.; Cole, Tia B. [Tumori Foundation, San Francisco, California (United States); Quivey, Jeanne M.; Phillips, Theodore L. [Department of Radiation Oncology, University of California, San Francisco, San Francisco, California (United States); Char, Devron H. [Tumori Foundation, San Francisco, California (United States)

    2017-01-01

    Purpose: To perform an in-depth temporal analysis of visual acuity (VA) outcomes after proton beam radiation therapy (PBRT) in a large, uniformly treated cohort of uveal melanoma (UM) patients, to determine trends in VA evolution depending on pretreatment and temporally defined posttreatment VA measurements; and to investigate the relevance of specific patient, tumor and dose-volume parameters to posttreatment vision loss. Methods and Materials: Uveal melanoma patients receiving PBRT were identified from a prospectively maintained database. Included patients (n=645) received 56 GyE in 4 fractions, had pretreatment best corrected VA (BCVA) in the affected eye of count fingers (CF) or better, with posttreatment VA assessment at specified post-PBRT time point(s). Patients were grouped according to the pretreatment BCVA into favorable (≥20/40) or unfavorable (20/50-20/400) and poor (CF) strata. Temporal analysis of BCVA changes was described, and univariate and forward stepwise multivariate logistic regression analyses were performed to identify predictors for VA loss. Results: Median VA follow-up was 53 months (range, 3-213 months). At 60-month follow up, among evaluable treated eyes with favorable pretreatment BCVA, 45% retained BCVA ≥20/40, whereas among evaluable treated eyes with initially unfavorable/poor BCVA, 21% had vision ≥20/100. Among those with a favorable initial BCVA, attaining BCVA of ≥20/40 at any posttreatment time point was associated with subsequent maintenance of excellent BCVA. Multivariate analysis identified volume of the macula receiving 28GyE (P<.0001) and optic nerve (P=.0004) as independent dose-volume histogram predictors of 48-month post-PBRT vision loss among initially favorable treated eyes. Conclusions: Approximately half of PBRT-treated UM eyes with excellent pretreatment BCVA assessed at 5 years after treatment will retain excellent long-term vision. 28GyE macula and optic nerve dose-volume histogram parameters allow for

  19. SMARTPHONE-BASED DILATED FUNDUS PHOTOGRAPHY AND NEAR VISUAL ACUITY TESTING AS INEXPENSIVE SCREENING TOOLS TO DETECT REFERRAL WARRANTED DIABETIC EYE DISEASE.

    Science.gov (United States)

    Toy, Brian C; Myung, David J; He, Lingmin; Pan, Carolyn K; Chang, Robert T; Polkinhorne, Alison; Merrell, Douglas; Foster, Doug; Blumenkranz, Mark S

    2016-05-01

    To compare clinical assessment of diabetic eye disease by standard dilated examination with data gathered using a smartphone-based store-and-forward teleophthalmology platform. 100 eyes of 50 adult patients with diabetes from a health care safety-net ophthalmology clinic. All patients underwent comprehensive ophthalmic examination. Concurrently, a smartphone was used to estimate near visual acuity and capture anterior and dilated posterior segment photographs, which underwent masked, standardized review. Quantitative comparison of clinic and smartphone-based data using descriptive, kappa, Bland-Altman, and receiver operating characteristic analyses was performed. Smartphone visual acuity was successfully measured in all eyes. Anterior and posterior segment photography was of sufficient quality to grade in 96 and 98 eyes, respectively. There was good correlation between clinical Snellen and smartphone visual acuity measurements (rho = 0.91). Smartphone-acquired fundus photographs demonstrated 91% sensitivity and 99% specificity to detect moderate nonproliferative and worse diabetic retinopathy, with good agreement between clinic and photograph grades (kappa = 0.91 ± 0.1, P smartphone-based telemedicine system that demonstrated sensitivity and specificity to detect referral-warranted diabetic eye disease as a proof-of-concept. Additional studies are warranted to evaluate this approach to expanding screening for diabetic retinopathy.

  20. Changes in visual acuity in patients with wet age-related macular degeneration treated with intravitreal ranibizumab in daily clinical practice: the LUMIERE study.

    Science.gov (United States)

    Cohen, Salomon Y; Mimoun, Gerard; Oubraham, Hassiba; Zourdani, Alain; Malbrel, Christian; Queré, Stephane; Schneider, Véronique

    2013-03-01

    To survey compliance with recommended intravitreal ranibizumab treatment protocols in daily clinical practice in France, with reference to outcomes. A retrospective, descriptive, observational study in patients with subfoveal wet age-related macular degeneration treated with ranibizumab. All historical data for the study period, including demographic, treatment, and disease details and visual acuity measurements (baseline, Month 3, and Month 12), were recorded retrospectively at least 12 months after the beginning of treatment. In 551 patients followed by 16 ophthalmologists, 12 months of intravitreal ranibizumab treatment induced a mean visual acuity gain of 3.2 ± 14.8 Early Treatment Diabetic Retinopathy Study-equivalent letters. Fewer than 40% of patients received the recommended treatment of initial 3 monthly injections. More than 50% had to wait >8 days between diagnosis and treatment. At Month 3, visual acuity gain was greater in patients who had received recommended induction and in whom treatment was initiated quickly. At Month 12, the induction-related effect had largely disappeared but the time-to-treatment effect persisted. Patients had an average of 5.1 injections (2.6 during induction period). No patients were monitored monthly as stipulated in the guidelines. Although poor compliance with recommendations has been reflected in mediocre outcomes, there is evidence that practice is improving.

  1. Cross-sectional study assessing the addition of contrast sensitivity to visual acuity when testing for fitness to drive

    Science.gov (United States)

    Spreng, Lucie; Favrat, Bernard; Borruat, François-Xavier; Vaucher, Paul

    2018-01-01

    Objectives The aim of this study is to quantify the importance of loss of contrast sensitivity (CS) and its relationship to loss of visual acuity (VA), driving restrictions and daytime, on-road driving evaluations in drivers aged 70+. Design A predictive cross-sectional study. Setting Volunteer participants to a drivers’ refresher course for adults aged 70+ delivered by the Swiss Automobile Club in western Switzerland from 2011 to 2013. Participants 162 drivers, male and female, aged 70 years or older. Clinical predictors We used a vision screener to estimate VA and the The Mars Letter Contrast Sensitivity Test to test CS. Outcomes We asked drivers to report whether they found five driving restrictions useful for their condition; restrict driving to known roads, avoid driving on highways, avoid driving in the dark, avoid driving in dense traffic and avoid driving in fog. All participants also underwent a standardised on-road evaluation carried out by a driving instructor. Results Moderate to severe loss of CS for at least one eye was frequent (21.0% (95% CI 15.0% to 28.1%)) and often isolated from a loss of VA (11/162 cases had a VA ≥0.8 decimal and a CS of ≤1.5 log(CS); 6.8% (95% CI 3.4% to 11.8%)). Drivers were more likely (R2=0.116, P=0.004) to report a belief that self-imposed driving restrictions would be useful if they had reduced CS in at least one eye. Daytime evaluation of driving performance seems limited in its ability to correctly identify difficulties related to CS loss (VA: R2=0.004, P=0.454; CS: R2=0.006, P=0.332). Conclusion CS loss is common for older drivers. Screening CS and referring for cataract surgery even in the absence of VA loss could help maintain mobility. Reduced CS and moderate reduction of VA were both poor predictors of daytime on-road driving performances in this research study. PMID:29374663

  2. Macular Morphology and Visual Acuity in the Second Year of the Comparison of Age-Related Macular Degeneration Treatments Trials.

    Science.gov (United States)

    Sharma, Sumit; Toth, Cynthia A; Daniel, Ebenezer; Grunwald, Juan E; Maguire, Maureen G; Ying, Gui-Shuang; Huang, Jiayan; Martin, Daniel F; Jaffe, Glenn J

    2016-04-01

    To describe the association between morphologic features on fundus photography (FP), fluorescein angiography (FA), and optical coherence tomography (OCT) and visual acuity (VA) in the second year of the Comparison of Age-related Macular Degeneration Treatments Trials (CATT). Prospective cohort study within a randomized clinical trial. Participants in the CATT. Study eye eligibility required angiographic and OCT evidence of choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD) and VA between 20/25 and 20/320. Treatment was assigned randomly to ranibizumab or bevacizumab with 3 different dosing regimens over a 2-year period. Fluid type, location, and thickness; retina and subretinal tissue complex thickness on OCT; size and lesion composition on FP and FA; and VA. Among 1185 CATT participants, 993 (84%) had fluid on OCT at baseline and completed 2 years of follow-up. At 2 years, intraretinal fluid (IRF), subretinal fluid (SRF), sub-retinal pigment epithelium (RPE) fluid, and subretinal tissue complex thickness decreased in all treatment groups. Ranibizumab monthly was best able to resolve each type of fluid. Eyes with SRF in the foveal center on OCT had better mean VA than eyes with no SRF (72.8 vs. 66.6 letters; P = 0.006). Eyes with IRF in the foveal center had worse mean VA than eyes without IRF (59.9 vs. 70.9 letters; P 212 μm (59.4 vs. 71.3 vs. 70.3 letters; P < 0.0001). At 2 years, the mean VA (letters) of eyes varied substantially by the type of subfoveal pathology on FP and FA: 70.6 for no pathology; 74.1 for fluid only; 73.3 for CNV or pigment epithelial (RPE) detachment; 68.4 for nongeographic atrophy; and 62.9 for geographic atrophy, hemorrhage, RPE tear, or scar (P < 0.0001). The associations between VA and morphologic features identified through year 1 were maintained or strengthened during year 2. Eyes with foveal IRF, abnormally thin retina, greater thickness of the subretinal tissue complex on OCT, and subfoveal

  3. Refractive error, visual acuity and causes of vision loss in children in Shandong, China. The Shandong Children Eye Study.

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    Jian Feng Wu

    Full Text Available PURPOSE: To examine the prevalence of refractive errors and prevalence and causes of vision loss among preschool and school children in East China. METHODS: Using a random cluster sampling in a cross-sectional school-based study design, children with an age of 4-18 years were selected from kindergartens, primary schools, and junior and senior high schools in the rural Guanxian County and the city of Weihai. All children underwent a complete ocular examination including measurement of uncorrected (UCVA and best corrected visual acuity (BCVA and auto-refractometry under cycloplegia. Myopia was defined as refractive error of ≤-0.5 diopters (D, high myopia as ≤ -6.0D, and amblyopia as BCVA ≤ 20/32 without any obvious reason for vision reduction and with strabismus or refractive errors as potential reasons. RESULTS: Out of 6364 eligible children, 6026 (94.7% children participated. Prevalence of myopia (overall: 36.9 ± 0.6%;95% confidence interval (CI:36.0,38.0 increased (P<0.001 from 1.7 ± 1.2% (95%CI:0.0,4.0 in the 4-years olds to 84.6 ± 3.2% (95%CI:78.0,91.0 in 17-years olds. Myopia was associated with older age (OR:1.56;95%CI:1.52,1.60;P<0.001, female gender (OR:1.22;95%CI:1.08,1.39;P = 0.002 and urban region (OR:2.88;95%CI:2.53,3.29;P<0.001. Prevalence of high myopia (2.0 ± 0.2% increased from 0.7 ± 0.3% (95%CI:0.1,1.3 in 10-years olds to 13.9 ± 3.0 (95%CI:7.8,19.9 in 17-years olds. It was associated with older age (OR:1.50;95%CI:1.41,1.60;P<0.001 and urban region (OR:3.11;95%CI:2.08,4.66;P<0.001. Astigmatism (≥ 0.75D (36.3 ± 0.6%;95%CI:35.0,38.0 was associated with older age (P<0.001;OR:1.06;95%CI:1.04,1.09, more myopic refractive error (P<0.001;OR:0.94;95%CI:0.91,0.97 and urban region (P<0.001;OR:1.47;95%CI:1.31,1.64. BCVA was ≤ 20/40 in the better eye in 19 (0.32% children. UCVA ≤ 20/40 in at least one eye was found in 2046 (34.05% children, with undercorrected refractive error as cause in 1975 (32.9% children. Amblyopia

  4. The prevalence and causes of decreased visual acuity – a study based on vision screening conducted at Enukweni and Mzuzu Foundation Primary Schools, Malawi

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    Thom L; Jogessar S; McGowan SL; Lawless F

    2016-01-01

    Leaveson Thom,1 Sanchia Jogessar,1,2 Sara L McGowan,1 Fiona Lawless,1,2 1Department of Optometry, Mzuzu University, Mzuzu, Malawi; 2Brienholden Vision Institute, Durban, South Africa Aim: To determine the prevalence and causes of decreased visual acuity (VA) among pupils recruited in two primary schools in Mzimba district, northern region of Malawi.Materials and methods: The study was based on the vision screening which was conducted by optometrists at Enukweni and Mzuzu Foundation Primary Sc...

  5. The prevalence and causes of decreased visual acuity – a study based on vision screening conducted at Enukweni and Mzuzu Foundation Primary Schools, Malawi

    OpenAIRE

    Thom,Leaveson; Jogessar,Sanchia; McGowan,Sara L; Lawless,Fiona

    2016-01-01

    Leaveson Thom,1 Sanchia Jogessar,1,2 Sara L McGowan,1 Fiona Lawless,1,2 1Department of Optometry, Mzuzu University, Mzuzu, Malawi; 2Brienholden Vision Institute, Durban, South Africa Aim: To determine the prevalence and causes of decreased visual acuity (VA) among pupils recruited in two primary schools in Mzimba district, northern region of Malawi.Materials and methods: The study was based on the vision screening which was conducted by optometrists at Enukweni and Mzuzu Foundation Primary Sc...

  6. Tactile acuity charts: a reliable measure of spatial acuity.

    Directory of Open Access Journals (Sweden)

    Patrick Bruns

    Full Text Available For assessing tactile spatial resolution it has recently been recommended to use tactile acuity charts which follow the design principles of the Snellen letter charts for visual acuity and involve active touch. However, it is currently unknown whether acuity thresholds obtained with this newly developed psychophysical procedure are in accordance with established measures of tactile acuity that involve passive contact with fixed duration and control of contact force. Here we directly compared tactile acuity thresholds obtained with the acuity charts to traditional two-point and grating orientation thresholds in a group of young healthy adults. For this purpose, two types of charts, using either Braille-like dot patterns or embossed Landolt rings with different orientations, were adapted from previous studies. Measurements with the two types of charts were equivalent, but generally more reliable with the dot pattern chart. A comparison with the two-point and grating orientation task data showed that the test-retest reliability of the acuity chart measurements after one week was superior to that of the passive methods. Individual thresholds obtained with the acuity charts agreed reasonably with the grating orientation threshold, but less so with the two-point threshold that yielded relatively distinct acuity estimates compared to the other methods. This potentially considerable amount of mismatch between different measures of tactile acuity suggests that tactile spatial resolution is a complex entity that should ideally be measured with different methods in parallel. The simple test procedure and high reliability of the acuity charts makes them a promising complement and alternative to the traditional two-point and grating orientation thresholds.

  7. Tactile acuity charts: a reliable measure of spatial acuity.

    Science.gov (United States)

    Bruns, Patrick; Camargo, Carlos J; Campanella, Humberto; Esteve, Jaume; Dinse, Hubert R; Röder, Brigitte

    2014-01-01

    For assessing tactile spatial resolution it has recently been recommended to use tactile acuity charts which follow the design principles of the Snellen letter charts for visual acuity and involve active touch. However, it is currently unknown whether acuity thresholds obtained with this newly developed psychophysical procedure are in accordance with established measures of tactile acuity that involve passive contact with fixed duration and control of contact force. Here we directly compared tactile acuity thresholds obtained with the acuity charts to traditional two-point and grating orientation thresholds in a group of young healthy adults. For this purpose, two types of charts, using either Braille-like dot patterns or embossed Landolt rings with different orientations, were adapted from previous studies. Measurements with the two types of charts were equivalent, but generally more reliable with the dot pattern chart. A comparison with the two-point and grating orientation task data showed that the test-retest reliability of the acuity chart measurements after one week was superior to that of the passive methods. Individual thresholds obtained with the acuity charts agreed reasonably with the grating orientation threshold, but less so with the two-point threshold that yielded relatively distinct acuity estimates compared to the other methods. This potentially considerable amount of mismatch between different measures of tactile acuity suggests that tactile spatial resolution is a complex entity that should ideally be measured with different methods in parallel. The simple test procedure and high reliability of the acuity charts makes them a promising complement and alternative to the traditional two-point and grating orientation thresholds.

  8. Reducing Short-Wavelength Blue Light in Dry Eye Patients with Unstable Tear Film Improves Performance on Tests of Visual Acuity.

    Science.gov (United States)

    Kaido, Minako; Toda, Ikuko; Oobayashi, Tomoo; Kawashima, Motoko; Katada, Yusaku; Tsubota, Kazuo

    2016-01-01

    To investigate whether suppression of blue light can improve visual function in patients with short tear break up time (BUT) dry eye (DE). Twenty-two patients with short BUT DE (10 men, 12 women; mean age, 32.4 ± 6.4 years; age range, 23-43 years) and 18 healthy controls (10 men, 8 women; mean age, 30.1 ± 7.4 years; age range, 20-49 years) underwent functional visual acuity (VA) examinations with and without wearing eyeglasses with 50% blue light blocked lenses. The functional VA parameters were starting VA, functional VA, and visual maintenance ratio. The baseline mean values (logarithm of the minimum angle of resolution, logMAR) of functional VA and the visual maintenance ratio were significantly worse in the DE patients than in the controls (P 0.05). The DE patients had significant improvement in mean functional VA and visual maintenance ratio while wearing the glasses (P 0.05). Protecting the eyes from short-wavelength blue light may help to ameliorate visual impairment associated with tear instability in patients with DE. This finding represents a new concept, which is that the blue light exposure might be harmful to visual function in patients with short BUT DE.

  9. Reducing Short-Wavelength Blue Light in Dry Eye Patients with Unstable Tear Film Improves Performance on Tests of Visual Acuity.

    Directory of Open Access Journals (Sweden)

    Minako Kaido

    Full Text Available To investigate whether suppression of blue light can improve visual function in patients with short tear break up time (BUT dry eye (DE.Twenty-two patients with short BUT DE (10 men, 12 women; mean age, 32.4 ± 6.4 years; age range, 23-43 years and 18 healthy controls (10 men, 8 women; mean age, 30.1 ± 7.4 years; age range, 20-49 years underwent functional visual acuity (VA examinations with and without wearing eyeglasses with 50% blue light blocked lenses. The functional VA parameters were starting VA, functional VA, and visual maintenance ratio.The baseline mean values (logarithm of the minimum angle of resolution, logMAR of functional VA and the visual maintenance ratio were significantly worse in the DE patients than in the controls (P 0.05. The DE patients had significant improvement in mean functional VA and visual maintenance ratio while wearing the glasses (P 0.05.Protecting the eyes from short-wavelength blue light may help to ameliorate visual impairment associated with tear instability in patients with DE. This finding represents a new concept, which is that the blue light exposure might be harmful to visual function in patients with short BUT DE.

  10. Visual Acuity Change over 12 Months in the Prospective Progression of Atrophy Secondary to Stargardt Disease (ProgStar) Study: ProgStar Report Number 6.

    Science.gov (United States)

    Kong, Xiangrong; Strauss, Rupert W; Cideciyan, Artur V; Michaelides, Michel; Sahel, José-Alain; Munoz, Beatriz; Ahmed, Mohamed; Ervin, Ann M; West, Sheila K; Cheetham, Janet K; Scholl, Hendrik P N

    2017-11-01

    To estimate the yearly rate of change of best-corrected visual acuity (BCVA) and the risk of loss 1 line or more over 1 year and to identify risk factors for BCVA loss in patients with Stargardt disease (STGD1). Multicenter, prospective cohort study. Two hundred fifty-nine patients (489 eyes) with molecularly confirmed STGD1 enrolled at 9 centers in the United States and Europe. Participants were followed up every 6 months, and data at the baseline and 6- and 12-month visits were analyzed. Best-corrected visual acuity was measured using the Early Treatment Diabetic Retinopathy Study (ETDRS) protocol. Standardized reporting forms were used to collect participants' characteristics and clinical observations. Linear mixed effects models were used to estimate the rate of BCVA loss. Linear models with generalized estimating equations were used to identify risk factors for BCVA loss of 1 line or more over 1 year. Change in BCVA over 1 year. Cross-sectional analysis at baseline showed that earlier symptom onset and longer duration since onset was associated with worse BCVA. Longitudinal analysis showed no overall significant change of BCVA within 12 months, but the rate of BCVA change was significantly different by baseline BCVA (P trials with 1 year's duration. Copyright © 2017 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  11. SURGICAL REMOVAL OF EPIRETINAL MEMBRANE WITH AND WITHOUT REMOVAL OF INTERNAL LIMITING MEMBRANE: Comparative Study of Visual Acuity, Features of Optical Coherence Tomography, and Recurrence Rate.

    Science.gov (United States)

    De Novelli, Fernando J; Goldbaum, Mauro; Monteiro, Mario L R; Bom Aggio, Fabio; Takahashi, Walter Y

    2017-12-05

    To study and compare visual acuity, foveal thickness, outer limiting layer, ellipsoid zone, and recurrence rate in patients undergoing removal of the epiretinal membrane with and without the removal of the internal limiting membrane (ILM). Sixty-three patients who had the epiretinal membrane removed by a single surgeon were randomly assigned into 2 groups: Group 1 without additional removal of the ILM and Group 2 with removal of the ILM. Patients were followed up and evaluated at the first month, third month, and sixth month, postoperatively. Patients from both groups had a gradual improvement in their vision over time. There was no significant difference in the improvement in visual acuity between the two groups. About tomographic assessment of alterations, no significant differences were found between the groups; however, Group 1 had a higher relapse rate (17%) compared with Group 2 (3.6%) (P = 0.09). Epiretinal membrane removal with and without ILM peeling shows similar functional and anatomical improvements, but the group in which the ILM was not removed seemed to have a higher recurrence rate.

  12. Comparison of bromfenac 0.09% QD to nepafenac 0.1% TID after cataract surgery: pilot evaluation of visual acuity, macular volume, and retinal thickness at a single site

    Directory of Open Access Journals (Sweden)

    Cable M

    2012-07-01

    then rescued with bromfenac 0.09% QD and difluprednate 0.05% QD.Conclusion: Both bromfenac and nepafenac resulted in positive clinical outcomes of Early Treatment Diabetic Retinopathy Study visual acuities. Postoperative measurements of macular volume and retinal thickness of bromfenac subjects showed a trend toward improved vision, less retinal thickening, and more stable macular volumes overall.Keywords: NSAIDs, phacoemulsification, inflammation, cataract, macular volume, retinal thickness

  13. Visual acuity, amplitude of accommodation and near point of convergence and academic achievement in primary school learners in Bloemfontein

    Directory of Open Access Journals (Sweden)

    Mariette Nel

    2014-08-01

    Conclusion: Of the three visual functions evaluated in this study, the only visual function associated with academic achievement was amplitude of accommodation. It would thus be recommended that learners are screened for optimal visual function earlier in life if especially the amplitude of accommodation is receded.

  14. Higher order optical aberrations and visual acuity in a randomized controlled trial comparing transepithelial versus epithelium-off corneal crosslinking for progressive keratoconus

    Directory of Open Access Journals (Sweden)

    Godefrooij DA

    2017-10-01

    Full Text Available Daniel A Godefrooij, Mustapha El Kandoussi, Nienke Soeters, Robert PL Wisse Utrecht Cornea Research Group, Department of Ophthalmology, University Medical Center Utrecht, Utrecht, the Netherlands Purpose: The purpose of this study was to compare the effects of transepithelial crosslinking (trans-CXL versus epithelium-off crosslinking (epi-off CXL for progressive keratoconus with respect to the development of higher order aberrations (HOAs and their effects on visual acuity.Materials and methods: A total of 61 patients were randomized and examined preoperatively and 1, 3, 6, and 12 months postoperatively in an academic referral center. Total corneal HOAs were compared between the two treatment groups using mixed linear modeling. Types of HOAs (coma, trefoil, and spherical aberration that differed between groups were entered in a multivariable analysis to test their effect on uncorrected distance visual acuity (UDVA and corrected distance visual acuity (CDVA.Results: The epi-off CXL group had more flattening in maximal keratometry compared to the trans-CXL group (P=0.02. UDVA did not differ significantly between the groups (P=0.59; however, CDVA was significantly more improved in the trans-CXL group (P=0.02. Horizontal trefoil improved more in the epi-off group compared to the trans-CXL group (P=0.04, whereas the other HOAs were virtually unchanged in both groups. Differences in changes in HOAs between the two groups had no effect on either UCVA (P=0.76 or CDVA (P=0.96.Conclusion: Although HOAs are clinically relevant determinants of vision quality in keratoconus patients, the change in total HOAs post treatment did not differ between the trans-CXL and epi-off CXL groups. Only horizontal trefoil differed significantly post treatment between the trans-CXL and epi-off CXL groups. However, this difference did not independently affect either UDVA or CDVA. Trans-CXL provides no benefit over epi-off CXL regarding visual relevant HOAs. Keywords

  15. The prevalence and causes of decreased visual acuity – a study based on vision screening conducted at Enukweni and Mzuzu Foundation Primary Schools, Malawi

    Directory of Open Access Journals (Sweden)

    Thom L

    2016-12-01

    Full Text Available Leaveson Thom,1 Sanchia Jogessar,1,2 Sara L McGowan,1 Fiona Lawless,1,2 1Department of Optometry, Mzuzu University, Mzuzu, Malawi; 2Brienholden Vision Institute, Durban, South Africa Aim: To determine the prevalence and causes of decreased visual acuity (VA among pupils recruited in two primary schools in Mzimba district, northern region of Malawi.Materials and methods: The study was based on the vision screening which was conducted by optometrists at Enukweni and Mzuzu Foundation Primary Schools. The measurements during the screening included unaided distance monocular VA by using Low Vision Resource Center and Snellen chart, pinhole VA on any subject with VA of less than 6/6, refraction, pupil evaluations, ocular movements, ocular health, and shadow test.Results: The prevalence of decreased VA was found to be low in school-going population (4%, n=594. Even though Enukweni Primary School had few participants than Mzuzu Foundation Primary School, it had high prevalence of decreased VA (5.8%, n=275 than Mzuzu Foundation Primary School (1.8%, n=319. The principal causes of decreased VA in this study were found to be amblyopia and uncorrected refractive errors, with myopia being the main cause than hyperopia.Conclusion: Based on the low prevalence of decreased VA due to myopia or hyperopia, it should not be concluded that refractive errors are an insignificant contributor to visual disability in Malawi. More vision screenings are required at a large scale on school-aged population to reflect the real situation on the ground. Cost-effective strategies are needed to address this easily treatable cause of vision impairment. Keywords: vision screening, refractive errors, visual acuity, Enukweni, Mzuzu foundation

  16. LONG-TERM RETROSPECTIVE ANALYSIS OF VISUAL ACUITY AND OPTICAL COHERENCE TOPOGRAPHIC CHANGES AFTER SINGLE VERSUS DOUBLE PEELING DURING VITRECTOMY FOR MACULAR EPIRETINAL MEMBRANES.

    Science.gov (United States)

    Jung, Jesse J; Hoang, Quan V; Ridley-Lane, Megan L; Sebrow, Dov B; Dhrami-Gavazi, Elona; Chang, Stanley

    2016-11-01

    To determine the long-term effect of internal limiting membrane with associated epiretinal membrane (ERM) peeling versus single peeling alone in terms of best-corrected visual acuity and anatomical outcomes on spectral-domain optical coherence tomography. This retrospective comparative cohort study of patients who had follow-up of >1 year and underwent surgery for ERM by a single surgeon (S.C.) from January 1, 2008 to December 31, 2012 compared cases in which the internal limiting membrane was stained with brilliant blue G to facilitate double peeling (n = 42) and single peeling (n = 43) of the ERM alone for up to 3 years of follow-up. For continuous variables, an independent two-tailed t-test was performed. For binary variables, the Fisher's exact test was performed. Statistical significance was defined as P peeling group were more likely to have ERM remaining in the central fovea postoperatively (P = 0.0020, becoming significant by postoperative Year 1, P = 0.022) and less likely to develop inner retinal dimpling (P = 0.000, becoming significant by postoperative Month 3, P = 0.015). At 3 years, central foveal thickness had decreased in the single-peeling group by -136.9 µm and by -84.1 μm in the double-peeling group, which was not significantly different (P = 0.08). Mean best-corrected visual acuity improved in both the groups at all time points. There was no statistically significant difference between the 2 groups at 3 years (P = 0.44; single-peeling group, 0.32 ± 0.42, Snellen 20/42; double-peeling group, 0.23 ± 0.27, Snellen 20/34). Brilliant blue G-assisted internal limiting membrane peeling for ERM results in a more thorough removal of residual ERM around the paracentral fovea. However, there is no difference in long-term best-corrected visual acuity at 3 years and a greater likelihood of inner retinal dimpling.

  17. Prenatal Co 60-irradiation effects on visual acuity, maturation of the fovea in the retina, and the striate cortex of squirrel monkey offspring

    International Nuclear Information System (INIS)

    Ordy, J.M.; Brizzee, K.R.; Young, R.

    1982-01-01

    In the present study, foveal striate cortex depth increased significantly from 1400 μm to 1650 μm by 90 days, whereas prenatal 100 rad exposure resulted in a significant reduction of foveal striate cortex thickness at 90 days of age. From birth to 90 days, cell packing density decreased, whereas overall neuropil density increased in both control and 100 rad exposed offspring. Regarding the effects of prenatal radiation on Meynert cells, there was a significant difference in the time course of early postnatal spine frequency reduction on apical dendrites of Meynert cells, particularly in laminae V and IV. It seems possible that the significant differences in the time course of perinatal increases and subsequent decreases of spines and synapses on such pyramidal neurons as Meynert cells in the deep layers of the striate cortex may play an important role in the development of binocular acuity. Future follow-up studies will be essential from 90 days to 1 and 2 years to determine the extent of recovery from, and persistence of visual acuity impairments in relation to structural alterations in the foveal projection of the retino-geniculo-striate system of diurnal primates. (orig./MG)

  18. Visual acuity in an Iranian cohort of patients with type 2 diabetes: the role of nephropathy and ischemic heart disease

    Directory of Open Access Journals (Sweden)

    Negar Horri

    2011-01-01

    Conclusions: The factors related to retinopathy play a role in affecting the degree of visual impairment in diabetic patients. Therefore, controlling risk factors can be useful in decreasing impairment of vision and blindness.

  19. Effects of early maternal docosahexaenoic acid intake on neuropsychological status and visual acuity at five years of age of breast-fed term infants.

    Science.gov (United States)

    Jensen, Craig L; Voigt, Robert G; Llorente, Antolin M; Peters, Sarika U; Prager, Thomas C; Zou, Yali L; Rozelle, Judith C; Turcich, Marie R; Fraley, J Kennard; Anderson, Robert E; Heird, William C

    2010-12-01

    We previously reported better psychomotor development at 30 months of age in infants whose mothers received a docosahexaenoic acid (DHA) (22:6n-3) supplement for the first 4 months of lactation. We now assess neuropsychological and visual function of the same children at 5 years of age. Breastfeeding women were assigned to receive identical capsules containing either a high-DHA algal oil (∼200 mg/d of DHA) or a vegetable oil (containing no DHA) from delivery until 4 months postpartum. Primary outcome variables at 5 years of age were measures of gross and fine motor function, perceptual/visual-motor function, attention, executive function, verbal skills, and visual function of the recipient children at 5 years of age. There were no differences in visual function as assessed by the Bailey-Lovie acuity chart, transient visual evoked potential or sweep visual evoked potential testing between children whose mothers received DHA versus placebo. Children whose mothers received DHA versus placebo performed significantly better on the Sustained Attention Subscale of the Leiter International Performance Scale (46.5 ± 8.9 vs 41.9 ± 9.3, P DHA supplementation versus placebo for the first 4 months of breastfeeding performed better on a test of sustained attention. This, along with the previously reported better performance of the children of DHA-supplemented mothers on a test of psychomotor development at 30 months of age, suggests that DHA intake during early infancy confers long-term benefits on specific aspects of neurodevelopment. Copyright © 2010 Mosby, Inc. All rights reserved.

  20. Comparação entre acuidade visual e photoscreening como métodos de triagem visual para crianças em idade escolar Comparison between visual acuity and photoscreening used like visual screening methods for scholar aged children

    Directory of Open Access Journals (Sweden)

    Roberta Lílian Fernandes de Sousa

    2012-12-01

    Full Text Available OBJETIVO: Avaliar a sensibilidade do aparelho photoscreener na detecção de alterações oculares em crianças informantes, comparando os dados à acuidade visual obtida pela tabela E de Snellen. MÉTODOS: Foram avaliadas 500 crianças de idades entre 5 e 12 anos, de escola do município de Botucatu, estado de São Paulo. As crianças foram submetidas ao teste de acuidade visual pela tabela E de Snellen e foram fotografadas utilizando-se o aparelho photoscreenerTM system model MTI-PS100, seguindo-se a análise das fotos obtidas. RESULTADOS: Houve concordância negativa (criança com boa acuidade visual e teste negativo com o photoscreener em 81,0%; concordância positiva (acuidade visual alterada e teste positivo em 7,6% e não houve concordância de resultados em 11,0% dos casos. CONCLUSÃO: A avaliação comparativa entre o método da acuidade visual pela tabela E de Snellen e o photocreener para detecção de problemas visuais mostrou alta concordância. Os autores sugerem entretanto, a triagem usando tabelas de acuidade visual quando se trata de crianças informantes, devido aos custos com o aparelho.PURPOSE: To evaluate the sensitivity of the photoscreener equipment to detect ocular changes in informative children comparing with the data obtained by the E Snellen´s table. METHODS: We evaluated 500 children between 5 and 12 years old, from a school of Botucatu city, São Paulo state. The children were submitted to a visual acuity test using the Snellen´s E Table and were photographed with the photoscreenerTM system model MTI-PS100, following the photos' analyze. RESULTS: There were negative agreement (children with a good visual acuity and a negative test with the Photoscreener in 81.0%; positive agreement (children without a good visual acuity and a positive test in 7.6% and there was no agreement of the results in 11.0% (9 of the cases. CONCLUSION: The comparative analysis between the visual acuity test using the Snellen's E table and

  1. A 5-year audit of cataract surgery outcomes after posterior capsule rupture and risk factors affecting visual acuity.

    Science.gov (United States)

    Ti, Seng-Ei; Yang, You-Nian; Lang, Stephanie S; Chee, Soon Phaik

    2014-01-01

    To describe the posterior capsule rupture rates and visual outcomes after phacoemulsification, analyze risk factors for poor vision, and compare results of faculty (F) and residents (R). Retrospective audit study. Visual success of all capsule ruptures (2006-2010) was analyzed and compared to uneventful cases. Rupture rates of faculty and residents were compared (χ², P risk factors were identified using multivariate logistic regression analysis. From 2006 to 2010, there were 887 capsule ruptures in 48 377 phacoemulsification cases (rate 1.8%). Uneventful cases had significantly better visual outcomes than capsule ruptures (98.5% vs 93.9%; P .05). Ruptures most frequently occurred during phacoemulsification (59.6%) and irrigation and aspiration (24.8%) stages. Risk factors for poor outcomes included age >65 years, dropped nuclei, and other complications. The overall capsule rupture rate was 1.8%. Although residents had higher rates, visual success matched faculty's, possibly attributable to case mix and close supervision. Associated risk factors for poor vision included age >65 years, dropped nuclei, and postoperative retinal, corneal, and IOL complications. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Improvement of uncorrected visual acuity (UCVA and contrast sensitivity (UCCS with perceptual learning and transcranial random noise stimulation (tRNS in individuals with mild myopia

    Directory of Open Access Journals (Sweden)

    Rebecca eCamilleri

    2014-10-01

    Full Text Available Perceptual learning has been shown to produce an improvement of visual acuity (VA and contrast sensitivity (CS both in subjects with amblyopia and refractive defects such as myopia or presbyopia. Transcranial random noise stimulation (tRNS has proven to be efficacious in accelerating neural plasticity and boosting perceptual learning in healthy participants. In this study we investigated whether a short behavioural training regime using a contrast detection task combined with online tRNS was as effective in improving visual functions in participants with mild myopia compared to a two-month behavioural training regime without tRNS (Camilleri et al., 2014. After two weeks of perceptual training in combination with tRNS, participants showed an improvement of 0.15 LogMAR in uncorrected VA (UCVA that was comparable with that obtained after eight weeks of training with no tRNS, and an improvement in uncorrected CS (UCCS at various spatial frequencies (whereas no UCCS improvement was seen after eight weeks of training with no tRNS. On the other hand, a control group that trained for two weeks without stimulation did not show any significant UCVA or UCCS improvement. These results suggest that the combination of behavioural and neuromodulatory techniques can be fast and efficacious in improving sight in individuals with mild myopia.

  3. Visual acuity and contrast sensitivity are two important factors affecting vision-related quality of life in advanced age-related macular degeneration.

    Science.gov (United States)

    Roh, Miin; Selivanova, Alexandra; Shin, Hyun Joon; Miller, Joan W; Jackson, Mary Lou

    2018-01-01

    Vision loss from age-related macular degeneration (AMD) has a profound effect on vision-related quality of life (VRQoL). The pupose of this study is to identify clinical factors associated with VRQoL using the Rasch- calibrated NEI VFQ-25 scales in bilateral advanced AMD patients. We retrospectively reviewed 47 patients (mean age 83.2 years) with bilateral advanced AMD. Clinical assessment included age, gender, type of AMD, high contrast visual acuity (VA), history of medical conditions, contrast sensitivity (CS), central visual field loss, report of Charles Bonnet Syndrome, current treatment for AMD and Rasch-calibrated NEI VFQ-25 visual function and socioemotional function scales. The NEI VFQ visual function scale includes items of general vision, peripheral vision, distance vision and near vision-related activity while the socioemotional function scale includes items of vision related-social functioning, role difficulties, dependency, and mental health. Multiple regression analysis (structural regression model) was performed using fixed item parameters obtained from the one-parameter item response theory model. Multivariate analysis showed that high contrast VA and CS were two factors influencing VRQoL visual function scale (β = -0.25, 95% CI-0.37 to -0.12, p<0.001 and β = 0.35, 95% CI 0.25 to 0.46, p<0.001) and socioemontional functioning scale (β = -0.2, 95% CI -0.37 to -0.03, p = 0.023, and β = 0.3, 95% CI 0.18 to 0.43, p = 0.001). Central visual field loss was not assoicated with either VRQoL visual or socioemontional functioning scale (β = -0.08, 95% CI-0.28 to 0.12,p = 0.44 and β = -0.09, 95% CI -0.03 to 0.16, p = 0.50, respectively). In patients with vision impairment secondary to bilateral advanced AMD, high contrast VA and CS are two important factors affecting VRQoL.

  4. Visual acuity and contrast sensitivity are two important factors affecting vision-related quality of life in advanced age-related macular degeneration

    Science.gov (United States)

    Selivanova, Alexandra; Shin, Hyun Joon; Miller, Joan W.; Jackson, Mary Lou

    2018-01-01

    Purpose Vision loss from age-related macular degeneration (AMD) has a profound effect on vision-related quality of life (VRQoL). The pupose of this study is to identify clinical factors associated with VRQoL using the Rasch- calibrated NEI VFQ-25 scales in bilateral advanced AMD patients. Methods We retrospectively reviewed 47 patients (mean age 83.2 years) with bilateral advanced AMD. Clinical assessment included age, gender, type of AMD, high contrast visual acuity (VA), history of medical conditions, contrast sensitivity (CS), central visual field loss, report of Charles Bonnet Syndrome, current treatment for AMD and Rasch-calibrated NEI VFQ-25 visual function and socioemotional function scales. The NEI VFQ visual function scale includes items of general vision, peripheral vision, distance vision and near vision-related activity while the socioemotional function scale includes items of vision related-social functioning, role difficulties, dependency, and mental health. Multiple regression analysis (structural regression model) was performed using fixed item parameters obtained from the one-parameter item response theory model. Results Multivariate analysis showed that high contrast VA and CS were two factors influencing VRQoL visual function scale (β = -0.25, 95% CI-0.37 to -0.12, p<0.001 and β = 0.35, 95% CI 0.25 to 0.46, p<0.001) and socioemontional functioning scale (β = -0.2, 95% CI -0.37 to -0.03, p = 0.023, and β = 0.3, 95% CI 0.18 to 0.43, p = 0.001). Central visual field loss was not assoicated with either VRQoL visual or socioemontional functioning scale (β = -0.08, 95% CI-0.28 to 0.12,p = 0.44 and β = -0.09, 95% CI -0.03 to 0.16, p = 0.50, respectively). Conclusion In patients with vision impairment secondary to bilateral advanced AMD, high contrast VA and CS are two important factors affecting VRQoL. PMID:29746512

  5. Visual field structure in the Empress Leilia, Asterocampa leilia (Lepidoptera, Nymphalidae): dimensions and regional variation in acuity.

    Science.gov (United States)

    Rutowski, Ronald L; Warrant, Eric J

    2002-02-01

    Male Empress Leilia butterflies ( Asterocampa leilia) use a sit-and-wait tactic to locate mates. To see how vision might influence male behavior, we studied the morphology, optics, and receptor physiology of their eyes and found the following. (1) Each eye's visual field is approximately hemispherical with at most a 10 degrees overlap in the fields of the eyes. There are no large sexual differences in visual field dimensions. (2) In both sexes, rhabdoms in the frontal and dorsal ommatidia are longer than those in other eye regions. (3) Interommatidial angles are smallest frontally and around the equator of the eye. Minimum interommatidial angles are 0.9-1 degrees in males and 1.3-1.4 degrees in females. (4) Acceptance angles of ommatidia closely match interommatidial angles in the frontal region of the eye. We conclude that vision in these butterflies is mostly monocular and that males have more acute vision than females, especially in the frontal region (large facets, small interommatidial angles, small acceptance angles, long rhabdoms, and a close match between interommatidial angles and acceptance angles). This study also suggests that perched males direct their most acute vision where females are likely to appear but show no eye modifications that appear clearly related to a mate-locating tactic.

  6. Long-Term Visual Training Increases Visual Acuity and Long-Term Monocular Deprivation Promotes Ocular Dominance Plasticity in Adult Standard Cage-Raised Mice

    OpenAIRE

    Hosang, Leon; Yusifov, Rashad; Löwel, Siegrid

    2018-01-01

    Abstract For routine behavioral tasks, mice predominantly rely on olfactory cues and tactile information. In contrast, their visual capabilities appear rather restricted, raising the question whether they can improve if vision gets more behaviorally relevant. We therefore performed long-term training using the visual water task (VWT): adult standard cage (SC)-raised mice were trained to swim toward a rewarded grating stimulus so that using visual information avoided excessive swimming toward ...

  7. Long-term visual acuity, retention and complications observed with the type-I and type-II Boston keratoprostheses in an Irish population.

    Science.gov (United States)

    Duignan, E S; Ní Dhubhghaill, S; Malone, C; Power, W

    2016-08-01

    To evaluate the outcomes of the type-I and type-II Boston keratoprostheses in a single Irish centre. A retrospective chart review of keratoprosthesis implantations carried out in our institution from November 2002 to March 2014 was performed. All procedures were performed by a single surgeon (WP). Thirty-four keratoprosthesis implantations were carried out in 31 patients with a mean follow-up of 42±31 months (range 2-110 months). Seventeen patients were female (54.8%) and 14 were male (45.2%). The majority of keratoprostheses implanted were type-I (31/34, 91.2%), and three were type-II (3/34, 8.8%). Twenty-nine patients (85.3%) had an improvement in distance best-corrected visual acuity (BCVA) from baseline. Fifty per cent (17/34) of patients had a best-ever BCVA of at least 6/12. Eighteen patients (64.3%) retained a BCVA of at least 6/60 at 1 year. Over the course of follow-up, six keratoprostheses were explanted from six eyes of five patients, one of which was a type-II keratoprosthesis. Twenty-six patients (76.5%) developed postoperative complications. Complications included retroprosthetic membrane (18 patients, 52.9%), an exacerbation or new diagnosis of glaucoma (6 patients, 17.6%), endophthalmitis (5 patients, 14.7%) and retinal detachment (2 patients, 5.9%). These data demonstrate excellent visual acuity and retention outcomes in a cohort with a long follow-up period in a single centre. Complications remain a considerable source of morbidity. These outcomes provide further evidence for the long-term stability of type-I and type-II Boston keratoprostheses in the management of patients in whom a traditional graft is likely to fail. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  8. Variação da acuidade visual em pacientes jovens com ectopia lentis submetidos à cirurgia Variation of visual acuity in young patients with ectopia lentis submitted to surgery

    Directory of Open Access Journals (Sweden)

    Mauro Waiswol

    2005-08-01

    Full Text Available OBJETIVOS:Avaliar os resultados quanto à acuidade visual, de dois procedimentos cirúrgicos para a ectopia lentis. MÉTODOS: Foram operados 51 olhos de 28 pacientes (16 do sexo masculino e 12 do feminino, com média de idade de 16,00±8,5 anos com ectopia lentis simples (19 casos, ou associada à síndrome de Marfan (nove casos, com diferentes graus de subluxação cristaliniana. Em 21 casos a técnica empregada foi a facectomia com implante de lente intra-ocular (LIO por fixação escleral e em 30 casos foi utilizada a facectomia com implante da lente intra-ocular no saco capsular, previamente expandido por anel endocapsular (ANEL. Os resultados enfatizaram a acuidade visual pré e pós-operatória em seguimento de seis meses. RESULTADOS:Em ambas as técnicas, a acuidade visual pós-operatória sem e com correção teve aumento significante, que foi maior nos casos operados com fixação escleral da lente intra-ocular. Mais do que a técnica empregada, os graus de subluxação pré-operatórios foram determinantes para os resultados. CONCLUSÕES: Mediante as técnicas operatórias apresentadas, a correção cirúrgica da ectopia lentis simples ou associada à síndrome de Marfan é segura e eficaz, com recuperação significante da acuidade visual, embora os resultados operatórios dependam, intrinsecamente, dos graus pré-operatórios de subluxação do cristalino.PURPOSE: To assess the results as to visual acuity of two different surgical procedures for ectopia lentis. METHODS: Fifty-one eyes of 28 patients (16 males and 12 females, mean age 16.00± 8.5 with simple (19 cases or Marfan syndrome-associated (9 cases ectopia lentis with different levels of subluxation underwent lens extraction with implantation of intraocular lenses (IOL with scleral fixation (21 cases or by lens extraction with implantation of the intraocular lenses in the capsular bag expanded by endocapsular ring (RING (30 cases. Result analysis emphasized pre- and

  9. Structural analysis of retinal photoreceptor ellipsoid zone and postreceptor retinal layer associated with visual acuity in patients with retinitis pigmentosa by ganglion cell analysis combined with OCT imaging

    Science.gov (United States)

    Liu, Guodong; Li, Hui; Liu, Xiaoqiang; Xu, Ding; Wang, Fang

    2016-01-01

    Abstract The aim of this study was to examine changes in photoreceptor ellipsoid zone (EZ) and postreceptor retinal layer in retinitis pigmentosa (RP) patients by ganglion cell analysis (GCA) combined with optical coherence tomography (OCT) imaging to evaluate the structure–function relationships between retinal layer changes and best corrected visual acuity (BCVA). Sixty-eight eyes of 35 patients with RP and 65 eyes of 35 normal controls were analyzed in the study. The average length of EZ was 911.1 ± 208.8 μm in RP patients, which was shortened with the progression of the disease on the OCT images. The average ganglion cell–inner plexiform layer thickness (GCIPLT) was 54.7 ± 18.9 μm in RP patients, while in normal controls it was 85.6 ± 6.8 μm. The GCIPLT in all quarters became significantly thinner along with outer retinal thinning. There was a significantly positive correlation between BCVA and EZ (r = −0.7622, P retinal layer changes from a new perspective in RP patients, which suggests that EZ and GCIPLT obtained by GCA combined with OCT imaging are the direct and valid indicators to diagnosis and predict the pathological process of RP. PMID:28033301

  10. Restoration of the photoreceptor layer and improvement of visual acuity in successfully treated optic disc pit maculopathy: a long follow-up study by optical coherence tomography.

    Science.gov (United States)

    Theodossiadis, George P; Grigoropoulos, Vlassis G; Liarakos, Vasilis S; Rouvas, Alexandros; Emfietzoglou, Ioannis; Theodossiadis, Panagiotis G

    2012-07-01

    To investigate by optical coherence tomography (OCT) the evolution of the photoreceptor layer and its association with best-corrected visual acuity (BCVA) in optic disc pit (ODP) maculopathy after successful surgical treatment. Fourteen eyes of 14 patients were included in this study, and followed up from 36 to 95 months (mean 57.36 ± 18.32 months). The follow-up period started at the time of complete subretinal fluid absorption. Examination was performed by time-domain OCT before and after treatment. Spectral-domain OCT was used after treatment. Parameters assessed were type of elevation, central foveal thickness, time elapsed from onset to treatment, type of treatment, BCVA, and inner segment outer segment (IS/OS) junction line. The IS/OS junction was characterized after treatment as intact, interrupted, or absent (not distinguishable). Significant restoration of the IS/OS junction line was first noticed between 6 and 12 months after fluid absorption (p = 0.02; Wilcoxon signed rank test). Restoration was continuous up to the 24th month of postoperative examination after fluid absorption (p = 0.14; Wilcoxon signed rank test). BCVA was 0.99 ± 0.38 logMar before treatment, 0.81 ± 0.26 logMar (p = 0.011; paired t-test) immediately after fluid absorption and 0.61 ± 0.33 logMar (p = 0.026; one-way ANOVA) 24 months after fluid resolution. BCVA was significantly positively correlated with the integrity of the IS/OS junction line during follow-up (Pearson r = 0.775; p final photoreceptor layer condition and BCVA immediately after fluid absorption are the main factors predicting final BCVA after successful surgical treatment of ODP maculopathy.

  11. Subluxação congênita do cristalino: resultados visuais e posição das lentes intraoculares após a cirurgia Congenital lens subluxation: visual acuity outcomes and intraocular lens postoperative position

    Directory of Open Access Journals (Sweden)

    Caroline Arraes

    2010-04-01

    Full Text Available OBJETIVO: Avaliar os resultados visuais e investigar, através da biomicroscopia ultrassônica, o posicionamento das lentes intraoculares e do anel endocapsular em 17 olhos de 10 portadores de subluxação congênita do cristalino, submetidos à mesma técnica cirúrgica pelo mesmo cirurgião. MÉTODOS: O estudo foi realizado no Hospital de Olhos de Pernambuco e Fundação Altino Ventura. A técnica cirúrgica consistiu em facoaspiração com implante de anel endocapsular e de lentes intraoculares com amputação de uma das alças. A idade variou entre 7 e 22 anos. Foram coletados dados sobre acuidade visual para longe pré e pós-operatória, tempo de seguimento após a cirurgia e complicações. Os pacientes foram submetidos à biomicroscopia ultrassônica. RESULTADOS: O tempo de seguimento médio foi de 2,8 anos. Houve melhora da acuidade visual para longe nos 17 (100% olhos: 12 olhos (70,6% apresentaram acuidade visual para longe melhor que 20/40; 4 (23,5% apresentaram acuidade visual para longe entre 20/40 e 20/100 e 1 (5,9% apresentou acuidade visual para longe pior que 20/100, porém melhor que acuidade visual para longe pré-operatória. A opacificação da cápsula posterior ocorreu em 10 olhos (58,9%. Na biomicroscopia ultrassônica observou-se que todas as lentes intraoculares estavam parcialmente descentralizadas, contudo sem atingir o bordo pupilar. Em todos os casos observou-se um adequado posicionamento do anel e um bom suporte capsular. CONCLUSÃO É possível concluir que o tratamento cirúrgico avaliado proporciona uma boa centralização das lentes intraoculares e do anel endocapsular, com melhora da acuidade visual para longe, sendo uma opção viável, eficaz e segura na reabilitação visual dos pacientes com subluxação congênita do cristalino.PURPOSE: To evaluate the visual acuity outcomes and to investigate the intraocular lens (IOL and endocapsular ring positions with ultrasound biomicroscopy in 17 eyes of 10 patients

  12. Evaluation of best corrected visual acuity and central macular thickness after intravitreal dexamethasone implant injections in patients with Irvine-Gass syndrome: A retrospective study of six cases.

    Science.gov (United States)

    Keilani, Chafik; Halalchi, Aziz; Wakpi Djeugue, Désiré; Regis, Anne; Abada, Samir

    2016-10-01

    Irvine-Gass syndrome is a macular edema (ME) that specifically occurs after cataract surgery. Its incidence varies from 0.2-2%. The purpose of this study is to evaluate the effectiveness of intravitreal dexamethasone implant injections in patients with Irvine-Gass syndrome. Patients with ME secondary to cataract surgery who underwent intravitreal injections of dexamethasone implant between December 2011 to October 2014 at François-Quesnay hospital (Mantes-la-Jolie, France) were retrospectively reviewed. The patients were followed for at least 10 months. All the patients were handled by intravitreal injection of dexamethasone in the eye of study among which some resisted to a preliminary treatment by non-steroidal anti-inflammatory drug (NSAID) and acetazolamide. The patients were examined each month. The patients were again handled by intravitreal injection of dexamethasone if they presented a recurrence. The primary endpoint of the study was determined on best corrected visual acuity (BCVA) using early diabetic retinopathy study (ETDRS) scale and central macular thickness (CMT) [μm] using optical coherence tomography (OCT) 3 and 6 months after the first injection. Secondary endpoints were the number of recurrences, the number of injections, the duration average before the first recurrence, the BCVA 10 months after the first injection and the tolerance. Six eyes of six patients were studied. At baseline, the mean (standard deviation [SD]) of the BCVA was 59.8±11. Three months after the first injection, the mean (SD) of the BCVA showed a statistically significant increase to 72.2±8.6 (P=0.03). Six months after the first injection, the mean (SD) of the BCVA showed a statistically significant increase to 72±11.8 (P=0.03). Concerning the CMT, the mean (SD) was 495.6±135.2 before treatment. Three months after the first injection, the mean (SD) of the CMT showed a statistically significant decrease to 268.6±57.8 (P=0.03). Six months after the first injection, the

  13. Statins in rhegmatogenous retinal detachment are associated with low intravitreal angiopoietin-2, VEGF and MMP-2 levels, and improved visual acuity gain in vitrectomized patients.

    Science.gov (United States)

    Tuuminen, Raimo; Haukka, Jari; Loukovaara, Sirpa

    2015-10-01

    In rhegmatogenous retinal detachment (RRD), intravitreal growth factors and cytokines may compromise post-vitrectomy outcomes. Here, we analysed perioperative intravitreal protein levels of potent vasoactive, pro-inflammatory, and extracellular matrix-remodelling factors in RRD eyes of patients treated with statins and evaluated post-vitrectomy outcome in the same study eyes. Institutional, retrospective, observational study of 14 patients operated on for RRD while on statins compared to patients without statin medication (n = 82). Vitreous samples were subjected to protein measurements of angiopoietin (ANGPT)-1 and -2, transforming growth factor-β1, and vascular endothelial growth factor (VEGF) by ELISA, and of matrix metalloproteinase (MMP)-2 and -9 by gelatin zymography. A 1-month best-corrected visual acuity (BCVA) gain was modelled by Student's T-test and multivariate linear regression with concomitant perioperative medication. Cumulative 12-month revitrectomy frequency was modelled by Kaplan-Meier log-rank test. Intravitreal levels of ANGPT-2 (49.2 ± 33.1 vs. 112.8 ± 134.1 pg/ml, mean ± SD, p < 0.001), VEGF (2.3 ± 2.4 vs. 17.7 ± 57.8 pg/ml, p = 0.021), and MMP-2 (1107.1 ± 884.6 vs 1976.4 ± 970.1 AU/ml, p = 0.005) in RRD eyes of patients treated with statins were lower than in non-statin-treated controls. Patients on statins had better 1-month BCVA improvement than did those not on statins (p = 0.022), with no difference in 1-year re-vitrectomy rates. Intravitreal levels of ANGPT-2, VEGF, factors involved in vascular permeability and inflammation, and activity of MMP-2, the factor connected with breakdown of basement membrane and fibroproliferation, were lower in RRD eyes of patients with statin treatment. At 1-month, postoperative BCVA gain was improved in statin-treated RRD eyes, suggesting that statin administration may be effective in preventing inflammation-related PVR formation.

  14. Assessment of Grating Acuity in Infants and Toddlers Using an Electronic Acuity Card: The Dobson Card.

    Science.gov (United States)

    Mohan, Kathleen M; Miller, Joseph M; Harvey, Erin M; Gerhart, Kimberly D; Apple, Howard P; Apple, Deborah; Smith, Jordana M; Davis, Amy L; Leonard-Green, Tina; Campus, Irene; Dennis, Leslie K

    2016-01-01

    To determine if testing binocular visual acuity in infants and toddlers using the Acuity Card Procedure (ACP) with electronic grating stimuli yields clinically useful data. Participants were infants and toddlers ages 5 to 36.7 months referred by pediatricians due to failed automated vision screening. The ACP was used to test binocular grating acuity. Stimuli were presented on the Dobson Card. The Dobson Card consists of a handheld matte-black plexiglass frame with two flush-mounted tablet computers and is similar in size and form to commercially available printed grating acuity testing stimuli (Teller Acuity Cards II [TACII]; Stereo Optical, Inc., Chicago, IL). On each trial, one tablet displayed a square-wave grating and the other displayed a luminance-matched uniform gray patch. Stimuli were roughly equivalent to the stimuli available in the printed TACII stimuli. After acuity testing, each child received a cycloplegic eye examination. Based on cycloplegic retinoscopy, patients were categorized as having high or low refractive error per American Association for Pediatric Ophthalmology and Strabismus vision screening referral criteria. Mean acuities for high and low refractive error groups were compared using analysis of covariance, controlling for age. Mean visual acuity was significantly poorer in children with high refractive error than in those with low refractive error (P = .015). Electronic stimuli presented using the ACP can yield clinically useful measurements of grating acuity in infants and toddlers. Further research is needed to determine the optimal conditions and procedures for obtaining accurate and clinically useful automated measurements of visual acuity in infants and toddlers. Copyright 2016, SLACK Incorporated.

  15. De olhos bem abertos: investigando acuidade visual em alunos de uma escola municipal de Vitória De ojos bien abiertos: investigar la agudeza visual de los alumnos de una escuela municipal en la ciudad de Vitória With opened eyes: evaluating the visual acuity of children at an elementary school in Vitória

    Directory of Open Access Journals (Sweden)

    Mariana Rabello Laignier

    2010-03-01

    profesional de la salud es esencial en el desarrollo de proyectos destinados a la salud escolar.This research evaluates the visual acuity of children at Prezideu Amorim Elementary School in the city of Vitória Espírito Santo, based on applying the scale of Snellen; and children who had visual disorders were referred to specialist examination at the ophthalmology clinic of Antônio Cassiano Moraes University Hospital. This essay develops a study of quantitative approach and discussed visual acuity related to sex, age, grade, use of corrective lenses and medical diagnosis. The results showed that the girls present greater prevalence of low visual acuity, as well as the younger age ranks; the use of lenses prevails on those that presented reduction of the visual acuity; and the majority of the children sent to the doctor presented some degree of ametropy. It concluded that prevention in order to get an excellent visual health is a duty of the health professional and of the professor, that together, they can develop other projects in the field of school health.

  16. A Data Mining Project to Identify Cardiovascular Related Factors That May Contribute to Changes in Visual Acuity Within the US Astronaut Corps

    Science.gov (United States)

    Westby, Christian M.; Stein, Sydney P.; Platts, Steven H.

    2011-01-01

    clearly differentiated the two mission types. Statistical analysis confirmed that pulse pressure was significantly higher before [45.6; (42.1 to 49.1)] and after [50.7; (46.9 to 54.6)] time on station compared with their most recent shuttle flight [31.6 (27.8 to 35.4), and 32.2 (28.3 to 36.0) respectively] even after correcting differences in age and cumulative number of mission hours. Without knowing the identity of which long duration crewmembers demonstrated visual changes, we were limited to examining whether certain crew regulate components of pulse pressure, systolic and diastolic blood pressure, differently due to microgravity exposure. To that end, we stratified crew into tertiles based on either their pre-flight measure of systolic or diastolic blood pressure. Those crew in the highest tertile for both systolic (lower tertile (n=8; 103-111), middle tertile (n=7; 113-121), and upper tertile (n=5; 125-136) and diastolic blood pressure (lower tertile (n=8; 58-64), middle tertile (n=7; 67-73), and upper tertile (n=5; 75-81) demonstrated less variability in pulse pressure between R+0 and L-10 (Figure 2). Interestingly, those crewmembers with the highest resting systolic blood pressure demonstrated either no change or in some instances an increase in total peripheral resistance, where those in the lower tertiles had lower values of total peripheral resistance compared to pre-flight levels. In this study, it was found that crewmembers in the highest tertile for both systolic and diastolic blood pressure demonstrated less variability in pulse pressure and that the decrease in variability was due in part to lower levels of compliance as indicated by similar or higher levels of total peripheral resistance after compared with before flight levels. Whether there is a relation between blood pressure regulation and total peripheral resistance in crew presenting with negative changes in visual acuity remains unknown.

  17. Validade da aferição da acuidade visual realizada pelo professor em escolares de 1ª à 4ª série de primeiro grau de uma escola pública do município de São Paulo, Brasil The validity of the visual acuity screening in school children carried oat by the teacher - comparative study of the visual acuity measurement by the teacher and the ophthalmologist from the city of S. Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Edméa Rita Temporini

    1977-06-01

    Full Text Available Trata-se de avaliação da medida da acuidade visual pelo professor, comparativamente àquela efetuada pelo médico-oftalmologista, utilizando-se ambos da tabela optométrica de Snellen. Éste estudo foi realizado em decorrência do Plano de Oftalmologia Sanitária Escolar (POSE, em desenvolvimento no Estado de São Paulo, que atinge escolares de 1ª série, classe especial e pré-primário das escolas estaduais de 1º grau, onde a atuação dos professores constitui fator básico da programação, principalmente no seu aspecto educativo e na verificação da acuidade visual. Foram testados 1.352 escolares de 1ª a 4ª série de 1º grau de um estabelecimento de ensino do município de São Paulo (SP em 1975. Encontrou-se uma concordância de resultados em 80,86% dos casos. Com a diferença de 2 linhas entre os resultados do professor e do médico, constataram-se 122 casos (9,02% e, com a diferença de 3 linhas, 54 casos (3,99%. À medida em que se consideravam diferenças maiores, decrescia progressivamente o número de casos discordantes encontrados. Observou-se que, à medida em que aumentava a desigualdade de aferição entre o professor e o oftalmologista, isto se verificava em ambos os olhos, o que evidencia uma dificuldade de interpretação daquelas crianças para responder o teste. Considerou-se altamente válida a aplicação do teste de acuidade visual pelo professor devidamente treinado, com a finalidade de triagem a nível de escola, como um dos aspectos para identificar alunos necessitados de exame médico-oftalmológico.The Sanitary Ophthalmology School Plan is in process in the State of S. Paulo, Brazil. It includes 1st grade primary school children, special classes and kindergarten of the government schools. The teachers play an important part in the programme as to the educational aspect and the visual acuity screening. This report presents an evaluation of the visual acuity test done by the teacher in comparison with the one

  18. Uncorrected and Corrected Distance Visual Acuity, Predictability, Efficacy, and Safety after Femtosecond Laser in Situ Keratomileusis (FS-LASIK) and Refractive Lenticule extraction (ReLEx) for Moderate and High Myopia

    DEFF Research Database (Denmark)

    Vestergaard, Anders; Justesen, Birgitte Larsen; Melsen, Charlotte

    Title: Uncorrected and Corrected Distance Visual Acuity, Predictability, Efficacy, and Safety after Femtosecond Laser in Situ Keratomileusis (FS-LASIK) and Refractive Lenticule extraction (ReLEx) for Moderate and High Myopia. Vestergaard A., Justesen B., Melsen C., Lyhne N., Department of Ophthal......Title: Uncorrected and Corrected Distance Visual Acuity, Predictability, Efficacy, and Safety after Femtosecond Laser in Situ Keratomileusis (FS-LASIK) and Refractive Lenticule extraction (ReLEx) for Moderate and High Myopia. Vestergaard A., Justesen B., Melsen C., Lyhne N., Department...... predictability, efficacy and safety after femtosecond LASIK (FS-LASIK) with ReLEx. Setting: Department of Ophthalmology, Odense University Hospital, Denmark. Methods: Retrospective study of results after FS-LASIK and ReLEx (including ReLEx flex, ReLEx pseudo-smile, and ReLEx smile). In total, 228 eyes were...... treated with FS-LASIK and 83 eyes with ReLEx, at the Department of Ophthalmology, Odense University Hospital in the period of April to November 2011. Only otherwise healthy myopic eyes with up to 3.00 D of astigmatism and with CDVA ≤ 0.30 (logMAR) before surgery were included in this study. FS-LASIK flaps...

  19. Diabetic macular oedema treated with intravitreal anti-vascular endothelial growth factor - 2-4 years follow-up of visual acuity and retinal thickness in 566 patients following Danish national guidelines

    DEFF Research Database (Denmark)

    Hodzic-Hadzibegovic, Delila; Sander, Birgit Agnes; Monberg, Tine Juul

    2017-01-01

    : Retrospective cohort study of 566 eyes in 566 patients with centre-involved DME who started intravitreal treatment with ranibizumab between January 2011 and December 2013 in the Greater Copenhagen region. Data were retrieved from a database and patient records between January 2011 and March 2016 and analysed...... using mixed-model statistics. Results: At the conclusion of follow-up, 24.6% were in active ranibizumab follow-up, 25.4% had switched to other intravitreal pharmacotherapy, 31.6% had been discontinued because of disease stability, 13.8% had been lost to follow-up, 1.4% had been discontinued because...... of low visual acuity (VA), and 3.2% had died. At baseline, mean best-corrected visual acuity (BCVA) and mean central subfield thickness (CST) were 64.9 (±15.0) letters and 400.2 (±120.3) μm. Mean change in BCVA and mean change in CST from baseline to 3, 12, 24, 36 and 48 months of follow-up were +3.9, +3...

  20. A variação da acuidade visual durante esforços físicos em atletas com baixa visão, participantes de seleção brasileira de atletismo The visual acuity variability during physical efforts in low vision athletes from the athletics Brazilian team

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    Ciro Winckler de Oliveira Filho

    2007-08-01

    Full Text Available INTRODUÇÃO E OBJETIVO: Esta pesquisa teve como objetivo avaliar o comportamento da acuidade visual em atletas com baixa visão, durante um protocolo de esforço contínuo. Pesquisas apontam que a acuidade visual apresenta variações de rendimento quando submetida a esforços físicos em sujeitos sem deficiência visual. MÉTODO: A população estudada foi composta por seis pessoas, praticantes de atletismo e integrantes da seleção brasileira em provas de pista. No primeiro dia aplicou-se o teste de esforço físico progressivo, realizado em esteira. No segundo dia realizou-se o teste de esforço contínuo, o qual foi dividido em três níveis, cada um com 15 minutos de duração e 30 minutos de intervalo entre eles. Como delimitador das intensidades aplicadas utilizaram-se os resultados obtidos no teste de físico progressivo (60% do VE pico, limiar de VE e 90% do VE pico. A aferição da acuidade visual aconteceu antes, durante e após cada nível de intensidade no protocolo de esforço contínuo. O teste t de Student foi utilizado para a análise estatística (p INTRODUCTION AND OBJECTIVE: This study had as an objective to evaluate the visual acuity behavior in athletes with low vision, during a continuous effort protocol. Researches point out that visual acuity presents performance varieties when submitted to physical efforts in subjects without visual impairment. METHOD: The studied population was composed by six peoples, who practiced athletics and were part of the Brazilian team in track events. The progressive physical effort test was applied on the first day in a treadmill. On the second day the continuous effort test was applied, which was divided in three levels, each one had a 15 and 30 minutes break between them. To determine the intensities, the results obtained in the progressive physical effort test (60% of VE peak, limiar VE and 90% VE peak were used. The visual acuity was measured before, during and after each level of

  1. An acuity cards cookbook.

    Science.gov (United States)

    Vital-Durand, F

    1996-01-01

    Acuity cards are being more commonly used in clinical and screening practice. The author describes his experience from over 6000 infants tested with the method, using two commercially available sets of cards to provide users with comprehensive guidelines to allow them to get the most out of this useful test.

  2. Resultados da correção cirúrgica de esotropias de grande ângulo, em portadores de baixa de acuidade visual unilateral Results of surgical treatment of large angle esotropia in patients with low visual acuity

    Directory of Open Access Journals (Sweden)

    Jorge Antonio Meireles-Teixeira

    2000-10-01

    Full Text Available Objetivo: Avaliar os resultados cirúrgicos de esotropias de grande ângulo (no mínimo 60 dioptrias prismáticas - dp, associadas à baixa de acuidade visual (BAV unilateral, cuja cirurgia foi planejada com o intuito de não se operar o olho de melhor visão. Casuística e Métodos: Foram selecionados 17 casos de esotropias não-acomodativas, associadas à BAV (AV 15 dp ou rotações de ± 4. Resultados: 13 (76,4% tinham AV de conta-dedos no olho não-fixador, 2 (11,7% atingiam 0,1 e outros 2 (11,7% 0,4. Em 3 havia alta miopia (equivalente esférico > ou = -6,00 dioptrias esféricas em ambos os olhos. Entre os 17 pacientes, 12 (70,5% obtiveram bom resultado cirúrgico, 3 (17,6% foram regulares e 2 (11,7% ruins. Conclusão: A cirurgia de estrabismo sob anestesia tópica mostrou ser eficaz e segura nestes casos especiais de BAV em um dos olhos, sendo que na maioria das vezes consegue-se não operar o olho de melhor visão; o que a nosso ver, só se tornou possível pelo uso da anestesia tópica.Purpose: To evaluate the surgical outcome of large angle esotropia (minimum of 60 prism diopters -- pd associated with unilateral low visual acuity (LVA in which the surgical strategy was applied in order to operate only the non-fixating eye. Patients and Methods: We selected 17 patients with non-accommodative esotropia, LVA (VA<= 0,4 in the non-fixating eye with the better visual correction and no previous treatment. Patients were classified as good result if they had a postoperative deviation of maximally 10 pd with binocular rotations of up to --2 of medial rectus and +2 of lateral rectus. Exotropia/esotropia between 10 and 15 pd or binocular rotations of ±3 were considered as a regular outcome. Deviations greater than 15 pd or binocular rotations of ±4 were included regarded as poor results. Results: Thirteen (76.4% patients had counts fingers VA in the non-fixating eye, 2 (11.7% achieved 0.1 and another two had 0.4. Three of them were also highly

  3. Age norms for monocular grating acuity measured by sweep-VEP in the first three years of age Estudo normativo de acuidade visual de resolução de grades medido pelo PVE de varredura nos três primeiros anos de vida

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    Solange Rios Salomão

    2008-08-01

    Full Text Available PURPOSE: To determine age norms for grating visual acuity and interocular acuity differences measured by the sweep-visually evoked potentials (VEP technique in the first three years of life. METHODS: Monocular grating visual acuity was measured using the sweep-VEP in 67 healthy normal infants and children in the first 36 months of life. RESULTS: Sweep-VEP grating acuity ranged from 0.80 logMAR (20/125 Snellen equivalent in the first month of life to 0.06 logMAR (20/20 Snellen equivalent at 36 months of age. Lower normal limits (95th percentile limit ranged from 0.95 logMAR (20/180 to 0.12 logMAR (20/25 with a progression of approximately 3 octaves in the first 36 months of age. The largest acceptable interocular acuity difference for clinical purposes was 0.10 logMAR. CONCLUSIONS: Age norms for grating acuity along with interocular acuity differences were determined using the sweep-VEP technique. These norms should be incorporated in clinical practice for precise diagnosis of visual status in infants and preverbal children.OBJETIVOS: Propor valores normativos de acuidade visual de grades e sua respectiva diferença interocular medidas pelo potencial visual evocado de varredura nos primeiros três anos de vida. MÉTODOS: Foram avaliadas 67 crianças sadias, sem doenças oculares, que tiveram a acuidade visual medida pelos potenciais evocados visuais de varredura. RESULTADOS: A acuidade visual média variou de 0,80 logMAR (equivalente de Snellen de 20/125 no primeiro mês de vida a 0,06 logMAR (equivalente de Snellen de 20/20 aos 36 meses. Os limites normais inferiores (percentil 95% variaram de 0,95 logMAR (20/180 a 0,12 logMAR (20/25 com progressão de aproximadamente 3 oitavas nos primeiros 36 meses de vida. A diferença interocular máxima aceitável foi de 0,10 logMAR. CONCLUSÕES: Os valores normativos de acuidade visual e de diferença interocular de acuidade foram obtidos pela técnica do potencial visual evocado de varredura. Prop

  4. Qualidade da avaliação da acuidade visual realizada pelos professores do programa " Olho no olho" da cidade de Marília, SP Assessment of visual acuity evaluation performed by teachers of the "Eye in eye" program in Marília-SP, Brazil

    Directory of Open Access Journals (Sweden)

    Lígia Issa De Fendi

    2008-08-01

    Full Text Available OBJETIVOS: Avaliar a qualidade e o ponto de corte (AV PURPOSE: To assess quality and cut-off point (VA <0.7 of the examinations performed by teachers to detect reduced visual acuity (VA in schoolchildren participants of the project called "Eye in eye " in Marilia-SP, Brazil. METHODS: Visual acuity measurements were performed by trained teachers using Snellen's chart. The children with VA <0.7 in one of the eyes were referred to an ophthalmic examination. The ophthalmic examination was considered gold standard to assess quality and cut-off point of the examinations performed by teachers. VA test was performed in 604 schoolchildren of state public schools (1,208 eyes. Analyses were based on examined eyes. We calculated sensitivity (S, specificity (E, positive predictive value (PPV, negative predictive value (NPV and likelihood rate (LR. We compared the means obtained by the teachers' examinations to means of the ophthalmologist's examinations. ROC curve was produced to evaluate whether VA lower than 0.7 is the best value for referral to an ophthalmic examination. RESULTS: VA means obtained by teachers and ophthalmologic examinations were 0.70 ± 0.16 and 0.88 ± 0.2 respectively. The difference between teachers' and ophthalmologists' examinations was 0.18 (p<0.0001. S, E, PPV, NPV e LR were: 82%, 40%, 27%, 89% and 1.37, respectively. False positive and negative rates were 59.5% and 18%. ROC curve evidenced that visual acuity of 0.7 was the best cut-off point to refer schoolchildren to an ophthalmic exam. CONCLUSIONS: We demonstrated the importance of the teachers' participation in improved schoolchildren ocular health. The examination performed by teachers obtained a satisfactory S with low E, NPV and high values of false positive results. The best cut-off point to refer schoolchildren to an ophthalmic examination was VA of 0.7.

  5. Color improves ‘visual’ acuity via sound

    Directory of Open Access Journals (Sweden)

    Shelly eLevy-Tzedek

    2014-11-01

    Full Text Available Visual-to-auditory sensory substitution devices (SSDs convey visual information via sound, with the primary goal of making visual information accessible to blind and visually impaired individuals. We developed the EyeMusic SSD, which transforms shape, location and color information into musical notes. We tested the 'visual' acuity of 23 individuals (13 blind and 10 blindfolded sighted on the Snellen tumbling-E test, with the EyeMusic. Participants were asked to determine the orientation of the letter ‘E’. The test was repeated twice: in one test, the letter ‘E’ was drawn with a single color (white, and in the other test, with two colors (red and white. In the latter case, the vertical line in the letter, when upright, was drawn in red, with the three horizontal lines drawn in white. We found no significant differences in performance between the blind and the sighted groups. We found a significant effect of the added color on the ‘visual’ acuity. The highest acuity participants reached in the monochromatic test was 20/800, whereas with the added color, acuity doubled to 20/400. We conclude that color improves 'visual' acuity via sound.

  6. Color improves “visual” acuity via sound

    OpenAIRE

    Levy-Tzedek, Shelly; Riemer, Dar; Amedi, Amir

    2014-01-01

    Visual-to-auditory sensory substitution devices (SSDs) convey visual information via sound, with the primary goal of making visual information accessible to blind and visually impaired individuals. We developed the EyeMusic SSD, which transforms shape, location, and color information into musical notes. We tested the “visual” acuity of 23 individuals (13 blind and 10 blindfolded sighted) on the Snellen tumbling-E test, with the EyeMusic. Participants were asked to determine the orientation of...

  7. Influência do astigmatismo corneano na acuidade visual final após implante de AcrySof® ReSTOR®: relato de caso Influence of corneal astigmatism in final visual acuity after implantation of AcrySofTM ReSTOR TM: case report

    Directory of Open Access Journals (Sweden)

    Ricardo de Carvalho Rocha

    2007-12-01

    Full Text Available Atualmente tem-se desenvolvido novos tipos de lentes intra-oculares (LIO que objetivam eliminar a presbiopia e o seu uso vem se popularizando. Descreve-se o caso de um paciente com catarata bilateral e irregularidades corneanas e astigmatismo maior que 2 D à topografia, no qual implantou-se a LIO AcrySof® ReSTOR® no olho esquerdo associado à realização de incisões limbares relaxantes para tentar diminuir o astigmatismo corneano observado. A acuidade visual pós-operatória, tanto para perto quanto para longe, ficou abaixo das expectativas, sem melhora à refração e sem uma outra alteração que a justificasse, além das citadas. Após 45 dias, sem melhora da acuidade visual, efetuou-se o explante desta LIO, seguindo-se de implante de uma monofocal, sendo observada melhora da acuidade visual corrigida final. Assim, o presente caso clínico reforça a necessidade de uma correta seleção pré-operatória dos pacientes candidatos ao implante deste tipo de LIO multifocal, atentando inclusive para os dados topográficos.Currently, new types of intraocular lenses have been developed aiming to eliminate presbyopia and the use has become more popular. The authors report the case of a patient with bilateral cataract and corneal irregularities and astigmatism higher than 2D in the corneal topography, in which AcrySofTM ReSTOR TM intraocular lens was implanted in the left eye associated to relaxing limbal incisions trying to reduce corneal astigmatism. The near and distance postoperative visual acuity were worse than expected, with no improvement with refraction. Apparently, no other reason apart from irregular astigmatism/multifocal lens justified the low vision. After 45 days, with no visual acuity improvement, the intraocular lens was explanted and a monofocal one was implanted. The final corrected visual acuity improved. Thus, the present case emphasizes the need of a correct preoperative selection of patients to implant this type of

  8. Standard-Fractionated Radiotherapy for Optic Nerve Sheath Meningioma: Visual Outcome Is Predicted by Mean Eye Dose

    Energy Technology Data Exchange (ETDEWEB)

    Abouaf, Lucie [Neuro-Ophthalmology Unit, Pierre-Wertheimer Hospital, Hospices Civils de Lyon, Lyon (France); Girard, Nicolas [Radiotherapy-Oncology Department, Lyon Sud Hospital, Hospices Civils de Lyon, Lyon (France); Claude Bernard University, Lyon (France); Lefort, Thibaud [Neuro-Radiology Department, Pierre-Wertheimer Hospital, Hospices Civils de Lyon, Lyon (France); D' hombres, Anne [Claude Bernard University, Lyon (France); Tilikete, Caroline; Vighetto, Alain [Neuro-Ophthalmology Unit, Pierre-Wertheimer Hospital, Hospices Civils de Lyon, Lyon (France); Claude Bernard University, Lyon (France); Mornex, Francoise, E-mail: francoise.mornex@chu-lyon.fr [Claude Bernard University, Lyon (France)

    2012-03-01

    Purpose: Radiotherapy has shown its efficacy in controlling optic nerve sheath meningiomas (ONSM) tumor growth while allowing visual acuity to improve or stabilize. However, radiation-induced toxicity may ultimately jeopardize the functional benefit. The purpose of this study was to identify predictive factors of poor visual outcome in patients receiving radiotherapy for ONSM. Methods and Materials: We conducted an extensive analysis of 10 patients with ONSM with regard to clinical, radiologic, and dosimetric aspects. All patients were treated with conformal radiotherapy and subsequently underwent biannual neuroophthalmologic and imaging assessments. Pretreatment and posttreatment values of visual acuity and visual field were compared with Wilcoxon's signed rank test. Results: Visual acuity values significantly improved after radiotherapy. After a median follow-up time of 51 months, 6 patients had improved visual acuity, 4 patients had improved visual field, 1 patient was in stable condition, and 1 patient had deteriorated visual acuity and visual field. Tumor control rate was 100% at magnetic resonance imaging assessment. Visual acuity deterioration after radiotherapy was related to radiation-induced retinopathy in 2 patients and radiation-induced mature cataract in 1 patient. Study of radiotherapy parameters showed that the mean eye dose was significantly higher in those 3 patients who had deteriorated vision. Conclusions: Our study confirms that radiotherapy is efficient in treating ONSM. Long-term visual outcome may be compromised by radiation-induced side effects. Mean eye dose has to be considered as a limiting constraint in treatment planning.

  9. Dynamic Visual Acuity Assessment Through Visors

    National Research Council Canada - National Science Library

    Pinkus, Alan

    2004-01-01

    ..., and aircraft windscreens. Transparency attributes that can be investigated include transmission coefficient, reflection coefficient, glare, light level, target contrast, target type, resolution, spectral transmission, haze...

  10. Clinical and social characteristics associated with reduced visual acuity at presentation in Australian patients with neovascular age-related macular degeneration: a prospective study from a long-term observational data set. The Fight Retinal Blindness! Project.

    Science.gov (United States)

    Nguyen, Vuong; Daien, Vincent; Guymer, Robyn H; McAllister, Ian L; Morlet, Nigel; Barthelmes, Daniel; Gillies, Mark C

    2018-04-01

    Identifying variables that influence presenting visual acuity (VA) in patients with neovascular age-related macular degeneration (nAMD) is important because it is a strong predictor of long-term outcomes. To assess the clinical and social characteristics associated with low presenting VA in nAMD patients. The present study is a cross-sectional analysis from a prospective, observational database. We identified 3242 treatment-naïve patients from 54 Australian practices in the Fight Retinal Blindness! registry. Age, gender, ethnicity and VA were recorded at the baseline visit. Socio-economic status was determined using the Australian Bureau of Statistics socio-economic indexes for areas. Association between clinical and socio-economic characteristics with presenting VA was identified. Poor VA (≤35 letters) in the presenting eye was associated with older age (adjusted odds ratio [AOR]: 1.33 for patients aged ≥80 years vs. <80 years [95% confidence interval, CI: 1.04, 1.71]), treatment at a public practice (AOR: 1.91 for public vs. private practices [95% CI: 1.46, 2.50]) and intermediate (36-69 letters) VA in the fellow eye (AOR: 0.67 [95% CI: 0.47, 0.95] and 0.64 [95% CI: 0.48, 0.85] for poor [≤35 letters] and good [≥70 letters] VA vs. intermediate VA in the fellow eye). Gender, ethnicity and socio-economic status were not independently associated with VA at presentation. Poor presenting vision is detrimental to the long-term outcomes of nAMD. Poor presentation of nAMD in Australia may not be related to socio-economic circumstances, but due to systems of care. Further research is warranted to determine why patients at public practices present with worse vision compared with private practices in Australia. © 2017 Royal Australian and New Zealand College of Ophthalmologists.

  11. Perfil morfofuncional de pacientes com retinopatia diabética sem baixa acuidade visual severa em hospital público de referência em diabetes no Brasil Morpho-functional profile of patients with diabetic retinopathy without severe loss of visual acuity in a public hospital of reference in diabetes in Brazil

    Directory of Open Access Journals (Sweden)

    Alípio de Sousa Neto

    2010-02-01

    que o grupo da endocrinologia.OBJECTIVE: To demonstrate the morpho-functional profile of the evaluation of patients with diabetic retinopathy without severe loss of visual acuity in a public hospital of reference in endocrinology, determining in this sample, the relation between the time of diabetes, age and visual acuity with the retinal thickness measured by the optical Coherence tomography (OCT and fundus picture (FP. METHODS: Prospective, linear study was carried through, in transversal cut of 61 consecutive patients with diabetic retinopathy registered in the HRT, and refered from the services of ophthalmology and endocrinology. Patients had been submitted to a complete ophthalmic evaluation including clinical history, visual acuity with correction and pin hole. The patients who had presented diabetic retinopathy, with transparent media, without previous surgery, nor previous Laser photocoagulation and with visual acuity better than 20/100 at Snelen scale, had been included in the study. After the elimination of the patients who had not obeyed the inclusion/exclusion criteria 109 eyes of 55 patients then had been submitted the OCT and FP for evaluation of the presence or absence of edema by the FP and of the quantitative evaluation (measured of the retinal thickness of the 9 regions of the pelo Early Tratment Diabetic Retinophaty Study (ETDRS, and of the qualitative evaluation (presence or absence of retinal edema for the central slit, number 1. RESULTS: The average time of diabetes was of 12 years, varying of 23 to 86 years old. 51% were female, and 49% male. The OCT demonstrated discrete reduction of the retinal thickness with elapsing of the age. The patients of the ophthalmology had greaters values of retinal thickness of what of the group of the endocrinology. The evaluation of the visual acuity improved with pin hole in 47% (51/109. The endocrinology group were 45% (23/50 of the eyes and the ophthalmology group were 55% (28/59. Only 22% (24/109 of the eyes

  12. Cardiac troponin T and CK-MB mass release after visually successful percutaneous transluminal coronary angioplasty in stable angina pectoris

    DEFF Research Database (Denmark)

    Ravkilde, J; Nissen, H; Mickley, H

    1994-01-01

    The incidence of cardiac troponin T (Tn-T) and creatine kinase (CK) isoenzyme MB mass release was studied in 23 patients with stable angina pectoris undergoing visually successful percutaneous transluminal coronary angioplasty (PTCA). Serial blood samples were drawn for measurement of serum Tn...

  13. VEP-based acuity assessment in low vision.

    Science.gov (United States)

    Hoffmann, Michael B; Brands, Jan; Behrens-Baumann, Wolfgang; Bach, Michael

    2017-12-01

    Objective assessment of visual acuity (VA) is possible with VEP methodology, but established with sufficient precision only for vision better than about 1.0 logMAR. We here explore whether this can be extended down to 2.0 logMAR, highly desirable for low-vision evaluations. Based on the stepwise sweep algorithm (Bach et al. in Br J Ophthalmol 92:396-403, 2008) VEPs to monocular steady-state brief onset pattern stimulation (7.5-Hz checkerboards, 40% contrast, 40 ms on, 93 ms off) were recorded for eight different check sizes, from 0.5° to 9.0°, for two runs with three occipital electrodes in a Laplace-approximating montage. We examined 22 visually normal participants where acuity was reduced to ≈ 2.0 logMAR with frosted transparencies. With the established heuristic algorithm the "VEP acuity" was extracted and compared to psychophysical VA, both obtained at 57 cm distance. In 20 of the 22 participants with artificially reduced acuity the automatic analysis indicated a valid result (1.80 logMAR on average) in at least one of the two runs. 95% test-retest limits of agreement on average were ± 0.09 logMAR for psychophysical, and ± 0.21 logMAR for VEP-derived acuity. For 15 participants we obtained results in both runs and averaged them. In 12 of these 15 the low-acuity results stayed within the 95% confidence interval (± 0.3 logMAR) as established by Bach et al. (2008). The fully automated analysis yielded good agreement of psychophysical and electrophysiological VAs in 12 of 15 cases (80%) in the low-vision range down to 2.0 logMAR. This encourages us to further pursue this methodology and assess its value in patients.

  14. Simulating Visibility Under Reduced Acuity and Contrast Sensitivity

    Science.gov (United States)

    Thompson, William B.; Legge, Gordon E.; Kersten, Daniel J.; Shakespeare, Robert A.; Lei, Quan

    2017-01-01

    Architects and lighting designers have difficulty designing spaces that are accessible to those with low vision, since the complex nature of most architectural spaces requires a site-specific analysis of the visibility of mobility hazards and key landmarks needed for navigation. We describe a method that can be utilized in the architectural design process for simulating the effects of reduced acuity and contrast on visibility. The key contribution is the development of a way to parameterize the simulation using standard clinical measures of acuity and contrast sensitivity. While these measures are known to be imperfect predictors of visual function, they provide a way of characterizing general levels of visual performance that is familiar to both those working in low vision and our target end-users in the architectural and lighting design communities. We validate the simulation using a letter recognition task. PMID:28375328

  15. Visualizing Microbial Biogeochemistry: NanoSIMS and Stable Isotope Probing (Invited)

    Science.gov (United States)

    Pett-Ridge, J.; Weber, P. K.

    2009-12-01

    Linking phylogenetic information to function in microbial communities is a key challenge for microbial ecology. Isotope-labeling experiments provide a useful means to investigate the ecophysiology of microbial populations and cells in the environment and allow measurement of nutrient transfers between cell types, symbionts and consortia. The combination of Nano-Secondary Ion Mass Spectrometry (NanoSIMS) analysis, in situ labeling and high resolution microscopy allows isotopic analysis to be linked to phylogeny and morphology and holds great promise for fine-scale studies of microbial systems. In NanoSIMS analysis, samples are sputtered with an energetic primary beam (Cs+, O-) liberating secondary ions that are separated by the mass spectrometer and detected in a suite of electron multipliers. Five isotopic species may be analyzed concurrently with spatial resolution as fine as 50nm. A high sensitivity isotope ratio ‘map’ can then be generated for the analyzed area. NanoSIMS images of 13C, 15N and Mo (a nitrogenase co-factor) localization in diazotrophic cyanobacteria show how cells differentially allocate resources within filaments and allow calculation of nutrient uptake rates on a cell by cell basis. Images of AM fungal hyphae-root and cyanobacteria-rhizobia associations indicate the mobilization and sharing (stealing?) of newly fixed C and N. In a related technique, “El-FISH”, stable isotope labeled biomass is probed with oligonucleotide-elemental labels and then imaged by NanoSIMS. In microbial consortia and cyanobacterial mats, this technique helps link microbial structure and function simultaneously even in systems with unknown and uncultivated microbes. Finally, the combination of re-engineered universal 16S oligonucleotide microarrays with NanoSIMS analyses may allow microbial identity to be linked to functional roles in complex systems such as mats and cellulose degrading hindgut communities. These newly developed methods provide correlated

  16. Predictive Factors in OCT Analysis for Visual Outcome in Exudative AMD

    Directory of Open Access Journals (Sweden)

    Maria-Andreea Gamulescu

    2012-01-01

    Full Text Available Background. Reliable predictive factors for therapy outcome may enable treating physicians to counsel their patients more efficiently concerning probability of improvement or time point of discontinuation of a certain therapy. Methods. This is a retrospective analysis of 87 patients with exudative age-related macular degeneration who received three monthly intravitreal ranibizumab injections. Visual acuity before initiation of intravitreal therapy and 4–6 weeks after last intravitreal injection was compared and related to the preoperative visualisation of continuity of the outer retinal layers as assessed by OCT: external limiting membrane (ELM, inner photoreceptor segments (IPS, junction between inner and outer segments (IS/OS, and outer photoreceptor segments (OPS. Results. Visual acuity increased in 40 of 87 (46.0% patients, it remained stable in 25 (28.7%, and 22 (25.3% patients had decreased visual acuity four to six weeks after triple intravitreal ranibizumab injections. No statistically significant predictive value could be demonstrated for grade of continuity of outer retinal layers concerning visual acuity development. Conclusions. In our series of AMD patients, grade of continuity of outer retinal layers was not a significant predictive value for visual acuity development after triple ranibizumab injections.

  17. Visual outcome in cystic craniopharyngiomas treated with intracavitary phosphorus-32

    International Nuclear Information System (INIS)

    Anderson, D.R.; Trobe, J.D.; Taren, J.A.; Gebarski, S.S.

    1989-01-01

    Seven patients with cystic craniopharyngiomas were treated with stereotactic instillation of radioactive phosphorus-32 (32P). Five patients had been previously treated with various combinations of surgery and external beam irradiation, whereas two had the 32 P instillation as a primary therapy. Visual acuity improved in 13 eyes and remained stable in 1. Visual fields normalized in three patients, improved in two, and remained stable in two. Two patients received single treatments with 32 P, whereas five required multiple instillations for recurrent cyst expansion

  18. Distinct Circuits for Recovery of Eye Dominance and Acuity in Murine Amblyopia.

    Science.gov (United States)

    Stephany, Céleste-Élise; Ma, Xiaokuang; Dorton, Hilary M; Wu, Jie; Solomon, Alexander M; Frantz, Michael G; Qiu, Shenfeng; McGee, Aaron W

    2018-05-24

    Degrading vision by one eye during a developmental critical period yields enduring deficits in both eye dominance and visual acuity. A predominant model is that "reactivating" ocular dominance (OD) plasticity after the critical period is required to improve acuity in amblyopic adults. However, here we demonstrate that plasticity of eye dominance and acuity are independent and restricted by the nogo-66 receptor (ngr1) in distinct neuronal populations. Ngr1 mutant mice display greater excitatory synaptic input onto both inhibitory and excitatory neurons with restoration of normal vision. Deleting ngr1 in excitatory cortical neurons permits recovery of eye dominance but not acuity. Reciprocally, deleting ngr1 in thalamus is insufficient to rectify eye dominance but yields improvement of acuity to normal. Abolishing ngr1 expression in adult mice also promotes recovery of acuity. Together, these findings challenge the notion that mechanisms for OD plasticity contribute to the alterations in circuitry that restore acuity in amblyopia. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Assessment of visual disability using visual evoked potentials.

    Science.gov (United States)

    Jeon, Jihoon; Oh, Seiyul; Kyung, Sungeun

    2012-08-06

    The purpose of this study is to validate the use of visual evoked potential (VEP) to objectively quantify visual acuity in normal and amblyopic patients, and determine if it is possible to predict visual acuity in disability assessment to register visual pathway lesions. A retrospective chart review was conducted of patients diagnosed with normal vision, unilateral amblyopia, optic neuritis, and visual disability who visited the university medical center for registration from March 2007 to October 2009. The study included 20 normal subjects (20 right eyes: 10 females, 10 males, ages 9-42 years), 18 unilateral amblyopic patients (18 amblyopic eyes, ages 19-36 years), 19 optic neuritis patients (19 eyes: ages 9-71 years), and 10 patients with visual disability having visual pathway lesions. Amplitude and latencies were analyzed and correlations with visual acuity (logMAR) were derived from 20 normal and 18 amblyopic subjects. Correlation of VEP amplitude and visual acuity (logMAR) of 19 optic neuritis patients confirmed relationships between visual acuity and amplitude. We calculated the objective visual acuity (logMAR) of 16 eyes from 10 patients to diagnose the presence or absence of visual disability using relations derived from 20 normal and 18 amblyopic eyes. Linear regression analyses between amplitude of pattern visual evoked potentials and visual acuity (logMAR) of 38 eyes from normal (right eyes) and amblyopic (amblyopic eyes) subjects were significant [y = -0.072x + 1.22, x: VEP amplitude, y: visual acuity (logMAR)]. There were no significant differences between visual acuity prediction values, which substituted amplitude values of 19 eyes with optic neuritis into function. We calculated the objective visual acuity of 16 eyes of 10 patients to diagnose the presence or absence of visual disability using relations of y = -0.072x + 1.22 (-0.072). This resulted in a prediction reference of visual acuity associated with malingering vs. real

  20. Local and non-local deficits in amblyopia: acuity and spatial interactions.

    Science.gov (United States)

    Bonneh, Yoram S; Sagi, Dov; Polat, Uri

    2004-12-01

    Amblyopic vision is thought to be limited by abnormal long-range spatial interactions, but their exact mode of action and relationship to the main amblyopic deficit in visual acuity is largely unknown. We studied this relationship in a group (N=59) of anisometropic (N=21) and strabismic (or combined, N=38) subjects, using (1) a single and multi-pattern (crowded) computerized static Tumbling-E test with scaled spacing of two pattern widths (TeVA), in addition to an optotype (ETDRS chart) acuity test (VA) and (2) contrast detection of Gabor patches with lateral flankers (lateral masking) along the horizontal and vertical axes as well as in collinear and parallel configurations. By correlating the different measures of visual acuity and contrast suppression, we found that (1) the VA of the strabismic subjects could be decomposed into two uncorrelated components measured in TeVA: acuity for isolated patterns and acuity reduction due to flanking patterns. The latter comprised over 60% of the VA magnitude, on the average and accounted for over 50% of its variance. In contrast, a slight reduction in acuity was found in the anisometropic subjects, and the acuity for a single pattern could account for 70% of the VA variance. (2) The lateral suppression (contrast threshold elevation) in a parallel configuration along the horizontal axis was correlated with the VA (R2=0.7), as well as with the crowding effect (TeVA elevation, R2=0.5) for the strabismic group. Some correlation with the VA was also found for the collinear configuration in the anisometropic group, but less suppression and no correlation were found for all the vertical configurations in all the groups. The results indicate the existence of a specific non-local component of the strabismic deficit, in addition to the local acuity deficit in all amblyopia types. This deficit might reflect long-range lateral inhibition, or alternatively, an inaccurate and scattered top-down attentional selection mechanism.

  1. Crowded letter and crowded picture logMAR acuity in children with amblyopia: a quantitative comparison.

    Science.gov (United States)

    O'Boyle, Cathy; Chen, Sean I; Little, Julie-Anne

    2017-04-01

    Clinically, picture acuity tests are thought to overestimate visual acuity (VA) compared with letter tests, but this has not been systematically investigated in children with amblyopia. This study compared VA measurements with the LogMAR Crowded Kay Picture test to the LogMAR Crowded Keeler Letter acuity test in a group of young children with amblyopia. 58 children (34 male) with amblyopia (22 anisometropic, 18 strabismic and 18 with both strabismic/anisometropic amblyopia) aged 4-6 years (mean=68.7, range=48-83 months) underwent VA measurements. VA chart testing order was randomised, but the amblyopic eye was tested before the fellow eye. All participants wore up-to-date refractive correction. The Kay Picture test significantly overestimated VA by 0.098 logMAR (95% limits of agreement (LOA), 0.13) in the amblyopic eye and 0.088 logMAR (95% LOA, 0.13) in the fellow eye, respectively (pocclusion therapy, refractive correction or type of amblyopia on VA results (p>0.23). For both the amblyopic and fellow eyes, Bland-Altman plots demonstrated a systematic and predictable difference between Kay Picture and Keeler Letter charts across the range of acuities tested (Keeler acuity: amblyopic eye 0.75 to -0.05 logMAR; fellow eye 0.45 to -0.15 logMAR). Linear regression analysis (pamblyopia. Due to the predictable difference found between both crowded logMAR acuity tests, it is reasonable to adjust Kay Picture acuity thresholds by +0.10 logMAR to compute expected Keeler Letter acuity scores. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  2. The Auckland Optotypes: An open-access pictogram set for measuring recognition acuity.

    Science.gov (United States)

    Hamm, Lisa M; Yeoman, Janice P; Anstice, Nicola; Dakin, Steven C

    2018-03-01

    When measuring recognition acuity in a research setting, the most widely used symbols are the Early Treatment of Diabetic Retinopathy Study (ETDRS) set of 10 Sloan letters. However, the symbols are not appropriate for patients unfamiliar with letters, and acuity for individual letters is variable. Alternative pictogram sets are available, but are generally comprised of fewer items. We set out to develop an open-access set of 10 pictograms that would elicit more consistent estimates of acuity across items than the ETDRS letters from visually normal adults. We measured monocular acuity for individual uncrowded optotypes within a newly designed set (The Auckland Optotype [TAO]), the ETDRS set, and Landolt Cs. Eleven visually normal adults were assessed on regular and vanishing formats of each set. Inter-optotype reliability and ability to detect subtle differences between participants were assessed using intraclass correlations (ICC) and fractional rank precision (FRP). The TAO vanishing set showed the strongest performance (ICC = 0.97, FRP = 0.90), followed by the other vanishing sets (Sloan ICC = 0.88, FRP = 0.74; Landolt ICC = 0.86, FRP = 0.80). Within the regular format, TAO again outperformed the existing sets (TAO ICC = 0.77, FRP = 0.75; Sloan ICC = 0.65, FRP = 0.64; Landolt ICC = 0.48, FRP = 0.63). For adults with normal visual acuity, the new optotypes (in both regular and vanishing formats) are more equally legible and sensitive to subtle individual differences than their Sloan counterparts. As this set does not require observers to be able to name Roman letters, and is freely available to use and modify, it may have wide application for measurement of acuity.

  3. Effects of Binaural Sensory Aids on the Development of Visual Perceptual Abilities in Visually Handicapped Infants. Final Report, April 15, 1982-November 15, 1982.

    Science.gov (United States)

    Hart, Verna; Ferrell, Kay

    Twenty-four congenitally visually handicapped infants, aged 6-24 months, participated in a study to determine (1) those stimuli best able to elicit visual attention, (2) the stability of visual acuity over time, and (3) the effects of binaural sensory aids on both visual attention and visual acuity. Ss were dichotomized into visually handicapped…

  4. Visual functions and disability in diabetic retinopathy patients

    Directory of Open Access Journals (Sweden)

    Gauri Shankar Shrestha

    2014-01-01

    Conclusion: Impairment of near visual acuity, contrast sensitivity, and peripheral visual field correlated significantly with different types of visual disability. Hence, these clinical tests should be an integral part of the visual assessment of diabetic eyes.

  5. Variable acuity remote viewing system flight demonstration

    Science.gov (United States)

    Fisher, R. W.

    1983-01-01

    The Variable Acuity Remote Viewing System (VARVS), originally developed under contract to the Navy (ONR) as a laboratory brassboard, was modified for flight demonstration. The VARVS system was originally conceived as a technique which could circumvent the acuity/field of view/bandwidth tradeoffs that exists in remote viewing to provide a nearly eye limited display in both field of view (160 deg) and resolution (2 min arc) while utilizing conventional TV sensing, transmission, and display equipment. The modifications for flight demonstration consisted of modifying the sensor so it could be installed and flow in a Piper PA20 aircraft, equipped for remote control and modifying the display equipment so it could be integrated with the NASA Research RPB (RPRV) remote control cockpit.

  6. Computed estimation of visual acuity after laser refractive keratectomy

    Science.gov (United States)

    Rol, Pascal O.; Parel, Jean-Marie A.; Hanna, Khalil

    1991-06-01

    A number of surgical techniques has been developed to correct ametropia (refractive defaults) of the eye by changing the anterior corneal radius. Because the air-cornea interface makes up for about two-third of the refractive power of the eye, a refractive correction is obtained by a suitable photoablation of the cornea. For this purpose, e.g., an ArF excimer laser which emits a wavelength of 193 nm is being used. After a mechanical removal of the epithelium, the Bowman's layer and the corneal stroma are photoablated on typically 50% of the central surface of the cornea with various precomputed shapes. Methods using a variable diaphragm1 or a scanning slit2 are being utilized. After regrowth of the epithelium, a smooth interface with air develops itself, which can be attributed to a mechanical equilibration. Yet, SEM studies have shown that with such kind of treatments, irregularities can remain in the new stromal surface (Fig. 1). A possible explanation for this effect is associated with an inhomogeneous energy distribution of the laser beam profile3. To some extent, the stromal surface is equalized by the epithelial layer during healing& However, as the corneal epithelium and stroma have different refractive indices, a scatter of the incident light may result causing a haze in the cornea and a blur of the image at the retina. In such a case the resolution and the contrast performance of the eye which is expected from a successful operation, may be reduced. This study is an attempt to quantify the vision blur as a function of the deformation observed at the epithelium-stroma interface.

  7. Correlation Between Near-Vision Acuity and the Incidence of Peritoneal Dialysis-Related Infections.

    Science.gov (United States)

    Kojima, Shigeki; Sakurada, Tsutomu; Koitabashi, Kenichiro; Kojima, Kaori; Watanabe, Shiika; Uchida, Daisuke; Kaneshiro, Nagayuki; Konno, Yusuke; Shibagaki, Yugo

    Peritoneal dialysis (PD)-related infections (PDIs) such as peritonitis, exit-site infection, and tunnel infection are serious complications affecting patients on PD. Because patients with diabetes (DM) and of older age have increased in number in Japan, the number of patients with visual impairment is estimated also to have increased. Near vision is necessary for performing proper PD daily care. However, no studies have reported whether visual impairment is likely to increase the risk of PDIs.Our study included 31 PD patients (16 men, 15 women; mean age: 61.5 ± 11.8 years; mean PD duration: 27.3 ± 20.3 months; 38.7% with DM; 54.8% wearing glasses) who performed their own PD care. At our facility and related facilities, we used a standard near-vision test chart, which classifies vision into 12 grades, from 0.1 (poor) to 1.5 (clear), to assess near-vision binocular visual acuity in those patients between March 2015 and September 2015. In addition, we retrospectively examined the medical records of the patients to determine their history of PDIs. We then evaluated the correlation between near-vision acuity and the incidence of PDIs.Mean measured near-vision acuity was 0.61 ± 0.29, and we observed no significant difference in the visual acuity of patients with and without DM (0.55 ± 0.31 vs. 0.63 ± 0.26 respectively, p = 0.477). In addition, we observed no significant difference in the incidence of PDIs between patients with and without DM (1.298 ± 1.609 per year vs. 1.164 ± 0.908 per year respectively, p = 0.804). We did not find a correlation between near-vision acuity and the incidence of PDIs (r = -0.071, p = 0.795).

  8. Adaptive learning in a compartmental model of visual cortex—how feedback enables stable category learning and refinement

    Science.gov (United States)

    Layher, Georg; Schrodt, Fabian; Butz, Martin V.; Neumann, Heiko

    2014-01-01

    The categorization of real world objects is often reflected in the similarity of their visual appearances. Such categories of objects do not necessarily form disjunct sets of objects, neither semantically nor visually. The relationship between categories can often be described in terms of a hierarchical structure. For instance, tigers and leopards build two separate mammalian categories, both of which are subcategories of the category Felidae. In the last decades, the unsupervised learning of categories of visual input stimuli has been addressed by numerous approaches in machine learning as well as in computational neuroscience. However, the question of what kind of mechanisms might be involved in the process of subcategory learning, or category refinement, remains a topic of active investigation. We propose a recurrent computational network architecture for the unsupervised learning of categorial and subcategorial visual input representations. During learning, the connection strengths of bottom-up weights from input to higher-level category representations are adapted according to the input activity distribution. In a similar manner, top-down weights learn to encode the characteristics of a specific stimulus category. Feedforward and feedback learning in combination realize an associative memory mechanism, enabling the selective top-down propagation of a category's feedback weight distribution. We suggest that the difference between the expected input encoded in the projective field of a category node and the current input pattern controls the amplification of feedforward-driven representations. Large enough differences trigger the recruitment of new representational resources and the establishment of additional (sub-) category representations. We demonstrate the temporal evolution of such learning and show how the proposed combination of an associative memory with a modulatory feedback integration successfully establishes category and subcategory representations

  9. Adaptive learning in a compartmental model of visual cortex - how feedback enables stable category learning and refinement

    Directory of Open Access Journals (Sweden)

    Georg eLayher

    2014-12-01

    Full Text Available The categorization of real world objects is often reflected in the similarity of their visual appearances. Such categories of objects do not necessarily form disjunct sets of objects, neither semantically nor visually. The relationship between categories can often be described in terms of a hierarchical structure. For instance, tigers and leopards build two separate mammalian categories, but both belong to the category of felines. In other words, tigers and leopards are subcategories of the category Felidae. In the last decades, the unsupervised learning of categories of visual input stimuli has been addressed by numerous approaches in machine learning as well as in the computational neurosciences. However, the question of what kind of mechanisms might be involved in the process of subcategory learning, or category refinement, remains a topic of active investigation. We propose a recurrent computational network architecture for the unsupervised learning of categorial and subcategorial visual input representations. During learning, the connection strengths of bottom-up weights from input to higher-level category representations are adapted according to the input activity distribution. In a similar manner, top-down weights learn to encode the characteristics of a specific stimulus category. Feedforward and feedback learning in combination realize an associative memory mechanism, enabling the selective top-down propagation of a category's feedback weight distribution. We suggest that the difference between the expected input encoded in the projective field of a category node and the current input pattern controls the amplification of feedforward-driven representations. Large enough differences trigger the recruitment of new representational resources and the establishment of (sub- category representations. We demonstrate the temporal evolution of such learning and show how the approach successully establishes category and subcategory

  10. Visual function after strontium-90 plaque irradiation in patients with age-related subfoveal choroidal neovascularization

    Energy Technology Data Exchange (ETDEWEB)

    Jaakkola, A.; Tarkkanen, A.; Immonen, I. [Helsinki Univ. Central Hospital, Dept. of Ophthalmology (Finland); Heikkonen, J. [Helsinki Univ. Central Hospital, Dept. of Oncology (Finland)

    1999-05-01

    Purpose: To report 2-year visual and angiographic results in eyes treated with strontium plaque irradiation for subfoveal choroidal neovascular membranes (CNVM) in age-related macular degeneration. Methods: Twenty eyes with recent subfoveal CNVM were treated with local irradiation. The impact of the treatment on visual function was evaluated by visual acuity, contrast sensitivity and reading speed testing. Results: At 12 months visual acuity had improved or remained the same in 9/20 eyes (45%). At 24 months visual acuity was stable in 5/18 eyes (28%). Eyes with signs of CNVM regression (13/18,72%) lost a mean of 3.3 lines, but eyes with recurrent CNVM lost a mean of 5.1 lines of vision. The mean contrast sensitivity was better in the irradiated eyes than in the fellow eyes with late age-related macular degeneration at 24 months. Six of 17 irradiated eyes (35%) could read at least some words at 24 months. Conclusion: Visual function decreases in patients treated with strontium irradiation, but less in eyes showing regression of the CNVM than in eyes with further growth of the CNVM. (au) 20 refs.

  11. Visual function of cataract with high myopia

    Directory of Open Access Journals (Sweden)

    Jian-Tao Ren

    2013-09-01

    Full Text Available Cataract with high myopia is research priority associated with the large amount of high myopia patients. The unaided visual acuity and the best-corrected visual acuity are partial for the visual acuity of the patients with cataract. The mechanism and clinical significance of modern visual function measurements associated with cataract and high myopia, including accommodation and convergence, stereoscopic vision, contrast sensitivity, have been introduced. These measurements could be of great value in early diagnosis of cataract, assessment of surgical indication, customized intraocular lens(IOLselection and evaluation of visual performance after IOL implantation. They could also be helpful to the analysis of postoperative impaired visual function and its management. Having an adequate understanding of the contents and significance of visual function was helpful to the improvement of cataract surgery techniques and postoperative visual acuity.

  12. Spontaneous Resolution of Long-Standing Macular Detachment due to Optic Disc Pit with Significant Visual Improvement.

    Science.gov (United States)

    Parikakis, Efstratios A; Chatziralli, Irini P; Peponis, Vasileios G; Karagiannis, Dimitrios; Stratos, Aimilianos; Tsiotra, Vasileia A; Mitropoulos, Panagiotis G

    2014-01-01

    To report a case of spontaneous resolution of a long-standing serous macular detachment associated with an optic disc pit, leading to significant visual improvement. A 63-year-old female presented with a 6-month history of blurred vision and micropsia in her left eye. Her best-corrected visual acuity was 6/24 in the left eye, and fundoscopy revealed serous macular detachment associated with optic disc pit, which was confirmed by optical coherence tomography (OCT). The patient was offered vitrectomy as a treatment alternative, but she preferred to be reviewed conservatively. Three years after initial presentation, neither macular detachment nor subretinal fluid was evident in OCT, while the inner segment/outer segment (IS/OS) junction line was intact. Her visual acuity was improved from 6/24 to 6/12 in her left eye, remaining stable at the 6-month follow-up after resolution. We present a case of spontaneous resolution of a long-standing macular detachment associated with an optic disc pit with significant visual improvement, postulating that the integrity of the IS/OS junction line may be a prognostic factor for final visual acuity and suggesting OCT as an indicator of visual prognosis and the probable necessity of a surgical management.

  13. Spontaneous Resolution ofLong-Standing Macular Detachment due to Optic Disc Pit with Significant Visual Improvement

    Directory of Open Access Journals (Sweden)

    Efstratios A. Parikakis

    2014-03-01

    Full Text Available Purpose: To report a case of spontaneous resolution of a long-standing serous macular detachment associated with an optic disc pit, leading to significant visual improvement. Case Presentation: A 63-year-old female presented with a 6-month history of blurred vision and micropsia in her left eye. Her best-corrected visual acuity was 6/24 in the left eye, and fundoscopy revealed serous macular detachment associated with optic disc pit, which was confirmed by optical coherence tomography (OCT. The patient was offered vitrectomy as a treatment alternative, but she preferred to be reviewed conservatively. Three years after initial presentation, neither macular detachment nor subretinal fluid was evident in OCT, while the inner segment/outer segment (IS/OS junction line was intact. Her visual acuity was improved from 6/24 to 6/12 in her left eye, remaining stable at the 6-month follow-up after resolution. Conclusion: We present a case of spontaneous resolution of a long-standing macular detachment associated with an optic disc pit with significant visual improvement, postulating that the integrity of the IS/OS junction line may be a prognostic factor for final visual acuity and suggesting OCT as an indicator of visual prognosis and the probable necessity of a surgical management.

  14. The association between higher education and approximate number system acuity

    Science.gov (United States)

    Lindskog, Marcus; Winman, Anders; Juslin, Peter

    2014-01-01

    Humans are equipped with an approximate number system (ANS) supporting non-symbolic numerosity representation. Studies indicate a relationship between ANS-precision (acuity) and math achievement. Whether the ANS is a prerequisite for learning mathematics or if mathematics education enhances the ANS remains an open question. We investigated the association between higher education and ANS acuity with university students majoring in subjects with varying amounts of mathematics (mathematics, business, and humanities), measured either early (First year) or late (Third year) in their studies. The results suggested a non-significant trend where students taking more mathematics had better ANS acuity and a significant improvement in ANS acuity as a function of study length that was mainly confined to the business students. The results provide partial support for the hypothesis that education in mathematics can enhance the ANS acuity. PMID:24904478

  15. The association between higher education and approximate number system acuity.

    Science.gov (United States)

    Lindskog, Marcus; Winman, Anders; Juslin, Peter

    2014-01-01

    Humans are equipped with an approximate number system (ANS) supporting non-symbolic numerosity representation. Studies indicate a relationship between ANS-precision (acuity) and math achievement. Whether the ANS is a prerequisite for learning mathematics or if mathematics education enhances the ANS remains an open question. We investigated the association between higher education and ANS acuity with university students majoring in subjects with varying amounts of mathematics (mathematics, business, and humanities), measured either early (First year) or late (Third year) in their studies. The results suggested a non-significant trend where students taking more mathematics had better ANS acuity and a significant improvement in ANS acuity as a function of study length that was mainly confined to the business students. The results provide partial support for the hypothesis that education in mathematics can enhance the ANS acuity.

  16. The Association Between Higher Education and Approximate Number System Acuity

    Directory of Open Access Journals (Sweden)

    Marcus eLindskog

    2014-05-01

    Full Text Available Humans are equipped with an Approximate Number System (ANS supporting non-symbolic numerosity representation. Studies indicate a relationship between ANS-precision (acuity and math achievement. Whether the ANS is a prerequisite for learning mathematics or if mathematics education enhances the ANS remains an open question. We investigated the association between higher education and ANS acuity with university students majoring in subjects with varying amounts of mathematics (mathematics, business, and humanities, measured either early (1th year or late (3rd year in their studies. The results suggested a non-significant trend where students taking more mathematics had better ANS acuity and a significant improvement in ANS acuity as a function of study length that was mainly confined to the business students. The results provide partial support for the hypothesis that education in mathematics can enhance the ANS acuity.

  17. Recovery of Visual Function in a Patient with an Onodi Cell Mucocele Compressive Optic Neuropathy Who Had a 5-Week Interval between Onset and Surgical Intervention: A Case Report

    Directory of Open Access Journals (Sweden)

    Wencan Wu

    2010-01-01

    Full Text Available Purpose. To report on a patient with compressive optic neuropathy secondary to an Onodi cell mucocele, who fully recovered visual function following surgery. Method. Case report. Results. A 28-year-old male was admitted with a right visual acuity of 20/100 following treatment for an initial diagnosis of optic neuritis. Subsequent examination suggested compressive optic neuropathy, and neuroimaging confirmed the presence of an Onodi mucocele compressing the optic nerve. The patient underwent a right endonasal sphenoethmoidectomy with decompression 5 weeks after the initial onset of symptoms. Three weeks following surgery, the visual acuity was 20/20, and there was complete resolution of the visual field defect, which has remained stable at 1 year. Conclusion. Onodi cell mucocele should be included in the differential diagnosis of a young patient with compressive optic neuropathy. Surgical decompression should be considered even when symptoms have been present for over a month.

  18. Association between visual impairment and patient-reported visual disability at different stages of cataract surgery.

    Science.gov (United States)

    Acosta-Rojas, E Ruthy; Comas, Mercè; Sala, Maria; Castells, Xavier

    2006-10-01

    To evaluate the association between visual impairment (visual acuity, contrast sensitivity, stereopsis) and patient-reported visual disability at different stages of cataract surgery. A cohort of 104 patients aged 60 years and over with bilateral cataract was assessed preoperatively, after first-eye surgery (monocular pseudophakia) and after second-eye surgery (binocular pseudophakia). Partial correlation coefficients (PCC) and linear regression models were calculated. In patients with bilateral cataracts, visual disability was associated with visual acuity (PCC = -0.30) and, to a lesser extent, with contrast sensitivity (PCC = 0.16) and stereopsis (PCC = -0.09). In monocular and binocular pseudophakia, visual disability was more strongly associated with stereopsis (PCC = -0.26 monocular and -0.51 binocular) and contrast sensitivity (PCC = 0.18 monocular and 0.34 binocular) than with visual acuity (PCC = -0.18 monocular and -0.18 binocular). Visual acuity, contrast sensitivity and stereopsis accounted for between 17% and 42% of variance in visual disability. The association of visual impairment with patient-reported visual disability differed at each stage of cataract surgery. Measuring other forms of visual impairment independently from visual acuity, such as contrast sensitivity or stereopsis, could be important in evaluating both needs and outcomes in cataract surgery. More comprehensive assessment of the impact of cataract on patients should include measurement of both visual impairment and visual disability.

  19. Relating Standardized Visual Perception Measures to Simulator Visual System Performance

    Science.gov (United States)

    Kaiser, Mary K.; Sweet, Barbara T.

    2013-01-01

    Human vision is quantified through the use of standardized clinical vision measurements. These measurements typically include visual acuity (near and far), contrast sensitivity, color vision, stereopsis (a.k.a. stereo acuity), and visual field periphery. Simulator visual system performance is specified in terms such as brightness, contrast, color depth, color gamut, gamma, resolution, and field-of-view. How do these simulator performance characteristics relate to the perceptual experience of the pilot in the simulator? In this paper, visual acuity and contrast sensitivity will be related to simulator visual system resolution, contrast, and dynamic range; similarly, color vision will be related to color depth/color gamut. Finally, we will consider how some characteristics of human vision not typically included in current clinical assessments could be used to better inform simulator requirements (e.g., relating dynamic characteristics of human vision to update rate and other temporal display characteristics).

  20. Water and carbon stable isotope records from natural archives: a new database and interactive online platform for data browsing, visualizing and downloading

    Science.gov (United States)

    Bolliet, Timothé; Brockmann, Patrick; Masson-Delmotte, Valérie; Bassinot, Franck; Daux, Valérie; Genty, Dominique; Landais, Amaelle; Lavrieux, Marlène; Michel, Elisabeth; Ortega, Pablo; Risi, Camille; Roche, Didier M.; Vimeux, Françoise; Waelbroeck, Claire

    2016-08-01

    Past climate is an important benchmark to assess the ability of climate models to simulate key processes and feedbacks. Numerous proxy records exist for stable isotopes of water and/or carbon, which are also implemented inside the components of a growing number of Earth system model. Model-data comparisons can help to constrain the uncertainties associated with transfer functions. This motivates the need of producing a comprehensive compilation of different proxy sources. We have put together a global database of proxy records of oxygen (δ18O), hydrogen (δD) and carbon (δ13C) stable isotopes from different archives: ocean and lake sediments, corals, ice cores, speleothems and tree-ring cellulose. Source records were obtained from the georeferenced open access PANGAEA and NOAA libraries, complemented by additional data obtained from a literature survey. About 3000 source records were screened for chronological information and temporal resolution of proxy records. Altogether, this database consists of hundreds of dated δ18O, δ13C and δD records in a standardized simple text format, complemented with a metadata Excel catalog. A quality control flag was implemented to describe age markers and inform on chronological uncertainty. This compilation effort highlights the need to homogenize and structure the format of datasets and chronological information as well as enhance the distribution of published datasets that are currently highly fragmented and scattered. We also provide an online portal based on the records included in this database with an intuitive and interactive platform (http://climateproxiesfinder.ipsl.fr/), allowing one to easily select, visualize and download subsets of the homogeneously formatted records that constitute this database, following a choice of search criteria, and to upload new datasets. In the last part, we illustrate the type of application allowed by our database by comparing several key periods highly investigated by the

  1. Modelling the training effects of kinaesthetic acuity measurement in children.

    Science.gov (United States)

    Sims, K; Morton, J

    1998-07-01

    In previous papers (Sims, Henderson, Hulme, & Morton, 1996a; Sims, Henderson, Morton, & Hulme, 1996b) we have found that the motor skills of clumsy children are capable of significant improvement following relatively brief interventions. Most remarkably, this included a 10-minute intervention while testing the kinaesthetic acuity of the children using a staircase method (Pest). In this paper, we show that Pest testing improves the kinaesthetic acuity of normal children as well. We analyse the available data on the development and improvement of motor skills and kinaesthetic acuity and derive a causal model for the underlying skills. We show that at least three independent cognitive/biological components are required to account for the data. These three components are affected differently by the various interventions that have been tried. We deduce that improvement on a general test of motor impairment can be found as a result of training in kinaesthetic acuity or through other, independent factors.

  2. Avoidable visual impairment among elderly people in a Slum of ...

    African Journals Online (AJOL)

    Methods: A survey was conducted between November and December 1997, in the slum of central Addis Ababa. Five hundred seventy one people above the age of 50 years underwent detailed eye examinations including visual acuity test and intra-ocular pressure measurements. Results: About 9% were blind [visual acuity ...

  3. RETENTION OF HIGH TACTILE ACUITY THROUGHOUT THE LIFESPAN IN BLINDNESS

    OpenAIRE

    Legge, Gordon E.; Madison, Cindee; Vaughn, Brenna N.; Cheong, Allen M.Y.; Miller, Joseph C.

    2008-01-01

    Previous studies of tactile acuity on the fingertip using passive touch have demonstrated an age-related decline in spatial resolution for both sighted and blind subjects. We have re-examined this age dependence with two newly designed tactile-acuity charts requiring active exploration of the test symbols. One chart used dot patterns similar to Braille and the other used embossed Landolt rings. Groups of blind Braille readers and sighted subjects, ranging in age from 12 to 85 years, were test...

  4. The Correlation between Subjective and Objective Visual Function Test in Optic Neuropathy Patients

    Directory of Open Access Journals (Sweden)

    Ungsoo Kim

    2012-10-01

    Full Text Available Purpose: To investigate the correlation between visual acuity and quantitative measurements of visual evoked potentials (VEP, optical coherence tomography (OCT, and visual field test (VF in optic neuropathy patients. Methods: We evaluated 28 patients with optic neuropathy. Patients who had pale disc, visual acuity of less than 0.5 and abnormal visual field defect were included. At the first visit, we performed visual acuity and VF as subjective methods and OCT and VEP as objective methods. In the spectral domain OCT, rim volume, average and temporal quadrant retinal nerve fiber layer (RNFL thickness were measured. And pattern VEP (N75, P100, N135 latency, and P100 amplitude and Humphrey 24-2 visual field test (mean deviation and pattern standard deviation were obtained. Using Spearman's correlation coefficient, the correlation between visual acuity and various techniques were assessed. Results: Visual acuity was most correlated with the mean deviation of Humphrey perimetry.

  5. Effect of ocular transverse chromatic aberration on detection acuity for peripheral vision.

    Science.gov (United States)

    Cheney, Frank; Thibos, Larry; Bradley, Arthur

    2015-01-01

    We examined the effect of transverse chromatic aberration (TCA) on detection acuity for white-light interference fringes seen in Maxwellian view at various orientations and locations in the visual field. A circular patch (3.5° diameter, 3.2 log Trolands) of nominally high-contrast fringes was produced on the retina by a commercial instrument (the Lotmar Visometer, Haag Streit) mounted on a gimbal for controlled positioning of the stimulus in the visual field from 0° to 35° eccentricity. Detection acuity for white light fringes for all meridians and eccentricities ≥15° was maximum when fringes were oriented parallel to the visual meridian line. This meridional effect disappeared when a narrow-band filter was used to eliminate TCA. The meridional effect also disappeared when the interferometric stimulator was displaced laterally to align the instrument with the eye's local achromatic axis. Modelling confirmed that TCA is the major factor responsible for white-light meridional bias, with minor contribution arising from higher-order monochromatic aberrations and neural factors. © 2014 The Authors Ophthalmic & Physiological Optics © 2014 The College of Optometrists.

  6. CAM visual stimulation with conventional method of occlusion treatment in amblyopia: a randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Ali Reza Jafari

    2014-04-01

    Conclusion: Using of CAM visual stimulation along with conventional occlusion will further improve visual acuity and stereopsis in amblyopic children. These findings recommended the CAM visual stimulation as an accompanying and complementary method in amblyopia treatment.

  7. Comparison on the visual quality after different multifocal lens implantation in cataract patients

    Directory of Open Access Journals (Sweden)

    Si-Meng Qu

    2018-02-01

    Full Text Available AIM: To compare the visual quality after different multifocal lens(MIOLimplantation in cataract patients. METHODS:Totally 78 cases(78 eyesof cataract patients who receiving phacoemulsification and implantation of different MIOL were enrolled from February 2016 to June 2017 in our hospital. According to the different type of implanted MIOL, the 78 cases(78 eyeswere divided Group A, B and C, each group was 26 cases(26 eyes. Patients in the Group A were implanted regional refraction MIOL SBL-3; patients in the Group B implanted step progressive diffraction MIOL SN6AD1; patients in the Group C implanted all-optical plane diffraction MIOL Tecnis ZMB00. The visual acuity, contrast sensitivity, defocus testing, contrast visual acuity and satisfaction of visual quality were compared in 3 groups at postoperative 3mo. RESULTS: There was no statistically significant difference in postoperative adverse reactions between the three groups(P>0.05. There was statistical difference in uncorrected intermediate visual acuity, uncorrected near visual acuity, distance-corrected intermediate visual acuity and distance-corrected near visual acuity in 3 groups(PPPPPPPPPCONCLUSION:The region refraction MIOL SBL-3 not only could provide better distant, intermediate and near visual acuity, but also could provide better contrast sensitivity and contrast visual acuity, thereby greatly increase visual quality satisfaction.

  8. Improved Mental Acuity Forecasting with an Individualized Quantitative Sleep Model

    Directory of Open Access Journals (Sweden)

    Brent D. Winslow

    2017-04-01

    Full Text Available Sleep impairment significantly alters human brain structure and cognitive function, but available evidence suggests that adults in developed nations are sleeping less. A growing body of research has sought to use sleep to forecast cognitive performance by modeling the relationship between the two, but has generally focused on vigilance rather than other cognitive constructs affected by sleep, such as reaction time, executive function, and working memory. Previous modeling efforts have also utilized subjective, self-reported sleep durations and were restricted to laboratory environments. In the current effort, we addressed these limitations by employing wearable systems and mobile applications to gather objective sleep information, assess multi-construct cognitive performance, and model/predict changes to mental acuity. Thirty participants were recruited for participation in the study, which lasted 1 week. Using the Fitbit Charge HR and a mobile version of the automated neuropsychological assessment metric called CogGauge, we gathered a series of features and utilized the unified model of performance to predict mental acuity based on sleep records. Our results suggest that individuals poorly rate their sleep duration, supporting the need for objective sleep metrics to model circadian changes to mental acuity. Participant compliance in using the wearable throughout the week and responding to the CogGauge assessments was 80%. Specific biases were identified in temporal metrics across mobile devices and operating systems and were excluded from the mental acuity metric development. Individualized prediction of mental acuity consistently outperformed group modeling. This effort indicates the feasibility of creating an individualized, mobile assessment and prediction of mental acuity, compatible with the majority of current mobile devices.

  9. Postoperative increase in grey matter volume in visual cortex after unilateral cataract surgery

    DEFF Research Database (Denmark)

    Lou, Astrid R.; Madsen, Kristoffer Hougaard; Julian, Hanne O.

    2013-01-01

    Purpose:  The developing visual cortex has a strong potential to undergo plastic changes. Little is known about the potential of the ageing visual cortex to express plasticity. A pertinent question is whether therapeutic interventions can trigger plastic changes in the ageing visual cortex by res...... of visual input from both eyes. We conclude that activity-dependent cortical plasticity is preserved in the ageing visual cortex and may be triggered by restoring impaired vision.......Purpose:  The developing visual cortex has a strong potential to undergo plastic changes. Little is known about the potential of the ageing visual cortex to express plasticity. A pertinent question is whether therapeutic interventions can trigger plastic changes in the ageing visual cortex...... surgery induces a regional increase in grey matter in areas V1 and V2 of the visual cortex. Results:  In all patients, cataract surgery immediately improved visual acuity, contrast sensitivity and mean sensitivity in the visual field of the operated eye. The improvement in vision was stable throughout...

  10. Visual Outcome and Tumor Control After Conformal Radiotherapy for Patients With Optic Nerve Sheath Meningioma

    International Nuclear Information System (INIS)

    Arvold, Nils D.; Lessell, Simmons; Bussiere, Marc; Beaudette, Kevin; Rizzo, Joseph F.; Loeffler, Jay S.; Shih, Helen A.

    2009-01-01

    Purpose: Optic nerve sheath meningioma (ONSM) is a rare tumor that almost uniformly leads to visual dysfunction and even blindness without intervention. Because surgical extirpation carries a high risk of postoperative blindness, vision-sparing treatment strategies are desirable. Methods and Materials: We retrospectively reviewed the outcomes of 25 patients (25 optic nerves) with ONSM, treated at a single institution with conformal fractionated radiotherapy by either stereotactic photon or proton radiation. Primary endpoints were local control and visual acuity. Results: The patients presented with symptoms of visual loss (21) or orbital pain (3) or were incidentally diagnosed by imaging (3). The mean age was 44 years, and 64% were female patients. The indication for treatment was the development or progression of symptoms. Of the patients, 13 were treated with photons, 9 were treated with protons, and 3 received a combination of photons and protons. The median dose delivered was 50.4 gray equivalents (range, 45-59.4 gray equivalents). Median follow-up after radiotherapy was 30 months (range, 3-168 months), with 3 patients lost to follow-up. At most recent follow-up, 21 of 22 patients (95%) had improved (14) or stable (7) visual acuity. One patient had worsened visual acuity after initial postirradiation improvement. Of the 22 patients, 20 (95%) had no radiographic progression. Three patients had evidence of asymptomatic, limited retinopathy on ophthalmologic examination, and one had recurrent ONSM 11 years after treatment. Conclusions: Highly conformal, fractionated radiation therapy for symptomatic primary ONSM provides tumor control and improvement in visual function in most cases, with minimal treatment-induced morbidity. Longer follow-up is needed to assess the durability of tumor control and treatment-related late effects.

  11. Arithmetic Training Does Not Improve Approximate Number System Acuity

    Directory of Open Access Journals (Sweden)

    Marcus Lindskog

    2016-10-01

    Full Text Available The Approximate Number System (ANS is thought to support non-symbolic representations of numerical magnitudes in humans. Recently much debate has focused on the causal direction for an observed relation between ANS acuity and arithmetic fluency. Here we investigate if arithmetic training can improve ANS acuity. We show with an experimental training study consisting of six 45-minute training sessions that although feedback during arithmetic training improves arithmetic performance substantially, it does not influence ANS acuity. Hence, we find no support for a causal link where symbolic arithmetic training influences the ANS acuity. Further, although short-term number memory is likely involved in arithmetic tasks we did not find that short-term memory capacity for numbers, measured by a digit-span test, was effected by arithmetic training. This suggests that the improvement in arithmetic fluency may have occurred independent of short-term memory efficiency, but rather due to long-term memory processes and/or mental calculation strategy development. The theoretical implications of these findings are discussed.

  12. A prospective, contralateral comparison of photorefractive keratectomy (PRK) versus thin-flap LASIK: assessment of visual function.

    Science.gov (United States)

    Hatch, Bryndon B; Moshirfar, Majid; Ollerton, Andrew J; Sikder, Shameema; Mifflin, Mark D

    2011-01-01

    To compare differences in visual acuity, contrast sensitivity, complications, and higher-order ocular aberrations (HOAs) in eyes with stable myopia undergoing either photo-refractive keratectomy (PRK) or thin-flap laser in situ keratomileusis (LASIK) (intended flap thickness of 90 μm) using the VISX Star S4 CustomVue excimer laser and the IntraLase FS60 femtosecond laser at 1, 3, and 6 months postoperatively. In this prospective, masked, and randomized pilot study, refractive surgery was performed contralaterally on 52 eyes: 26 with PRK and 26 with thin-flap LASIK. Primary outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), contrast sensitivity, and complications. At 6 months, mean values for UDVA (logMAR) were -0.043 ± 0.668 and -0.061 ± 0.099 in the PRK and thin-flap LASIK groups, respectively (n = 25, P = 0.466). UDVA of 20/20 or better was achieved in 96% of eyes undergoing PRK and 92% of eyes undergoing thin-flap LASIK, whereas 20/15 vision or better was achieved in 73% of eyes undergoing PRK and 72% of eyes undergoing thin-flap LASIK (P > 0.600). Significant differences were not found between treatment groups in contrast sensitivity (P ≥ 0.156) or CDVA (P = 0.800) at postoperative 6 months. Types of complications differed between groups, notably 35% of eyes in the thin-flap LASIK group experiencing complications, including microstriae and 2 flap tears. Under well-controlled surgical conditions, PRK and thin-flap LASIK refractive surgeries achieve similar results in visual acuity, contrast sensitivity, and induction of HOAs, with differences in experienced complications.

  13. The high cost of low-acuity ICU outliers.

    Science.gov (United States)

    Dahl, Deborah; Wojtal, Greg G; Breslow, Michael J; Holl, Randy; Huguez, Debra; Stone, David; Korpi, Gloria

    2012-01-01

    Direct variable costs were determined on each hospital day for all patients with an intensive care unit (ICU) stay in four Phoenix-area hospital ICUs. Average daily direct variable cost in the four ICUs ranged from $1,436 to $1,759 and represented 69.4 percent and 45.7 percent of total hospital stay cost for medical and surgical patients, respectively. Daily ICU cost and length of stay (LOS) were higher in patients with higher ICU admission acuity of illness as measured by the APACHE risk prediction methodology; 16.2 percent of patients had an ICU stay in excess of six days, and these LOS outliers accounted for 56.7 percent of total ICU cost. While higher-acuity patients were more likely to be ICU LOS outliers, 11.1 percent of low-risk patients were outliers. The low-risk group included 69.4 percent of the ICU population and accounted for 47 percent of all LOS outliers. Low-risk LOS outliers accounted for 25.3 percent of ICU cost and incurred fivefold higher hospital stay costs and mortality rates. These data suggest that severity of illness is an important determinant of daily resource consumption and LOS, regardless of whether the patient arrives in the ICU with high acuity or develops complications that increase acuity. The finding that a substantial number of long-stay patients come into the ICU with low acuity and deteriorate after ICU admission is not widely recognized and represents an important opportunity to improve patient outcomes and lower costs. ICUs should consider adding low-risk LOS data to their quality and financial performance reports.

  14. Individual differences in non-verbal number acuity correlate with maths achievement.

    Science.gov (United States)

    Halberda, Justin; Mazzocco, Michèle M M; Feigenson, Lisa

    2008-10-02

    Human mathematical competence emerges from two representational systems. Competence in some domains of mathematics, such as calculus, relies on symbolic representations that are unique to humans who have undergone explicit teaching. More basic numerical intuitions are supported by an evolutionarily ancient approximate number system that is shared by adults, infants and non-human animals-these groups can all represent the approximate number of items in visual or auditory arrays without verbally counting, and use this capacity to guide everyday behaviour such as foraging. Despite the widespread nature of the approximate number system both across species and across development, it is not known whether some individuals have a more precise non-verbal 'number sense' than others. Furthermore, the extent to which this system interfaces with the formal, symbolic maths abilities that humans acquire by explicit instruction remains unknown. Here we show that there are large individual differences in the non-verbal approximation abilities of 14-year-old children, and that these individual differences in the present correlate with children's past scores on standardized maths achievement tests, extending all the way back to kindergarten. Moreover, this correlation remains significant when controlling for individual differences in other cognitive and performance factors. Our results show that individual differences in achievement in school mathematics are related to individual differences in the acuity of an evolutionarily ancient, unlearned approximate number sense. Further research will determine whether early differences in number sense acuity affect later maths learning, whether maths education enhances number sense acuity, and the extent to which tertiary factors can affect both.

  15. Stable isotopes

    International Nuclear Information System (INIS)

    Evans, D.K.

    1986-01-01

    Seventy-five percent of the world's stable isotope supply comes from one producer, Oak Ridge Nuclear Laboratory (ORNL) in the US. Canadian concern is that foreign needs will be met only after domestic needs, thus creating a shortage of stable isotopes in Canada. This article describes the present situation in Canada (availability and cost) of stable isotopes, the isotope enrichment techniques, and related research programs at Chalk River Nuclear Laboratories (CRNL)

  16. Merging Psychophysical and Psychometric Theory to Estimate Global Visual State Measures from Forced-Choices

    International Nuclear Information System (INIS)

    Massof, Robert W; Schmidt, Karen M; Laby, Daniel M; Kirschen, David; Meadows, David

    2013-01-01

    Visual acuity, a forced-choice psychophysical measure of visual spatial resolution, is the sine qua non of clinical visual impairment testing in ophthalmology and optometry patients with visual system disorders ranging from refractive error to retinal, optic nerve, or central visual system pathology. Visual acuity measures are standardized against a norm, but it is well known that visual acuity depends on a variety of stimulus parameters, including contrast and exposure duration. This paper asks if it is possible to estimate a single global visual state measure from visual acuity measures as a function of stimulus parameters that can represent the patient's overall visual health state with a single variable. Psychophysical theory (at the sensory level) and psychometric theory (at the decision level) are merged to identify the conditions that must be satisfied to derive a global visual state measure from parameterised visual acuity measures. A global visual state measurement model is developed and tested with forced-choice visual acuity measures from 116 subjects with no visual impairments and 560 subjects with uncorrected refractive error. The results are in agreement with the expectations of the model

  17. Pattern visual evoked potentials in malingering.

    Science.gov (United States)

    Nakamura, A; Akio, T; Matsuda, E; Wakami, Y

    2001-03-01

    We previously developed a new method for estimating objective visual acuity by means of pattern visual evoked potentials (PVEP). In this study, this method was applied to the diagnosis of malingering. Six patients ranging in age from 40 to 54 years (mean 47 years) with suspected malingering were evaluated by means of the visual evoked potential test, optokinetic nystagmus (OKN) inhibition test, and the visual field test. In the PVEP study, the stimulus consisted of black and white checkerboards (39', 26', 15', and 9') with a visual angle of 8 degrees, contrast level of 15%, and a frequency of 0.7 Hz. One hundred PVEP responses were averaged per session. Routine ophthalmic examinations were normal in all patients. Five patients had a tubularly constricted visual field, and the remaining patient had a normal visual field. The objective visual acuities of the six patients estimated from PVEP were better than their subjective visual acuities estimated with Landolt rings. Among a variety of psychophysical and electrophysiologic ancillary tests, we consider our PVEP method a useful method for objectively determining visual acuity in a patient with signs of ocular malingering.

  18. Radiation-induced changes in taste acuity in cancer patients

    International Nuclear Information System (INIS)

    Mossman, K.L.; Henkin, R.I.

    1978-01-01

    Changes in taste acuity were measured in 27 patients with various forms of cancer who received radiation to the head and neck region. In 9 of these patients (group I), measurements of taste acuity were made more than 1 year after completion of radiation therapy. In the other 18 patients (group II), taste measurements were made before, during, and approximately 1 month after radiation therapy. Taste acuity was measured for four taste qualities (salt, sweet, sour, and bitter) by a forced choice-three stimulus drop technique which measured detection and recognition thresholds and by a forced scaling technique which measured taste intensity responsiveness. In group II patients, impaired acuity, as indicated by elevated detection and recognition thresholds, was observed approximately 3 weeks after initiation of radiotherapy. The bitter and salt qualities showed the earliest and greatest impairment and the sweet quality the least. Taste intensity responsiveness also was impaired in group II patients. As for thresholds, scaling impairment was most severe for bitter and salt taste qualities. Scaling impairment occurred before changes in either detection or recognition thresholds. Detection and recognition thresholds determined in group I patients also showed salt and bitter qualities were affected more severely than either sweet or sour qualities. Zinc administration to group I patients in an uncontrolled study suggested that zinc therapy may be useful in ameliorating taste impairment in some patients. These results suggest that taste loss may be a factor in the anorexia and weight loss that is observed commonly in patients who have undergone radiation treatment. Correction of this abnormality may be useful in aiding the nutritional status of these patients

  19. Long-term visual changes following pituitary irradiation

    International Nuclear Information System (INIS)

    Movsas, Benjamin; Movsas, Tammy Z.; Steinberg, Seth M.; Okunieff, Paul

    1995-01-01

    Purpose: To analyze possible long-term effects of pituitary irradiation on visual fields and acuity. Methods and Materials: Eighty-six patients were treated with radiotherapy for pituitary tumors at the National Cancer Institute between 1980 and 1991. Twenty-one patients had baseline preradiation and long-term follow-up visual fields. Eyes were followed with serial Goldmann or Humphrey visual field testing. Neuroradiologic correlation was made with the available brain scans. There were 12 females and 9 males with an median age of 44. Eighteen patients had hormone-secreting tumors and three had chromophobe adenomas. All but one patient with an inoperable invasive macroadenoma were irradiated after one or more transphenoidal resections or a craniotomy. The indications for radiation in the operable patients were: nine patients, partial tumor resection; nine patients, tumor recurrence; and two patients, persistent hormonal elevation after surgery. The median dose delivered was 50 Gy (45-59.4 Gy). The average field size was 6 x 6 cm (5 x 5 cm to 10 x 12.5 cm). Results: With a median follow-up of 48 months (14-128) after radiotherapy, 1 out of 21 patients has recurred (at 8 months) and all patients are alive. Of the 38 sighted eyes, 27 had normal visual fields before and after radiation, 7 eyes showed improvement, and 4 eyes had a stable defect, mostly in the superior temporal region. There were no cases of radiation-induced visual field or acuity deterioration. Six out of 21 patients (29%) had neurologic symptoms in follow-up, most of which appeared vascular in nature. Four patients complained of atypical migranous-like headaches that first began 1.5-3 years following treatment. One patient complained of recurrent vertical diplopia and one patient had a cerebral vascular accident 7 years following therapy. A dose-related association with these neurovascular symptoms approached statistical significance. Only 1 out of 11 (9%) patients who received doses less than or equal

  20. Indoor Spatial Updating with Reduced Visual Information

    OpenAIRE

    Legge, Gordon E.; Gage, Rachel; Baek, Yihwa; Bochsler, Tiana M.

    2016-01-01

    Purpose Spatial updating refers to the ability to keep track of position and orientation while moving through an environment. People with impaired vision may be less accurate in spatial updating with adverse consequences for indoor navigation. In this study, we asked how artificial restrictions on visual acuity and field size affect spatial updating, and also judgments of the size of rooms. Methods Normally sighted young adults were tested with artificial restriction of acuity in Mild Blur (S...

  1. Visual and flight performance recovery after PRK or LASIK in helicopter pilots.

    Science.gov (United States)

    Van de Pol, Corina; Greig, Joanna L; Estrada, Art; Bissette, Gina M; Bower, Kraig S

    2007-06-01

    Refractive surgery, specifically photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK), is becoming more accepted in the military environment. Determination of the impact on visual performance in the more demanding aviation environment was the impetus for this study. A prospective evaluation of 20 Black Hawk pilots pre-surgically and at 1 wk, 1 mo, and 6 mo postsurgery was conducted to assess both PRK and LASIK visual and flight performance outcomes on the return of aviators to duty. Of 20 pilots, 19 returned to flight status at 1 mo after surgery; 1 PRK subject was delayed due to corneal haze and subjective visual symptoms. Improvements were seen under simulator night and night vision goggle flight after LASIK; no significant changes in flight performance were measured in the aircraft. Results indicated a significantly faster recovery of all visual performance outcomes 1 wk after LASIK vs. PRK, with no difference between procedures at 1 and 6 mo. Low contrast acuity and contrast sensitivity only weakly correlated to flight performance in the early post-operative period. Overall flight performance assessed in this study after PRK and LASIK was stable or improved from baseline, indicating a resilience of performance despite measured decrements in visual performance, especially in PRK. More visually demanding flight tasks may be impacted by subtle changes in visual performance. Contrast tests are more sensitive to the effects of refractive surgical intervention and may prove to be a better indicator of visual recovery for return to flight status.

  2. Bilateral Simultaneous Macular Infarction with Spontaneous Visual ...

    African Journals Online (AJOL)

    To report the rare and dramatic event of bilateral macular infarction in a sickle cell hemoglobinopathy (SS genotype) patient, resulting in bilateral severe reduction in visual acuity. Without any intervention, the patient's vision gradually improved over the follow‑up period. Central visual field defects however persisted.

  3. The Mozart effect in biofeedback visual rehabilitation: a case report.

    Science.gov (United States)

    Salvatore, Serena; Librando, Aloisa; Esposito, Mariacristina; Vingolo, Enzo M

    2011-01-01

    To evaluate the usefulness of acoustic biofeedback by means of Mozart's Sonata for Two Pianos in D Major K. 448 to maintain and/or restore visual performance in a patient with macular pucker and glaucoma. A 74-year-old patient with open angle glaucoma in both eyes and macular pucker in the right eye (RE) underwent visual rehabilitation with acoustic biofeedback by means of the MAIA™ Vision Training Module (Centervue, Padova, Italy) 10 minutes each eye once a week for 5 weeks. The patient was asked to move his eyes according to a sound which changed into Mozart's Sonata for Two Pianos when the patient locked the fixation target. Best-corrected visual acuity improved in his right eye (RE) and was stable in the left eye (LE). Fixation stability improved in both eyes, and retinal sensitivity decreased in the RE and improved in the LE. The characteristic of the macular pucker did not change during the training as demonstrated with optical coherence tomography. The patient was very satisfied with the training, as demonstrated by a 25-item questionnaire (National Eye Institute - Visual Functioning Questionnaire, NEI-VFQ-25). The patient's reading speed and the character size which he was able to read improved in his RE. Music could enhance synaptic plasticity and affect neural learning and fixation training by means of MAIA vision training. Therefore it can improve visual performance in patients with macular pucker, postpone the surgical time, and assure a better quality of life for the patient.

  4. The influence of tongue strength on oral viscosity discrimination acuity.

    Science.gov (United States)

    Steele, Catriona M

    2018-06-01

    The ability to generate tongue pressures is widely considered to be critical for liquid bolus propulsion in swallowing. It has been proposed that the application of tongue pressure may also serve the function of collecting sensory information regarding bolus viscosity (resistance to flow). In this study, we explored the impact of age-related reductions in tongue strength on oral viscosity discrimination acuity. The experiment employed a triangle test discrimination protocol with an array of xanthan-gum thickened liquids in the mildly to moderately thick consistency range. A sample of 346 healthy volunteers was recruited, with age ranging from 12 to 86 (164 men, 182 women). On average, participants were able to detect a 0.29-fold increase in xanthan-gum concentration, corresponding to a 0.5-fold increase in viscosity at 50/s. Despite having significantly reduced tongue strength on maximum isometric tongue-palate pressure tasks, and regardless of sex, older participants in this study showed no reductions in viscosity discrimination acuity. In this article, the relationship between tongue strength and the ability to discriminate small differences in liquid viscosity during oral processing is explored. Given that tongue strength declines with age in healthy adults and is also reduced in individuals with dysphagia, it is interesting to determine whether reduced tongue strength might contribute to difficulties in evaluating liquid viscosity during the oral stage of swallowing. Using an array of mildly to moderately thick xanthan-gum thickened liquids, this experiment failed to find any evidence that reductions in tongue strength influence oral viscosity discrimination acuity. © 2017 Wiley Periodicals, Inc.

  5. Unpredictably Stable

    DEFF Research Database (Denmark)

    Failla, Virgilio; Melillo, Francesca; Reichstein, Toke

    2014-01-01

    Is entrepreneurship a more stable career choice for high employment turnover individuals? We find that a transition to entrepreneurship induces a shift towards stayer behavior and identify job matching, job satisfaction and lock-in effects as main drivers. These findings have major implications...

  6. 38 CFR 4.75 - General considerations for evaluating visual impairment.

    Science.gov (United States)

    2010-07-01

    ... for evaluating visual impairment. 4.75 Section 4.75 Pensions, Bonuses, and Veterans' Relief DEPARTMENT... § 4.75 General considerations for evaluating visual impairment. (a) Visual impairment. The evaluation of visual impairment is based on impairment of visual acuity (excluding developmental errors of...

  7. Influences of multiple memory systems on auditory mental image acuity.

    Science.gov (United States)

    Navarro Cebrian, Ana; Janata, Petr

    2010-05-01

    The influence of different memory systems and associated attentional processes on the acuity of auditory images, formed for the purpose of making intonation judgments, was examined across three experiments using three different task types (cued-attention, imagery, and two-tone discrimination). In experiment 1 the influence of implicit long-term memory for musical scale structure was manipulated by varying the scale degree (leading tone versus tonic) of the probe note about which a judgment had to be made. In experiments 2 and 3 the ability of short-term absolute pitch knowledge to develop was manipulated by presenting blocks of trials in the same key or in seven different keys. The acuity of auditory images depended on all of these manipulations. Within individual listeners, thresholds in the two-tone discrimination and cued-attention conditions were closely related. In many listeners, cued-attention thresholds were similar to thresholds in the imagery condition, and depended on the amount of training individual listeners had in playing a musical instrument. The results indicate that mental images formed at a sensory/cognitive interface for the purpose of making perceptual decisions are highly malleable.

  8. Stimulus-dependent effects on tactile spatial acuity

    Directory of Open Access Journals (Sweden)

    Tommerdahl M

    2005-10-01

    Full Text Available Abstract Background Previous studies have shown that spatio-tactile acuity is influenced by the clarity of the cortical response in primary somatosensory cortex (SI. Stimulus characteristics such as frequency, amplitude, and location of tactile stimuli presented to the skin have been shown to have a significant effect on the response in SI. The present study observes the effect of changing stimulus parameters of 25 Hz sinusoidal vertical skin displacement stimulation ("flutter" on a human subject's ability to discriminate between two adjacent or near-adjacent skin sites. Based on results obtained from recent neurophysiological studies of the SI response to different conditions of vibrotactile stimulation, we predicted that the addition of 200 Hz vibration to the same site that a two-point flutter stimulus was delivered on the skin would improve a subject's spatio-tactile acuity over that measured with flutter alone. Additionally, similar neurophysiological studies predict that the presence of either a 25 Hz flutter or 200 Hz vibration stimulus on the unattended hand (on the opposite side of the body from the site of two-point limen testing – the condition of bilateral stimulation – which has been shown to evoke less SI cortical activity than the contralateral-only stimulus condition would decrease a subject's ability to discriminate between two points on the skin. Results A Bekesy tracking method was employed to track a subject's ability to discriminate between two-point stimuli delivered to the skin. The distance between the two points of stimulation was varied on a trial-by-trial basis, and several different stimulus conditions were examined: (1 The "control" condition, in which 25 Hz flutter stimuli were delivered simultaneously to the two points on the skin of the attended hand, (2 the "complex" condition, in which a combination of 25 Hz flutter and 200 Hz vibration stimuli were delivered to the two points on the attended hand, and (3 a

  9. Visual function, driving safety, and the elderly.

    Science.gov (United States)

    Keltner, J L; Johnson, C A

    1987-09-01

    The authors have conducted a survey of the Departments of Motor Vehicles in all 50 states, the District of Columbia, and Puerto Rico requesting information about the visual standards, accidents, and conviction rates for different age groups. In addition, we have reviewed the literature on visual function and traffic safety. Elderly drivers have a greater number of vision problems that affect visual acuity and/or peripheral visual fields. Although the elderly are responsible for a small percentage of the total number of traffic accidents, the types of accidents they are involved in (e.g., failure to yield the right-of-way, intersection collisions, left turns onto crossing streets) may be related to peripheral and central visual field problems. Because age-related changes in performance occur at different rates for various individuals, licensing of the elderly driver should be based on functional abilities rather than age. Based on information currently available, we can make the following recommendations: (1) periodic evaluations of visual acuity and visual fields should be performed every 1 to 2 years in the population over age 65; (2) drivers of any age with multiple accidents or moving violations should have visual acuity and visual fields evaluated; and (3) a system should be developed for physicians to report patients with potentially unsafe visual function. The authors believe that these recommendations may help to reduce the number of traffic accidents that result from peripheral visual field deficits.

  10. Stable particles

    International Nuclear Information System (INIS)

    Samios, N.P.

    1993-01-01

    I have been asked to review the subject of stable particles, essentially the particles that eventually comprised the meson and baryon octets. with a few more additions -- with an emphasis on the contributions made by experiments utilizing the bubble chamber technique. In this activity, much work had been done by the photographic emulsion technique and cloud chambers-exposed to cosmic rays as well as accelerator based beams. In fact, many if not most of the stable particles were found by these latter two techniques, however, the forte of the bubble chamber (coupled with the newer and more powerful accelerators) was to verify, and reinforce with large statistics, the existence of these states, to find some of the more difficult ones, mainly neutrals and further to elucidate their properties, i.e., spin, parity, lifetimes, decay parameters, etc

  11. Set size influences the relationship between ANS acuity and math performance: a result of different strategies?

    Science.gov (United States)

    Dietrich, Julia Felicitas; Nuerk, Hans-Christoph; Klein, Elise; Moeller, Korbinian; Huber, Stefan

    2017-08-29

    Previous research has proposed that the approximate number system (ANS) constitutes a building block for later mathematical abilities. Therefore, numerous studies investigated the relationship between ANS acuity and mathematical performance, but results are inconsistent. Properties of the experimental design have been discussed as a potential explanation of these inconsistencies. In the present study, we investigated the influence of set size and presentation duration on the association between non-symbolic magnitude comparison and math performance. Moreover, we focused on strategies reported as an explanation for these inconsistencies. In particular, we employed a non-symbolic magnitude comparison task and asked participants how they solved the task. We observed that set size was a significant moderator of the relationship between non-symbolic magnitude comparison and math performance, whereas presentation duration of the stimuli did not moderate this relationship. This supports the notion that specific design characteristics contribute to the inconsistent results. Moreover, participants reported different strategies including numerosity-based, visual, counting, calculation-based, and subitizing strategies. Frequencies of these strategies differed between different set sizes and presentation durations. However, we found no specific strategy, which alone predicted arithmetic performance, but when considering the frequency of all reported strategies, arithmetic performance could be predicted. Visual strategies made the largest contribution to this prediction. To conclude, the present findings suggest that different design characteristics contribute to the inconsistent findings regarding the relationship between non-symbolic magnitude comparison and mathematical performance by inducing different strategies and additional processes.

  12. Factors influencing visual rehabilitation after occlusion therapy in unilateral amblyopia in children.

    Science.gov (United States)

    Menon, Vimla; Chaudhuri, Zia; Saxena, Rohit; Gill, Kulwant; Sachdeva, M M

    2005-12-01

    Amblyopia is one of the most common causes of visual impairment in adults and children, and visual loss may be permanent if not treated in time. Though many studies have been done on occlusion therapy which is the mainstay in the treatment of unilateral amblyopia, discrepancies exist in literature about quantification of treatment and follow up measures. The present study was undertaken to evaluate the factors responsible for the successful outcome of treatment and the optimum time required for the same in children with unilateral amblyopia. Baseline characteristics of 63 verbal patients with unilateral amblyopia (strabismic, anisometropic, mixed) referred to the Strabismus and Amblyopia Clinic at the Dr Rajendra Prasad Centre for Ophthalmic Sciences, New Delhi between September 2001 to December 2002 who improved to the desired level of visual acuity after treatment for amblyopia in the mentioned time period, were analyzed to assess for factors that directly or indirectly influenced the optimum visual rehabilitation and the average duration of therapy required for the same. The evaluation included assessment of the baseline best-corrected visual acuity (BCVA) and refractive status in both eyes, the age at presentation, the type of amblyopia present, fixation pattern in the amblyopic eye, inter-eye visual acuity difference, and evaluation of compliance through a parental diary system. Baseline BCVA in the amblyopic eye was similar in all the three groups. Patients with anisometropic amblyopia showed a quicker response to therapy. Compliance to treatment was the major factor affecting the overall time required for a successful outcome in most cases. The overall time required for the treatment to be successful (including the period of maintenance) was about 1,089 h. This hospital-based study showed that the average duration of occlusion therapy to achieve stable isoacuity was 7.2 months with an average occlusion of 6-7 h/day. Compliance to therapy was the most

  13. Artificial Intelligence Can Predict Daily Trauma Volume and Average Acuity.

    Science.gov (United States)

    Stonko, David P; Dennis, Bradley M; Betzold, Richard D; Peetz, Allan B; Gunter, Oliver L; Guillamondegui, Oscar D

    2018-04-19

    The goal of this study was to integrate temporal and weather data in order to create an artificial neural network (ANN) to predict trauma volume, the number of emergent operative cases, and average daily acuity at a level 1 trauma center. Trauma admission data from TRACS and weather data from the National Oceanic and Atmospheric Administration (NOAA) was collected for all adult trauma patients from July 2013-June 2016. The ANN was constructed using temporal (time, day of week), and weather factors (daily high, active precipitation) to predict four points of daily trauma activity: number of traumas, number of penetrating traumas, average ISS, and number of immediate OR cases per day. We trained a two-layer feed-forward network with 10 sigmoid hidden neurons via the Levenberg-Marquardt backpropagation algorithm, and performed k-fold cross validation and accuracy calculations on 100 randomly generated partitions. 10,612 patients over 1,096 days were identified. The ANN accurately predicted the daily trauma distribution in terms of number of traumas, number of penetrating traumas, number of OR cases, and average daily ISS (combined training correlation coefficient r = 0.9018+/-0.002; validation r = 0.8899+/- 0.005; testing r = 0.8940+/-0.006). We were able to successfully predict trauma and emergent operative volume, and acuity using an ANN by integrating local weather and trauma admission data from a level 1 center. As an example, for June 30, 2016, it predicted 9.93 traumas (actual: 10), and a mean ISS score of 15.99 (actual: 13.12); see figure 3. This may prove useful for predicting trauma needs across the system and hospital administration when allocating limited resources. Level III STUDY TYPE: Prognostic/Epidemiological.

  14. Stable isotopes

    International Nuclear Information System (INIS)

    Brazier, J.L.; Guinamant, J.L.

    1995-01-01

    According to the progress which has been realised in the technology of separating and measuring isotopes, the stable isotopes are used as preferable 'labelling elements' for big number of applications. The isotopic composition of natural products shows significant variations as a result of different reasons like the climate, the seasons, or their geographic origins. So, it was proved that the same product has a different isotopic composition of alimentary and agriculture products. It is also important in detecting the pharmacological and medical chemicals. This review article deals with the technology, like chromatography and spectrophotometry, adapted to this aim, and some important applications. 17 refs. 6 figs

  15. Stable Tetraquarks

    Energy Technology Data Exchange (ETDEWEB)

    Quigg, Chris [Fermilab

    2018-04-13

    For very heavy quarks, relations derived from heavy-quark symmetry imply novel narrow doubly heavy tetraquark states containing two heavy quarks and two light antiquarks. We predict that double-beauty states will be stable against strong decays, whereas the double-charm states and mixed beauty+charm states will dissociate into pairs of heavy-light mesons. Observing a new double-beauty state through its weak decays would establish the existence of tetraquarks and illuminate the role of heavy color-antitriplet diquarks as hadron constituents.

  16. [Visual diagnosis: Waardenburg syndrome].

    Science.gov (United States)

    Hager, T; Walter, H-S; Seitz, B; Käsmann-Kellner, B

    2010-07-01

    Waardenburg syndrome (WS) is a rare disease characterized by a sensorineural hearing loss and pigment anomalies of the iris, skin and hair due to mutations in PAX3. WS can be subdivided into four groups according to major and minor clinical signs. We report the case of a 2 1/2-year-old coloured patient who presented in our department of paediatric ophthalmology for a syndrome search. The patient presented with hearing loss, brilliant blue iris colour and dystopia canthorum. The patient was slightly hypermetropic. Visual acuity was within normal limits according to the Cardiff acuity test. The ocular fundus examination revealed no abnormalities. According to the major and minor criteria defined by the Waardenburg consortium our patient showed the major criteria of WS1, i.e. hearing loss, hypopigmentation of the pigment epithelium of the iris and dystopic canthi. Diagnosis of WS is usually based on the clinical presentation. An additional molecular genetic analysis is possible.

  17. Stable beams

    CERN Multimedia

    2015-01-01

    Stable beams: two simple words that carry so much meaning at CERN. When LHC page one switched from "squeeze" to "stable beams" at 10.40 a.m. on Wednesday, 3 June, it triggered scenes of jubilation in control rooms around the CERN sites, as the LHC experiments started to record physics data for the first time in 27 months. This is what CERN is here for, and it’s great to be back in business after such a long period of preparation for the next stage in the LHC adventure.   I’ve said it before, but I’ll say it again. This was a great achievement, and testimony to the hard and dedicated work of so many people in the global CERN community. I could start to list the teams that have contributed, but that would be a mistake. Instead, I’d simply like to say that an achievement as impressive as running the LHC – a machine of superlatives in every respect – takes the combined effort and enthusiasm of everyone ...

  18. Visual attention and stability

    NARCIS (Netherlands)

    Mathot, Sebastiaan; Theeuwes, Jan

    2011-01-01

    In the present review, we address the relationship between attention and visual stability. Even though with each eye, head and body movement the retinal image changes dramatically, we perceive the world as stable and are able to perform visually guided actions. However, visual stability is not as

  19. Visual functions in amblyopia as determinants of response to treatment.

    Science.gov (United States)

    Singh, Vinita; Agrawal, Siddharth

    2013-01-01

    To describe the visual functions in amblyopia as determinants of response to treatment. Sixty-nine patients with unilateral and bilateral amblyopia (114 amblyopic eyes) 3 to 15 years old (mean age: 8.80 ± 2.9 years), 40 males (58%) and 29 females (42%), were included in this study. All patients were treated by conventional occlusion 6 hours per day for mild to moderate amblyopia (visual acuity 0.70 or better) and full-time for 4 weeks followed by 6 hours per day for severe amblyopia (visual acuity 0.8 or worse). During occlusion, near activities requiring hand-eye coordination were advised. The follow-up examination was done at 3 and 6 months. Improvement in visual acuity was evaluated on the logMAR chart and correlated with the visual functions. Statistical analysis was done using Wilcoxon rank sum test (Mann-Whitney U test) and Kruskal-Wallis analysis. There was a statistically significant association of poor contrast sensitivity with the grade of amblyopia (P amblyopia (P amblyopia therapy. The grade of amblyopia (initial visual acuity) and accommodation are strong determinants of response to amblyopia therapy, whereas stereopsis and mesopic visual acuity have some value as determinants. Copyright 2013, SLACK Incorporated.

  20. Human locognosic acuity on the arm varies with explicit and implicit manipulations of attention: implications for interpreting elevated tactile acuity on an amputation stump.

    Science.gov (United States)

    O'Boyle, D J; Moore, C E; Poliakoff, E; Butterworth, R; Sutton, A; Cody, F W

    2001-06-01

    In Experiment 1, normal subjects' ability to localize tactile stimuli (locognosia) delivered to the upper arm was significantly higher when they were instructed explicitly to direct their attention selectively to that segment than when they were instructed explicitly to distribute their attention across the whole arm. This elevation of acuity was eliminated when subjects' attentional resources were divided by superimposition of an effortful, secondary task during stimulation. In Experiment 2, in the absence of explicit attentional instruction, subjects' locognosic acuity on one of three arm segments was significantly higher when stimulation of that segment was 2.5 times more probable than that of stimulation of the other two segments. We surmise that the attentional mechanisms responsible for such modulations of locognosic acuity in normal subjects may contribute to the elevated sensory acuity observed on the stumps of amputees.

  1. [Epidemiological survey of visual impairment in Funing County, Jiangsu].

    Science.gov (United States)

    Yang, M; Zhang, J F; Zhu, R R; Kang, L H; Qin, B; Guan, H J

    2017-07-11

    Objective: To investigate the prevalence of visual impairment and factors associated with visual impairment among people aged 50 years and above in Funing County, Jiangsu Province. Methods: Cross-sectional study. Random cluster sampling was used in selecting individuals aged ≥50 years in 30 clusters, and 5 947 individuals received visual acuity testing and eye examination. Stata 13.0 software was used to analyze the data. Multivariate logistic regression was used to detect possible factors of visual impairment such as age, gender and education. Statistical significance was defined as Pvisual impairment classification and presenting visual acuity, 138 persons were diagnosed as blindness, and 1 405 persons were diagnosed as low vision. The prevalence of blindness and low vision was 2.32% and 23.63%, respectively. And the prevalence of visual impairment was 25.95%. Based on the criteria of WHO visual impairment classification and best-corrected visual acuity, 92 persons were diagnosed as blindness, and 383 persons were diagnosed as low vision. The prevalence of blindness and low vision was 1.55% and 6.44%, respectively. And the prevalence of visual impairment was 7.99%. Concerning presenting visual acuity and best-corrected visual acuity, the prevalence of blindness and low vision was higher in old people, females and less educated persons. Cataract (46.63%) was the leading cause of blindness. Uncorrected refractive error (36.51%) was also a main cause of visual impairment. Conclusion: The prevalence of visual impairment is higher in old people, females and less educated persons in Funing County, Jiangsu Province. Cataract is still the leading cause of visual impairment. (Chin J Ophthalmol, 2017, 53: 502-508) .

  2. 45 CFR 1308.13 - Eligibility criteria: Visual impairment including blindness.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Eligibility criteria: Visual impairment including... impairment including blindness. (a) A child is classified as visually impaired when visual impairment, with...) A child is classified as having a visual impairment if central acuity with corrective lenses is...

  3. Visual functions and disability in diabetic retinopathy patients.

    Science.gov (United States)

    Shrestha, Gauri Shankar; Kaiti, Raju

    2014-01-01

    This study was undertaken to find correlations between visual functions and visual disabilities in patients with diabetic retinopathy. A cross-sectional study was carried out among 38 visually impaired diabetic retinopathy subjects at the Low Vision Clinic of B.P. Koirala Lions Centre for Ophthalmic Studies, Kathmandu. The subjects underwent assessment of distance and near visual acuity, objective and subjective refraction, contrast sensitivity, color vision, and central and peripheral visual fields. The visual disabilities of each subject in their daily lives were evaluated using a standard questionnaire. Multiple regression analysis between visual functions and visual disabilities index was assessed. The majority of subjects (42.1%) were of the age group 60-70 years. Best corrected visual acuity was found to be 0.73±0.2 in the better eye and 0.93±0.27 in the worse eye, which was significantly different at p=0.002. Visual disability scores were significantly higher for legibility of letters (1.2±0.3) and sentences (1.4±0.4), and least for clothing (0.7±0.3). Visual disability index for legibility of letters and sentences was significantly correlated with near visual acuity and peripheral visual field. Contrast sensitivity was also significantly correlated with the visual disability index, and total scores. Impairment of near visual acuity, contrast sensitivity, and peripheral visual field correlated significantly with different types of visual disability. Hence, these clinical tests should be an integral part of the visual assessment of diabetic eyes. Copyright © 2013 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

  4. Effect of methods of myopia correction on visual acuity, contrast sensitivity, and depth of focus

    NARCIS (Netherlands)

    Nio, YK; Jansonius, NM; Wijdh, RHJ; Beekhuis, WH; Worst, JGF; Noorby, S; Kooijman, AC

    Purpose. To psychophysically measure spherical and irregular aberrations in patients with various types of myopia correction. Setting: Laboratory of Experimental Ophthalmology, University of Groningen, Groningen, The Netherlands. Methods: Three groups of patients with low myopia correction

  5. Learner-to-learner visual acuity screening: A solution for early ...

    African Journals Online (AJOL)

    The National School Health Policy guidelines (2002) stipulate that primary school learners should have their vision, speech, hearing, mental health, teeth, ... This project created greater awareness among learners, parents and teachers ...

  6. Impact of examinees' stereopsis and near visual acuity on laparoscopic virtual reality performance.

    Science.gov (United States)

    Hoffmann, Henry; Ruiz-Schirinzi, Rebecca; Goldblum, David; Dell-Kuster, Salome; Oertli, Daniel; Hahnloser, Dieter; Rosenthal, Rachel

    2015-10-01

    Laparoscopic surgery represents specific challenges, such as the reduction of a three-dimensional anatomic environment to two dimensions. The aim of this study was to investigate the impact of the loss of the third dimension on laparoscopic virtual reality (VR) performance. We compared a group of examinees with impaired stereopsis (group 1, n = 28) to a group with accurate stereopsis (group 2, n = 29). The primary outcome was the difference between the mean total score (MTS) of all tasks taken together and the performance in task 3 (eye-hand coordination), which was a priori considered to be the most dependent on intact stereopsis. The MTS and performance in task 3 tended to be slightly, but not significantly, better in group 2 than in group 1 [MTS: -0.12 (95 % CI -0.32, 0.08; p = 0.234); task 3: -0.09 (95 % CI -0.29, 0.11; p = 0.385)]. The difference of MTS between simulated impaired stereopsis between group 2 (by attaching an eye patch on the adominant eye in the 2nd run) and the first run of group 1 was not significant (MTS: p = 0.981; task 3: p = 0.527). We were unable to demonstrate an impact of impaired examinees' stereopsis on laparoscopic VR performance. Individuals with accurate stereopsis seem to be able to compensate for the loss of the third dimension in laparoscopic VR simulations.

  7. Visual Acuity and Its Dependence Upon Receptor Density and Retinal Ganglion Cell Receptive Field Overlap.

    Science.gov (United States)

    1981-11-01

    organization of retinal receptive fields in monkeys and cats has been used to model the information flow to the retina in relation to the psychophysical...EXPERIMENTAL PROCEDURE Types of Animals Used Three types of monkeys were used in the present study, rhesus (Macaca mulatta), the Himalayan Macaque (Macaca...during the course of the program, although one died of Shigella infection. Attempts were made to trade the animals with local users in order to obtain

  8. When approximate number acuity predicts math performance: The moderating role of math anxiety

    Science.gov (United States)

    Libertus, Melissa E.

    2018-01-01

    Separate lines of research suggest that people who are better at estimating numerical quantities using the approximate number system (ANS) have better math performance, and that people with high levels of math anxiety have worse math performance. Only a handful of studies have examined both ANS acuity and math anxiety in the same participants and those studies report contradictory results. To address these inconsistencies, in the current study 87 undergraduate students completed assessments of ANS acuity, math anxiety, and three different measures of math. We considered moderation models to examine the interplay of ANS acuity and math anxiety on different aspects of math performance. Math anxiety and ANS acuity were both unique significant predictors of the ability to automatically recall basic number facts. ANS acuity was also a unique significant predictor of the ability to solve applied math problems, and this relation was further qualified by a significant interaction with math anxiety: the positive association between ANS acuity and applied problem solving was only present in students with high math anxiety. Our findings suggest that ANS acuity and math anxiety are differentially related to various aspects of math and should be considered together when examining their respective influences on math ability. Our findings also raise the possibility that good ANS acuity serves as a protective factor for highly math-anxious students on certain types of math assessments. PMID:29718939

  9. Tactile acuity is disrupted in osteoarthritis but is unrelated to disruptions in motor imagery performance.

    NARCIS (Netherlands)

    Stanton, T.R.; Lin, C.W.; Bray, H.; Smeets, R.J.P.; Taylor, D.; Law, R.Y.; Moseley, G.L.

    2013-01-01

    OBJECTIVE: To determine whether tactile acuity is disrupted in people with knee OA and to determine whether tactile acuity, a clinical signature of primary sensory cortex representation, is related to motor imagery performance (MIP; evaluates working body schema) and pain. METHODS: Experiment 1:

  10. When approximate number acuity predicts math performance: The moderating role of math anxiety.

    Science.gov (United States)

    Braham, Emily J; Libertus, Melissa E

    2018-01-01

    Separate lines of research suggest that people who are better at estimating numerical quantities using the approximate number system (ANS) have better math performance, and that people with high levels of math anxiety have worse math performance. Only a handful of studies have examined both ANS acuity and math anxiety in the same participants and those studies report contradictory results. To address these inconsistencies, in the current study 87 undergraduate students completed assessments of ANS acuity, math anxiety, and three different measures of math. We considered moderation models to examine the interplay of ANS acuity and math anxiety on different aspects of math performance. Math anxiety and ANS acuity were both unique significant predictors of the ability to automatically recall basic number facts. ANS acuity was also a unique significant predictor of the ability to solve applied math problems, and this relation was further qualified by a significant interaction with math anxiety: the positive association between ANS acuity and applied problem solving was only present in students with high math anxiety. Our findings suggest that ANS acuity and math anxiety are differentially related to various aspects of math and should be considered together when examining their respective influences on math ability. Our findings also raise the possibility that good ANS acuity serves as a protective factor for highly math-anxious students on certain types of math assessments.

  11. When approximate number acuity predicts math performance: The moderating role of math anxiety.

    Directory of Open Access Journals (Sweden)

    Emily J Braham

    Full Text Available Separate lines of research suggest that people who are better at estimating numerical quantities using the approximate number system (ANS have better math performance, and that people with high levels of math anxiety have worse math performance. Only a handful of studies have examined both ANS acuity and math anxiety in the same participants and those studies report contradictory results. To address these inconsistencies, in the current study 87 undergraduate students completed assessments of ANS acuity, math anxiety, and three different measures of math. We considered moderation models to examine the interplay of ANS acuity and math anxiety on different aspects of math performance. Math anxiety and ANS acuity were both unique significant predictors of the ability to automatically recall basic number facts. ANS acuity was also a unique significant predictor of the ability to solve applied math problems, and this relation was further qualified by a significant interaction with math anxiety: the positive association between ANS acuity and applied problem solving was only present in students with high math anxiety. Our findings suggest that ANS acuity and math anxiety are differentially related to various aspects of math and should be considered together when examining their respective influences on math ability. Our findings also raise the possibility that good ANS acuity serves as a protective factor for highly math-anxious students on certain types of math assessments.

  12. Tactile spatial acuity in childhood: effects of age and fingertip size.

    Directory of Open Access Journals (Sweden)

    Ryan M Peters

    Full Text Available Tactile acuity is known to decline with age in adults, possibly as the result of receptor loss, but less is understood about how tactile acuity changes during childhood. Previous research from our laboratory has shown that fingertip size influences tactile spatial acuity in young adults: those with larger fingers tend to have poorer acuity, possibly because mechanoreceptors are more sparsely distributed in larger fingers. We hypothesized that a similar relationship would hold among children. If so, children's tactile spatial acuity might be expected to worsen as their fingertips grow. However, concomitant CNS maturation might result in more efficient perceptual processing, counteracting the effect of fingertip growth on tactile acuity. To investigate, we conducted a cross-sectional study, testing 116 participants ranging in age from 6 to 16 years on a precision-controlled tactile grating orientation task. We measured each participant's grating orientation threshold on the dominant index finger, along with physical properties of the fingertip: surface area, volume, sweat pore spacing, and temperature. We found that, as in adults, children with larger fingertips (at a given age had significantly poorer acuity, yet paradoxically acuity did not worsen significantly with age. We propose that finger growth during development results in a gradual decline in innervation density as receptive fields reposition to cover an expanding skin surface. At the same time, central maturation presumably enhances perceptual processing.

  13. The contributions of numerical acuity and non-numerical stimulus features to the development of the number sense and symbolic math achievement.

    Science.gov (United States)

    Starr, Ariel; DeWind, Nicholas K; Brannon, Elizabeth M

    2017-11-01

    Numerical acuity, frequently measured by a Weber fraction derived from nonsymbolic numerical comparison judgments, has been shown to be predictive of mathematical ability. However, recent findings suggest that stimulus controls in these tasks are often insufficiently implemented, and the proposal has been made that alternative visual features or inhibitory control capacities may actually explain this relation. Here, we use a novel mathematical algorithm to parse the relative influence of numerosity from other visual features in nonsymbolic numerical discrimination and to examine the strength of the relations between each of these variables, including inhibitory control, and mathematical ability. We examined these questions developmentally by testing 4-year-old children, 6-year-old children, and adults with a nonsymbolic numerical comparison task, a symbolic math assessment, and a test of inhibitory control. We found that the influence of non-numerical features decreased significantly over development but that numerosity was a primary determinate of decision making at all ages. In addition, numerical acuity was a stronger predictor of math achievement than either non-numerical bias or inhibitory control in children. These results suggest that the ability to selectively attend to number contributes to the maturation of the number sense and that numerical acuity, independent of inhibitory control, contributes to math achievement in early childhood. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. A prospective, contralateral comparison of photorefractive keratectomy (PRK versus thin-flap LASIK: assessment of visual function

    Directory of Open Access Journals (Sweden)

    Hatch BB

    2011-04-01

    Full Text Available Bryndon B Hatch1, Majid Moshirfar1, Andrew J Ollerton1, Shameema Sikder2, Mark D Mifflin11John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA; 2Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USAPurpose: To compare differences in visual acuity, contrast sensitivity, complications, and higher-order ocular aberrations (HOAs in eyes with stable myopia undergoing either photorefractive keratectomy (PRK or thin-flap laser in situ keratomileusis (LASIK (intended flap thickness of 90 µm using the VISX Star S4 CustomVue excimer laser and the IntraLase FS60 femtosecond laser at 1, 3, and 6 months postoperatively.Methods: In this prospective, masked, and randomized pilot study, refractive surgery was performed contralaterally on 52 eyes: 26 with PRK and 26 with thin-flap LASIK. Primary outcome measures were uncorrected distance visual acuity (UDVA, corrected distance visual acuity (CDVA, contrast sensitivity, and complications.Results: At 6 months, mean values for UDVA (logMAR were -0.043 ± 0.668 and -0.061 ± 0.099 in the PRK and thin-flap LASIK groups, respectively (n = 25, P = 0.466. UDVA of 20/20 or better was achieved in 96% of eyes undergoing PRK and 92% of eyes undergoing thin-flap LASIK, whereas 20/15 vision or better was achieved in 73% of eyes undergoing PRK and 72% of eyes undergoing thin-flap LASIK (P > 0.600. Significant differences were not found between treatment groups in contrast sensitivity (P ≥ 0.156 or CDVA (P = 0.800 at postoperative 6 months. Types of complications differed between groups, notably 35% of eyes in the thin-flap LASIK group experiencing complications, including microstriae and 2 flap tears.Conclusion: Under well-controlled surgical conditions, PRK and thin-flap LASIK refractive surgeries achieve similar results in visual acuity, contrast sensitivity, and induction of HOAs, with differences in experienced complications.Keywords: photorefractive keratectomy, thin-flap LASIK, visual

  15. Improvements in clinical and functional vision and perceived visual disability after first and second eye cataract surgery

    OpenAIRE

    Elliott, D.; Patla, A.; Bullimore, M.

    1997-01-01

    AIMS—To determine the improvements in clinical and functional vision and perceived visual disability after first and second eye cataract surgery.
METHODS—Clinical vision (monocular and binocular high and low contrast visual acuity, contrast sensitivity, and disability glare), functional vision (face identity and expression recognition, reading speed, word acuity, and mobility orientation), and perceived visual disability (Activities of Daily Vision Scale) were measured in 25 subjects before a...

  16. Correlation of visual performance with quality of life and intraocular aberrometric profile in patients implanted with rotationally asymmetric multifocal IOLs.

    Science.gov (United States)

    Ramón, María L; Piñero, David P; Pérez-Cambrodí, Rafael J

    2012-02-01

    To examine the visual performance of a rotationally asymmetric multifocal intraocular lens (IOL) by correlating the defocus curve of the IOL-implanted eye with the intraocular aberrometric profile and impact on the quality of life. A prospective, consecutive, case series study including 26 eyes from 13 patients aged between 50 and 83 years (mean: 65.54±7.59 years) was conducted. All patients underwent bilateral cataract surgery with implantation of a rotationally asymmetric multifocal IOL (Lentis Mplus LS-312 MF30, Oculentis GmbH). Distance and near visual acuity outcomes, intraocular aberrations, defocus curve, and quality of life (assessed using the National Eye Institute Visual Functioning Questionnaire-25) were evaluated postoperatively (mean follow-up: 6.42±2.24 months). A significant improvement in distance visual acuity was found postoperatively (P<.01). Mean postoperative logMAR distance-corrected near visual acuity was 0.19±0.12 (∼20/30). Corrected distance visual acuity and near visual acuity of 20/20 or better were achieved by 30.8% and 7.7% of eyes, respectively. Of all eyes, 96.2% had a postoperative addition between 0 and 1.00 diopter (D). The defocus curve showed two peaks of maximum visual acuity (0 and 3.00 D of defocus), with an acceptable range of intermediate vision. LogMAR visual acuity corresponding to near defocus was directly correlated with some higher order intraocular aberrations (r⩾0.44, P⩽.04). Some difficulties evaluated with the quality of life test correlated directly with near and intermediate visual acuity (r⩾0.50, P⩽.01). The Lentis Mplus multifocal IOL provides good distance, intermediate, and near visual outcomes; however, the induced intraocular aberrometric profile may limit the potential visual benefit. Copyright 2012, SLACK Incorporated.

  17. Relationship between Vision and Visual Perception in Hong Kong Preschoolers.

    Science.gov (United States)

    Ho, Wing-Cheung; Tang, Minny Mei-Miu; Fu, Ching-Wah; Leung, Ka-Yan; Pang, Peter Chi-Kong; Cheong, Allen Ming-Yan

    2015-05-01

    Although superior performance in visual motor and visual perceptual skills of preschool children has been documented in the Chinese population, a normative database is only available for the US population. This study aimed to determine the normative values for these visuomotor and visual perceptual tests for preschool children in the Hong Kong Chinese population and to investigate the effect of fundamental visual functions on visuomotor and visual perceptual skills. One hundred seventy-four children from six different kindergartens in Hong Kong were recruited. Distance visual acuity, near visual acuity, and stereopsis were tested, along with two measures of visual perception (VP): Visual-Motor Integration (VMI) and Test of Visual-Perceptual Skills (TVPS). Raw VMI and TVPS scores were converted into standard/scaled scores. The impact of basic visual functions on VP (VMI and TVPS) was examined using multiple regression. Visual functions were generally good: only 9.2 and 4.6% of subjects had unilateral and bilateral reduced habitual vision, respectively (distance visual acuity in the better eye >0.3 logMAR [logarithm of the minimum angle of resolution]). Performance in the VMI and in the visual memory and spatial relationships subtests of the TVPS exceeded that reported for age-matched children from the United States. Multiple regression analysis provided evidence that age had the strongest predictive value for the VMI and VP skills. In addition, near visual acuity was weakly associated with performance in the VMI and the visual discrimination and spatial relationships subtests of the TVPS, accounting for a limited proportion of the intersubject variability (R memory/spatial relationships of TVPS subtests, perhaps attributed to greater exposure to such material during their preschool home education. This study provided normality data for VMI and four subtests of the TVPS for Hong Kong Chinese preschool children as a reference for future studies.

  18. Visual functions and disability in diabetic retinopathy patients

    OpenAIRE

    Shrestha, Gauri Shankar; Kaiti, Raju

    2013-01-01

    Purpose: This study was undertaken to find correlations between visual functions and visual disabilities in patients with diabetic retinopathy. Method: A cross-sectional study was carried out among 38 visually impaired diabetic retinopathy subjects at the Low Vision Clinic of B.P. Koirala Lions Centre for Ophthalmic Studies, Kathmandu. The subjects underwent assessment of distance and near visual acuity, objective and subjective refraction, contrast sensitivity, color vision, and central a...

  19. Bilateral Simultaneous Macular Infarction with Spontaneous Visual ...

    African Journals Online (AJOL)

    2018-01-30

    Jan 30, 2018 ... eyes and near acuity was; right eye: N24, left eye: N36. ... Keywords: Macular infarction, macular ischemia, sickle cell, visual loss ... and build upon the work non-commercially, as long as the author is credited and the new.

  20. ANS acuity and mathematics ability in preschoolers from low-income homes: contributions of inhibitory control.

    Science.gov (United States)

    Fuhs, Mary Wagner; McNeil, Nicole M

    2013-01-01

    Recent findings by Libertus, Feigenson, and Halberda (2011) suggest that there is an association between the acuity of young children's approximate number system (ANS) and their mathematics ability before exposure to instruction in formal schooling. The present study examined the generalizability and validity of these findings in a sample of preschoolers from low-income homes. Children attending Head Start (N = 103) completed measures to assess ANS acuity, mathematics ability, receptive vocabulary, and inhibitory control. Results showed only a weak association between ANS acuity and mathematics ability that was reduced to non-significance when controlling for a direct measure of receptive vocabulary. Results also revealed that inhibitory control plays an important role in the relation between ANS acuity and mathematics ability. Specifically, ANS acuity accounted for significant variance in mathematics ability over and above receptive vocabulary, but only for ANS acuity trials in which surface area conflicted with numerosity. Moreover, this association became non-significant when controlling for inhibitory control. These results suggest that early mathematical experiences prior to formal schooling may influence the strength of the association between ANS acuity and mathematics ability and that inhibitory control may drive that association in young children. © 2012 Blackwell Publishing Ltd.

  1. Retention of high tactile acuity throughout the life span in blindness.

    Science.gov (United States)

    Legge, Gordon E; Madison, Cindee; Vaughn, Brenna N; Cheong, Allen M Y; Miller, Joseph C

    2008-11-01

    Previous studies of tactile acuity on the fingertip, using passive touch, have demonstrated an age-related decline in spatial resolution for both sighted and blind subjects. We have reexamined this age dependence with two newly designed tactile-acuity charts that require active exploration of the test symbols. One chart used dot patterns similar to braille, and the other used embossed Landolt rings. Groups of blind braille readers and sighted subjects ranging from 12 to 85 years old were tested in two experiments. We replicated previous findings for sighted subjects by showing an age-related decrease in tactile acuity by nearly 1% per year. Surprisingly, the blind subjects retained high acuity into old age, showing no age-related decline. For the blind subjects, tactile acuity did not correlate with braille reading speed, the amount of daily reading, or the age at which braille was learned. We conclude that when measured with active touch, blind subjects retain high tactile acuity into old age, unlike their aging sighted peers. We propose that blind people's use of active touch in daily activities, not specifically braille reading, results in preservation of tactile acuity across the life span.

  2. Factors accounting for the 4-year change in acuity in patients between 50 and 80 years.

    Science.gov (United States)

    Koenig, Darren E; Nguyen, Lan Chi; Parker, Katrina E; Applegate, Raymond A

    2013-07-01

    It is well known that acuity slowly decreases in the later decades of life. We wish to determine the extent by which 4-year longitudinal acuity changes can be accounted for by changes in optical quality, or combination of optical quality metrics and of age between 50 and 80 years. High-contrast logMAR acuity, 35 image quality metrics, 4 intraocular scatter metrics, and 4 Lens Opacification Classification System III metrics and entry age were measured on one eye of each of the 148 subjects. Acuity change between baseline and the last visit was regressed against change in each metric for all eyes and a faster changing subset of 50 eyes with a gain or loss of four or more letters. Average change across 148 subjects was a 1.6 ± 4 letter loss (t148 = 4.31, p model for faster changing eyes included change in point spread function entropy, posterior subcapsular cataract, and trefoil and baseline age (sequential r adjusted values of 0.19, 0.27, 0.32, and 0.34, respectively; p = 1.48 × 10 for the full four-factor model). The same variables entered the multiple-regression model for the full 148 data set where most of the acuity measurements were within test-retest error and accounted for less of the variance (r adjusted = 0.15, p = 2.37 × 10). Despite being near noise levels for the measurement of acuity, change in optical quality metrics was the most important factor in eyes that lost or gained four or more letters of acuity. These findings should be generalizable given that our 4-year acuity change is essentially identical to other studies and indicate that these optical quality markers can be used to help identify those on a faster track to an acuity change.

  3. A Visual Profile of Queensland Indigenous Children.

    Science.gov (United States)

    Hopkins, Shelley; Sampson, Geoff P; Hendicott, Peter L; Wood, Joanne M

    2016-03-01

    Little is known about the prevalence of refractive error, binocular vision, and other visual conditions in Australian Indigenous children. This is important given the association of these visual conditions with reduced reading performance in the wider population, which may also contribute to the suboptimal reading performance reported in this population. The aim of this study was to develop a visual profile of Queensland Indigenous children. Vision testing was performed on 595 primary schoolchildren in Queensland, Australia. Vision parameters measured included visual acuity, refractive error, color vision, nearpoint of convergence, horizontal heterophoria, fusional vergence range, accommodative facility, AC/A ratio, visual motor integration, and rapid automatized naming. Near heterophoria, nearpoint of convergence, and near fusional vergence range were used to classify convergence insufficiency (CI). Although refractive error (Indigenous, 10%; non-Indigenous, 16%; p = 0.04) and strabismus (Indigenous, 0%; non-Indigenous, 3%; p = 0.03) were significantly less common in Indigenous children, CI was twice as prevalent (Indigenous, 10%; non-Indigenous, 5%; p = 0.04). Reduced visual information processing skills were more common in Indigenous children (reduced visual motor integration [Indigenous, 28%; non-Indigenous, 16%; p < 0.01] and slower rapid automatized naming [Indigenous, 67%; non-Indigenous, 59%; p = 0.04]). The prevalence of visual impairment (reduced visual acuity) and color vision deficiency was similar between groups. Indigenous children have less refractive error and strabismus than their non-Indigenous peers. However, CI and reduced visual information processing skills were more common in this group. Given that vision screenings primarily target visual acuity assessment and strabismus detection, this is an important finding as many Indigenous children with CI and reduced visual information processing may be missed. Emphasis should be placed on identifying

  4. Temporal versus Superior Limbal Incision: Any difference in visual ...

    African Journals Online (AJOL)

    Aim: To compare the visual outcome of a superiorly placed limbal incision with a temporal limbal incision in extracapsular cataract surgery. The main outcome measures are visual acuity and the degree of stigmatism based on refraction. Method: A retrospective non randomized comparative study. Medical records of 40 ...

  5. Visual Field Measurement with Motion Sensitivity Screening Test in ...

    African Journals Online (AJOL)

    Eye disease is a frequent complication of onchocerciasis in countrise where the disease is highly endemic. It has been shown that early ocular lesions which manifest as visual field defects or reduction in visual acuity can be reversed following treatment with ivermectin. At the community level, it is important to detect ...

  6. Visual outcome with the Oculentis Mplus intraocular lens

    Directory of Open Access Journals (Sweden)

    Si-Yuan Liu

    2017-11-01

    Full Text Available AIM: To evaluate the visual outcome of Oculentis Mplus intraocular lens(IOL.METHODS: Totally 20 eyes in 20 patients received phacoemulsification and Oculentis Mplus intraocular lens implantation were as test group, and 20 eyes(Aspira-aA IOLwere as control group. The following postoperative examinations were performed after operation for 3mo: uncorrected visual acuity of distance and near, refractive results, UBM examination, the rate of wearing spectacles and the complications. RESULTS: At 3mo after surgery, distance visual acuity of test group with Oculentis Mplus IOL were 0.10±0.03,the difference with control group was not significant(t=1.74, P>0.05. Eyes in test group had an uncorrected near acuity 0.11±0.04, the difference with control group was significant(t=15.53, PCONCLUSION: The implantation of Oculentis Mplus IOL not only has a good distance uncorrected visual acuity, but also with better near visual acuity. The surgery is safe, reliable and no special complication induced.

  7. The visual communication in the optonometric scales.

    Science.gov (United States)

    Dantas, Rosane Arruda; Pagliuca, Lorita Marlena Freitag

    2006-01-01

    Communication through vision involves visual apprenticeship that demands ocular integrity, which results in the importance of the evaluation of visual acuity. The scale of images, formed by optotypes, is a method for the verification of visual acuity in kindergarten children. To identify the optotype the child needs to know the image in analysis. Given the importance of visual communication during the process of construction of the scale of images, one presents a bibliographic, analytical study aiming at thinking about the principles for the construction of those tables. One considers the draw inserted as an optotype as a non-verbal symbolic expression of the body and/or of the environment constructed based on the caption of experiences by the individual. One contests the indiscriminate use of images, for one understands that there must be previous knowledge. Despite the subjectivity of the optotypes, the scales continue valid if one adapts images to those of the universe of the children to be examined.

  8. Acuity and case management: a healthy dose of outcomes, part III.

    Science.gov (United States)

    Huber, Diane L; Craig, Kathy

    2007-01-01

    This is the third of a 3-part series presenting 2 effective applications--acuity and dosage--that describe how the business case for case management (CM) can be made. In Part I, dosage and acuity concepts were explained as client need-severity, CM intervention-intensity, and CM activity-dose prescribed by amount, frequency, duration, and breadth of activities. Concepts were presented that related the practice of CM to the use of evidence-based practice (EBP), knowledge, and methods and the development of instruments that measure and score pivotal CM actions. Part I also featured a specific exemplar, the CM Acuity Tool, and described how to use acuity to identify and score the complexity of a CM case. Part II further explained dosage and 2 acuity instruments, the Acuity Tool and AccuDiff. Part III presents linkage to EBP and practical applications. The information contained in the 3-part series applies to all CM practice settings and contains ideas and recommendations useful to CM generalists, specialists, supervisors, and business and outcomes managers. The Acuity Tools Project was developed from frontline CM practice in one large, national telephonic CM company. Dosage: A literature search failed to find research into dosage of a behavioral intervention. The Huber-Hall model was developed and tested in a longitudinal study of CM models in substance abuse treatment and reported in the literature. Acuity: A structured literature search and needs assessment launched the development of the suite of acuity tools. A gap analysis identified that an instrument to assign and measure case acuity specific to CM activities was needed. Clinical experts, quality specialists, and business analysts (n = 7) monitored the development and testing of the tools, acuity concepts, scores, differentials, and their operating principles and evaluated the validity of the acuity tools' content related to CM activities. During the pilot phase of development, interrater reliability testing of

  9. Acuity and case management: a healthy dose of outcomes, part II.

    Science.gov (United States)

    Craig, Kathy; Huber, Diane L

    2007-01-01

    This is the second of a 3-part series presenting 2 effective applications-acuity and dosage-that describe how the business case for case management (CM) can be made. In Part I, dosage and acuity concepts were explained as client need-severity, CM intervention-intensity, and CM activity-dose prescribed by amount, frequency, duration, and breadth of activities. Part I also featured a specific exemplar, the CM Acuity Tool, and described how to use acuity to identify and score the complexity of a CM case. Appropriate dosage prescription of CM activity was discussed. Part II further explains dosage and presents two acuity instruments, the Acuity Tool and AccuDiff. Details are provided that show how these applications produce opportunities for better communication about CM cases and for more accurate measurement of the right content that genuinely reflects the essentials of CM practice. The information contained in the 3-part series applies to all CM practice settings and contains ideas and recommendations useful to CM generalists, specialists, and supervisors, plus business and outcomes managers. The Acuity Tools Project was developed from frontline CM practice in one large, national telephonic CM company. Dosage: A literature search failed to find research into dosage of a behavioral intervention. The Huber-Hall model was developed and tested in a longitudinal study of CM models in substance abuse treatment and reported in the literature. Acuity: A structured literature search and needs assessment launched the development of the suite of acuity tools. A gap analysis identified that an instrument to assign and measure case acuity specific to CM activities was needed. Clinical experts, quality specialists, and business analysts (n = 7) monitored the development and testing of the tools, acuity concepts, scores, differentials, and their operating principles and evaluated the validity of the Acuity Tools' content related to CM activities. During the pilot phase of

  10. Factors affecting visual outcomes after treatment of infectious endophthalmitis in northeastern Thailand

    Directory of Open Access Journals (Sweden)

    Yospaiboon Y

    2018-04-01

    Full Text Available Yosanan Yospaiboon, Anocha Intarapanich, Wipada Laovirojjanakul, Tanapat Ratanapakorn, Suthasinee Sinawat, Thuss Sanguansak, Chavakij Bhoomibunchoo KKU Eye Center, Department of Ophthalmology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand Objective: To determine factors affecting visual outcomes after treatment of infectious endophthalmitis during 2012–2016 at a large referral eye center in northeastern Thailand. Patients and methods: Medical charts of patients with a diagnosis of infectious endophthalmitis including demographic data, types of endophthalmitis, causative organisms, methods of treatment, anatomical, and functional outcomes were retrospectively reviewed. Factors associated with improved visual outcomes were analyzed.Results: Four hundred and eleven patients (417 eyes were recruited for the study. The three most common types were post-traumatic (44.53%, post-operative (31.87%, and endogenous endophthalmitis (17.52%. Vitreous cultures revealed causative organisms in 41.25%. Most common Gram-positive organisms were coagulase-negative Staphylococcus 30% (36/120, Bacillus spp. 20% (24/120, and Streptococcus pneumoniae 18.33% (20/120. Most common Gram-negatives were Pseudomonas spp. 24.32% (9/37, Klebsiella spp. 24.32% (9/37, and Enterobacter spp. 16.21% (6/37. Methods of treatment were medical treatment (18.71% and surgical treatment (81.29%, including pars plana vitrectomy with or without silicone oil tamponade (62.59% and destructive surgery (18.71%. After treatment, visual improvement was noted in 44.6%, stable vision in 18.47%, and worse vision in 36.93%. Factors associated with improved visual outcomes were post-operative endophthalmitis (P<0.001, coagulase-negative Staphylococcus (P=0.003, and initial visual acuity before treatment of hand motion or better (P=0.017.Conclusion: Most infectious endophthalmitis patients were post-traumatic, post-operative, and endogenous. The most common method of treatment was

  11. Change in vision, visual disability, and health after cataract surgery.

    Science.gov (United States)

    Helbostad, Jorunn L; Oedegaard, Maria; Lamb, Sarah E; Delbaere, Kim; Lord, Stephen R; Sletvold, Olav

    2013-04-01

    Cataract surgery improves vision and visual functioning; the effect on general health is not established. We investigated if vision, visual functioning, and general health follow the same trajectory of change the year after cataract surgery and if changes in vision explain changes in visual disability and general health. One-hundred forty-eight persons, with a mean (SD) age of 78.9 (5.0) years (70% bilateral surgery), were assessed before and 6 weeks and 12 months after surgery. Visual disability and general health were assessed by the CatQuest-9SF and the Short Formular-36. Corrected binocular visual acuity, visual field, stereo acuity, and contrast vision improved (P visual acuity evident up to 12 months (P = 0.034). Cataract surgery had an effect on visual disability 1 year later (P visual disability and general health 6 weeks after surgery. Vision improved and visual disability decreased in the year after surgery, whereas changes in general health and visual functioning were short-term effects. Lack of associations between changes in vision and self-reported disability and general health suggests that the degree of vision changes and self-reported health do not have a linear relationship.

  12. Managing the impact of growing low-acuity demand on ambulance services

    OpenAIRE

    KATHRYN JEAN EASTWOOD

    2018-01-01

    Increasing demand for emergency ambulances places a substantial burden on ambulance services. Many cases are low-acuity, having no urgent clinical need for paramedic treatment. Ambulance Victoria implemented a secondary telephone triage services to divert low-acuity cases away from emergency ambulances to more appropriate care. This research found this ‘Referral Service’ has had a substantial impact upon emergency operations, referring over 70% of the cases it managed away from emergency am...

  13. The effect of state medicaid case-mix payment on nursing home resident acuity.

    Science.gov (United States)

    Feng, Zhanlian; Grabowski, David C; Intrator, Orna; Mor, Vincent

    2006-08-01

    To examine the relationship between Medicaid case-mix payment and nursing home resident acuity. Longitudinal Minimum Data Set (MDS) resident assessments from 1999 to 2002 and Online Survey Certification and Reporting (OSCAR) data from 1996 to 2002, for all freestanding nursing homes in the 48 contiguous U.S. states. We used a facility fixed-effects model to examine the effect of introducing state case-mix payment on changes in nursing home case-mix acuity. Facility acuity was measured by aggregating the nursing case-mix index (NCMI) from the MDS using the Resource Utilization Group (Version III) resident classification system, separately for new admits and long-stay residents, and by an OSCAR-derived index combining a range of activity of daily living dependencies and special treatment measures. We followed facilities over the study period to create a longitudinal data file based on the MDS and OSCAR, respectively, and linked facilities with longitudinal data on state case-mix payment policies for the same period. Across three acuity measures and two data sources, we found that states shifting to case-mix payment increased nursing home acuity levels over the study period. Specifically, we observed a 2.5 percent increase in the average acuity of new admits and a 1.3 to 1.4 percent increase in the acuity of long-stay residents, following the introduction of case-mix payment. The adoption of case-mix payment increased access to care for higher acuity Medicaid residents.

  14. Proprioceptive acuity into knee hypermobile range in children with Joint Hypermobility Syndrome

    OpenAIRE

    Pacey, Verity; Adams, Roger D; Tofts, Louise; Munns, Craig F; Nicholson, Leslie L

    2014-01-01

    Background Children with Joint Hypermobility Syndrome (JHS) have reduced knee joint proprioceptive acuity compared to peers. Altered proprioception at end of range in individuals with JHS is hypothesised to contribute to recurrent joint injuries and instability. This study aims to provide the first objective comparison of functional knee joint proprioceptive acuity in hyperextension range compared to early flexion range in children with JHS. Methods Active, weight-bearing knee joint proprioce...

  15. The Mozart effect in biofeedback visual rehabilitation: a case report

    Directory of Open Access Journals (Sweden)

    Salvatore S

    2011-09-01

    Full Text Available Serena Salvatore, Aloisa Librando, Mariacristina Esposito, Enzo M VingoloDepartment of Ophthalmology, University La Sapienza, Polo Pontino, Alfredo Fiorini Hospital, Terracina, ItalyPurpose: To evaluate the usefulness of acoustic biofeedback by means of Mozart’s Sonata for Two Pianos in D Major K. 448 to maintain and/or restore visual performance in a patient with macular pucker and glaucoma.Methods: A 74-year-old patient with open angle glaucoma in both eyes and macular pucker in the right eye (RE underwent visual rehabilitation with acoustic biofeedback by means of the MAIA™ Vision Training Module (Centervue, Padova, Italy 10 minutes each eye once a week for 5 weeks. The patient was asked to move his eyes according to a sound which changed into Mozart’s Sonata for Two Pianos when the patient locked the fixation target.Results: Best-corrected visual acuity improved in his right eye (RE and was stable in the left eye (LE. Fixation stability improved in both eyes, and retinal sensitivity decreased in the RE and improved in the LE. The characteristic of the macular pucker did not change during the training as demonstrated with optical coherence tomography. The patient was very satisfied with the training, as demonstrated by a 25-item questionnaire (National Eye Institute – Visual Functioning Questionnaire, NEI-VFQ-25. The patient’s reading speed and the character size which he was able to read improved in his RE.Conclusion: Music could enhance synaptic plasticity and affect neural learning and fixation training by means of MAIA vision training. Therefore it can improve visual performance in patients with macular pucker, postpone the surgical time, and assure a better quality of life for the patient.Keywords: glaucoma, macular cellophane, music, vision training

  16. Influence of Passive Joint Stiffness on Proprioceptive Acuity in Individuals With Functional Instability of the Ankle.

    Science.gov (United States)

    Marinho, Hellen Veloso Rocha; Amaral, Giovanna Mendes; de Souza Moreira, Bruno; Araújo, Vanessa Lara; Souza, Thales Rezende; Ocarino, Juliana Melo; da Fonseca, Sérgio Teixeira

    2017-12-01

    Study Design Controlled laboratory study, cross-sectional. Background Deficits in ankle proprioceptive acuity have been reported in persons with functional instability of the ankle. Passive stiffness has been proposed as a possible mechanism underlying proprioceptive acuity. Objective To compare proprioceptive acuity and passive ankle stiffness in persons with and without functional ankle instability, and to assess the influence of passive joint stiffness on proprioceptive acuity in persons with functional ankle instability. Methods A sample of 18 subjects with and 18 without complaints of functional ankle instability following lateral ankle sprain participated. An isokinetic dynamometer was used to compare motion perception threshold, passive position sense, and passive ankle stiffness between groups. To evaluate the influence of passive stiffness on proprioceptive acuity, individuals in the lateral functional ankle instability group were divided into 2 subgroups: "high" and "low" passive ankle stiffness. Results The functional ankle instability group exhibited increased motion perception threshold when compared with the corresponding limb of the control group. Between-group differences were not found for passive position sense and passive ankle stiffness. Those in the functional ankle instability group with higher passive ankle stiffness had smaller motion perception thresholds than those with lower passive ankle stiffness. Conclusion Unlike motion perception threshold, passive position sense is not affected by the presence of functional ankle instability. Passive ankle stiffness appears to influence proprioceptive acuity in persons with functional ankle instability. J Orthop Sports Phys Ther 2017;47(12):899-905. Epub 7 Oct 2017. doi:10.2519/jospt.2017.7030.

  17. Tactile acuity and lumbopelvic motor control in patients with back pain and healthy controls.

    Science.gov (United States)

    Luomajoki, H; Moseley, G L

    2011-04-01

    Voluntary lumbopelvic control is compromised in patients with back pain. Loss of proprioceptive acuity is one contributor to decreased control. Several reasons for decreased proprioceptive acuity have been proposed, but the integrity of cortical body maps has been overlooked. We investigated whether tactile acuity, a clear clinical signature of primary sensory cortex organisation, relates to lumbopelvic control in people with back pain. Forty-five patients with back pain and 45 age- and sex-matched healthy controls participated in this cross-sectional study. Tactile acuity at the back was assessed using two-point discrimination (TPD) threshold in vertical and horizontal directions. Voluntary motor control was assessed using an established battery of clinical tests. Patients performed worse on the voluntary lumbopelvic tasks than healthy controls did (p<0.001). TPD threshold was larger in patients (mean (SD)=61 (13) mm) than in healthy controls (44 (10) mm). Moreover, larger TPD threshold was positively related to worse performance on the voluntary lumbopelvic tasks (Pearson's r=0.49; p<0.001). Tactile acuity, a clear clinical signature of primary sensory cortex organisation, relates to voluntary lumbopelvic control. This relationship raises the possibility that the former contributes to the latter, in which case training tactile acuity may aid recovery and assist in achieving normal motor performance after back injury.

  18. Buccal mucosal cancer patient who failed to recover taste acuity after partial oral cavity irradiation

    International Nuclear Information System (INIS)

    Saito, Tsutomu; Fukushima, Shoko; Furuhashi, Satoru; Yoshinobu, Takashi; Takahashi, Motoichiro; Miyake, Masahiko; Kawamori, Jiro; Tanaka, Yoshiaki

    2002-01-01

    We report a patient who suffered from prolonged loss of taste acuity after partial oral cavity irradiation. The electric taste threshold (ETT) of each point in the oral cavity was measured with an electric gustometer to evaluate quantitative local taste acuity. A subjective total taste acuity (STTA) scale was used to evaluate subjective total taste acuity. A 61-year-old male patient with right buccal mucosal cancer underwent radiation therapy more than 11 years ago, and has suffered from loss of taste acuity since then. He received electron beam irradiation to part of the oral cavity and right upper neck, mainly the right buccal mucosa near the retromolar trigone and a metastatic right submandibular node. He did not receive irradiation to the anterior portion of the tongue or left side of the posterior portion of the tongue. His ETT scores for each point were equal to or greater than 26, and his STTA score was grade 3. The present case implies that radiation damage to part of the oral cavity can cause the loss of subjective total taste acuity. (author)

  19. Buccal mucosal cancer patient who failed to recover taste acuity after partial oral cavity irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Tsutomu; Fukushima, Shoko; Furuhashi, Satoru; Yoshinobu, Takashi; Takahashi, Motoichiro [Nihon Univ., Tokyo (Japan). Surugadai Hospital; Miyake, Masahiko [Nihon Univ., Tokyo (Japan). School of Dentistry; Kawamori, Jiro; Tanaka, Yoshiaki [Nihon Univ., Tokyo (Japan). School of Medicine

    2002-10-01

    We report a patient who suffered from prolonged loss of taste acuity after partial oral cavity irradiation. The electric taste threshold (ETT) of each point in the oral cavity was measured with an electric gustometer to evaluate quantitative local taste acuity. A subjective total taste acuity (STTA) scale was used to evaluate subjective total taste acuity. A 61-year-old male patient with right buccal mucosal cancer underwent radiation therapy more than 11 years ago, and has suffered from loss of taste acuity since then. He received electron beam irradiation to part of the oral cavity and right upper neck, mainly the right buccal mucosa near the retromolar trigone and a metastatic right submandibular node. He did not receive irradiation to the anterior portion of the tongue or left side of the posterior portion of the tongue. His ETT scores for each point were equal to or greater than 26, and his STTA score was grade 3. The present case implies that radiation damage to part of the oral cavity can cause the loss of subjective total taste acuity. (author)

  20. Evaluation of Post-Operative Visual Outcomes of Cataract Surgery in ...

    African Journals Online (AJOL)

    Data was compiled on demographic characteristics, pre- and postoperative visual acuities and surgical complications. The preoperative and postoperative visual status was classified using the World Health Organization (WHO) category of Visual Impairment and Blindness. The standard parameters of assessing outcome of ...

  1. [Change settings for visual analyzer of child users of mobile communication: longitudinal study].

    Science.gov (United States)

    Khorseva, N I; Grigor'ev, Iu G; Gorbunova, N V

    2014-01-01

    The paper represents theresults of longitudinal monitoring of the changes in the parameters of simple visual-motor reaction, the visual acuity and the rate of the visual discrimination in the child users of mobile communication, which indicate the multivariability of the possible effects of radiation from mobile phones on the auditory system of children.

  2. Correction of refractive errors in rhesus macaques (Macaca mulatta) involved in visual research.

    Science.gov (United States)

    Mitchell, Jude F; Boisvert, Chantal J; Reuter, Jon D; Reynolds, John H; Leblanc, Mathias

    2014-08-01

    Macaques are the most common animal model for studies in vision research, and due to their high value as research subjects, often continue to participate in studies well into old age. As is true in humans, visual acuity in macaques is susceptible to refractive errors. Here we report a case study in which an aged macaque demonstrated clear impairment in visual acuity according to performance on a demanding behavioral task. Refraction demonstrated bilateral myopia that significantly affected behavioral and visual tasks. Using corrective lenses, we were able to restore visual acuity. After correction of myopia, the macaque's performance on behavioral tasks was comparable to that of a healthy control. We screened 20 other male macaques to assess the incidence of refractive errors and ocular pathologies in a larger population. Hyperopia was the most frequent ametropia but was mild in all cases. A second macaque had mild myopia and astigmatism in one eye. There were no other pathologies observed on ocular examination. We developed a simple behavioral task that visual research laboratories could use to test visual acuity in macaques. The test was reliable and easily learned by the animals in 1 d. This case study stresses the importance of screening macaques involved in visual science for refractive errors and ocular pathologies to ensure the quality of research; we also provide simple methodology for screening visual acuity in these animals.

  3. Developmental abilities in children with mild visual impairment

    Directory of Open Access Journals (Sweden)

    Vučinić Vesna

    2012-01-01

    Full Text Available This paper presents the results of analyzing the relation between visual acuity and developmental abilities (perceptive functions, verbal and non-verbal abilities in younger school children. The sample consists of 1165 children from urban, suburban, and rural parts of Belgrade, of both genders, aged between 7.5 and 11. American 'Lighthouse' Optotype was used for screening assessment of visual acuity. Mild visual impairment, i.e. near visual acuity in the better eye ranging from 0.3 to 0.7, was detected in 7.9% of the pupils. ACADIA test of developmental abilities was used for the assessment of developmental abilities. When compared to the examinees with visual acuity in the better eye ranging from 0.3 to 0.7 (mild amblyopia, the examinees with normal visual acuity achieved better results in visuomotor coordination, non-verbal reasoning (Visual Association subtest, and concept formation in non-verbal domain (Sequence and Coding subtest. No significant differences were determined in constructive praxis (Drawing Shapes subtest and representational dimension of a drawing (Drawing subtest. According to the criterion of age standard deviation, a statistically significant difference was determined between the examinees with mild visual impairment and the examinees with normal vision (χ2=13,425, df=2, p=0,001; ρ=0,103, p≤0,000. The results of 24.8% of the examinees with mild visual impairment deviate from age norms in one or two SD (14.9% in one SD, and 9.9% in two SD. In the group of examinees with normal vision 12.5% of the results deviate from age norms in one or two SD (8.7% in one SD, and 3.8% in two SD.

  4. Hypnosis and Osteopathic Manipulative Treatment for Visual Disorders During Pregnancy: A Case Report.

    Science.gov (United States)

    Russo, Giancarlo; Remonato, Alessandro; Remonato, Roberto; Zanier, Emiliano

    2017-01-01

    Context • Pregnancy causes physiological alterations to the visual system, particularly in relation to retinal vascularization, with a consequent increase of intraocular pressure, and to the lacrimal fluid, with a consequent ocular dryness, which both can lead to a reduction in visual acuity. Numerous case reports refer to the employment of hypnotic treatment in cases of myopia, but the literature does not report any case of decreased visual acuity postpartum that was treated with hypnosis. Objective • For women with visual disorders that had appeared during pregnancy or were preexisting, the study intended to evaluate the benefits of treatment of the diaphragm by hypnotherapy and osteopathy to modify intracorporeal pressure and restore the women's visual function. Design • The research team performed a case study. Setting • The setting was a private osteopathic clinic. Participant • The participant was a 35-y-old woman lacking visual acuity postpartum. Intervention • The study took place during a period of 1 d. The participant first took part in a hypnotherapy session, the first intervention, and then participated in an osteopathic session, the second intervention. Outcome Measures • For the first evaluation of visual function at baseline, 3 tests were performed: (1) a visual acuity test; (2) a cover test for near and distance vision; and (3) a test for near point convergence. The visual function evaluation (all 3 tests) occurred after the 2 types of treatment (T1, T2). Finally, a visual function evaluation (all 3 tests) occurred at a follow-up session 1 mo after the end of treatment (T3). Results • The intervention produced a significant improvement in visual acuity, due to the multidisciplinary approach of treatment with hypnotherapy and osteopathy, and achieved a result that was maintained in the medium term. Conclusions • Hypnosis and osteopathy produced a significant improvement in visual acuity and the result was maintained in the medium

  5. Functional MRI of the visual cortex and visual testing in patients with previous optic neuritis

    DEFF Research Database (Denmark)

    Langkilde, Annika Reynberg; Frederiksen, J.L.; Rostrup, Egill

    2002-01-01

    to both the results of the contrast sensitivity test and to the Snellen visual acuity. Our results indicate that fMRI is a useful method for the study of ON, even in cases where the visual acuity is severely impaired. The reduction in activated volume could be explained as a reduced neuronal input......The volume of cortical activation as detected by functional magnetic resonance imaging (fMRI) in the visual cortex has previously been shown to be reduced following optic neuritis (ON). In order to understand the cause of this change, we studied the cortical activation, both the size...... of the activated area and the signal change following ON, and compared the results with results of neuroophthalmological testing. We studied nine patients with previous acute ON and 10 healthy persons served as controls using fMRI with visual stimulation. In addition to a reduced activated volume, patients showed...

  6. Meningioma Causing Visual Impairment: Outcomes and Toxicity After Intensity Modulated Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Maclean, Jillian, E-mail: jillian.maclean@uclh.nhs.uk [Radiotherapy Department, University College London Hospital, London (United Kingdom); Fersht, Naomi [Radiotherapy Department, University College London Hospital, London (United Kingdom); Bremner, Fion [Neuro-Ophthalmology Department, National Hospital for Neurology and Neurosurgery, London (United Kingdom); Stacey, Chris; Sivabalasingham, Suganya [Radiotherapy Department, University College London Hospital, London (United Kingdom); Short, Susan [Radiotherapy Department, University College London Hospital, London (United Kingdom); Leeds Institute of Molecular Medicine, St James University Hospital, Leeds (United Kingdom)

    2013-03-15

    Purpose: To evaluate ophthalmologic outcomes and toxicity of intensity modulated radiation therapy (IMRT) in patients with meningiomas causing visual deficits. Methods and Materials: A prospective observational study with formal ophthalmologic and clinical assessment of 30 consecutive cases of meningioma affecting vision treated with IMRT from 2007 to 2011. Prescriptions were 50.4 Gy to mean target dose in 28 daily fractions. The median follow-up time was 28 months. Twenty-six meningiomas affected the anterior visual pathway (including 3 optic nerve sheath meningiomas); 4 were posterior to the chiasm. Results: Vision improved objectively in 12 patients (40%). Improvements were in visual field (5/16 patients), color vision (4/9 patients), acuity (1/15 patients), extraocular movements (3/11 patients), ptosis (1/5 patients), and proptosis (2/6 patients). No predictors of clinical response were found. Two patients had minor reductions in tumor dimensions on magnetic resonance imaging, 1 patient had radiological progression, and the other patients were stable. One patient experienced grade 2 keratitis, 1 patient had a minor visual field loss, and 5 patients had grade 1 dry eye. Conclusion: IMRT is an effective method for treating meningiomas causing ophthalmologic deficits, and toxicity is minimal. Thorough ophthalmologic assessment is important because clinical responses often occur in the absence of radiological change.

  7. Stable Isotope Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tissue samples (skin, bone, blood, muscle) are analyzed for stable carbon, stable nitrogen, and stable sulfur analysis. Many samples are used in their entirety for...

  8. Visual Abilities in Children with Developmental Delay

    DEFF Research Database (Denmark)

    Welinder, Lotte G; Baggesen, Kirsten L

    for vision. All students with visual acuities ≤6/12 were refractioned and examined by an ophthalmologist. Results:  Of 502 students, 56 (11%) had visual impairment (VI) [visual acuity (VA) ≤ 6/18], of which 21 had been previously undiagnosed. Legal blindness was found in 15 students (3%), of whom three had......Purpose:  To investigate the visual abilities of students with severe developmental delay (DD) age 6-8 starting in special needs education. Methods:  Between 1 January 2000 and 31 December 2008, we screened all students with severe DD starting in special needs schools in Northern Jutland, Denmark...... previously been undiagnosed. Students tested with preferential looking systems (N = 78) had significantly lower visual acuities [VA (decimal) = 0.55] than students tested with ortho types [VA (decimal) = 0.91] and had problems participating in the colour and form tests, possibly due to cerebral VI...

  9. Acuity-adaptable nursing care: exploring its place in designing the future patient room.

    Science.gov (United States)

    Kwan, Melissa A

    2011-01-01

    To substantiate the anticipated benefits of the original acuity-adaptable care delivery model as defined by innovator Ann Hendrich. In today's conveyor belt approach to healthcare, upon admission and through discharge, patients are commonly transferred based on changing acuity needs. Wasted time and money and inefficiencies in hospital operations often result-in addition to jeopardizing patient safety. In the last decade, a handful of hospitals pioneered the implementation of the acuity-adaptable care delivery model. Built on the concept of eliminating patient transfers, the projected outcomes of acuity-adaptable units-decreased average lengths of stay, increased patient safety and satisfaction, and increased nurses' satisfaction from reduced walking distances-make a good case for a model patient room. Although some hospitals experienced the projected benefits of the acuity-adaptable care delivery model, sustaining the outcomes proved to be difficult; hence, the original definition of acuity-adaptable units has not fared well. Variations on the original concept demonstrate that eliminating patient transfers has not been completely abandoned in healthcare redesign and construction initiatives. Terms such as flex-up, flex-down, universal room, and single-stay unit have since emerged. These variations convolute the search for empirical evidence to support the anticipated benefits of the original concept. To determine the future of this concept and its variants, a significant amount of outcome data must be generated by piloting the concept in different hospital settings. As further refinements and adjustments to the concept emerge, the acuity-adaptable room may find a place in future hospitals.

  10. Visual Outcomes of Parapapillary Uveal Melanomas Following Proton Beam Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Thariat, Juliette, E-mail: jthariat@gmail.com [Department of Radiation Therapy, Cancer Center Antoine Lacassagne-Nice Sophia Antipolis University Hospital, Nice (France); Grange, Jean-Daniel [Department of Ophthalmology, Eye University Clinic la Croix Rousse, Lyon (France); Mosci, Carlo [Department of Ophthalmology, National Institute for Cancer Research, Mura Delle Cappucine, Genova (Italy); Rosier, Laurence [Eye Clinic, Centre d' Exploration et de Traitement de la Retine et de la Macula, Bordeaux (France); Maschi, Celia [Department of Ophthalmology, Eye University Clinic Pasteur 2, Nice (France); Lanza, Francesco [Department of Ophthalmology, National Institute for Cancer Research, Mura Delle Cappucine, Genova (Italy); Nguyen, Anh Minh [Department of Ophthalmology, Eye University Clinic la Croix Rousse, Lyon (France); Jaspart, Franck; Bacin, Franck; Bonnin, Nicolas [Department of Ophthalmology, Eye University Clinic Gabriel Montpied, Clermont Ferrand (France); Gaucher, David [Department of Ophthalmology, Eye University Clinic, Hopital Civil, Strasbourg (France); Sauerwein, Wolfgang [Department of Radiation Therapy, NCTeam, Strahlenklinik, Universitätsklinikum Essen, Essen (Germany); Angellier, Gaelle; Hérault, Joel [Department of Radiation Therapy, Cancer Center Antoine Lacassagne-Nice Sophia Antipolis University Hospital, Nice (France); Caujolle, Jean-Pierre [Department of Ophthalmology, Eye University Clinic Pasteur 2, Nice (France)

    2016-05-01

    Purpose: In parapapillary melanoma patients, radiation-induced optic complications are frequent and visual acuity is often compromised. We investigated dose-effect relationships for the optic nerve with respect to visual acuity after proton therapy. Methods and Materials: Of 5205 patients treated between 1991 and 2014, those treated using computed tomography (CT)-based planning to 52 Gy (prescribed dose, not accounting for relative biologic effectiveness correction of 1.1) in 4 fractions, with minimal 6-month follow-up and documented initial and last visual acuity, were included. Deterioration of ≥0.3 logMAR between initial and last visual acuity results was reported. Results: A total of 865 consecutive patients were included. Median follow-up was 69 months, mean age was 61.7 years, tumor abutted the papilla in 35.1% of patients, and tumor-to-fovea distance was ≤3 mm in 74.2% of patients. Five-year relapse-free survival rate was 92.7%. Visual acuity was ≥20/200 in 72.6% of patients initially and 47.2% at last follow-up. A wedge filter was used in 47.8% of the patients, with a positive impact on vision and no impact on relapse. Glaucoma, radiation-induced optic neuropathy, maculopathy were reported in 17.9%, 47.5%, and 33.6% of patients, respectively. On multivariate analysis, age, diabetes, thickness, initial visual acuity and percentage of macula receiving 26 Gy were predictive of visual acuity. Furthermore, patients irradiated to ≥80% of their papilla had better visual acuity when limiting the 50% (30-Gy) and 20% (12-Gy) isodoses to ≤2 mm and 6 mm of optic nerve length, respectively. Conclusions: A personalized proton therapy plan with optic nerve and macular sparing can be used efficiently with good oncological and functional results in parapapillary melanoma patients.

  11. Visual Outcomes of Parapapillary Uveal Melanomas Following Proton Beam Therapy

    International Nuclear Information System (INIS)

    Thariat, Juliette; Grange, Jean-Daniel; Mosci, Carlo; Rosier, Laurence; Maschi, Celia; Lanza, Francesco; Nguyen, Anh Minh; Jaspart, Franck; Bacin, Franck; Bonnin, Nicolas; Gaucher, David; Sauerwein, Wolfgang; Angellier, Gaelle; Hérault, Joel; Caujolle, Jean-Pierre

    2016-01-01

    Purpose: In parapapillary melanoma patients, radiation-induced optic complications are frequent and visual acuity is often compromised. We investigated dose-effect relationships for the optic nerve with respect to visual acuity after proton therapy. Methods and Materials: Of 5205 patients treated between 1991 and 2014, those treated using computed tomography (CT)-based planning to 52 Gy (prescribed dose, not accounting for relative biologic effectiveness correction of 1.1) in 4 fractions, with minimal 6-month follow-up and documented initial and last visual acuity, were included. Deterioration of ≥0.3 logMAR between initial and last visual acuity results was reported. Results: A total of 865 consecutive patients were included. Median follow-up was 69 months, mean age was 61.7 years, tumor abutted the papilla in 35.1% of patients, and tumor-to-fovea distance was ≤3 mm in 74.2% of patients. Five-year relapse-free survival rate was 92.7%. Visual acuity was ≥20/200 in 72.6% of patients initially and 47.2% at last follow-up. A wedge filter was used in 47.8% of the patients, with a positive impact on vision and no impact on relapse. Glaucoma, radiation-induced optic neuropathy, maculopathy were reported in 17.9%, 47.5%, and 33.6% of patients, respectively. On multivariate analysis, age, diabetes, thickness, initial visual acuity and percentage of macula receiving 26 Gy were predictive of visual acuity. Furthermore, patients irradiated to ≥80% of their papilla had better visual acuity when limiting the 50% (30-Gy) and 20% (12-Gy) isodoses to ≤2 mm and 6 mm of optic nerve length, respectively. Conclusions: A personalized proton therapy plan with optic nerve and macular sparing can be used efficiently with good oncological and functional results in parapapillary melanoma patients.

  12. How to improve the efficient use of functional vision of people with visual impairment

    OpenAIRE

    Mohorko, Ana

    2013-01-01

    Barraga was the first researcher to study the effects of a special program for developing visual efficiency which showed improvements in visual acuity and visual functioning in blind children with remaining vision. Her breakthrough findings helped develop new theories of visual functioning. These theories represent a foundation from which a professional can understand the visual functioning of an individual with low vision. Providing opportunities for individuals to learn how to use their vis...

  13. The flex track: flexible partitioning between low- and high-acuity areas of an emergency department.

    Science.gov (United States)

    Laker, Lauren F; Froehle, Craig M; Lindsell, Christopher J; Ward, Michael J

    2014-12-01

    Emergency departments (EDs) with both low- and high-acuity treatment areas often have fixed allocation of resources, regardless of demand. We demonstrate the utility of discrete-event simulation to evaluate flexible partitioning between low- and high-acuity ED areas to identify the best operational strategy for subsequent implementation. A discrete-event simulation was used to model patient flow through a 50-bed, urban, teaching ED that handles 85,000 patient visits annually. The ED has historically allocated 10 beds to a fast track for low-acuity patients. We estimated the effect of a flex track policy, which involved switching up to 5 of these fast track beds to serving both low- and high-acuity patients, on patient waiting times. When the high-acuity beds were not at capacity, low-acuity patients were given priority access to flexible beds. Otherwise, high-acuity patients were given priority access to flexible beds. Wait times were estimated for patients by disposition and Emergency Severity Index score. A flex track policy using 3 flexible beds produced the lowest mean patient waiting time of 30.9 minutes (95% confidence interval [CI] 30.6 to 31.2 minutes). The typical fast track approach of rigidly separating high- and low-acuity beds produced a mean patient wait time of 40.6 minutes (95% CI 40.2 to 50.0 minutes), 31% higher than that of the 3-bed flex track. A completely flexible ED, in which all beds can accommodate any patient, produced mean wait times of 35.1 minutes (95% CI 34.8 to 35.4 minutes). The results from the 3-bed flex track scenario were robust, performing well across a range of scenarios involving higher and lower patient volumes and care durations. Using discrete-event simulation, we have shown that adding some flexibility into bed allocation between low and high acuity can provide substantial reductions in overall patient waiting and a more efficient ED. Copyright © 2014 American College of Emergency Physicians. Published by Elsevier Inc

  14. Visual recovery and predictors of visual prognosis after managing traumatic cataracts in 555 patients

    Directory of Open Access Journals (Sweden)

    Mehul Shah

    2011-01-01

    Full Text Available The aim was to evaluate the visual recovery after managing traumatic cataracts and determine the predictors of a better visual prognosis. This was a prospective study. We enrolled patients with specific inclusion criteria, examined their eyes to review the comorbidities due to trauma, performed surgery for traumatic cataracts, and implanted lenses. The patients were reexamined 6 weeks postoperatively. We divided the cases of traumatic cataract into two groups, the "open globe" (Group 1 and "closed globe" (Group 2 groups, according to the ocular trauma based on the Birmingham Eye Trauma Terminology System (BETTS and compared the determinants of visual acuity. Our cohort of 555 eyes with traumatic cataracts included 394 eyes in Group 1 and 161 in Group 2. Six weeks postoperatively, the visual acuity in the operated eye was >20/60 in 193 (48% and 49 (29% eyes in Groups 1 and 2, respectively (P = 0.002, ANOVA. At follow-up, >20/60 vision was significantly higher in Group 1 than in Group 2 (OR = 1.61; 95% CI, 0.85-3.02. Overall 242 (43.5% eyes gained a final visual acuity of >20/60. Open globe injury has a favorable prognosis for satisfactory (>20/60 visual recovery after the management of traumatic cataracts.

  15. Development of microcomputer-based mental acuity tests

    Science.gov (United States)

    Turnage, J. J.; Kennedy, R. S.; Smith, M. G.; Baltzley, D. R.; Lane, N. E.

    1992-01-01

    Recent disasters have focused attention on performance problems due to the use of alcohol and controlled substances in the workplace. Environmental stressors such as thermal extremes, mixed gases, noise, motion, and vibration also have adverse effects on human performance and operator efficiency. However, the lack of a standardized, sensitive, human performance assessment battery has probably delayed the systematic study of the deleterious effects of various toxic chemicals and drugs at home and in the workplace. The collective goal of the research reported here is the development of a menu of tests embedded in a coherent package of hardware and software that may be useful in repeated-measures studies of a broad range of agents that can degrade human performance. A menu of 40 tests from the Automated Performance Test System (APTS) is described, and the series of interlocking studies supporting its development is reviewed. The APTS tests, which run on several versions of laptop portables and desktop personal computers, have been shown to be stable, reliable, and factorially rich, and to have predictive validities with holistic measures of intelligence and simulator performances. In addition, sensitivity studies have been conducted in which performance changes due to stressors, agents, and treatments were demonstrated. We believe that tests like those described here have prospective use as an adjunct to urine testing for the screening for performance loss of individuals who are granted access to workplaces and stations that impact public safety.

  16. Blindness and Visual Impairment in an Urban West African Population: The Tema Eye Survey

    Science.gov (United States)

    Budenz, Donald L.; Bandi, Jagadeesh R.; Barton, Keith; Nolan, Winifred; Herndon, Leon; Whiteside-de Vos, Julia; Hay-Smith, Graham; Kim, Hanna; Tielsch, James

    2012-01-01

    Objective To determine the prevalence, etiologies, and risk factors of blindness and visual impairment among persons age 40 years and older residing in an urban West African location. Design Population-based cross-sectional study. Participants Five thousand six hundred and three participants residing in Tema, Ghana. Methods Proportionate random cluster sampling was used to select participants age 40 and over living in the city of Tema. Presenting distance visual acuity was measured at 4 and 1 meters using a reduced Logarithm of the Minimum Angle of Resolution (logMAR) tumbling E chart and then with trial frame based on autorefraction. A screening examination was performed in the field on all participants. Complete clinical examination by an ophthalmologist was performed on participants with best corrected visual acuity blindness (visual acuity in the better eye of blindness was 1.2%. After refraction and spectacle correction, the prevalence of visual impairment and blindness decreased to 6.7% and 0.75% respectively, suggesting that refractive error is the major correctable etiology of visual impairment and blindness in this population. Of 65 subjects having visual acuity blindness and visual impairment. Conclusions There is a high prevalence of blindness and visual impairment among those aged ≥40 years in Tema, Ghana, West Africa. Refractive error is a major cause of blindness and visual impairment in this population, followed by cataract, glaucoma, and corneal disease. PMID:22677425

  17. Visual abilities in two raptors with different ecology.

    Science.gov (United States)

    Potier, Simon; Bonadonna, Francesco; Kelber, Almut; Martin, Graham R; Isard, Pierre-François; Dulaurent, Thomas; Duriez, Olivier

    2016-09-01

    Differences in visual capabilities are known to reflect differences in foraging behaviour even among closely related species. Among birds, the foraging of diurnal raptors is assumed to be guided mainly by vision but their foraging tactics include both scavenging upon immobile prey and the aerial pursuit of highly mobile prey. We studied how visual capabilities differ between two diurnal raptor species of similar size: Harris's hawks, Parabuteo unicinctus, which take mobile prey, and black kites, Milvus migrans, which are primarily carrion eaters. We measured visual acuity, foveal characteristics and visual fields in both species. Visual acuity was determined using a behavioural training technique; foveal characteristics were determined using ultra-high resolution spectral-domain optical coherence tomography (OCT); and visual field parameters were determined using an ophthalmoscopic reflex technique. We found that these two raptors differ in their visual capacities. Harris's hawks have a visual acuity slightly higher than that of black kites. Among the five Harris's hawks tested, individuals with higher estimated visual acuity made more horizontal head movements before making a decision. This may reflect an increase in the use of monocular vision. Harris's hawks have two foveas (one central and one temporal), while black kites have only one central fovea and a temporal area. Black kites have a wider visual field than Harris's hawks. This may facilitate the detection of conspecifics when they are scavenging. These differences in the visual capabilities of these two raptors may reflect differences in the perceptual demands of their foraging behaviours. © 2016. Published by The Company of Biologists Ltd.

  18. Predictors of visual outcome in patients operated for craniopharyngioma - a Danish national study.

    Science.gov (United States)

    Jacobsen, Mads Forslund; Thomsen, Ann Sofia Skou; Bach-Holm, Daniella; Doroudian, Ghazaleh; Nissen, Kamilla Rothe; Fugleholm, Kåre; Poulsgaard, Lars; Siersma, Volkert; Heegaard, Steffen

    2018-02-01

    Craniopharyngioma often causes visual loss due to the close relation to the anterior visual pathways. This study investigates the incidence and predictors of visual outcomes in patients with craniopharyngioma. Data from sixty-six patients who underwent surgery for craniopharyngioma from 2009 to 2013 in Denmark were reviewed. Primary outcomes were visual acuity (VA) and visual field (VF) defects from pre-and postoperative visits. Secondary outcomes were optic nerve atrophy (OA) and papilledema. Fifty-eight patients were included. The VA of the patients 1-year after surgery improved by -0.16 log(MAR) (95%CI: -0.30 to -0.02; p = 0.0266). Visual field (VF) defects worsened in 17 eyes (30%), remained stable in 21 eyes (37%) and improved in 19 eyes (33%). The presence of papilledema and the absence of OA were significantly correlated with an improvement in VA postoperatively (p = 0.011 and p = 0.011, respectively). Patients undergoing surgery within a week or less after their first ophthalmological examination had a significant improvement in VA (-0.36; 95%CI: -0.62 to -0.09; p = 0.0099). Patients undergoing surgery using a subfrontal approach also showed improvement in VA (p = 0.048). Tumour recurrence had a significantly worse VA outcome (p = 0.0074). Patients show a slight improvement in VA 1-year after operation for craniopharyngioma. The presence of papilledema and early surgical intervention is associated with a significant improvement in VA. Early involvement of a dedicated ophthalmologist is recommended to secure an early detection of a visual decline and potential tumour recurrence. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  19. Sensorimotor posture control in the blind: superior ankle proprioceptive acuity does not compensate for vision loss.

    Science.gov (United States)

    Ozdemir, Recep A; Pourmoghaddam, Amir; Paloski, William H

    2013-09-01

    To better understand sensorimotor posture control differences between blind and sighted individuals, we examined the role of ankle joint proprioception and ankle muscle strength on postural control in healthy blind (n=13, 25-58 years) and age- and sex-matched sighted (n=15, 20-65 years) volunteers. We measured ankle joint proprioceptive acuity and isokinetic muscle strength in plantarflexion and dorsiflexion using an isokinetic dynamometer. We also assessed postural control performance during quiet bipedal stance with and without sudden postural perturbations, and during quiet unipedal stance. We found that while our blind subjects exhibited significantly better proprioceptive acuity than our sighted subjects their postural control performance was significantly poorer than that of the sighted group with eyes open, and no different from that of the sighted group with eyes closed suggesting that their superior proprioceptive acuity does not translate to improved balance control. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. The use of acuity and frailty measures for district nursing workforce plans.

    Science.gov (United States)

    David, Ami; Saunders, Mary

    2018-02-02

    This article discusses the use of Quest acuity and frailty measures for community nursing interventions to quantify and qualify the contributions of district nursing teams. It describes the use of a suite of acuity and frailty tools tested in 8 UK community service trusts over the past 5years. In addition, a competency assessment tool was used to gauge both capacity and capability of individual nurses. The consistency of the results obtained from the Quest audits offer significant evidence and potential for realigning community nursing services to offer improvements in efficiency and cost-effectiveness. The National Quality Board (NQB) improvement resource for the district nursing services ( NQB, 2017 ) recommends a robust method for classifying patient acuity/frailty/dependency. It is contended the Quest tools and their usage articulated here offer a suitable methodology.

  1. Armstrong Laboratory Space Visual Function Tester Program

    Science.gov (United States)

    Oneal, Melvin R.; Task, H. Lee; Gleason, Gerald A.

    1992-01-01

    Viewgraphs on space visual function tester program are presented. Many astronauts and cosmonauts have commented on apparent changes in their vision while on-orbit. Comments have included descriptions of earth features and objects that would suggest enhanced distance visual acuity. In contrast, some cosmonaut observations suggest a slight loss in their object discrimination during initial space flight. Astronauts have also mentioned a decreased near vision capability that did not recover to normal until return to earth. Duntley space vision experiment, USSR space vision experiments, and visual function testers are described.

  2. Stable convergence and stable limit theorems

    CERN Document Server

    Häusler, Erich

    2015-01-01

    The authors present a concise but complete exposition of the mathematical theory of stable convergence and give various applications in different areas of probability theory and mathematical statistics to illustrate the usefulness of this concept. Stable convergence holds in many limit theorems of probability theory and statistics – such as the classical central limit theorem – which are usually formulated in terms of convergence in distribution. Originated by Alfred Rényi, the notion of stable convergence is stronger than the classical weak convergence of probability measures. A variety of methods is described which can be used to establish this stronger stable convergence in many limit theorems which were originally formulated only in terms of weak convergence. Naturally, these stronger limit theorems have new and stronger consequences which should not be missed by neglecting the notion of stable convergence. The presentation will be accessible to researchers and advanced students at the master's level...

  3. Longitudinal study of visual function in patients with relapsing-remitting multiple sclerosis with and without a history of optic neuritis.

    Science.gov (United States)

    González Gómez, A; García-Ben, A; Soler García, A; García-Basterra, I; Padilla Parrado, F; García-Campos, J M

    2017-03-15

    The contrast sensitivity test determines the quality of visual function in patients with multiple sclerosis (MS). The purpose of this study is to analyse changes in visual function in patients with relapsing-remitting MS with and without a history of optic neuritis (ON). We conducted a longitudinal study including 61 patients classified into 3 groups as follows: a) disease-free patients (control group); b) patients with MS and no history of ON; and c) patients with MS and a history of unilateral ON. All patients underwent baseline and 6-year follow-up ophthalmologic examinations, which included visual acuity and monocular and binocular Pelli-Robson contrast sensitivity tests. Monocular contrast sensitivity was significantly lower in MS patients with and without a history of ON than in controls both at baseline (P=.00 and P=.01, respectively) and at 6 years (P=.01 and P=.02). Patients with MS and no history of ON remained stable throughout follow-up whereas those with a history of ON displayed a significant loss of contrast sensitivity (P=.01). Visual acuity and binocular contrast sensitivity at baseline and at 6 years was significantly lower in the group of patients with a history of ON than in the control group (P=.003 and P=.002 vs P=.006 and P=.005) and the group with no history of ON (P=.04 and P=.038 vs P=.008 and P=.01). However, no significant differences were found in follow-up results (P=.1 and P=.5). Monocular Pelli-Robson contrast sensitivity test may be used to detect changes in visual function in patients with ON. Copyright © 2017 The Author(s). Publicado por Elsevier España, S.L.U. All rights reserved.

  4. Visual impairment evaluation in 119 children with congenital Zika syndrome.

    Science.gov (United States)

    Ventura, Liana O; Ventura, Camila V; Dias, Natália de C; Vilar, Isabelle G; Gois, Adriana L; Arantes, Tiago E; Fernandes, Luciene C; Chiang, Michael F; Miller, Marilyn T; Lawrence, Linda

    2018-06-01

    To assess visual impairment in a large sample of infants with congenital Zika syndrome (CZS) and to compare with a control group using the same assessment protocol. The study group was composed of infants with confirmed diagnosis of CZS. Controls were healthy infants matched for age, sex, and socioeconomic status. All infants underwent comprehensive ophthalmologic evaluation including visual acuity, visual function assessment, and visual developmental milestones. The CZS group included 119 infants; the control group, 85 infants. At examination, the mean age of the CZS group was 8.5 ± 1.2 months (range, 6-13 months); of the controls, 8.4 ± 1.8 months (range, 5-12 months; P = 0.598). Binocular Teller Acuity Card (TAC) testing was abnormal in 107 CZS infants and in 4 controls (89.9% versus 5% [P visual development milestones were less achieved by infants with CZS compared to controls (P visual impairment. A protocol for assessment of the ocular findings, visual acuity, and visual developmental milestones tested against age-matched controls is suggested. Copyright © 2018 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

  5. Vision screening in children: Is 7-9 years of age a threshold for visual impairment?

    Science.gov (United States)

    Ertekin, Yusuf Haydar; Tekin, Murat; Uludag, Aysegul; Arikan, Sedat; Sahin, Erkan Melih

    2016-01-01

    The present study aimed to assess the prevalence of decreased visual acuity, strabismus, and spectacle wear in children aged 5 to 13 years. A cross-sectional study was performed in primary education schools. A total of 1938 participants, including 940 females (48.5%) and 998 males (51.5%) with a mean age 8.96 ± 2.31 (5-13 years old), were screened. The comparisons were performed with gender, age, and age groups. The children attended to vision screening were assigned to three age groups as 5-6 years, 7-9 years, and 10-13 years. The prevalence of the parameters was detected as decreased visual acuity 12.4%, strabismus 2.2%, and spectacle wear 6.9%. The prevalence of decreased visual acuity was significantly higher in girls and in children aged 7-9 years old (p = 0.013, p children aged 7-9 years old (p = 0.019, p visual acuity decrease in 33 of 106 (31.1%) children despite wearing own spectacle. There was no significant difference among three age groups for strabismus. Increased prevalence of decreased visual acuity, as well as the higher frequency of spectacle wear in children at ages of 7-9 years old may point out a threshold for visual impairment.

  6. Efficacy and complications of radiotherapy of anterior visual pathway tumors

    International Nuclear Information System (INIS)

    Capo, H.; Kupersmith, M.J.

    1991-01-01

    A progressive disturbance in visual acuity or visual field, along with an unexplained optic nerve atrophy, suggests the possibility of a tumor. Tumors that frequently affect the anterior visual pathway include primary optic nerve sheath meningiomas, intracranial meningiomas, optic gliomas, pituitary tumors, and craniopharyngiomas. The location of these tumors sometimes prohibits a complete surgical excision that might jeopardize the visual system. Radiation therapy, however, can be beneficial in these cases. This article reviews the indications for radiotherapy of tumors that involve the anterior visual pathway, along with the possible complications. Cases that present the effect of radiation therapy and radiation damage are presented.131 references

  7. Using patient acuity data to manage patient care outcomes and patient care costs.

    Science.gov (United States)

    Van Slyck, A; Johnson, K R

    2001-01-01

    This article describes actual reported uses for patient acuity data that go beyond historical uses in determining staffing allocations. These expanded uses include managing patient care outcomes and health care costs. The article offers the patient care executive examples of how objective, valid, and reliable data are used to drive approaches to effectively influence decision making in an increasingly competitive health care environment.

  8. The Microcirculation is Preserved in Emergency Department Low‐acuity Sepsis Patients Without Hypotension

    DEFF Research Database (Denmark)

    Skibsted, Simon; Filbin, Michael; Hou, Peter

    2014-01-01

    -acuity sepsis patients. The hypothesis was that patients with sepsis, but without hypotension, will demonstrate signs of flow abnormalities compared to noninfected control patients. Methods This was a prospective, observational study in a convenience sample of patients with sepsis and noninfected controls...

  9. Cultivating Perspectival Acuity: The Value and Cost of Integrating Theory, Craft, Research, and Practice

    Directory of Open Access Journals (Sweden)

    Joe Manganelli

    2016-10-01

    Full Text Available This paper presents reflections on integrating theory, craft, research, and practice to improve the accuracy and resiliency of each. The reflections build toward a set of statements about the value and the cost of integrating theory, craft, research, and practice. Specifically, the authors offer the Privileged Work / Non-Privileged Work Framework and concept of cultivating Perspectival Acuity.

  10. stableGP

    Data.gov (United States)

    National Aeronautics and Space Administration — The code in the stableGP package implements Gaussian process calculations using efficient and numerically stable algorithms. Description of the algorithms is in the...

  11. Angina Pectoris (Stable Angina)

    Science.gov (United States)

    ... Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More Angina Pectoris (Stable Angina) Updated:Aug 21,2017 You may have heard the term “angina pectoris” or “stable angina” in your doctor’s office, ...

  12. Predictors of visual outcomes following Boston type 1 keratoprosthesis implantation.

    Science.gov (United States)

    Ahmad, Sumayya; Akpek, Esen K; Gehlbach, Peter L; Dunlap, Karen; Ramulu, Pradeep Y

    2015-04-01

    To identify predictors of visual outcomes following Boston type 1 Keratoprosthesis (KPro) implantation. Retrospective chart review. Data regarding preoperative clinical and demographic characteristics and postoperative course were collected. Fifty-nine eyes of 59 adult patients who underwent KPro implantation between January 2006 and March 2012 at a single tertiary care center. Preoperative factors associated with all-cause and glaucoma-related loss of visual acuity from the best postoperative visual acuity noted. Fifty-two of 59 eyes (88%) achieved improved vision post implantation, with 7 eyes failing to gain vision as a result of pre-existing glaucoma (n = 4) or retino-choroidal disease (n = 3). Twenty-one eyes (21/52, 40%) maintained their best-ever visual acuity at last visit (mean follow-up period was 37.8 months). The likelihood of maintaining best-ever vision was 71% at 1 year, 59% at 2 years, and 48% at 3 years. Primary KPro implantation was associated with a higher likelihood of losing best-ever vision as compared to KPro implantation as a repeat corneal procedure (hazard ratio [HR] = 3.06; P = 006). The main reasons for postimplantation vision loss was glaucoma (12/31, 39%), and the risk of glaucomatous visual acuity loss was 15% at 2 years and 27% at 3 years. Prior trabeculectomy was associated with a higher rate of vision loss from glaucoma (HR = 3.25, P = .04). Glaucoma is the primary reason for loss of visual acuity after KPro implantation. Conditions necessitating primary KPro surgery are associated with more frequent all-cause vision loss. Prospective trials are necessary to better determine which clinical features best predict KPro success. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. New classification system-based visual outcome in Eales′ disease

    Directory of Open Access Journals (Sweden)

    Saxena Sandeep

    2007-01-01

    Full Text Available Purpose: A retrospective tertiary care center-based study was undertaken to evaluate the visual outcome in Eales′ disease, based on a new classification system, for the first time. Materials and Methods: One hundred and fifty-nine consecutive cases of Eales′ disease were included. All the eyes were staged according to the new classification: Stage 1: periphlebitis of small (1a and large (1b caliber vessels with superficial retinal hemorrhages; Stage 2a: capillary non-perfusion, 2b: neovascularization elsewhere/of the disc; Stage 3a: fibrovascular proliferation, 3b: vitreous hemorrhage; Stage 4a: traction/combined rhegmatogenous retinal detachment and 4b: rubeosis iridis, neovascular glaucoma, complicated cataract and optic atrophy. Visual acuity was graded as: Grade I 20/20 or better; Grade II 20/30 to 20/40; Grade III 20/60 to 20/120 and Grade IV 20/200 or worse. All the cases were managed by medical therapy, photocoagulation and/or vitreoretinal surgery. Visual acuity was converted into decimal scale, denoting 20/20=1 and 20/800=0.01. Paired t-test / Wilcoxon signed-rank tests were used for statistical analysis. Results: Vitreous hemorrhage was the commonest presenting feature (49.32%. Cases with Stages 1 to 3 and 4a and 4b achieved final visual acuity ranging from 20/15 to 20/40; 20/80 to 20/400 and 20/200 to 20/400, respectively. Statistically significant improvement in visual acuities was observed in all the stages of the disease except Stages 1a and 4b. Conclusion: Significant improvement in visual acuities was observed in the majority of stages of Eales′ disease following treatment. This study adds further to the little available evidences of treatment effects in literature and may have effect on patient care and health policy in Eales′ disease.

  14. FACTORS ASSOCIATED WITH VISUAL OUTCOME AFTER MACULA-OFF RHEGMATOGENOUS RETINAL DETACHMENT SURGERY.

    Science.gov (United States)

    Park, Dae Hyun; Choi, Kyung Seek; Sun, Hae Jung; Lee, Sung Jin

    2018-01-01

    To evaluate preoperative factors influencing the visual outcome and postoperative factors associated with the changes in visual acuity, after reattachment surgery to treat macula-off rhegmatogenous retinal detachment. A total of 180 eyes of 180 patients who underwent reattachment surgery to treat macula-off rhegmatogenous retinal detachment, and who were followed up for more than 12 months, were reviewed retrospectively. Preoperative and postoperative characteristics, including optical coherence tomography findings, were comprehensively analyzed using univariate and multivariate models to evaluate preoperative factors influencing best-corrected visual acuity 12 months after macula-off rhegmatogenous retinal detachment surgery and postoperative factors associated with changes in best-corrected visual acuity after surgery. Preoperatively, the extent of detachment (P = 0.037), macula-off duration (P macula-off rhegmatogenous retinal detachment surgery were the extent of detachment, macula-off duration, and external limiting membrane integrity. Postoperatively, predictive factors were the outer retinal microstructures, particularly the photoreceptor outer segment layer.

  15. Global-local visual biases correspond with visual-spatial orientation.

    Science.gov (United States)

    Basso, Michael R; Lowery, Natasha

    2004-02-01

    Within the past decade, numerous investigations have demonstrated reliable associations of global-local visual processing biases with right and left hemisphere function, respectively (cf. Van Kleeck, 1989). Yet the relevance of these biases to other cognitive functions is not well understood. Towards this end, the present research examined the relationship between global-local visual biases and perception of visual-spatial orientation. Twenty-six women and 23 men completed a global-local judgment task (Kimchi and Palmer, 1982) and the Judgment of Line Orientation Test (JLO; Benton, Sivan, Hamsher, Varney, and Spreen, 1994), a measure of visual-spatial orientation. As expected, men had better performance on JLO. Extending previous findings, global biases were related to better visual-spatial acuity on JLO. The findings suggest that global-local biases and visual-spatial orientation may share underlying cerebral mechanisms. Implications of these findings for other visually mediated cognitive outcomes are discussed.

  16. Visual Outcome Of Traumatic Cataract Surgery In Ibadan, Nigeria ...

    African Journals Online (AJOL)

    Causes of traumatic cataract includedwood /stick splinters in 7 (21.9%), cane/ whiplash injury 6(18.8%), and propelled missile injuries, 5(15.6%). Less important cause of injuries were gun shot, road traffic accident and fist injuries. 11 (35.6%) of the patients had best corrected post operative visual acuity of >6/18, 10 (32.2%) ...

  17. Visual screening of incercerated juvenile delinquents: a study of ...

    African Journals Online (AJOL)

    Further analysis revealed significantly higher frequencies for convergence, phoria, hyperopia, pursuit and saccadic eye movement subtest (P<0.05) in male offenders as compared with male control population. Also higher frequencies for visual acuity (distant and near), hyperopia, phoria, pursuit and saccadic eye movement ...

  18. Visual and refractive outcomes following myopic laser-assisted subepithelial keratectomy with a flying-spot excimer laser.

    Science.gov (United States)

    McAlinden, Colm; Skiadaresi, Eirini; Moore, Jonathan E

    2011-05-01

    To investigate the visual and refractive outcomes following laser-assisted subepithelial keratectomy (LASEK) surgery with a flying-spot excimer laser. Private practice, Ireland. Case series. In this prospective study, the mean manifest spherical equivalent (SE), sphere, and cylinder were measured preoperatively. All eyes had LASEK surgery with an aberration-free algorithm with the Schwind Amaris excimer laser. Outcomes measured at 1 month, 6 months, and 1 year were uncorrected distance visual acuity (UDVA), manifest refraction, corrected distance visual acuity, contrast sensitivity, aberrometry, and complications. Accuracy, efficacy, and safety were evaluated at 1 year. Preoperatively, the mean SE, sphere, and cylinder in the 80 eyes (48 patients) were -3.58 diopters (D) ± 2.00 (SD), -3.23 ± 1.93 D, and -0.85 ± 0.65 D, respectively. One year postoperatively, the mean SE was -0.00 ± 0.22 D; 57 eyes (71%) were within -0.13 to +0.13 D of the SE, and 71 eyes (98%) were within ±0.50 D. The mean UDVA was -0.06 ± 0.07 logMAR, with an efficacy index of 1.04. The postoperative SE was stable between 1 month, 3 months, and 1 year. One eye (1%) had a change in SE by more than 0.50 D at 6 months and 1 year. There were no statistically significant differences in any aberrations at 1 year. The contrast sensitivity improved from 1.66 ± 0.17 log units preoperatively to 1.72 ± 0.15 log units at 1 month postoperatively (P=.0003), which was unchanged at 6 months and 1 year. This study demonstrated the effectiveness of LASEK for the treatment of myopia with this flying-spot excimer laser. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  19. [Survey on avoidable blindness and visual impairment in Panama].

    Science.gov (United States)

    López, Maritza; Brea, Ileana; Yee, Rita; Yi, Rodolfo; Carles, Víctor; Broce, Alberto; Limburg, Hans; Silva, Juan Carlos

    2014-12-01

    Determine prevalence of blindness and visual impairment in adults aged ≥ 50 years in Panama, identify their main causes, and characterize eye health services. Cross-sectional population study using standard Rapid Assessment of Avoidable Blindness methodology. Fifty people aged ≥ 50 years were selected from each of 84 clusters chosen through representative random sampling of the entire country. Visual acuity was assessed using a Snellen chart; lens and posterior pole status were assessed by direct ophthalmoscopy. Cataract surgery coverage was calculated and its quality assessed, along with causes of visual acuity blindness was 3.0% (95% CI: 2.3-3.6). The main cause of blindness was cataract (66.4%), followed by glaucoma (10.2%). Cataract (69.2%) was the main cause of severe visual impairment and uncorrected refractive errors were the main cause of moderate visual impairment (60.7%). Surgical cataract coverage in individuals was 76.3%. Of all eyes operated for cataract, 58.0% achieved visual acuity ≤ 20/60 with available correction. Prevalence of blindness in Panama is in line with average prevalence found in other countries of the Region. This problem can be reduced, since 76.2% of cases of blindness and 85.0% of cases of severe visual impairment result from avoidable causes.

  20. Longterm visual prognosis in Usher syndrome types 1 and 2.

    Science.gov (United States)

    Sadeghi, André M; Eriksson, Kristina; Kimberling, William J; Sjöström, Anders; Möller, Claes

    2006-08-01

    To estimate the age at diagnosis of retinitis pigmentosa and to determine visual acuity deterioration, visual field impairment and the frequency of cataracts in Usher syndrome types 1 and 2. We carried out a retrospective study of 328 affected subjects with Usher syndrome types 1 and 2. Study subjects were divided into seven different age groups by decade. Data were analysed using descriptive statistics, general linear model anova and survival analysis. Retinitis pigmentosa was diagnosed significantly earlier in subjects with Usher syndrome type 1 than in those with type 2. Visual acuity was significantly more impaired in affected subjects with Usher syndrome type 1 than in those with type 2 from 50 years of age onwards. Survival analysis revealed a significant difference in visual field loss (type 2 subjects tending to be more impaired, while comparison indicated no significant differences between the groups in any of the other visual field categories. Cataract was found to be generally more common in Usher syndrome type 1 than type 2. Progressive loss of visual acuity and visual field begins to be substantial between the second and third decades of life in both Usher types. The rate of degeneration varies between individuals in both groups. The data are useful for the counselling of affected subjects with Usher syndrome types 1 and 2.

  1. Visual indices of motor vehicle drivers in relation to road safety in ...

    African Journals Online (AJOL)

    olayemitoyin

    (96.8%) had normal confrontation visual field while 95.3% of study group and 97.7% of control ... The most prevailing eye conditions that may reduce visual acuity were pterygium (51.3% ... were reported, except in the analysis of near vision of.

  2. Long-term visual outcome in a Danish population of patients with idiopathic intracranial hypertension

    DEFF Research Database (Denmark)

    Hatem, Christina F; Yri, Hanne M; Sørensen, Anne L

    2018-01-01

    . METHODS: Retrospective chart review of 41 women diagnosed with IIH between June 2007 and March 2013. Best-corrected visual acuity (BCVA), colour vision, grade and type of visual field (VF) defects and grade of papilloedema according to the Modified Frisén Score were recorded at baseline visit (V0), 2...

  3. Effect of visual impairment on goal-directed aiming movements in children.

    NARCIS (Netherlands)

    Reimer, A.M.; Cox, R.F.A.; Boonstra, F.N.; Smits-Engelsman, B.C.M.

    2008-01-01

    This study investigated potential differences in motor control between children with a visual impairment (diagnosed albinism; n=11, mean age 8y 4mo [SD 7mo]; seven males, four females,) and children with normal vision (n=11, mean age 8y 4mo [SD 7mo]; six males, five females). Mean near visual acuity

  4. Effect of visual impairment on goal-directed aiming movements in children

    NARCIS (Netherlands)

    Reimer, A.M.; Cox, R.F.A.; Boonstra, F.N.; Smits-Engelsman, B.C.M.

    2008-01-01

    This study investigated potential differences in motor control between children with a visual impairment (diagnosed albinism; n=11, mean age 8y 4mo [SD 7mo]; seven males, four females,) and children with normal vision (n=11, mean age 8y 4mo [SD 7mo]; six males, five females). Mean near visual acuity

  5. Motor skills of children with unilateral visual impairment in the Infant Aphakia Treatment Study.

    Science.gov (United States)

    Celano, Marianne; Hartmann, E Eugenie; DuBois, Lindreth G; Drews-Botsch, Carolyn

    2016-02-01

    To assess motor functioning in children aged 4 years 6 months enrolled in the Infant Aphakia Treatment Study, and to determine contributions of visual acuity and stereopsis to measured motor skills. One hundred and four children (53% female) with unilateral aphakia randomized to intraocular lens or contact lens treatment were evaluated at 4 years 6 months (age range 4y 6mo-4y 11mo) for monocular recognition visual acuity, motor skills, and stereopsis by a traveling examiner masked to treatment condition. Motor skills were assessed with the Movement Assessment Battery for Children--Second Edition (MABC-2). Visual acuity was operationalized as log10 of the minimum angle of resolution (logMAR) value for treated eye, best logMAR value for either eye, and intraocular logMAR difference. Student's t-tests showed no significant differences in MABC-2 scores between the intraocular lens and contact lens groups. The mean total score was low (6.43; 18th centile) compared with the normative reference group. Motor functioning was not related to visual acuity in the treated eye or to intraocular logMAR difference, but was predicted in a regression model by the better visual acuity of either eye (usually the fellow eye), even after accounting for the influence of age at surgery, examiner, orthotropic ocular alignment, and stereopsis. Children with unilateral congenital cataract may have delayed motor functioning at 4 years 6 months, which may adversely affect their social and academic functioning. © 2015 Mac Keith Press.

  6. Psychological distress and visual functioning in relation to vision-related disability in older individuals with cataracts.

    Science.gov (United States)

    Walker, J G; Anstey, K J; Lord, S R

    2006-05-01

    To determine whether demographic, health status and psychological functioning measures, in addition to impaired visual acuity, are related to vision-related disability. Participants were 105 individuals (mean age=73.7 years) with cataracts requiring surgery and corrected visual acuity in the better eye of 6/24 to 6/36 were recruited from waiting lists at three public out-patient ophthalmology clinics. Visual disability was measured with the Visual Functioning-14 survey. Visual acuity was assessed using better and worse eye logMAR scores and the Melbourne Edge Test (MET) for edge contrast sensitivity. Data relating to demographic information, depression, anxiety and stress, health care and medication use and numbers of co-morbid conditions were obtained. Principal component analysis revealed four meaningful factors that accounted for 75% of the variance in visual disability: recreational activities, reading and fine work, activities of daily living and driving behaviour. Multiple regression analyses determined that visual acuity variables were the only significant predictors of overall vision-related functioning and difficulties with reading and fine work. For the remaining visual disability domains, non-visual factors were also significant predictors. Difficulties with recreational activities were predicted by stress, as well as worse eye visual acuity, and difficulties with activities of daily living were associated with self-reported health status, age and depression as well as MET contrast scores. Driving behaviour was associated with sex (with fewer women driving), depression, anxiety and stress scores, and MET contrast scores. Vision-related disability is common in older individuals with cataracts. In addition to visual acuity, demographic, psychological and health status factors influence the severity of vision-related disability, affecting recreational activities, activities of daily living and driving.

  7. Visual search deficits in amblyopia.

    Science.gov (United States)

    Tsirlin, Inna; Colpa, Linda; Goltz, Herbert C; Wong, Agnes M F

    2018-04-01

    Amblyopia is a neurodevelopmental disorder defined as a reduction in visual acuity that cannot be corrected by optical means. It has been associated with low-level deficits. However, research has demonstrated a link between amblyopia and visual attention deficits in counting, tracking, and identifying objects. Visual search is a useful tool for assessing visual attention but has not been well studied in amblyopia. Here, we assessed the extent of visual search deficits in amblyopia using feature and conjunction search tasks. We compared the performance of participants with amblyopia (n = 10) to those of controls (n = 12) on both feature and conjunction search tasks using Gabor patch stimuli, varying spatial bandwidth and orientation. To account for the low-level deficits inherent in amblyopia, we measured individual contrast and crowding thresholds and monitored eye movements. The display elements were then presented at suprathreshold levels to ensure that visibility was equalized across groups. There was no performance difference between groups on feature search, indicating that our experimental design controlled successfully for low-level amblyopia deficits. In contrast, during conjunction search, median reaction times and reaction time slopes were significantly larger in participants with amblyopia compared with controls. Amblyopia differentially affects performance on conjunction visual search, a more difficult task that requires feature binding and possibly the involvement of higher-level attention processes. Deficits in visual search may affect day-to-day functioning in people with amblyopia.

  8. An Acuity Tool for Heart Failure Case Management: Quantifying Workload, Service Utilization, and Disease Severity.

    Science.gov (United States)

    Kilgore, Matthew D

    The cardiology service line director at a health maintenance organization (HMO) in Washington State required a valid, reliable, and practical means for measuring workloads and other productivity factors for six heart failure (HF) registered nurse case managers located across three geographical regions. The Kilgore Heart Failure Case Management (KHFCM) Acuity Tool was systematically designed, developed, and validated to measure workload as a dependent function of the number of heart failure case management (HFCM) services rendered and the duration of times spent on various care duties. Research and development occurred at various HMO-affiliated internal medicine and cardiology offices throughout Western Washington. The concepts, methods, and principles used to develop the KHFCM Acuity Tool are applicable for any type of health care professional aiming to quantify workload using a high-quality objective tool. The content matter, scaling, and language on the KHFCM Acuity Tool are specific to HFCM settings. The content matter and numeric scales for the KHFCM Acuity Tool were developed and validated using a mixed-method participant action research method applied to a group of six outpatient HF case managers and their respective caseloads. The participant action research method was selected, because the application of this method requires research participants to become directly involved in the diagnosis of research problems, the planning and execution of actions taken to address those problems, and the implementation of progressive strategies throughout the course of the study, as necessary, to produce the most credible and practical practice improvements (; ; ; ). Heart failure case managers served clients with New York Heart Association Functional Class III-IV HF (), and encounters were conducted primarily by telephone or in-office consultation. A mix of qualitative and quantitative results demonstrated a variety of quality improvement outcomes achieved by the design

  9. Causes of visual loss in uveitis

    Directory of Open Access Journals (Sweden)

    Stanković Zora

    2009-01-01

    Full Text Available Background/Aim. Epidemiological studies of blindness in a working age population require a precise definition of the true connection of uveitis and visual damage. Since most patients with more severe types of uveitis are hospitalized in tertiary referral uveitis service, our aim was to determine whether age, sex and age of onset of uveitis, as well as duration of visual loss and its causes influence the degree of visual damage in patients with different types of uveitis. Methods. The data were collected from medical records of 237 patients at the Department for Uveitis of the Institute for Eye Diseases in Belgrade over a three-year period (March 2005 to March 2008. Results. Visual acuity reduction (≤ 0.3 was found in 161/237 (67.9% patients, 85 of whom had visual acuity of ≤ 0.1 later. Working age patients (up to 60 years of age most often suffered from uveitis (173/237; 73%. The highest number of patients with visual loss was in the group suffering from panuveitis (77/94; 81.91%. The age of onset of uveitis and sex have no statistically significant influence on visual loss. The most common causes of visual loss (34/161; 21.1% were cystoid macular oedema (CMO (43/161; 26.7%, cataract (28/161; 17.39% and combination of CMO and cataract. Conclusion. The risk factors for severe visual loss (≤ 0.1 are panuveitis, bilateral inflammation, prolonged visual reduction and a significant number of relapses. The main causes of visual loss in 65.2% of our patients were CMO and cataract.

  10. Visual outcome with the Oculentis Mplus intraocular lens

    OpenAIRE

    Si-Yuan Liu; Xu Yang

    2017-01-01

    AIM: To evaluate the visual outcome of Oculentis Mplus intraocular lens(IOL).METHODS: Totally 20 eyes in 20 patients received phacoemulsification and Oculentis Mplus intraocular lens implantation were as test group, and 20 eyes(Aspira-aA IOL)were as control group. The following postoperative examinations were performed after operation for 3mo: uncorrected visual acuity of distance and near, refractive results, UBM examination, the rate of wearing spectacles and the complications. RESULTS: At ...

  11. Community screening for visual impairment in older people.

    Science.gov (United States)

    Clarke, Emily L; Evans, Jennifer R; Smeeth, Liam

    2018-02-20

    Visual problems in older people are common and frequently under-reported. The effects of poor vision in older people are wide reaching and include falls, confusion and reduced quality of life. Much of the visual impairment in older ages can be treated (e.g. cataract surgery, correction of refractive error). Vision screening may therefore reduce the number of older people living with sight loss. The objective of this review was to assess the effects on vision of community vision screening of older people for visual impairment. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2017, Issue 10); Ovid MEDLINE; Ovid Embase; the ISRCTN registry; ClinicalTrials.gov and the ICTRP. The date of the search was 23 November 2017. We included randomised controlled trials (RCTs) that compared vision screening alone or as part of a multi-component screening package as compared to no vision screening or standard care, on the vision of people aged 65 years or over in a community setting. We included trials that used self-reported visual problems or visual acuity testing as the screening tool. We used standard methods expected by Cochrane. We graded the certainty of the evidence using GRADE. Visual outcome data were available for 10,608 people in 10 trials. Four trials took place in the UK, two in Australia, two in the United States and two in the Netherlands. Length of follow-up ranged from one to five years. Three of these studies were cluster-randomised trials whereby general practitioners or family physicians were randomly allocated to undertake vision screening or no vision screening. All studies were funded by government agencies. Overall we judged the studies to be at low risk of bias and only downgraded the certainty of the evidence (GRADE) for imprecision.Seven trials compared vision screening as part of a multi-component screening versus no screening. Six of these studies used self

  12. UV-blocking spectacle lens protects against UV-induced decline of visual performance.

    Science.gov (United States)

    Liou, Jyh-Cheng; Teng, Mei-Ching; Tsai, Yun-Shan; Lin, En-Chieh; Chen, Bo-Yie

    2015-01-01

    Excessive exposure to sunlight may be a risk factor for ocular diseases and reduced visual performance. This study was designed to examine the ability of an ultraviolet (UV)-blocking spectacle lens to prevent visual acuity decline and ocular surface disorders in a mouse model of UVB-induced photokeratitis. Mice were divided into 4 groups (10 mice per group): (1) a blank control group (no exposure to UV radiation), (2) a UVB/no lens group (mice exposed to UVB rays, but without lens protection), (3) a UVB/UV400 group (mice exposed to UVB rays and protected using the CR-39™ spectacle lens [UV400 coating]), and (4) a UVB/photochromic group (mice exposed to UVB rays and protected using the CR-39™ spectacle lens [photochromic coating]). We investigated UVB-induced changes in visual acuity and in corneal smoothness, opacity, and lissamine green staining. We also evaluated the correlation between visual acuity decline and changes to the corneal surface parameters. Tissue sections were prepared and stained immunohistochemically to evaluate the structural integrity of the cornea and conjunctiva. In blank controls, the cornea remained undamaged, whereas in UVB-exposed mice, the corneal surface was disrupted; this disruption significantly correlated with a concomitant decline in visual acuity. Both the UVB/UV400 and UVB/photochromic groups had sharper visual acuity and a healthier corneal surface than the UVB/no lens group. Eyes in both protected groups also showed better corneal and conjunctival structural integrity than unprotected eyes. Furthermore, there were fewer apoptotic cells and less polymorphonuclear leukocyte infiltration in corneas protected by the spectacle lenses. The model established herein reliably determines the protective effect of UV-blocking ophthalmic biomaterials, because the in vivo protection against UV-induced ocular damage and visual acuity decline was easily defined.

  13. Visual function affects prosocial behaviors in older adults.

    Science.gov (United States)

    Teoli, Dac A; Smith, Merideth D; Leys, Monique J; Jain, Priyanka; Odom, J Vernon

    2016-02-01

    Eye-related pathological conditions such as glaucoma, diabetic retinopathy, and age-related macular degeneration commonly lead to decreased peripheral/central field, decreased visual acuity, and increased functional disability. We sought to answer if relationships exist between measures of visual function and reported prosocial behaviors in an older adult population with eye-related diagnoses. The sample consisted of adults, aged ≥ 60 years old, at an academic hospital's eye institute. Vision ranged from normal to severe impairment. Medical charts determined the visual acuities, ocular disease, duration of disease (DD), and visual fields (VF). Measures of giving help were via validated questionnaires on giving formal support (GFS) and giving informal support; measures of help received were perceived support (PS) and informal support received (ISR). ISR had subscales: tangible support (ISR-T), emotional support (ISR-E), and composite (ISR-C). Visual acuities of the better and worse seeing eyes were converted to LogMAR values. VF information converted to a 4-point rating scale of binocular field loss severity. DD was in years. Among 96 participants (mean age 73.28; range 60-94), stepwise regression indicated a relationship of visual variables to GFS (p T (p prosocial behavior in older adults.

  14. Visual performance in cataract patients with low levels of postoperative astigmatism: full correction versus spherical equivalent correction

    Directory of Open Access Journals (Sweden)

    Lehmann RP

    2012-03-01

    Full Text Available Robert P Lehmann1, Diane M Houtman21Lehmann Eye Center, Nacogdoches, TX, 2Alcon Research Ltd, Fort Worth, TX, USAPurpose: To evaluate whether visual performance could be improved in pseudophakic subjects by correcting low levels of postoperative astigmatism.Methods: An exploratory, noninterventional study was conducted using subjects who had been implanted with an aspheric intraocular lens and had 0.5–0.75 diopter postoperative astigmatism. Monocular visual performance using full correction was compared with visual performance using spherical equivalent correction. Testing consisted of high- and low-contrast visual acuity, contrast sensitivity, and reading acuity and speed using the Radner Reading Charts.Results: Thirty-eight of 40 subjects completed testing. Visual acuities at three contrast levels (100%, 25%, and 9% were significantly better using full correction than when using spherical equivalent correction (all P < 0.001. For contrast sensitivity testing under photopic, mesopic, and mesopic with glare conditions, only one out of twelve outcomes demonstrated a significant improvement with full correction compared with spherical equivalent correction (at six cycles per degree under mesopic without glare conditions, P = 0.046. Mean reading speed was numerically faster with full correction across all print sizes, reaching statistical significance at logarithm of the reading acuity determination (logRAD 0.2, 0.7, and 1.1