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Sample records for included 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. 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...

  3. 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.

  4. [Calculating the mean visual acuity and the change in visual acuity with a decimal acuity chart].

    Science.gov (United States)

    Touzeau, O

    2003-06-01

    The decimal visual acuity chart is not easy to use for statistical analysis and requires a transformation into LogMAR units (decimal logarithm of the Minimum Angle Resolution). In contrast to the decimal chart, the logarithmic chart has an arithmetic progression and a constant interval between lines. The LogMAR chart makes statistical analysis of visual acuity easy. Change in visual acuity is calculated directly by subtracting LogMAR data, while the average visual acuity is obtained with the arithmetic mean value of the LogMAR data. The mean acuity expressed in LogMAR units can be transformed into a decimal chart for a more comprehensive result. To calculate the average visual acuity directly from the decimal data, the geometric mean value must be used instead of the arithmetic mean value.

  5. Review of dynamic visual acuity

    Directory of Open Access Journals (Sweden)

    Pablo SANTOS-GORJÓN

    2018-01-01

    Full Text Available Introduction and objective: To maintain gaze on a stationary target despite rapid cephalic movements we make in our everyday life, it is necessary that the vestibular system detects the velocity of the head and through the vestibular-ocular reflex (VOR induce a movement of the eye of equal magnitude and opposite direction. If this mechanism fails, as happens with the vestibular hypofunction, the patient complains of blurred vision (oscillopsia. One way of checking the operation of this reflex is through quantification of visual acuity during head movements. In this paper, we will describe tests that allow its valuation. Method: Narrative review. Results: There are two types of tools that allow us to measure the dynamic visual acuity (DVA, the clinical tests, and the computerized. Reliability can be increased if in the clinical evaluation we add some system that allows us to control the frequency and the amplitude of the movement which we induce to the head. Discussion: Clinical tests are more simple, accessible and cost-effective, and however, the computerized are more accurate, but require more expensive and less close instruments. Conclusion: Even featuring a variety of objective procedures, the clinical determination of the DVA remains useful for screening the vestibular function and to measure the degree of compensation, during rehabilitation.

  6. Predicting visual acuity from detection thresholds.

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    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).

  7. New mobile technologies and visual acuity.

    Science.gov (United States)

    Livingstone, I A T; Lok, A S L; Tarbert, C

    2014-01-01

    Mobile devices have shown promise in visual assessment. Traditional acuity measurement involves retro-illuminated charts or card-based modalities. Mobile platforms bring potential to improve on both portability and objectivity. The present research activity relates to design and validation of a novel tablet-based infant acuity test. Early results in an adult cohort, with various levels of artificially degraded vision, suggest improved test-retest reliability compared with current standards for infant acuity. Future pragmatic trials will assess the value of this emerging technology in pediatric visual screening.

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

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    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.

  9. Habitual vs optimal distance visual acuity.

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    Pointer, Jonathan S

    2008-09-01

    The maintenance of a good level of vision is desirable for developmental and social reasons; it is also a requirement that should not be overlooked in the clinical research environment. This study set out to quantify and analyse any difference between 'habitual' (pre-sight test) and 'optimal' (post-refraction) distance visual acuity in an optometric population. It is intended that the outcome of this work will inform not only clinicians but also those undertaking vision research. Binocular logMAR visual acuity was determined at 6 m before and after optometric intervention in patients attending optometric practice for a routine sight test. Cases were recorded seriatim but restricted to the 'core' refraction range representative of typical optometric practice; three further exemption criteria included subject illiteracy, the necessity for a non-standard test distance and contact lens wear. Over a 12-month period, two-thirds of patients examined satisfied the study inclusion criteria; it is the clinical data of these 1288 individuals that are described and analysed here. These data provide a quantitative demonstration that an optometric intervention will most likely improve the habitual distance visual acuity of subjects, irrespective of gender, age group, time interval since last test, refractive status and whether or not the subject is a habitual spectacle wearer. The improvement found was typically within one logMAR chart line (<5 letters), being greatest in spectacle-wearing teenagers and in individuals beyond retirement age (increasing to eight letters in elderly habitual non-spectacle wearers); also in non-wearers who left an interval of 2 years or more between sight tests. Clinical and laboratory-based investigators are advised that a current and optimal refractive correction should be worn by subjects of all ages enrolled in vision-related studies. Refractive defocus may introduce or exaggerate test outcome variability.

  10. [Contrast sensitivity and visual acuity in animals].

    Science.gov (United States)

    Harmening, W M

    2017-11-01

    Fundamental spatial vision capabilities of visual systems can be characterized by their contrast sensitivity and visual acuity. Comparison of contrast sensitivity and visual acuity in humans and other animals. An analysis of known contrast sensitivity functions and maximum visual acuity across selected taxa was carried out, with consideration of measurement principles, viewing conditions and allometry. Comparing across all analyzed species, contrast sensitivity functions have inverted U‑shape characteristics, with key differences in both position and absolute sensitivity within the spectrum of spatial frequencies. Humans, for example, have a maximum sensitivity at 5 cycles/degree and mice at approximately 0.1 cycles/degree. Body and eye size generally correlate well with maximum visual acuity. Across eye types, lens eyes have the highest optical and visual resolution, all other things being equal. Diurnal species typically outperform crepuscular or nocturnal species. Humans generally excel at both maximum contrast sensitivity as well as visual acuity. Despite great differences in optical, anatomical and neurophysiological structures between humans and animals, spatial vision capabilities are generally comparable across taxa. This favors the hypothesis that spatial vision in animals develops primarily towards meeting similar evolutionary needs within the limits of biophysical and optical laws.

  11. Computerized method of visual acuity testing: adaptation of the amblyopia treatment study visual acuity testing protocol.

    Science.gov (United States)

    Moke, P S; Turpin, A H; Beck, R W; Holmes, J M; Repka, M X; Birch, E E; Hertle, R W; Kraker, R T; Miller, J M; Johnson, C A

    2001-12-01

    To report a computerized method for determining visual acuity in children using the Amblyopia Treatment Study visual acuity testing protocol. A computerized visual acuity tester was developed that uses a programmed handheld device that uses the Palm operating system (Palm, Inc, Santa Clara, California). The handheld device communicates with a personal computer running a Linux operating system and 17-inch monitor. At a test distance of 3 m, single letters can be displayed from 20/800 to 20/12. A C program on the handheld device runs the Amblyopia Treatment Study visual acuity testing protocol. Using this method, visual acuity was tested in both the right and left eyes, and then the testing was repeated in 156 children age 3 to 7 years at four clinical sites. Test-retest reliability was high (r =.92 and 0.95 for and right and left eyes, respectively), with 88% of right eye retests and 94% of left eye retests within 0.1 logarithm of minimal angle of resolution (logMAR) units of the initial test. The 95% confidence interval for an acuity score was calculated to be the score +/- 0.13 logMAR units. For a change between two acuity scores, the 95% confidence interval was the difference +/- 0.19 logMAR units. We have developed a computerized method for measurement of visual acuity. Automation of the Amblyopia Treatment Study visual acuity testing protocol is an effective method of testing visual acuity in children 3 to 7 years of age.

  12. New standardized visual acuity charts in hindi and gujarati

    Directory of Open Access Journals (Sweden)

    Khamar Bakulesh

    1996-01-01

    Full Text Available Conventional Snellen visual acuity chart has unequal difficulty score and irregular progression in letter size causing jumping effect at different visual acuity levels. There is also increase in number of letters from above downwards. Consequently one or two mistakes per line has different meaning of visual acuity at different levels. We designed a new visual acuity chart of fourteen lines in Hindi and Gujarati to facilitate standardization in visual acuity measurement. These charts are designed for use at six meter distance, and the illumination is provided from front. These charts provide a standardized way of measuring visual acuity using local languages.

  13. Visual Acuity Assessment in Persons with Dementia. Research Report

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    Morse, Alan R.; Teresi, Jeanne; Rosenthal, Bruce; Holmes, Douglas; Yatzkan, Elaine S.

    2004-01-01

    Most studies of vision in persons with Alzheimer's disease either exclude those with advanced dementia or are unable to assess their vision adequately, and therefore, improperly report these persons' visual acuity status. In this study, visual acuity was assessed using the ETDRS Snellen-type acuity chart and Teller Acuity Cards. The Teller Acuity…

  14. 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

  15. [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

  16. 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 ...

  17. Visual acuity estimation from simulated images

    Science.gov (United States)

    Duncan, William J.

    Simulated images can provide insight into the performance of optical systems, especially those with complicated features. Many modern solutions for presbyopia and cataracts feature sophisticated power geometries or diffractive elements. Some intraocular lenses (IOLs) arrive at multifocality through the use of a diffractive surface and multifocal contact lenses have a radially varying power profile. These type of elements induce simultaneous vision as well as affecting vision much differently than a monofocal ophthalmic appliance. With myriad multifocal ophthalmics available on the market it is difficult to compare or assess performance in ways that effect wearers of such appliances. Here we present software and algorithmic metrics that can be used to qualitatively and quantitatively compare ophthalmic element performance, with specific examples of bifocal intraocular lenses (IOLs) and multifocal contact lenses. We anticipate this study, methods, and results to serve as a starting point for more complex models of vision and visual acuity in a setting where modeling is advantageous. Generating simulated images of real- scene scenarios is useful for patients in assessing vision quality with a certain appliance. Visual acuity estimation can serve as an important tool for manufacturing and design of ophthalmic appliances.

  18. Visual acuity in pelagic fishes and mollusks.

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    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.

  19. 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.

  20. Screening for significant refractive error using a combination of distance visual acuity and near visual acuity.

    Directory of Open Access Journals (Sweden)

    Peiyao Jin

    Full Text Available To explore the effectiveness of using a series of tests combining near visual acuity (NVA and distance visual acuity (DVA for large-scale screenings for significant refractive error (SRE in primary school children.Each participant underwent DVA, NVA and cycloplegic autorefraction measurements. SREs, including high myopia, high hyperopia and high astigmatism were analyzed. Cycloplegic refraction results were considered to be the gold standard for the comparison of different screening measurements. Receiver-operating characteristic (ROC curves were constructed to compare the area under the curve (AUC and the Youden index among DVA, NVA and the series combined tests of DVA and NVA. The efficacies (including sensitivity, specificity, positive predictive value, and negative predictive value of each test were evaluated. Only the right eye data of each participant were analysed for statistical purpose.A total of 4416 children aged 6 to 12 years completed the study, among which 486 students had right eye SRE (SRE prevalence rate = 11.01%. There was no difference in the prevalence of high hyperopia and high astigmatism among different age groups. However, the prevalence of high myopia significantly increased with the age (χ² = 381.81, p<0.01. High hyperopia was the biggest SRE factor associated with amblyopia(p<0.01,OR = 167.40, 95% CI: 75.14∼372.94. The DVA test was better than the NVA test for detecting high myopia (Z = 2.71, p<0.01, but the NVA test was better for detecting high hyperopia (Z = 2.35, p = 0.02 and high astigmatism (Z = 4.45, p<0.01. The series combined DVA and NVA test had the biggest AUC and the highest Youden Index for detecting high hyperopia, myopia, astigmatism, as well as all of the SREs (all p<0.01.The series combined DVA and NVA test was more accurate for detecting SREs than either of the two tests alone. This new method could be applied to large-scale SRE screening of children, aged 6 to 12, in areas that are less

  1. Screening for significant refractive error using a combination of distance visual acuity and near visual acuity.

    Science.gov (United States)

    Jin, Peiyao; Zhu, Jianfeng; Zou, Haidong; Lu, Lina; Zhao, Huijuan; Li, Qiangqiang; He, Xiangui

    2015-01-01

    To explore the effectiveness of using a series of tests combining near visual acuity (NVA) and distance visual acuity (DVA) for large-scale screenings for significant refractive error (SRE) in primary school children. Each participant underwent DVA, NVA and cycloplegic autorefraction measurements. SREs, including high myopia, high hyperopia and high astigmatism were analyzed. Cycloplegic refraction results were considered to be the gold standard for the comparison of different screening measurements. Receiver-operating characteristic (ROC) curves were constructed to compare the area under the curve (AUC) and the Youden index among DVA, NVA and the series combined tests of DVA and NVA. The efficacies (including sensitivity, specificity, positive predictive value, and negative predictive value) of each test were evaluated. Only the right eye data of each participant were analysed for statistical purpose. A total of 4416 children aged 6 to 12 years completed the study, among which 486 students had right eye SRE (SRE prevalence rate = 11.01%). There was no difference in the prevalence of high hyperopia and high astigmatism among different age groups. However, the prevalence of high myopia significantly increased with the age (χ² = 381.81, p<0.01). High hyperopia was the biggest SRE factor associated with amblyopia(p<0.01,OR = 167.40, 95% CI: 75.14∼372.94). The DVA test was better than the NVA test for detecting high myopia (Z = 2.71, p<0.01), but the NVA test was better for detecting high hyperopia (Z = 2.35, p = 0.02) and high astigmatism (Z = 4.45, p<0.01). The series combined DVA and NVA test had the biggest AUC and the highest Youden Index for detecting high hyperopia, myopia, astigmatism, as well as all of the SREs (all p<0.01). The series combined DVA and NVA test was more accurate for detecting SREs than either of the two tests alone. This new method could be applied to large-scale SRE screening of children, aged 6 to 12, in areas that are less

  2. 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.

  3. Training on spatiotemporal masking improves crowded and uncrowded visual acuity.

    Science.gov (United States)

    Yehezkel, Oren; Sterkin, Anna; Lev, Maria; Polat, Uri

    2015-01-01

    Spatial crowding impairs conscious visual perception and object recognition in clutter.Short presentation times produce crowding in the normal fovea, in young participants and in uncorrected presbyopes ("aging eye"), measured as reduced visual acuity (VA). On the other hand, perceptual learning improves near VA in healthy young adults, in presbyopia, and in amblyopia. Here we aimed at exploring the effects of perceptual training on crowded VA in uncorrected presbyopes with naturally decreased VA, with two specific objectives: (a) to objectively measure crowded VA, taking advantage of the natural deterioration of near visual acuity from being normal or better than normal (i.e., 20/20 or better) in young participants to naturally decreasing in uncorrected presbyopes; and (b) to explore whether perceptual training previously shown to improve visual functions as complex as reading will affect crowded VA. Visual acuity was measured under crowded and uncrowded conditions by having subjects identify letters presented for short durations ranging from 34 to 116 msec. Training consisted of detecting brief Gabor stimuli under spatial and temporal masking conditions, using the GlassesOff mobile application (GlassesOff, Inc., New York, NY)on iOS devices from a distance of 40 cm. Before training, a robust reduction in crowded VA was found in the fovea of presbyopes. Training resulted in significant improvement of letter identification under both crowded and uncrowded VA conditions for all stimulus durations. After training, the crowded condition threshold reached the level of the uncrowded threshold measured before training. Thus, training enabled the subjects to overcome the effect of reduced VA under the crowded condition. We suggest that more efficient spatial and temporal processing induced by perceptual learning allows one to improve crowded VA, including that found on naturally reduced near VA, and that this effect may transfer to improve complex visual functions, such as

  4. [New DIN norms for determination of visual acuity].

    Science.gov (United States)

    Wesemann, W; Schiefer, U; Bach, M

    2010-09-01

    In 2009 the DIN 58220 norms for determination of visual acuity were revised. The new rules came into force on 1(st) November 2009. The new regulations on expert assessment of visual acuity (DIN norm 58220, part 3) are particularly important for ophthalmologists because as a result of the revisions the approach to testing visual acuity in patients with low acuity must be changed in the future. The background and potential problems will be presented and a simple solution for the lower acuity range will be suggested. Parts 5 (general test of vision) and 6 (driving-related vision test) of DIN 58220 remain practically unchanged. Part 7 of DIN 58220 is newly introduced, in which regulations for testing mesopic contrast vision with and without glare are defined for the first time.

  5. Assessment of visual acuity in patients with dementia using teller acuity cards.

    Science.gov (United States)

    Ciocler Froiman, Priscila; Dantas, Paulo Elias Correa

    2013-06-01

    Assessing visual acuity in adults or children at an eye exam is generally simple and has become routine procedure in clinical practice. However, depending on severity and stage of clinical evolution, elderly patients with dementia may experience difficulties performing tests of recognition, because these tests depend not only on perception, but also cognition and its response. Testing visual functions in such cases represents a challenge in clinical practice and a task that requires proper skills and methods. To evaluate the effectiveness of objective measurement of visual acuity by behavioral methods using Teller acuity cards in elderly patients with dementia, diagnosed with presumed Alzheimer's disease. The visual acuity of 20 elderly patients diagnosed with presumed Alzheimer's disease and 24 controls with no cognitive impairment was assessed using the recognition method (Lea symbols) and resolution grating method (Teller acuity cards). The results found for the two methods were statistically well correlated. An alternative method for assessing visual function in patients with Alzheimer's disease, even at early stages, is of utmost relevance not only for monitoring disease progression, but also to quantitatively determine the impact of eye treatments and determine potential visual loss, guiding optical and non-optical strategies for optimal use of residual vision.

  6. Visual acuity in the striped skunk (Mephitis mephitis).

    Science.gov (United States)

    Johnson-Ulrich, Zoe; Hoffmaster, Eric; Robeson, Audrey; Vonk, Jennifer

    2017-11-01

    The visual acuity of striped skunks (Mephitis mephitis) was tested using a 2 alternative forced-choice task with square wave gratings. Skunks were reinforced with food items for touching a ball in front of a striped stimulus when paired with a ball in front of a solid gray stimulus. Skunks demonstrated a maximum visual acuity of 0.42 cycles per degree when tested with bright outdoor illumination. This poor visual acuity may be due to their nocturnal lifestyle, lack of predation, and is consistent with their preferential use of smell and sound during foraging. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  7. Effects of single-segment Intacs implantation on visual acuity and corneal topographic indices of keratoconus

    Directory of Open Access Journals (Sweden)

    Kazem Amanzadeh

    2017-09-01

    Conclusion: Intacs implantation in keratoconic eyes increased visual acuity and made corneal shape less irregular. However, the improvements of visual acuity and corneal shape were not strongly correlated.

  8. 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.

  9. 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

  10. 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

  11. Visual acuity in institutionalized seniors with moderate to severe dementia.

    Science.gov (United States)

    Chriqui, Estefania; Kergoat, Marie-Jeanne; Champoux, Nathalie; Leclerc, Bernard-Simon; Kergoat, Hélène

    2013-04-01

    The evaluation of visual acuity (VA) in cognitively impaired older individuals may be limited by a reduced ability to cooperate or communicate. The objective of this research was to assess VA in older institutionalized individuals with cognitive impairment, including severe dementia, using various acuity charts. Three groups of 30 participants each were recruited: (1) young participants; (2) older participants with no history of cognitive or communication disorders; and (3) older participants with cognitive impairment, including severe dementia, residing in long term care facilities. The Mini-Mental State Examination was performed for each institutionalized subject. VA was measured using 6 validated charts [Snellen, Teller cards, Early Treatment Diabetic Retinopathy Study (ETDRS)-letters, -numbers, -Patty Pics, -Tumbling Es] presented in random order. Nonparametric tests were used to compare VA scores between charts, after Bonferroni-Holm corrections for multiple comparisons. Participants in groups 1 and 2 responded to all charts. A large proportion of participants with dementia responded to all charts (n = 19), whereas only one did not respond to any chart. In group 3, VA charts with the lowest scores were the Teller cards (20/65) and Patty Pics (20/62), regardless of the level of dementia, whereas the highest VA scores were obtained with the Snellen (20/35) and ETDRS-letter (20/36) charts. Across all groups, the ETDRS-letter chart was the only one whose scores did not differ from those obtained with the standard Snellen chart. Visual acuity can be measured, and should at least be attempted, in older cognitively impaired individuals having a reduced ability to communicate. Copyright © 2013 American Medical Directors Association, Inc. Published by Elsevier Inc. All rights reserved.

  12. Recognition acuity, grating acuity, contrast sensitivity, and visual fields in 6-year-old children.

    Science.gov (United States)

    Hargadon, Deborah D; Wood, Jeffrey; Twelker, J Daniel; Harvey, Erin M; Dobson, Velma

    2010-01-01

    To measure monocular distance visual acuity (VA), grating VA, contrast sensitivity, and visual field extent in full-term, 6-year-old children. Subjects were 59 healthy full-term children aged 5.8 to 6.3 years who had no ocular abnormalities and no myopia of 1.00 diopter (D) or greater, hyperopia of 4.00 D or greater, astigmatism of 1.50 D or greater, or anisometropia of 1.50 D or greater spherical equivalent or cylinder, as evaluated by a standard eye examination with cycloplegic refraction. All were tested monocularly for recognition acuity (Early Treatment Diabetic Retinopathy Study VA charts), grating acuity (Teller acuity cards), contrast sensitivity (Pelli-Robson contrast sensitivity charts), and visual field extent (white-sphere kinetic perimetry). Right and left eye values did not differ significantly. Mean values for the right eye were 0.040 logMAR (SD, 0.075 log units) for Early Treatment Diabetic Retinopathy Study VA, 24.5 cycles per degree (SD, 0.3 octaves) for grating acuity, and 1.63 (SD, 0.12 log units) for contrast sensitivity. Mean visual field extent for the inferonasal, superonasal, superotemporal, and inferotemporal meridians was 59.1 degrees (SD, 9.7 degrees), 57.8 degrees (SD, 9.6 degrees), 71.2 degrees (SD, 12.3 degrees), and 100.4 degrees (SD, 6.6 degrees), respectively. The results provide additional normative monocular data on visual function in 6-year-old children and indicate that their thresholds are less than those of adults for distance recognition VA, grating VA, and contrast sensitivity, but similar to those of adults for white-sphere kinetic perimetry.

  13. A portable device for the assessment of dynamic visual acuity.

    Science.gov (United States)

    Al-Awar Smither, Janan; Kennedy, Robert S

    2010-03-01

    Dynamic visual acuity (DVA) thresholds are among the few visual functions predictive of automobile crashes. DVA is also sensitive to alcohol and aging. However, measuring DVA is awkward because there is no standardized, efficient, flexible apparatus for DVA assessment. In this project, we developed a prototype of an automated, portable DVA system using a low-energy laser, and we compared this laser DVA with the traditional device in two within-subjects, repeated measures designs. The two studies included 48 participants (22 males and 26 females with an average age of 18.33 years). The most important findings were that: (1) retest reliabilities of the two DVA devices were comparable and higher with the laser; (2) average correlations between the two devices were r=0.62 (pDVA laser device can be developed to measure the same construct as the more traditional bulky DVA device.

  14. Human performance at sea assessed by dynamic visual acuity

    NARCIS (Netherlands)

    Bos, J.E.; Hogervorst, M.A.; Munnoch, K.; Perrault, D.

    2008-01-01

    Human performance may, among other things, depend on the ability to visually discern (small) objects. This ability is generally quantified under static conditions by means of the visual acuity, a measure of the minimum angle resolved by the eye. However, when the subject himself, his or her eyes,

  15. 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.

  16. Visual function versus visual acuity in older people.

    Science.gov (United States)

    Hidalgo, Jesús López-Torres; Martínez, Ignacio Párraga; Bravo, Beatriz Navarro; Pretel, Fernando Andrés; Ferrer, Alejandro Villena; Verdejo, Maria Angeles López

    2009-01-01

    To determine visual function (VF) status in older people, to establish its degree of correlation with visual acuity (VA), and to assess its association with other physical and mental functional limitations. A sample of 1,160 persons aged 65 years or over were selected by simple randomization. The participants' VF (The Visual Function Index - VF-14), VA, self-reported vision, mental and physical function (Katz Index, Pfeiffer's test, and Geriatric Depression Scale), and socio-demographic data were determined. Multiple linear regression was used to assess the association between VF and its conditioning factors. Statistical adjustment was made for the possible confounding variables. Of the studied subjects, 6.3% (95% confidence interval (CI) = 4.93-7.82) had VA of less than 6/18 in the better eye and 20.9% (95% CI = 18.6-23.3) had VA of less than 6/12. The best corrected VA of each participant demonstrated moderate correlation with his or her VF-14 score (r = 0.416; p visual impairment, self-reported poor vision, dependence in daily activities, cognitive impairment, depressive symptoms, female gender and older age. These independent variables explain 34.4% (r(2) = 0.344) of the variation in the data. VF impairment is common in older persons and when associated with other limitations, it may be considered a major health problem with important consequences. As a complement to the preventive care guidelines on VA in older persons, assessment of VF impairment in clinical practice, using appropriate visual screening tools, is advisable.

  17. The visual acuity and refractive state of the American kestrel (Falco sparverius).

    Science.gov (United States)

    Gaffney, Matthew F; Hodos, William

    2003-09-01

    The pattern electroretinogram (PERG) was used to measure the visual acuity and refractive state of nine American kestrels (Falco sparverius). Visual acuity was determined from psychometric functions of PERG amplitude vs. spatial frequency. Refractive state was measured by finding the trial lens that resulted in the highest acuity. All nine kestrels were found to be emmetropic. Their median visual acuity was 29 c/deg. The PERG, however, underestimates behaviorally determined visual acuity by approximately 37%. When adjusted for this underestimation, the median kestrel acuity was 46 c/deg. The visual acuity of American kestrels is compared to reports in the literature of 17 other species of birds.

  18. 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 ... Colour vision, flicker sensitivity, contrast sensitivity, pupillary responses and motion testing are some of the other methods of quantitating vision (Attebo, 1996; .... Ametropia and risk factors affecting visual acuity.

  19. 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.

  20. Visual Acuity and Contrast Sensitivity with compressed motion video

    NARCIS (Netherlands)

    Bijl, P.; Vries, S.C. de

    2009-01-01

    Video of Visual Acuity (VA) and Contrast Sensitivity (CS) test charts in a complex background was recorded using a CCD camera mounted on a computer-controlled tripod and fed into real-time MPEG2 compression/decompression equipment. The test charts were based on the Triangle Orientation

  1. 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 ...

  2. 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.

  3. Closed surfaces of constant visual acuity in symmetric dioptric power space.

    Science.gov (United States)

    Rubin, A; Harris, W F

    2001-10-01

    This paper demonstrates a multivariate approach to understanding the complicated relations of visual acuity to refractive state or ametropia. Other approaches, as previously used, included graphical representations of lines or profiles of iso-oxyopia (Peters, 1961). But one limitation of Peters' method is that cylinder axis was ignored. However, here the relationship between visual acuity and refractive power will be represented by estimated closed surfaces of constant visual acuity in symmetric dioptric power space. At or near the common center (of several closed surfaces, for example) is the refractive compensation. Coming outwards from such a center, the visual acuity drops in all directions in the space. The primary purpose of this paper was to present estimated closed surfaces of constant visual acuity for several eyes. Various procedures were performed on several subjects including measurement of iris aperture diameter, subjective refraction, and autorefraction. Thereafter, an automated phoropter and either Jackson cross-cylinders or spheres were used to influence dioptric blur or defocus in the subjects. The visual stimulus was a computer-generated nondirectional or meridionally independent letter O. Ovoidal surfaces fit the measurements obtained (with Jackson cross-cylinders and spheres) better than ellipsoidal surfaces. The cross-section, in symmetric dioptric power space, at powers with the same nearest equivalent sphere as the refractive compensation is elliptical in many cases and reflects a dependence of visual acuity on cylinder axis. The surfaces differ when powers are changed so that one is moving away from (decompensation surfaces) or toward (accompensation surfaces) the refractive compensation. The multivariate and graphical methods used in this paper probably have implications for the direction of future research in a number of areas involving measures of vision function such as autorefraction, retinoscopy, subjective refraction, and visual

  4. 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.

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

    Science.gov (United States)

    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

  6. [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.

  7. 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

  8. Effects of horizontal acceleration on human visual acuity and stereopsis.

    Science.gov (United States)

    Horng, Chi-Ting; Hsieh, Yih-Shou; Tsai, Ming-Ling; Chang, Wei-Kang; Yang, Tzu-Hung; Yauan, Chien-Han; Wang, Chih-Hung; Kuo, Wu-Hsien; Wu, Yi-Chang

    2015-01-19

    The effect of horizontal acceleration on human visual acuity and stereopsis is demonstrated in this study. Twenty participants (mean age 22.6 years) were enrolled in the experiment. Acceleration from two different directions was performed at the Taiwan High-Speed Rail Laboratory. Gx and Gy (0.1 g) were produced on an accelerating platform where the subjects stood. The visual acuity and stereopsis of the right eye were measured before and during the acceleration. Acceleration 0.1 g. Visual acuity worsened (mean from 0.02 logMAR to 0.19 logMAR) and poor stereopsis was noted (mean from 40 s to 50.2 s of arc) when Gy > 0.1 g. The effect of acceleration from the X-axis on the visual system was higher than that from the Y-axis. During acceleration, most subjects complained of ocular strain when reading. To our knowledge, this study is the first to report the exact levels of visual function loss during Gx and Gy.

  9. Effect of reduced visual acuity on precision of two-dimensional tracing movements

    Directory of Open Access Journals (Sweden)

    Dmitry Domkin

    2016-04-01

    Conclusion: Testing of fine motor functions with objective kinematic measures during visuomotor tasks may help differentiating between actual effects of reduced visual acuity on eye–hand coordination in individuals with similar levels of impairment of visual acuity.

  10. 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.

  11. Canal plane dynamic visual acuity in superior canal dehiscence.

    Science.gov (United States)

    Janky, Kristen L; Zuniga, M Geraldine; Ward, Bryan; Carey, John P; Schubert, Michael C

    2014-06-01

    1) To characterize normal, horizontal active dynamic visual acuity (DVA) and passive canal plane head thrust DVA (htDVA) across ages to establish appropriate control data and 2) to determine whether horizontal active DVA and passive canal plane htDVA are significantly different in individuals with superior canal dehiscence syndrome (SCDS) before and after surgical repair in the acute (within 10 d) and nonacute stage (>6 wk). Prospective study. Tertiary referral center Patients diagnosed with SCDS (n = 32) and healthy control subjects (n = 51). Surgical canal plugging on a subset of patients. Static visual acuity (SVA), active horizontal DVA, and canal plane htDVA. Visual acuity (SVA, active DVA, and htDVA) declines with age. In SCDS, SVA and active DVA are not significantly affected in individuals after surgical canal plugging; however, htDVA in the plane of the affected canal is significantly worse after canal plugging. Age-based normative data are necessary for DVA testing. In SCDS, htDVA in the plane of the affected canal is normal before surgery but permanently reduced afterward.

  12. Cortical sources of Vernier acuity in the human visual system: An EEG-source imaging study

    Science.gov (United States)

    Hou, Chuan; Kim, Yee-Joon; Verghese, Preeti

    2017-01-01

    Vernier acuity determines the relative position of visual features with a precision better than the sampling resolution of cone receptors in the retina. Because Vernier displacement is thought to be mediated by orientation-tuned mechanisms, Vernier acuity is presumed to be processed in striate visual cortex (V1). However, there is considerable evidence suggesting that Vernier acuity is dependent not only on structures in V1 but also on processing in extrastriate cortical regions. Here we used functional magnetic resonance imaging–informed electroencephalogram source imaging to localize the cortical sources of Vernier acuity in observers with normal vision. We measured suprathreshold and near-threshold responses to Vernier onset/offset stimuli at different stages of the visual cortical hierarchy, including V1, hV4, lateral occipital cortex (LOC), and middle temporal cortex (hMT+). These responses were compared with responses to grating on/off stimuli, as well as to stimuli that control for lateral motion in the Vernier task. Our results show that all visual cortical regions of interest (ROIs) responded to both suprathreshold Vernier and grating stimuli. However, thresholds for Vernier displacement (Vernier acuity) were lowest in V1 and LOC compared with hV4 and hMT+, whereas all visual ROIs had identical thresholds for spatial frequency (grating acuity) and for relative motion. The cortical selectivity of sensitivity to Vernier displacement provides strong evidence that LOC, in addition to V1, is involved in Vernier acuity processing. The robust activation of LOC might be related to the sensitivity to the relative position of features, which is common to Vernier displacement and to some kinds of texture segmentation. PMID:28586896

  13. Temporal perceptual coding using a visual acuity model

    Science.gov (United States)

    Adzic, Velibor; Cohen, Robert A.; Vetro, Anthony

    2014-02-01

    This paper describes research and results in which a visual acuity (VA) model of the human visual system (HVS) is used to reduce the bitrate of coded video sequences, by eliminating the need to signal transform coefficients when their corresponding frequencies will not be detected by the HVS. The VA model is integrated into the state of the art HEVC HM codec. Compared to the unmodified codec, up to 45% bitrate savings are achieved while maintaining the same subjective quality of the video sequences. Encoding times are reduced as well.

  14. 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

  15. 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

  16. 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

  17. 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

  18. Change in dynamic visual acuity (DVA) by pupil dilation.

    Science.gov (United States)

    Ueda, Tetsuo; Nawa, Yoshiaki; Yukawa, Eiichi; Taketani, Futoshi; Hara, Yoshiaki

    2006-01-01

    This study was conducted to assess dynamic visual acuity (DVA) under pupil dilation. Pupil dilation may negatively affect driving performance. Thirty healthy young adults (mean age 29.4 years) with pupil dilation participated in this study as the Mydrin P group. In addition to them, 15 healthy young adults (mean age 28.5 years) without pupil dilation were enrolled as the control group. DVA was measured binocularly with free-head viewing at 0, 30, 60, 120, and 360 min after mydriatic drop instillation in both eyes. Pupil size was measured at each time. In the Mydrin P group, DVA significantly improved at 30, 60, and 120 min (ANOVA; p DVA did not significantly change at all measured times (ANOVA; p > .9). DVA was significantly (p DVA was related to the enlargement of the pupil. This study suggests that the pupil size is one factor that may affect DVA. Potential applications of this study include useful information to assess the effect of pupil dilation on driving performance.

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

    Directory of Open Access Journals (Sweden)

    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. 

  20. Visual acuity evaluated by pattern-reversal visual-evoked potential is affected by check size/visual angle.

    Science.gov (United States)

    Chen, Xiping; Li, Qianqian; Liu, Xiaoqin; Yang, Li; Xia, Wentao; Tao, Luyang

    2012-12-01

    To systemically explore the range of visual angles that affect visual acuity, and to establish the relationship between the P1 component (peak latency ~100 ms) of the pattern-reversal visual-evoked potential (PRVEP) and the visual acuity at particular visual angles. Two hundred and ten volunteers were divided into seven groups, according to visual acuity as assessed by the standard logarithmic visual acuity chart (SLD-ii). For each group, the PRVEP components were elicited in response to visual angle presentations at 8°, 4°, 2°, 1°/60', 30', 15', and 7.5', in the whiteblack chess-board reversal mode with a contrast level of 100% at a frequency of 2 Hz. Visual stimuli were presented monocularly, and 200 presentations were averaged for each block of trials. The early and stable component P1 was recorded at the mid-line of the occipital region (oz) and analyzed with SPSS 13.00. (1) oz had the maximum P1 amplitude; there was no significant difference between genders or for interocular comparison in normal controls and subjects with optic myopia. (2) The P1 latency decreased slowly below 30', then increased rapidly. The P1 amplitude initially increased with check size, and was maximal at ~1° and ~30'. (3) The P1 latency in the group with visual acuity ≤0.2 was significantly different at 8°, 15' and 7.5', while the amplitude differed at all visual angles, compared with the group with normal vision. Differences in P1 for the groups with 0.5 and 0.6 acuity were only present at visual angles <1°. (4) Regression analysis showed that the P1 latency and amplitude were associated with visual acuity over the full range of visual angles. There was a moderate correlation at visual angles <30'. Regression equations were calculated for the P1 components and visual acuity, based on visual angle. (1) Visual angle should be taken into consideration when exploring the function of the visual pathway, especially visual acuity. A visual angle ~60' might be appropriate when using

  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. Vestibular, Visual Acuity, and Balance Outcomes in Children With Cochlear Implants: A Preliminary Report.

    Science.gov (United States)

    Janky, Kristen L; Givens, Diane

    2015-01-01

    There is a high incidence of vestibular loss in children with cochlear implants (CCI). However, the relationship between vestibular loss and various outcomes is unknown in children. The objectives of this study are to (1) determine whether age-related changes in peripheral vestibular tests occur; (2) quantify peripheral vestibular function in children with normal hearing and CCI; and (3) determine whether amount of vestibular loss predicts visual acuity and balance performance. Eleven CCI and 12 children with normal hearing completed the following tests of vestibular function: ocular and cervical vestibular-evoked myogenic potential to assess utricle and saccule function and the video head impulse test to assess semicircular canal function. The relationship between amount of vestibular loss and the following balance and visual acuity outcomes was assessed: dynamic gait index, single-leg stance, the sensory organization test, and tests of visual acuity, including dynamic visual acuity and the gaze stabilization test. (1) There were no significant age-related changes in peripheral vestibular testing with the exception of the n23 cervical vestibular-evoked myogenic potential latency, which was moderately correlated with age. (2) CCI had significantly higher rates of vestibular loss for each test of canal and otolith function. (3) Amount of vestibular loss predicted performance on single-leg stance, the dynamic gait index, some conditions of the sensory organization test, and the dynamic visual acuity test. Age was also a contributing factor for predicting the performance of almost all outcomes. Preliminarily, children with vestibular loss do not recover naturally to levels of their healthy peers, particularly with activities that utilize vestibular input; they have poorer visual acuity and balance function.

  3. 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

  4. 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

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. PERSPECTIVE: Is acuity enough? Other considerations in clinical investigations of visual prostheses

    Science.gov (United States)

    Lepri, Bernard P.

    2009-06-01

    Visual impairing eye diseases are the major frontier facing ophthalmic research today in light of our rapidly aging population. The visual skills necessary for improving the quality of daily function and life are inextricably linked to these impairing diseases. Both research and reimbursement programs are emphasizing outcome-based results. Is improvement in visual acuity alone enough to improve the function and quality of life of visually impaired persons? This perspective summarizes the types of effectiveness endpoints for clinical investigations of visual prostheses that go beyond visual acuity. The clinical investigation of visual prostheses should include visual function, functional vision and quality of life measures. Specifically, they encompass contrast sensitivity, orientation and mobility, activities of daily living and quality of life assessments. The perspective focuses on the design of clinical trials for visual prostheses and the methods of determining effectiveness above and beyond visual acuity that will yield outcomes that are measured by improved function in the visual world and quality of life. The visually impaired population is the primary consideration in this presentation with particular emphases on retinitis pigmentosa and age-related macular degeneration. Clinical trials for visual prostheses cannot be isolated from the need for medical rehabilitation in order to obtain measurements of effectiveness that produce outcomes/evidence-based success. This approach will facilitate improvement in daily function and quality of life of patients with diseases that cause chronic vision impairment. The views and opinions are those of the author and do not necessarily reflect those of the US Food and Drug Administration, the US Department of Health and Human Services or the Public Health Service.

  11. Comparison of visual acuity estimates using three different letter charts under two ambient room illuminations

    OpenAIRE

    Chen, Ai-Hong; Norazman, Fatin Nur Najwa; Buari, Noor Halilah

    2012-01-01

    Background: Visual acuity is an essential estimate to assess ability of the visual system and is used as an indicator of ocular health status. Aim: The aim of this study is to investigate the consistency of acuity estimates from three different clinical visual acuity charts under two levels of ambient room illumination. Materials and Methods: This study involved thirty Malay university students aged between 19 and 23 years old (7 males, 23 females), with their spherical refractive error rangi...

  12. Features of Dynamic Visual Acuity and Patterns in Target Tracking Observed in Volleyball Players

    OpenAIRE

    石垣, 尚男

    2002-01-01

    Volleyball players showed superior dynamic visual acuity when tracking a target moving from right to left. Using an eye mark recorder, patterns in target tracking were compared between volleyball players who showed especially high dynamic visual acuity and non-players of sport who showed especially low dynamic visual acuity. It was found that the width of eye movement was broad in the volleyball players while that in the non-players of sport was narrow.

  13. 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.).

  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. Phacoemulsification cataract surgery in a large cohort of diabetes patients: visual acuity outcomes and prognostic factors

    DEFF Research Database (Denmark)

    Ostri, Christoffer; Lund-Andersen, Henrik; Sander, Birgit

    2011-01-01

    To assess visual acuity outcomes after phacoemulsification cataract surgery in a large population of diabetic patients with all degrees of diabetic retinopathy.......To assess visual acuity outcomes after phacoemulsification cataract surgery in a large population of diabetic patients with all degrees of diabetic retinopathy....

  16. 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 ...

  17. 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)

  18. 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.

  19. [Prevalence of reduced visual acuity among Chinese Han students in 2014].

    Science.gov (United States)

    Song, Y; Hu, P J; Dong, Y H; Zhang, B; Ma, J

    2017-06-18

    To analyze the prevalence of reduced visual acuity (VA) and to examine the association between reduced visual acuity and influencing factors among Chinese Han students, so as to provide bases for the prevention and treatment of reduced visual acuity. Subjects were from 2014 Chinese National Surveys on Students' Constitution and Health (CNSSCH). In this survey, 261 832 Han students aged 7-22 years participated. Unaided distance VA was measured using a retro-illuminated lgMAR chart with tumbling-E optotypes. Ametropia was determined by using serial bronchoscopy. Logistic regression was used to assess the association between reduced visual acuity and influencing factors. ArcMap 10 was used to map the regional distribution of reduced visual acuity. Nationwide, the overall prevalence of reduced visual acuity was 66.6%, and was highest among the urban girls (73.5%). The prevalence of myopia was 60.8% and accounted for more than 90% among the students with reduced visual acuity. Compared with 2010 CNSSCH, the increments of reduced visual acuity were highest in the students aged 13-15 years (6.8 percentage points). The prevalence of reduced visual acuity ranged from 50.6% to 76.2% in each province (autonomous region, municipality) in 2014 CNSSCH. The top three of the prevalence of reduced visual acuity were Jiangsu (76.2%), Zhejiang (76.0%) and Shandong (75.9%), and the lowest three were Hainan (50.6%), Guizhou (53.9%) and Xinjiang (57.6%). Logistic regression showed that the girls, urban students, and students who spent ≥2 h per day in their after school homework were more likely to develop reduced visual acuity, but the students with physical activity time ≥2 h per day were less likely to develop reduced visual acuity. Although the situation was different in each province (autonomous region, municipality), reduced visual acuity has become a public concern affecting the health of students in China. Based on the intervention on the key populations, such as urban girls

  20. 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.

  1. Effect of testing position on dynamic visual acuity.

    Science.gov (United States)

    Danenbaum, Elizabeth; Chilingaryan, Gevorg; Fung, Joyce

    2008-12-01

    To investigate the effect of altering testing position on dynamic visual acuity (DVA) in vestibulopathic adults. Quasiexperimental research. Outpatient vestibular program. Twelve vestibulopathic adults with impaired DVA in the sitting position. DVA scores were collected during (1) sitting, (2) standing comfortably, and (3) semitandem standing as subjects viewed a vision (E) chart 3.48 m in front of them. DVA was obtained as the head was passively moved by the evaluator at a frequency of 1.5 Hz in both horizontal and vertical directions. A further subgroup of subjects (n=5) was retested after performing the "viewing x1" gaze stability home exercise four times daily (1 minute duration in the horizontal direction while sitting) for 2 months. Noncomputerized DVA score. The DVA score remained constant independent of testing position as the Friedman test did not reveal any significant differences in the DVA scores in the horizontal or vertical direction. Subjects who improved after performing the viewing x1 exercise in the horizontal direction in the sitting position tended to have the same improvement in DVA in all three positions. The results of this study show that DVA score is independent of testing position. This is clinically important since it shows that the results of DVA testing in one position are valid for other positions and that subjects can be trained to improve their DVA in a sitting posture while having carry-over effects to other, more challenging postures.

  2. 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.

  3. [Long-term course of visual acuity in patients with cataract surgery].

    Science.gov (United States)

    Chiseliţă, Dorin; Huţuleac, Alexandra; Cantemir, Alina; Irod, Alexandra; Obadă, Otilia; Juverdeanu, Raluca

    2012-01-01

    To compare immediate and 5 years postoperatively visual acuity (VA), after uncomplicated cataract surgery and emphasizing the main causes of visual acuity loss. This is a retrospective study that included 475 eyes that underwent uncomplicated cataract surgery between 2003-2007 by the same surgeon. 51 patients (73 eyes) returned to the last followup visit, 5 years postoperatively. Of 73 eyes, 18 eyes (24.66%) had VA 1, 5 years postoperatively. 26% (19 eyes) revealed reduced best corrected visual acuity in comparison to that from 6 weeks postoperatively Causes that led to reduced VA are: posterior capsular opacification (46.57%), age related macular degeneration (26.02%), glaucoma (10.95%), diabetic retinopathy (9.58%). Approximately a quarter of patients showed reduced VA after more than 5 years postoperatively; more than three quarters had VA > 0.5 on the last follow-up visit. The most frequent causes of reduced VA are age-related macular degeneration, glaucoma, appearence or worsening of diabetic retinopathy, posterior capsular opacification.

  4. Development of Pocket Vision Screener and its effectiveness at screening visual acuity deficits

    Directory of Open Access Journals (Sweden)

    Monica Raja

    2014-01-01

    Full Text Available Aim: The aim was to construct a visual acuity chart and find its effectiveness at screening visual acuity deficits. Materials and Methods: Two phases were involved in this study.Construction of the screener: Ten Sloan letters (C, D, H, K, N, O, R, S, V, and Z were selected and the letters were constructed and reduced to 0.2 logMAR acuity size (6.92 mm for viewing at 3 m. The screener contains three lines with seven letters in each. Few combinations of the seven letter sequences were chosen based on the row legibility scores. Three seven letter combinations close to the median of all combinations were selected, such that maximum difficulty score difference between the lines are <1%. Finding the effectiveness of the screener: 100 literate subjects with unaided visual acuity better than or equal to 6/60 were recruited for the study. Unaided visual acuity was tested using both the newly constructed Pocket Vision Screener and a logMAR visual acuity chart and the time taken to measure the visual acuity using both the charts was noted. Results: The mean age of the subjects was 43 ± 17 years. Subjects were classified as normal or deficient based on the logMAR visual acuity measurement. The screener was found to have 81% sensitivity, 94% specificity. The positive and negative predictive values were found to be 91% and 87%, respectively. A significant difference (P < 0.001 was found in the time taken to record visual acuity using both the charts. Conclusion: The Pocket Vision Screener can be used as a quick and accurate tool to screen subjects for visual acuity deficits, being highly sensitive, specific, and cost-effective.

  5. Effect of reduced visual acuity on precision of two-dimensional tracing movements.

    Science.gov (United States)

    Domkin, Dmitry; Richter, Hans O; Zetterlund, Christina; Lundqvist, Lars-Olov

    2016-01-01

    We intended to assess consequences of reduced visual acuity for performance in a natural simple motor task (tracing) using objective kinematic performance measures. Specifically, we intended to elucidate the kind of relationship between the task performance and best corrected binocular visual acuity and to determine the threshold of visual acuity when task performance starts to deteriorate. Ninety-five individuals with different best corrected visual acuity participated in the study (age 49±12 years, mean±SD, 27 men and 68 women). The participants manually traced maze-like visual patterns of different spatial complexity presented on the screen of a portable notebook computer using Clinical Kinematic Assessment Tool software. Tracing error was computed as performance measure in each trial with a spatial pattern matching technique - rigid point set registration method. The segmented linear regression analysis showed that the relation between visual acuity and tracing errors was best described with a regression function having a break point between two data segments. Tracing performance was unaffected by values of visual acuity below 0.2 on logMAR scale, but when logMAR values increased above this critical limit (i.e. when visual acuity is further reduced), tracing errors linearly increased. The rate of the increase of the tracing error correlated with the complexity of visual stimulus shape. Testing of fine motor functions with objective kinematic measures during visuomotor tasks may help differentiating between actual effects of reduced visual acuity on eye-hand coordination in individuals with similar levels of impairment of visual acuity. Copyright © 2014 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    OpenAIRE

    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 alon...

  9. Validity of low-contrast letter acuity as a visual performance outcome measure for multiple sclerosis.

    Science.gov (United States)

    Balcer, Laura J; Raynowska, Jenelle; Nolan, Rachel; Galetta, Steven L; Kapoor, Raju; Benedict, Ralph; Phillips, Glenn; LaRocca, Nicholas; Hudson, Lynn; Rudick, Richard

    2017-04-01

    Low-contrast letter acuity (LCLA) has emerged as the leading outcome measure to assess visual disability in multiple sclerosis (MS) research. As visual dysfunction is one of the most common manifestations of MS, sensitive visual outcome measures are important in examining the effect of treatment. Low-contrast acuity captures visual loss not seen in high-contrast visual acuity (HCVA) measurements. These issues are addressed by the MS Outcome Assessments Consortium (MSOAC), including representatives from advocacy organizations, Food and Drug Administration (FDA), European Medicines Agency (EMA), National Institute of Neurological Disorders and Stroke (NINDS), academic institutions, and industry partners along with persons living with MS. MSOAC goals are acceptance and qualification by regulators of performance outcomes that are highly reliable and valid, practical, cost-effective, and meaningful to persons with MS. A critical step is elucidation of clinically relevant benchmarks, well-defined degrees of disability, and gradients of change that are clinically meaningful. This review shows that MS and disease-free controls have similar median HCVA, while MS patients have significantly lower LCLA. Deficits in LCLA and vision-specific quality of life are found many years after an episode of acute optic neuritis, even when HCVA has recovered. Studies reveal correlations between LCLA and the Expanded Disability Status Score (EDSS), Multiple Sclerosis Functional Composite (MSFC), retinal nerve fiber layer (RNFL) and ganglion cell layer plus inner plexiform layer (GCL + IPL) thickness on optical coherence tomography (OCT), brain magnetic resonance imaging (MRI), visual evoked potential (VEP), electroretinogram (ERG), pupillary function, and King-Devick testing. This review also concludes that a 7-point change in LCLA is clinically meaningful. The overall goal of this review is to describe and characterize the LCLA metric for research and clinical use among persons with MS.

  10. 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

  11. 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...

  12. Visual Acuity of Simulated Thalamic Visual Prostheses in Normally Sighted Humans

    Science.gov (United States)

    Jeffries, Ailsa; Pezaris, John S.

    2013-01-01

    Simulation in normally sighted individuals is a crucial tool to evaluate the performance of potential visual prosthesis designs prior to human implantation of a device. Here, we investigated the effects of electrode count on visual acuity, learning rate and response time in 16 normally sighted subjects using a simulated thalamic visual prosthesis, providing the first performance reports for thalamic designs. A new letter recognition paradigm using a multiple-optotype two-alternative forced choice task was adapted from the Snellen eye chart, and specifically devised to be readily communicated to both human and non-human primate subjects. Validation of the method against a standard Snellen acuity test in 21 human subjects showed no significant differences between the two tests. The novel task was then used to address three questions about simulations of the center-weighted phosphene patterns typical of thalamic designs: What are the expected Snellen acuities for devices with varying numbers of contacts, do subjects display rapid adaptation to the new visual modality, and can response time in the task provide clues to the mechanisms of perception in low-resolution artificial vision? Population performance (hit rate) was significantly above chance when viewing Snellen 20/200 optotypes (Log MAR 1.0) with 370 phosphenes in the central 10 degrees of vision, ranging to Snellen 20/800 (Log MAR 1.6) with 25 central phosphenes. Furthermore, subjects demonstrated learning within the 1–2 hours of task experience indicating the potential for an effective rehabilitation and possibly better visual performance after a longer period of training. Response time differences suggest that direct letter perception occurred when hit rate was above 75%, whereas a slower strategy like feature-based pattern matching was used in conditions of lower relative resolution. As pattern matching can substantially boost effective acuity, these results suggest post-implant therapy should specifically

  13. Visual acuity of simulated thalamic visual prostheses in normally sighted humans.

    Directory of Open Access Journals (Sweden)

    Béchir Bourkiza

    Full Text Available Simulation in normally sighted individuals is a crucial tool to evaluate the performance of potential visual prosthesis designs prior to human implantation of a device. Here, we investigated the effects of electrode count on visual acuity, learning rate and response time in 16 normally sighted subjects using a simulated thalamic visual prosthesis, providing the first performance reports for thalamic designs. A new letter recognition paradigm using a multiple-optotype two-alternative forced choice task was adapted from the Snellen eye chart, and specifically devised to be readily communicated to both human and non-human primate subjects. Validation of the method against a standard Snellen acuity test in 21 human subjects showed no significant differences between the two tests. The novel task was then used to address three questions about simulations of the center-weighted phosphene patterns typical of thalamic designs: What are the expected Snellen acuities for devices with varying numbers of contacts, do subjects display rapid adaptation to the new visual modality, and can response time in the task provide clues to the mechanisms of perception in low-resolution artificial vision? Population performance (hit rate was significantly above chance when viewing Snellen 20/200 optotypes (Log MAR 1.0 with 370 phosphenes in the central 10 degrees of vision, ranging to Snellen 20/800 (Log MAR 1.6 with 25 central phosphenes. Furthermore, subjects demonstrated learning within the 1-2 hours of task experience indicating the potential for an effective rehabilitation and possibly better visual performance after a longer period of training. Response time differences suggest that direct letter perception occurred when hit rate was above 75%, whereas a slower strategy like feature-based pattern matching was used in conditions of lower relative resolution. As pattern matching can substantially boost effective acuity, these results suggest post-implant therapy

  14. Influence of different types of astigmatism on visual acuity.

    Science.gov (United States)

    Remón, Laura; Monsoriu, Juan A; Furlan, Walter D

    To investigate the change in visual acuity (VA) produced by different types of astigmatism (on the basis of the refractive power and position of the principal meridians) on normal accommodating eyes. The lens induced method was employed to simulate a set of 28 astigmatic blur conditions on different healthy emmetropic eyes. Additionally, 24 values of spherical defocus were also simulated on the same eyes for comparison. VA was measured in each case and the results, expressed in logMAR units, were represented against of the modulus of the dioptric power vector (blur strength). LogMAR VA varies in a linear fashion with increasing astigmatic blur, being the slope of the line dependent on the accommodative demand in each type of astigmatism. However, in each case, we found no statistically significant differences between the three axes investigated (0°, 45°, 90°). Non-statistically significant differences were found either for the VA achieved with spherical myopic defocus (MD) and mixed astigmatism (MA). VA with simple hyperopic astigmatism (SHA) was higher than with simple myopic astigmatism (SMA), however, in this case non conclusive results were obtained in terms of statistical significance. The VA achieved with imposed compound hyperopic astigmatism (CHA) was highly influenced by the eye's accommodative response. VA is correlated with the blur strength in a different way for each type of astigmatism, depending on the accommodative demand. VA is better when one of the focal lines lie on the retina irrespective of the axis orientation; accommodation favors this situation. Copyright © 2016 Spanish General Council of Optometry. Published by Elsevier España, S.L.U. All rights reserved.

  15. Real-time computer-based visual feedback improves visual acuity in downbeat nystagmus - a pilot study.

    Science.gov (United States)

    Teufel, Julian; Bardins, S; Spiegel, Rainer; Kremmyda, O; Schneider, E; Strupp, M; Kalla, R

    2016-01-04

    Patients with downbeat nystagmus syndrome suffer from oscillopsia, which leads to an unstable visual perception and therefore impaired visual acuity. The aim of this study was to use real-time computer-based visual feedback to compensate for the destabilizing slow phase eye movements. The patients were sitting in front of a computer screen with the head fixed on a chin rest. The eye movements were recorded by an eye tracking system (EyeSeeCam®). We tested the visual acuity with a fixed Landolt C (static) and during real-time feedback driven condition (dynamic) in gaze straight ahead and (20°) sideward gaze. In the dynamic condition, the Landolt C moved according to the slow phase eye velocity of the downbeat nystagmus. The Shapiro-Wilk test was used to test for normal distribution and one-way ANOVA for comparison. Ten patients with downbeat nystagmus were included in the study. Median age was 76 years and the median duration of symptoms was 6.3 years (SD +/- 3.1y). The mean slow phase velocity was moderate during gaze straight ahead (1.44°/s, SD +/- 1.18°/s) and increased significantly in sideward gaze (mean left 3.36°/s; right 3.58°/s). In gaze straight ahead, we found no difference between the static and feedback driven condition. In sideward gaze, visual acuity improved in five out of ten subjects during the feedback-driven condition (p = 0.043). This study provides proof of concept that non-invasive real-time computer-based visual feedback compensates for the SPV in DBN. Therefore, real-time visual feedback may be a promising aid for patients suffering from oscillopsia and impaired text reading on screen. Recent technological advances in the area of virtual reality displays might soon render this approach feasible in fully mobile settings.

  16. Age Differences in the Relationship between Visual Movement Imagery and Performance on Kinesthetic Acuity Tests.

    Science.gov (United States)

    Livesey, David J.

    2002-01-01

    Investigated the relationship between Vividness of Movement Imagery Questionnaire scores and kinesthetic acuity--the sense of body position and movement--among 10- and 14-year-olds. Found that in the older group, those with high levels of visual movement imagery performed better on measures of kinesthetic acuity; no such effect was found for…

  17. Functional and visual acuity outcomes of cataract surgery in Timor-Leste (East Timor).

    Science.gov (United States)

    Naidu, Girish; Correia, Marcelino; Nirmalan, Praveen; Verma, Nitin; Thomas, Ravi

    2014-12-01

    To report functional outcomes following cataract surgery in Timor-Leste. Pre- and post-intervention study measuring visual function improvement following cataract surgery. Presenting visual acuity (VA) was measured and visual function documented using the Indian vision function questionnaire (IND-VFQ). All 174 persons undergoing cataract surgery from November 2009 to January 2011 in Timor-Leste were included. Mean age was 65.4 years; 113 (64.9%) were male, 143 (82.1%) were from a rural background and 151 (86.8%) were illiterate. Pre-operatively, 77 of 174 patients (44.3%, 95% confidence interval, CI, 37.0-51.7%) were blind (VA ≤3/60), 77 (44.3%, 95% CI 37.0-51.7%) were visually impaired (VA 3/60), while 20 (11.5%, 95% CI 7.4-16.9%) had presenting acuity ≥6/18 in the better eye. Following surgery, significant improvement in visual function was demonstrated by an effect size of 2.8, 3.7 and 3.9 in the domains of general functioning, psychosocial impact and visual symptoms, respectively. Four weeks following surgery, 85 patients (48.9%, 95% CI 41.5-66.3%) had a presenting VA ≥6/18, 74 (42.5%, 95% CI 35.3-45.9%) were visually impaired and 15 (8.6%, 95% CI 5.0-13.6%) were blind. IND-VFQ improvement occurred even in patients remaining visually impaired or blind following surgery. In this setting, cataract surgery led to a significant improvement in visual function but the VA results did not meet World Health Organization quality criteria. IND-VFQ results, although complementary to clinical VA outcomes did not, in isolation, reflect the need to improve program quality.

  18. Functional visual acuity in patients with successfully treated amblyopia: a pilot study.

    Science.gov (United States)

    Hoshi, Sujin; Hiraoka, Takahiro; Kotsuka, Junko; Sato, Yumiko; Izumida, Shinya; Kato, Atsuko; Ueno, Yuta; Fukuda, Shinichi; Oshika, Tetsuro

    2017-06-01

    The aim of this study was to use conventional visual acuity measurements to quantify the functional visual acuity (FVA) in eyes with successfully treated amblyopia, and to compare the findings with those for contralateral normal eyes. Nineteen patients (7 boys, 12 girls; age 7.5 ± 2.2 years) with successfully treated unilateral amblyopia and the same conventional decimal visual acuity in both eyes (better than 1.0) were enrolled. FVA, the visual maintenance ratio (VMR), maximum and minimum visual acuity, and the average response time were recorded for both eyes of all patients using an FVA measurement system. The differences in FVA values between eyes were analyzed. The mean LogMAR FVA scores, VMR (p amblyopia than for the contralateral normal eyes. There was no significant difference in the average response time. Our results indicate that FVA and VMR were poorer for eyes with treated amblyopia than for normal eyes, even though the treatment for amblyopia was considered successful on the basis of conventional visual acuity measurements. These results suggest that visual function is impaired in eyes with amblyopia, regardless of treatment success, and that FVA measurements can provide highly valuable diagnosis and treatment information that is not readily provided by conventional visual acuity measurements.

  19. [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.

  20. 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...

  1. 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.

  2. Use of optical coherence tomography to evaluate visual acuity and visual field changes in dengue fever.

    Science.gov (United States)

    Rhee, Taek Kwan; Han, Jung Il

    2014-02-01

    Dengue fever is a viral disease that is transmitted by mosquitoes and affects humans. In rare cases, dengue fever can cause visual impairment, which usually occurs within 1 month after contracting dengue fever and ranges from mild blurring of vision to severe blindness. Visual impairment due to dengue fever can be detected through angiography, retinography, optical coherence tomography (OCT) imaging, electroretinography, event electroencephalography (visually evoked potentials), and visual field analysis. The purpose of this study is to report changes in the eye captured using fluorescein angiography, indocyanine green, and OCT in 3 cases of dengue fever visual impairment associated with consistent visual symptoms and similar retinochoroidopathic changes. The OCT results of the three patients with dengue fever showed thinning of the outer retinal layer and disruption of the inner segment/outer segment (IS/OS) junction. While thinning of the retina outer layer is an irreversible process, disruption of IS/OS junction is reported to be reversible. Follow-up examination of individuals with dengue fever and associated visual impairment should involve the use of OCT to evaluate visual acuity and visual field changes in patients with acute choroidal ischemia.

  3. 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.

  4. 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)

  5. Laser refractive correction of myopia in visually impaired patients improves visual acuity.

    Science.gov (United States)

    Vuori, Elisa; Tervo, Timo M T; Holopainen, Juha M

    2011-09-01

    To retrospectively evaluate the visual and refractive outcome of visually impaired adults treated with refractive surgery (photorefractive keratectomy or laser-assisted in situ keratomileusis). We searched a refractive surgery database comprising 1716 mildly visually impaired patients [best spectacle-corrected visual acuity (BSCVA) on a logMAR scale ≤ -0.1 (Snellen ≤ 0.8)] who had undergone either PRK or LASIK (n = 96). PRK patients who had visits at 5-7, 8-13 and 14-24 months postoperatively were selected. Eleven patients and nine PRK control myopic patients were found (cohort 1). From the same database, 41 visually impaired patients and 54 controls who had a postoperative control at 14-24 months postoperatively were chosen. These patients formed cohort 2. Preoperatively, in cohort 1, the mean BSCVA on a logMAR scale was -0.15 ± 0.13 (Snellen 0.73 ± 0.16) in visually impaired patients and 0.04 ± 0.02 (Snellen 1.11 ± 0.17) in myopic controls. At 14-24 months postoperatively, the mean BSCVA improved to 0.05 ± 0.04 (Snellen 1.13 ± 0.10) in visually impaired patients and 0.05 ± 0.08 (Snellen 1.13 ± 0.21) in control patients. In cohort 2, preoperatively the mean BSCVA on a logMAR scale was -0.15 ± 0.12 (Snellen 0.74 ± 0.14) in visually impaired patients and 0.01 ± 0.03 (Snellen 1.04 ± 0.10) in myopic controls. At 14-24 months postoperatively, the mean BSCVA improved to 0.02 ± 0.07 (Snellen 1.06 ± 0.16) in visually impaired patients and 0.06 ± 0.06 (Snellen 1.15 ± 0.16) in control patients. Refractive surgery improves BSCVA in visually impaired patients, possibly through plastic changes in the visual cortex. Consequently, refractive surgery may be used successfully for the treatment of visually impaired adults to enhance their visual acuity. © 2009 The Authors. Journal compilation © 2009 Acta Ophthalmol.

  6. 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.

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

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    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.

  8. [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.

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

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    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

  10. [The key parameters of design research and analysis of the Chinese reading visual acuity chart].

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    Wang, Chen-xiao; Liu, Zhi-hui; Gao, Ji-tuo; Guo, Ying-xuan; He, Ji-cang; Qu, Jia; Lü, Fan

    2013-06-01

    Reading is a visual function human being used to understand environmental events based on writing materials. This study investigated the feasibility of reading visual acuity chart in assessment of reading ability by analysis of the key factors involved in the design of the visual acuity chart. The reading level was determined as grade 3 primary school with Song as the font and 30 characters included in the sentences. Each of the sentences consisted of 27 commonly-used Chinese characters (9 characters between any two punctuations) and 3 punctuations. There were no contextual clues between the 80 sentences selected. The characters had 13 different sizes with an increment of 0.1 log unit (e.g.1.2589) and 2.5 pt was determined as the critical threshold. Readable test for visual target was followed as (1) 29 candidates with a raw or corrected visual acuity (VA)of at least 1.0 were selected to read 80 selected sentences with the size of characters of 2.5 pt at a distance of 40 cm, (2) the time used for reading with the number of characters wrongly read was recorded, (3) 39 sentences were selected as visual targets based on reading speed, effective reading position and total number of character strokes, (4) The 39 selected sentences were then randomly divided into 3 groups with no significant difference among the groups in the 3 factors listed at (3) with paired t-test. This reading visual chart was at level of Grade 3 primary school with a total stroke number of 165-210(Mean 185 ± 10), 13 font sizes a 0.1 log unit increment, a song pattern and 2.5 pt as the critical threshold. All candidates achieved 100% correct in reading test under 2.5 pt with an effective reading speed as 120.65-162 wpm (Mean 142.93 ± 11.80) and effective reading position as 36.03-61.48(Mean 48.85 ± 6.81). The reading test for the 3 groups of sentences showed effective reading speed as (142.49 ± 12.14) wpm,(142.86 ± 12.55) wpm and (143.44 ± 11.63) wpm respectively(t1-2 = -0.899, t2-3 = -1

  11. The Handy Eye Check: a mobile medical application to test visual acuity in children.

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    Toner, Keri N; Lynn, Michael J; Candy, T Rowan; Hutchinson, Amy K

    2014-06-01

    To compare visual acuity results obtained with the Handy Eye Chart to results obtained using the Handy Eye Check, a mobile medical application that electronically presents isolated Handy Eye Chart optotypes according the Amblyopia Treatment Study (ATS) protocol. Consecutive patients 6-18 years of age presenting for eye examinations between May 30, 2012, and June 26, 2012, were invited to participate. Monocular visual acuity testing was performed on the subject's poorer-seeing eye using both the Handy Eye Check and the Handy Eye Chart under the same conditions. Visual acuity was first tested using the mobile application, then using the chart, followed by repeated application testing. Patients were excluded if they were unable to undergo the required visual acuity testing or if visual acuity in the worse-seeing eye was less than 20/200 (for validity testing, but not reliability testing). There was a strong linear correlation (r = 0.92) and a mean difference in acuity of -0.005 logMAR, or less than one letter (95% CI, -0.03 to 0.02), between the two tests. The 95% limits of agreement were ± 2 lines. Test-retest reliability was high, with 81% of retest scores within 0.1 logMAR (5 letters) and 100% within 0.2 logMAR (10 letters), an intraclass correlation coefficient of 0.93, and a standard error of measurement of 0.08. The Handy Eye Check mobile application compares similarly to the Handy Eye Chart as a valid and reliable test of visual acuity in children age 6-18 years. Published by Mosby, Inc.

  12. Microperimetric Biofeedback Training Improved Visual Acuity after Successful Macular Hole Surgery

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    Tomoko Ueda-Consolvo

    2015-01-01

    Full Text Available Purpose. To evaluate the efficacy of setting a preferred retinal locus relocation target (PRT and performing Macular Integrity Assessment (MAIA biofeedback training in patients showing insufficient recovery of best corrected visual acuity (BCVA despite successful closure of an idiopathic macular hole (MH. Methods. Retrospective interventional case series. Nine eyes of 9 consecutive patients with the decimal BCVA of less than 0.6 at more than 3 months after successful MH surgery were included. A PRT was chosen based on MAIA microperimetry and the patients underwent MAIA biofeedback training. BCVA, reading speed, fixation stability, and 63% bivariate contour ellipse area (BCEA were evaluated before and after the training. Statistical analysis was carried out using paired Student’s t-test. Results. PRT was chosen on the nasal side of the closed MH fovea in 8 patients. After the MAIA training, BCVA improved in all patients. The mean logMAR value of BCVA significantly improved from 0.33 to 0.12 (p=0.007. Reading speed improved in all patients (p=0.29, fixation stability improved in 5 patients (p=0.70, and 63% BCEA improved in 7 patients (p=0.21, although these improvements were not statistically significant. Conclusion. MAIA biofeedback training improved visual acuity in patients with insufficient recovery of BCVA after successful MH surgery.

  13. Assessing visual acuity across five disease types: ETDRS charts are faster with clinical outcome comparable to Landolt Cs.

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    Koenig, Simone; Tonagel, Felix; Schiefer, Ulrich; Bach, Michael; Heinrich, Sven P

    2014-07-01

    Given the diversity of visual acuity tests being employed across the world, we compared two frequently applied tests: ETDRS charts and an eight-orientation projected Landolt C test in accordance with ISO 8596 and DIN 58220 part 3. The goals of the investigation were to determine (i) test agreement and (ii) test-retest reliability, to assess (iii) test durations, and (iv) the acceptance of the tests by the examinees as well as the subjects' coping with the tests as rated by the examiner. Seventy-five adult subjects with a visual acuity of ≥0.2 (4/20) were included in one of the following groups: normal, media opacity, maculopathy, optic neuropathy, (post)chiasmal lesion, or amblyopia. Visual acuity testing was carried out monocularly, in balanced randomized order and in two runs for each test on the same eye, applying forced choice. Agreement: Within each group, all tests were performed similarly, within ±0.048 logMAR. Reliability: Across all subject groups, with a probability of 95 %, test-retest differences were visual acuity and test-retest reliability in all disease groups. The ETDRS test was usually faster and more accepted by both examiners and examinees than the Landolt test.

  14. Motor proficiency and dynamic visual acuity in children with bilateral sensorineural hearing loss.

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    Martin, Willemien; Jelsma, Jennifer; Rogers, Christine

    2012-10-01

    Due to the close relationship between the cochlea and the peripheral vestibular system, the function of the vestibular system may be impaired in children with sensorineural hearing loss. The aims of this study were to determine the prevalence of impairments of motor performance and dynamic visual acuity, and the nature and extent of interaction between these in children with sensorineural hearing loss between the ages of 4 and 14 years. This research utilized a correlational, cross-sectional, descriptive design. Thirty-two children with sensorineural hearing loss were matched according to age and gender with children with no hearing impairment. Motor performance was evaluated by means of the Movement Assessment Battery for Children-2 and dynamic visual acuity was evaluated with the dynamic visual acuity test. The performances of the two groups on the different tests were then compared. The one-sided chi-square test or Fisher's exact test was used to determine whether there was any association between sensorineural hearing loss, impaired motor performance and poor dynamic visual acuity. The Mann-Whitney U-test was used to determine the difference between children with sensorineural hearing loss and those with normal hearing on the Movement Assessment Battery for Children-2. Forward stepwise regression was used to establish the predictors of the Movement Assessment Battery for Children-2 total standard score. The Kruskal-Wallis test was used to compare scores of children with normal hearing and those with a mild to moderate sensorineural hearing loss on the Movement Assessment Battery for Children-2. Reduced dynamic visual acuity is associated with sensorineural hearing loss (p=0.026). Motor performance is dependent on dynamic visual acuity and severity of sensorineural hearing loss (r(2)=0.41, p=0.001). The results of this study indicate that in children with sensorineural hearing loss, the prevalence of reduced dynamic visual acuity is 15.6% and of motor impairment

  15. Contrast visual acuity in patients with retinitis pigmentosa assessed by a contrast sensitivity tester

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    Maho Oishi

    2012-01-01

    Full Text Available Purpose: To assess contrast visual acuity (CVA in patients with retinitis pigmentosa (RP and compare the result with standard visual acuity (VA, retinal thickness, status of inner segment/outer segment junction, and central visual field. Materials and Methods: Thirty-nine eyes of 39 patients with RP and 39 eyes of 39 healthy individuals were studied. To see the difference in CVA between RP patients and normal controls, only subjects with standard VA of 1.0 (20/20 or better were included. This was a cross-sectional study. CVA in various light conditions was measured with CAT-2000 and was compared between patients and controls. CVA of patients was further analyzed for association with other parameters including foveal retinal thickness, outer nuclear layer thickness, the status of inner segment/outer segment junction measured with optical coherence tomography (OCT, and visual field mean deviation (MD measured with Humphrey field analyzer 10-2 program. Results: CVA impairment was evident in RP patients compared to controls (P < 0.01, in all measurement conditions. Multivariate analysis showed association of logarithm of the minimum angle of resolution (logMAR with CVAs in several conditions. None of the OCT measurements was associated with CVA. When patients were divided into three groups based on MD, the most advanced group (MD worse than or equal to –20 dB showed impairment of mesopic CVA (P < 0.05, under mesopic condition of 100% without glare, with glare, and 25% without glare. Conclusion: CVA impairment was confirmed in RP patients, especially in advanced cases. CVA measured with CAT-2000 may be a useful tool for assessing foveal function in RP patients.

  16. Relationship between Functional Visual Acuity and Useful Field of View in Elderly Drivers.

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    Kazuno Negishi

    Full Text Available To investigate the relationship between the functional visual acuity (FVA and useful field of view (UFOV in elderly drivers and assess the usefulness of the FVA test to screen driving aptitude in elderly drivers.This study included 45 elderly drivers (31 men, 14 women; mean age, 68.1 years and 30 younger drivers (26 men, 4 women; mean age, 34.2 years who drive regularly. All participants underwent measurement of the binocular corrected distant visual acuity (CDVA, binocular corrected distant FVA (CDFVA, and Visual Field with Inhibitory Tasks Elderly Version (VFIT-EV to measure UFOV. The tear function and cognitive status also were evaluated.The CDVA, the CDFVA, cognitive status, and the correct response rate (CAR of the VFIT-EV were significantly worse in the elderly group than in the control group (P = 0.000 for all parameters. The cognitive status was correlated significantly with the CDVA (r = -0.301, P = 0.009, CDFVA (r = -0.402, P = 0.000, and the CAR of the VFIT-EV (r = 0.348, P = 0.002 in all subjects. The results of the tear function tests were not correlated with the CDVA, CDFVA, or VFIT-EV in any subjects. Stepwise regression analysis for all subjects in the elderly and control groups showed that the CDFVA predicted the CAR most significantly among the clinical factors evaluated.The FVA test is a promising method to screen the driving aptitude, including both visual and cognitive functions, in a short time.

  17. On the role of body size, brain size, and eye size in visual acuity.

    Science.gov (United States)

    Corral-López, Alberto; Garate-Olaizola, Maddi; Buechel, Severine D; Kolm, Niclas; Kotrschal, Alexander

    2017-01-01

    The visual system is highly variable across species, and such variability is a key factor influencing animal behavior. Variation in the visual system, for instance, can influence the outcome of learning tasks when visual stimuli are used. We illustrate this issue in guppies ( Poecilia reticulata ) artificially selected for large and small relative brain size with pronounced behavioral differences in learning experiments and mate choice tests. We performed a study of the visual system by quantifying eye size and optomotor response of large-brained and small-brained guppies. This represents the first experimental test of the link between brain size evolution and visual acuity. We found that female guppies have larger eyes than male guppies, both in absolute terms and in relation to their body size. Likewise, individuals selected for larger brains had slightly larger eyes but not better visual acuity than small-brained guppies. However, body size was positively associated with visual acuity. We discuss our findings in relation to previous macroevolutionary studies on the evolution of brain morphology, eye morphology, visual acuity, and ecological variables, while stressing the importance of accounting for sensory abilities in behavioral studies. Pre-existing perceptual biases can be keys for the development of specific behavioral patterns. Hence, potential differences in sensory systems need to be taken into account in the study of animal behavior. We highlight this necessity concentrating on the visual domain and using experimental data on brain size-selected guppies in which we assessed eye size and visual acuity. Behavioral differences between large-brained and small-brained guppies in learning and mate choice predominantly relied on tests using visual cues. Analyses of visual capabilities in this system are therefore necessary. Furthermore, this system offers the unprecedented opportunity to experimentally test the relationship between brain size, eye morphology

  18. 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

  19. 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.

  20. Graded changes in balancing behavior as a function of visual acuity.

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    Schmid, M; Casabianca, L; Bottaro, A; Schieppati, M

    2008-06-02

    In a dynamic postural task, visual information plays a fundamental role in the selection of the balancing strategy. While standing on a platform oscillating in the antero-posterior direction, subjects almost fix their head in space when vision is allowed and oscillate with the platform with eyes closed. We investigated two competing hypotheses regarding the relationship between visual acuity and balance control strategy. One hypothesis refers to the existence of a threshold value of visual acuity as a turning point between the eyes-open and eyes-closed strategy. The other assumes that the change from eyes-open to eyes-closed behavior is continuous and parallels the progressive worsening of visual acuity. Ten subjects balanced on the mobile platform wearing an examination frame and a facemask occluding peripheral vision. Seven different test lenses were used in different trials to modify visual acuity, from a visus value of 10/10 to severely blurred vision. Head stabilization in space progressively worsened with the decrease in visual acuity and turned toward the eyes-closed behavior when vision was blurred. The increase in head oscillation as a function of visual acuity was best fitted by a logarithmic function. In five of the subjects, additional trials were performed without facemask, to add peripheral vision to each visual acuity level, and with black lenses to allow peripheral vision alone. Addition of peripheral vision gave a significant contribution to head stabilization. With peripheral vision alone, head stabilization was intermediate between the eyes-closed and 10/10 visus value condition. We conclude that, in order to stabilize the head in space, visual information of the environment must be definite and worsening of central vision leads to a graded modification of the 'head fixed in space' behavior. Thus, the more conservative hypothesis of two different fundamental balancing strategies is not supported. Instead, the body exhibits a continuous mode of

  1. Visual acuity, residual amblyopia and ocular pathology in a screened population of 12-13-year-old children in Sweden.

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    Ohlsson, J; Villarreal, G; Sjöström, A; Abrahamsson, M; Sjöstrand, J

    2001-12-01

    To establish the distribution of visual acuity and the prevalence of residual amblyopia and other ocular disorders in a vision-screened population group of 12-13-year-old children. In total 1046 children were examined in a field study in Sweden. The examination included visual acuity, stereopsis, cover testing, red reflex, refractive retinoscopy and examination of the posterior pole. In selected cases VEP was also performed. Visual acuity > or =1.0 in at least one eye was present in 98% of cases. Residual amblyopia (albinism was found in 7 cases. In 15 children the cause of subnormal VA was unexplained. Results for visual acuity, residual amblyopia and other ocular disorders are very similar to previous Nordic, vision-screened populations.

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

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    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.

  3. 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

  4. Avaliação da acuidade visual Snellen Snellen visual acuity evaluation

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    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

  5. Strabismus, visual acuity, and uncorrected refractive error in portuguese children aged 6 to 11 years.

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    Lança, Carla; Serra, Helena; Prista, João

    2014-09-01

    Visual anomalies that affect school-age children represent an important public health problem. Data on the prevalence are lacking in Portugal but is needed for planning vision services. This study was conducted to determine the prevalence of strabismus, decreased visual acuity, and uncorrected refractive error in Portuguese children aged 6 to 11 years. A cross-sectional study was carried out on a sample of 672 school-age children (7.69±1.19 years). Children received an orthoptic assessment (visual acuity, ocular alignment, and ocular movements) and non-cycloplegic autorefraction. After orthoptic assessment, 13.8% of children were considered abnormal (n=93). Manifest strabismus was found in 4% of the children. Rates of esotropia (2.1%) were slightly higher than exotropia (1.8%). Strabismus rates were not statistically significant different per sex (p=0.681) and grade (p=0.228). Decreased visual acuity at distance was present in 11.3% of children. Visual acuity≤20/66 (0.5 logMAR) was found in 1.3% of the children. We also found that 10.3% of children had an uncorrected refractive error. Strabismus affects a small proportion of the Portuguese school-age children. Decreased visual acuity and uncorrected refractive error affected a significant proportion of school-age children. New policies need to be developed to address this public health problem.

  6. 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.

  7. Efficacy of neural vision therapy to enhance contrast sensitivity function and visual acuity in low myopia.

    Science.gov (United States)

    Tan, Donald T H; Fong, Allan

    2008-04-01

    To evaluate the efficacy and safety of neural vision enhancement technology (NVC, NeuroVision, Inc.) to improve visual acuity and contrast sensitivity function in eyes with low myopia. Singapore Eye Research Institute, Singapore, Singapore. This noncomparative interventional case series comprised 20 Asian adults between 19 and 53 years of age with low myopia (cycloplegic spherical equivalence [SE] from -0.5 diopter [D] to -1.5 D in the worst eye; astigmatism not exceeding 0.5 D in either eye; uncorrected visual acuity [UCVA] myopia.

  8. Correlation-based evaluation of visual performance to reduce the statistical error of visual acuity.

    Science.gov (United States)

    Fülep, Csilla; Kovács, Illés; Kránitz, Kinga; Erdei, Gábor

    2017-07-01

    Ophthalmologists evaluate visual acuity tests by the number of correctly recognized optotypes (usually letters) in the different lines of an eye chart. This probability-based scoring results in significant statistical error that can only be decreased by the time-consuming analysis of a larger number of optotypes. In this paper, we present a new, more precise correlation-based scoring method that takes the degree of misidentification into consideration too, rather than the mere fact of it. According to our experimental results, this new method decreases the uncertainty error by 28% if using the same number of optotypes at a given letter size or requires half the optotype number to produce the same error as that of probability-based scoring.

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

    African Journals Online (AJOL)

    Background: Visual impairment is usually due to conditions that could be diagnosed and corrected if discovered early. However many cases go undiagnosed. Restoration of sight is among the most cost-effective interventions in health care. Methodology: This is a descriptive cross-sectional study, carried out to determine the ...

  10. Association of Visual Acuity and Cognitive Impairment in Older Individuals: Fujiwara-kyo Eye Study

    Directory of Open Access Journals (Sweden)

    Masashi Mine

    2016-08-01

    Full Text Available Both visual impairment and cognitive impairment are essential factors that determine the quality of life in the aged population. The aim of this study was to determine if a correlation existed between visual acuity and cognitive impairment in an elderly Japanese population. The Fujiwara-kyo Eye Study was a cross-sectional study of individuals aged ≥68 years who lived in Nara Prefecture of Japan. Participants underwent ophthalmological examinations and cognitive function test. A mild visual impairment was defined as having a best corrected visual acuity (BCVA >0.2 logarithm of the minimum angle of resolution (logMAR units in the better eye. Cognitive impairment was defined as having a Mini-Mental State Examination (MMSE score of ≤23 points. A total to 2818 individuals completed the examinations. The mean age of the participants was 76.3 ± 4.8 years (mean ± standard deviation. The mean BCVA of the better eye was −0.02 ± 0.13 logMAR units and 6.6% subjects were classified as being mildly visually impaired. The mean MMSE score was 27.3 ± 2.3 and 5.7% subjects were classified as being cognitively impaired. The proportion of subjects with cognitive or moderate visual impairment increased with age, and there was a significant correlation between the visual acuity and MMSE score (r = −0.10, p < 0.0001. Subjects with mild visual impairments had 2.4 times higher odds of having cognitive impairment than those without visual impairment (odds ratio 2.4, 95% confidence interval, 1.5–3.8, p < 0.001 after adjusting for age, sex, and length of education. We conclude that it may be important to maintain good visual acuity to reduce the risk of having cognitive impairment.

  11. Association of Visual Acuity and Cognitive Impairment in Older Individuals: Fujiwara-kyo Eye Study.

    Science.gov (United States)

    Mine, Masashi; Miyata, Kimie; Morikawa, Masayuki; Nishi, Tomo; Okamoto, Nozomi; Kawasaki, Ryo; Yamashita, Hidetoshi; Kurumatani, Norio; Ogata, Nahoko

    2016-01-01

    Both visual impairment and cognitive impairment are essential factors that determine the quality of life in the aged population. The aim of this study was to determine if a correlation existed between visual acuity and cognitive impairment in an elderly Japanese population. The Fujiwara-kyo Eye Study was a cross-sectional study of individuals aged ≥68 years who lived in Nara Prefecture of Japan. Participants underwent ophthalmological examinations and cognitive function test. A mild visual impairment was defined as having a best corrected visual acuity (BCVA) >0.2 logarithm of the minimum angle of resolution (logMAR) units in the better eye. Cognitive impairment was defined as having a Mini-Mental State Examination (MMSE) score of ≤23 points. A total to 2818 individuals completed the examinations. The mean age of the participants was 76.3 ± 4.8 years (mean ± standard deviation). The mean BCVA of the better eye was -0.02 ± 0.13 logMAR units and 6.6% subjects were classified as being mildly visually impaired. The mean MMSE score was 27.3 ± 2.3 and 5.7% subjects were classified as being cognitively impaired. The proportion of subjects with cognitive or moderate visual impairment increased with age, and there was a significant correlation between the visual acuity and MMSE score (r = -0.10, p visual impairments had 2.4 times higher odds of having cognitive impairment than those without visual impairment (odds ratio 2.4, 95% confidence interval, 1.5-3.8, p education. We conclude that it may be important to maintain good visual acuity to reduce the risk of having cognitive impairment.

  12. Visual acuity and retinal function in patients with Bardet-Biedl syndrome

    Directory of Open Access Journals (Sweden)

    Adriana Berezovsky

    2012-01-01

    Full Text Available OBJECTIVE: Bardet-Biedl syndrome is a genetic, multisystem disorder that causes severe visual impairment. This condition is characterized by retinal dystrophy, obesity, digit anomalies, renal disease, and hypogonadism. The purpose of this study was to analyze visual acuity and full-field electroretinogram findings in patients with the Bardet-Biedl syndrome phenotype. METHODS: The visual acuity of a group of 23 patients (15 males with ages ranging from 6-36 years (mean = 15.8±6.4; median = 14.7 was assessed. Retinal function was evaluated by full-field electroretinography, and dark-adapted thresholds were assessed. RESULTS: Visual acuity in the better-seeing eye was 20/40 or better in 5 patients (21.7%, 20/50-20/150 in 13 (56.5% patients, 20/200-20/400 in 2 (8.7% patients and worse than 20/400 in one (4.3% patient. The mean acuity in the better-seeing eye was 0.7±0.6 logMAR (20/100, Snellen equivalent. Scotopic rod and maximal responses were nondetectable in 21 (91.3% patients, and cone responses were non-detectable in 15 (65.2% patients. Elevated darkadapted visual thresholds were observed in all 19 patients who were able to be assessed, with 10 (52.6% patients having thresholds greater than 30 dB. CONCLUSIONS: In a relatively young cohort of patients with Bardet-Biedl syndrome, only 21% had 20/40 or better vision. ERG scotopic responses were absent in the majority of cases, with cone responses being observed in less than half of cases. These findings showed the early deleterious effects in retinal function and visual acuity caused by this condition.

  13. Significant improvement in dynamic visual acuity after cataract surgery: a promising potential parameter for functional vision.

    Science.gov (United States)

    Ao, Mingxin; Li, Xuemin; Huang, Chen; Hou, Zhiqiang; Qiu, Weiqiang; Wang, Wei

    2014-01-01

    Dynamic visual acuity (DVA) is a relatively independent parameter for evaluating the ability to distinguish details of a moving target. The present study has been designed to discuss the extent to which age-related cataract impacts DVA in elderly individuals and to determine whether it could be restored after bilateral phacoemulsification combined with intraocular lens implantation surgery. Twenty-six elderly cataract patients scheduled for binocular cataract surgery and 30 elderly volunteers without cataract were enrolled in the study. DVA at 15, 30, 60 and 90 degree per second (dps) was assessed, and velocity-dependent visual acuity decreases between consecutive speed levels were calculated. Compared with the control group, the patient group exhibited significantly worse DVA performance at all speed levels (pDVA performance at every speed level in the patient group clearly improved (pDVA was more pronounced than the improvement in static visual acuity (p15 dps = 0.001 and pDVA was more severe than its effects on static visual acuity. After cataract surgery, not only static vision of the patients was restored markedly, but also the dynamic vision. DVA could be an important adjunct to the current evaluation system of functional vision, thereby meriting additional attention in clinical assessment.

  14. Visual acuity, contrast sensitivity, and range performance with compressed motion video

    NARCIS (Netherlands)

    Bijl, P.; Vries, S.C. de

    2010-01-01

    Video of visual acuity (VA) and contrast sensitivity (CS) test charts in a complex background was recorded using a CCD color camera mounted on a computer-controlled tripod and was fed into real-time MPEG-2 compression/decompression equipment. The test charts were based on the triangle orientation

  15. 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.

  16. The incidence and visual acuity outcomes of children identified with ametropic amblyopia by vision screening.

    Science.gov (United States)

    Maqsud, Mohammed Aftab; Arblaster, Gemma E

    2015-04-01

    To determine the incidence of ametropic amblyopia within a vision screening program's population and report the visual acuity outcomes of children identified with the condition. The medical records of children who underwent vision screening as their first assessment at 4-5 years of age between September 1, 2005 and August 31, 2006, were retrospectively reviewed. Children referred with ≤0.30 logMAR in each eye with at least 1 year of follow-up had their hospital notes reviewed and data on final visual acuity, refractive error, and follow-up period collected. A total of 33 children identified as having ametropic amblyopia with a follow-up of at least 1 year. The incidence of ametropic amblyopia was 2%-3.2%, depending on the definition used. The mean visual acuity achieved after treatment was 0.12 logMAR, which is significantly less than the age-appropriate mean of 0.00 logMAR (P amblyopia responds to treatment, but most children demonstrate persistent reduced visual acuity at age 7 years. The incidence of ametropic amblyopia within a routine vision screening population shows that significant numbers fail to self-present. Copyright © 2015 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

  17. A Close Eye on the Eagle-Eyed Visual Acuity Hypothesis of Autism

    Science.gov (United States)

    Bolte, Sven; Schlitt, Sabine; Gapp, Volker; Hainz, Daniela; Schirman, Shella; Poustka, Fritz; Weber, Bernhard; Freitag, Christine; Ciaramidaro, Angela; Walter, Henrik

    2012-01-01

    Autism spectrum disorders (ASD) have been associated with sensory hypersensitivity. A recent study reported visual acuity (VA) in ASD in the region reported for birds of prey. The validity of the results was subsequently doubted. This study examined VA in 34 individuals with ASD, 16 with schizophrenia (SCH), and 26 typically developing (TYP).…

  18. A new test of visual acuity using a holographic phase grating and a laser.

    Science.gov (United States)

    Smith, T W; Remijan, P W; Remijan, W; Kolder, H E; Snyder, J

    1979-04-01

    A new visual acuity testing device is able to determine a specific visual acuity of the retina even in the presence of opacities of the ocular media, such as a cataract. This is achieved by forming two spatially coherent, quasimonochromatic point sources near the nodal point of the eye. The two spherical waves that emanate from the point sources interact to produce a pattern of stripes on the retina. The intensity of the pattern is easily varied. More importantly, the pattern can be projected over different-sized retinal areas corresponding to visual fields of 0.5 to 15 degrees in diameter. The device may be useful for vision research and preoperative assessments of visual potential.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. 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.

  1. Cataract Surgery and Visual Acuity in Elderly Japanese: Results of Fujiwara-kyo Eye Study

    Directory of Open Access Journals (Sweden)

    Kimie Miyata

    2017-04-01

    Full Text Available The aim of this study was to determine the presence of prior cataract surgery and best-corrected visual acuity (BCVA in an elderly Japanese cohort. The Fujiwara-kyo Eye Study was a prospective, population-based, cross-sectional epidemiological study. The subjects were ≥68 years who lived in the Nara Prefecture and responded to recruitment notices. All of the subjects underwent comprehensive ophthalmological examinations, and the sociodemographic information and medical history, including prior cataract surgery, were obtained by answers to a questionnaire. The associations between the BCVA, age, sex, and history of cataract surgery were determined. A total of 2,873 subjects whose mean age was 76.3 ± 4.9 (mean ± standard deviation years were studied. The mean BCVA was −0.020 ± 0.14 logarithm of the minimum angle of resolution units, and it was significantly better in the group with education ≥13 years (p < 0.01. Overall, 24.2% of the subjects had undergone cataract surgery, and 41.7% of the subjects ≥80 years had undergone cataract surgery. The incidence of prior cataract surgery increased with increasing age (p < 0.001 for trend. The mean BCVA of eyes with cataract surgery was significantly better than that of eyes without cataract surgery in subjects ≥80 years (p < 0.01. Visual acuity was generally good in this cohort of elderly Japanese subjects. In this cohort, 24.2% of the subjects had undergone cataract surgery, and the subjects ≥80 years had better BCVA than those without cataract surgery.

  2. MOBILE VISUAL ACUITY ASSESSMENT APPLICATION: AcuMob

    OpenAIRE

    AKBULUT, Akhan; AYDIN, Muhammed Ali; ZAİM, Abdül Halim

    2018-01-01

    This paper presents a mobile healthcare (mHealth) system for estimation of visual impairment that provides easiness by specifying the degree of an eye as orthoscopes. Our proposed system called AcuMob which is an Android based mobile application aimed to be used by patients who have myopia. In the crowd society, our proposed app will be implemented faster than the traditional ophthalmologic examination treatments as an alternative. Because AcuMob can be used in everywhere in any time slot, it...

  3. Impact of visual acuity on developing literacy at age 4–5 years: a cohort-nested cross-sectional study

    Science.gov (United States)

    Bruce, Alison; Fairley, Lesley; Chambers, Bette; Wright, John; Sheldon, Trevor A

    2016-01-01

    Objectives To estimate the prevalence of poor vision in children aged 4–5 years and determine the impact of visual acuity on literacy. Design Cross-sectional study linking clinical, epidemiological and education data. Setting Schools located in the city of Bradford, UK. Participants Prevalence was determined for 11 186 children participating in the Bradford school vision screening programme. Data linkage was undertaken for 5836 Born in Bradford (BiB) birth cohort study children participating both in the Bradford vision screening programme and the BiB Starting Schools Programme. 2025 children had complete data and were included in the multivariable analyses. Main outcome measures Visual acuity was measured using a logMAR Crowded Test (higher scores=poorer visual acuity). Literacy measured by Woodcock Reading Mastery Tests-Revised (WRMT-R) subtest: letter identification (standardised). Results The mean (SD) presenting visual acuity was 0.14 (0.09) logMAR (range 0.0–1.0). 9% of children had a presenting visual acuity worse than 0.2logMAR (failed vision screening), 4% worse than 0.3logMAR (poor visual acuity) and 2% worse than 0.4logMAR (visually impaired). Unadjusted analysis showed that the literacy score was associated with presenting visual acuity, reducing by 2.4 points for every 1 line (0.10logMAR) reduction in vision (95% CI −3.0 to −1.9). The association of presenting visual acuity with the literacy score remained significant after adjustment for demographic and socioeconomic factors reducing by 1.7 points (95% CI −2.2 to −1.1) for every 1 line reduction in vision. Conclusions Prevalence of decreased visual acuity was high compared with other population-based studies. Decreased visual acuity at school entry is associated with reduced literacy. This may have important implications for the children's future educational, health and social outcomes. PMID:26883240

  4. Impact of visual acuity on developing literacy at age 4-5 years: a cohort-nested cross-sectional study.

    Science.gov (United States)

    Bruce, Alison; Fairley, Lesley; Chambers, Bette; Wright, John; Sheldon, Trevor A

    2016-02-16

    To estimate the prevalence of poor vision in children aged 4-5 years and determine the impact of visual acuity on literacy. Cross-sectional study linking clinical, epidemiological and education data. Schools located in the city of Bradford, UK. Prevalence was determined for 11,186 children participating in the Bradford school vision screening programme. Data linkage was undertaken for 5836 Born in Bradford (BiB) birth cohort study children participating both in the Bradford vision screening programme and the BiB Starting Schools Programme. 2025 children had complete data and were included in the multivariable analyses. Visual acuity was measured using a logMAR Crowded Test (higher scores=poorer visual acuity). Literacy measured by Woodcock Reading Mastery Tests-Revised (WRMT-R) subtest: letter identification (standardised). The mean (SD) presenting visual acuity was 0.14 (0.09) logMAR (range 0.0-1.0). 9% of children had a presenting visual acuity worse than 0.2logMAR (failed vision screening), 4% worse than 0.3logMAR (poor visual acuity) and 2% worse than 0.4logMAR (visually impaired). Unadjusted analysis showed that the literacy score was associated with presenting visual acuity, reducing by 2.4 points for every 1 line (0.10logMAR) reduction in vision (95% CI -3.0 to -1.9). The association of presenting visual acuity with the literacy score remained significant after adjustment for demographic and socioeconomic factors reducing by 1.7 points (95% CI -2.2 to -1.1) for every 1 line reduction in vision. Prevalence of decreased visual acuity was high compared with other population-based studies. Decreased visual acuity at school entry is associated with reduced literacy. This may have important implications for the children's future educational, health and social outcomes. 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/

  5. 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

    : The refractive distribution presented a myopic tail (4.5%) and a hyperopic tail (11.9% ≥+2.5 D) as special preterm features, and corneas were more curved. Astigmatism and anisometropia were only marginally increased, and visual acuities were generally good. Best-corrected binocular median logMAR visual acuity...

  6. 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

  7. Automatic Conflict Monitoring by Event-Related Potentials Could be used to Estimate Visual Acuity Levels.

    Science.gov (United States)

    Huang, Wenwen; Liu, Sinan; Luo, Bin; Meng, Huanhuan; Ji, Mengmeng; Li, Maojuan; Chen, Xiping; Tao, Luyang

    2018-03-15

    Numerous studies have explored the physical attribute features or face perceptions in conflict processing, while complicate gradient conflicts were rarely discussed. The aim of the study was to discuss the relationship between the event-related potential (ERP) component features and different visual acuity levels by using the modified S1-S2 task under non-attention status. Three visual acuity levels were applied, each with four orientations of "E" optotype stimuli randomly presented in the center of the visual field while participants were required to concentrate on listening to stories. The results showed that the amplitudes of P1 and P3 as well as difference P3 were larger in supra-threshold condition. In threshold condition, larger amplitudes for both N2 and difference N2 exhibited in frontal and central areas. In sub-threshold condition, there was no endogenous component elicited by mismatch stimuli except smaller anterior N1. Meanwhile, the specific distributions of N1 and N2 were presented and compared with previous face processing. The findings showed that visual conflict processing took place not only at an early stage but also at the late period, which might be as the consequences of interaction between conflict strength and involuntary attention. We concluded that automatic conflict detecting of visual icons by the serial ERP components could distinguish different visual acuity levels. The involvement of endogenous components could reveal the specific mechanism of more precise and fine conflict identification of complex physical attributes under non-attention status, furthermore could be used as valid markers to estimate the magnitude of visual acuity objectively. Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.

  8. 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.

  9. Significant improvement in dynamic visual acuity after cataract surgery: a promising potential parameter for functional vision.

    Directory of Open Access Journals (Sweden)

    Mingxin Ao

    Full Text Available PURPOSE: Dynamic visual acuity (DVA is a relatively independent parameter for evaluating the ability to distinguish details of a moving target. The present study has been designed to discuss the extent to which age-related cataract impacts DVA in elderly individuals and to determine whether it could be restored after bilateral phacoemulsification combined with intraocular lens implantation surgery. METHODS: Twenty-six elderly cataract patients scheduled for binocular cataract surgery and 30 elderly volunteers without cataract were enrolled in the study. DVA at 15, 30, 60 and 90 degree per second (dps was assessed, and velocity-dependent visual acuity decreases between consecutive speed levels were calculated. RESULTS: Compared with the control group, the patient group exhibited significantly worse DVA performance at all speed levels (p<0.001, and the decreases in velocity-dependent visual acuity were more serious in the patient group at the intervals of 0-15 dps (p<0.001, 15-30 dps (p = 0.007 and 30-60 dps (p = 0.008. Postoperatively, DVA performance at every speed level in the patient group clearly improved (p<0.001 and recovered to levels compatible to the control group. The decrease in visual acuity with increasing speed was less pronounced than during the preoperative phase (p0-15 dps = 0.001, p15-30 dps<0.001 and p30-60 dps = 0.001 and became similar to that of the control group. The postoperative visual benefit regarding DVA was more pronounced than the improvement in static visual acuity (p15 dps = 0.001 and p<0.001 at 30 dps, 60 dps and 90 dps. CONCLUSIONS: The impact of age-related cataract on DVA was more severe than its effects on static visual acuity. After cataract surgery, not only static vision of the patients was restored markedly, but also the dynamic vision. DVA could be an important adjunct to the current evaluation system of functional vision, thereby meriting additional attention in clinical assessment.

  10. 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.

  11. Relationship between Body Mass Index, Blood Pressure, and Visual Acuity in Residents of Esan West Local Government Area of Edo State, Nigeria

    Directory of Open Access Journals (Sweden)

    I. O. Ernest-Nwoke

    2014-01-01

    Full Text Available Aim. To study the relationship between body mass index (BMI and blood pressure (BP on visual acuity among apparently healthy residents of Ekpoma, Esan West Local Government Area of Edo State, Nigeria. Methodology. This is a cross-sectional descriptive study among 225 subjects (ages of 18–35 years from whom BP, body weight, and height were collected. Visual acuity was measured using the Snellen chart following standard procedures of number of letters seen at 6-metre distance. The data were then analyzed using SPSS version 17. Results. The sampled population consists of 112 male and 113 female (mean age 31.72±14.2 years. Majority (180 of the respondents had normal visual acuity. However, compared with the respondents with normal BMI (R19.61±1.5; L19.67±1.70, visual acuity of underweight (R18.53±2.30; L18.53±2.70 and obese (R15.68±4.79; L17.73±1.70 were more deviated. Similarly, compared with respondent with normal BP (120–125/80–85 mmHg; R18.00±2.53; L18.07±3.11, hypotensive (R15.5±7.35; L15.00±10.20, and hypertensive (R15.01±21.25; L15.00±11.91 respondents had deviated visual acuity. Conclusion. Abnormal body weight (underweight and obese and BP (hypotension and hypertension have potential negative impacts on visual acuity. Based on the observed relationship between weights, BP, and visual acuity, eye examinations can be included as regular screening exercise for abnormal BMI and BP conditions.

  12. REPRODUCIBILITY AND COMPARISON OF VISUAL ACUITY OBTAINED WITH SIGHTBOOK MOBILE APPLICATION TO NEAR CARD AND SNELLEN CHART.

    Science.gov (United States)

    Phung, Lam; Gregori, Ninel Z; Ortiz, Angelica; Shi, Wei; Schiffman, Joyce C

    2016-05-01

    To investigate test-retest reproducibility of visual acuities obtained with a popular mobile application (app) and to explore the agreement with the standard clinic charts. Records of patients who had visual acuity measured during the same routine clinic visit with Snellen chart, Rosenbaum near vision card, and SightBook mobile app were reviewed. Acuities were converted to approximate ETDRS letters for statistical purposes. One hundred and twenty-six patients were identified. SightBook, Snellen, and near card acuities had excellent test-retest reproducibility. SightBook acuities were significantly different from the near card acuities (mean absolute difference of 5.4 and 6.1 letters in the right and left eyes) and the Snellen acuities (mean absolute difference of 7.7 and 7.9 letters in the right and left eyes). The agreement was also poor between the near card and the Snellen acuities (mean absolute difference of 6.4 and 7.6 letters in the right and left eyes). The discrepancy between SightBook mobile app and the clinic charts acuities may be large; however, the results are highly reproducible. Obtaining baseline SightBook acuity allows future vision comparisons. SightBook mobile app offers a new portable vision assessment tool for the office and remote patient monitoring.

  13. Visual acuity and nystagmus following strabismus surgery in patients with oculocutaneous albinism.

    Science.gov (United States)

    Villegas, Victor M; Díaz, Lilliam; Emanuelli, Andres; Izquierdo, Natalio J

    2010-12-01

    To evaluate the effect of strabismus surgery on nystagmus and visual acuity in patients with oculocutaneous albinism. We conducted a non-concurrent retrospective study of 13 Puerto Rican patients with all types of oculocutaneous albinism who underwent strabismus surgery. Patients underwent genetic linkage analysis to reach a final oculocutaneous albinism classification prior to surgery. Strabismus surgery was modified by under-correction of 0.5 mm in each muscle from the standard Marshall Parks' measurements in all patients. Six of the 13 patients with oculocutaneous reported an improved best corrected visual acuity after surgery. Two of the 13 patients with oculocutaneous had no nystagmus following strabismus surgery. All patients were orthotropic following surgery. Strabismus surgical undercorrection may be of benefit in patients with oculocutaneous albinism.

  14. Evaluation of the degree of turbidity of cataract lens and its correlation with retinal visual acuity

    Science.gov (United States)

    Akchurin, Garif G.; Bakutkin, Valery V.; Zimnyakov, Dmitry A.; Radchenko, Elena Y.; Tuchin, Valery V.; Akchurin, Alexander G.

    1999-06-01

    Experimental in vitro studies of speckle-modulated laser field arising after transmission through different type of human cataractous lenses are presented. Computer analysis of digital imaging has allowed to determinate the degree of destruction of spatial coherence scattered laser beam and the angle of resolution of the retina using Retinal Analyzer of Vision (AROL-1) in diagnosis of cataract. Measurement of retinal visual acuity (RVA) in 135 patient with different types of cataract (senile, complicated, posterior capsular) before and after cataract extraction and also in vitro measurement of RVA with extracted cataractal lenses has shown that laser retinometer can be used for evaluating visual acuity within 0.3 - 1, practically for all types of cataracts.

  15. 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.

  16. A phytochemical-rich diet may explain the absence of age-related decline in visual acuity of Amazonian hunter-gatherers in Ecuador.

    Science.gov (United States)

    London, Douglas S; Beezhold, Bonnie

    2015-02-01

    Myopia is absent in undisturbed hunter-gatherers but ubiquitous in modern populations. The link between dietary phytochemicals and eye health is well established, although transition away from a wild diet has reduced phytochemical variety. We hypothesized that when larger quantities and greater variety of wild, seasonal phytochemicals are consumed in a food system, there will be a reduced prevalence of degenerative-based eye disease as measured by visual acuity. We compared food systems and visual acuity across isolated Amazonian Kawymeno Waorani hunter-gatherers and neighboring Kichwa subsistence agrarians, using dietary surveys, dietary pattern observation, and Snellen Illiterate E visual acuity examinations. Hunter-gatherers consumed more food species (130 vs. 63) and more wild plants (80 vs. 4) including 76 wild fruits, thereby obtaining larger variety and quantity of phytochemicals than agrarians. Visual acuity was inversely related to age only in agrarians (r = -.846, P .05). This unusual absence of juvenile-onset vision problems may be related to local, organic, whole food diets of subsistence food systems isolated from modern food production. Our results suggest that intake of a wider variety of plant foods supplying necessary phytochemicals for eye health may help maintain visual acuity and prevent degenerative eye conditions as humans age. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. 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.

  18. Analysis of visual acuity before and after refraction in people over 50 in ophthalmic outpatients

    Directory of Open Access Journals (Sweden)

    Dan Shui

    2013-08-01

    Full Text Available AIM: To investigate the visual acuity of people over 50 years in ophthalmic clinic and visual impairment before and after refractive correction.METHODS: Totally 149 cases(298 eyesof refractive error were examined and corrected using autorefractor and retinal optometry. The information of age, sex, economy, income and living standard were collected by questionnaire.RESULTS: Out of 149 cases(298 eyes, 281 eyes(98.6%had refractive error. 119 eyes(42.3%had myopia, 94 eyes(33.5%had hyperopia and 68 eyes(24.2%had mixed astigmatism. The mean visual acuity was 0.42±0.21 and 0.63±0.32 respectively before and after correction. Corrected visual impairment was in 186 eyes(65.3%. Old age, low education, low income and rural area were risk factors for visual impairment. CONCLUSION: Uncorrected refractive error is an important cause of visual impairment in elderly people. It can be promoted by refractive correction, which may benefit for their living quality.

  19. Change in visual acuity in albinism in the early school years.

    Science.gov (United States)

    Dijkstal, Johanna M; Cooley, San-San; Holleschau, Ann M; King, Richard A; Summers, C Gail

    2012-01-01

    To determine whether binocular best-corrected visual acuity (B-BCVA) improves in the early school years in patients with albinism and whether this is related to type of albinism, ocular pigment, or appearance of the macula. Patients with albinism seen between 5.5 and 9 years (Visit A) and 9.5 and 14 years of age (Visit B), with visits separated by at least 2.5 years, were included. Type of albinism, B-BCVA, glasses wear, iris pigment and macular transparency grade, and presence or absence of an annular reflex and melanin in the macula were recorded. Mean B-BCVA was 20/84 at Visit A and 20/61 at Visit B (P albinism in the early school years and this observation should be included in counseling. The etiology is unknown but may be related to change in nystagmus, use of precise null point, developmental maturation, and/or some of the ocular characteristics evaluated in this study. Copyright 2012, SLACK Incorporated.

  20. 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...... tomography was used to assess central foveal thickness, central photoreceptor layer thickness (CPRT), central photoreceptor layer discontinuity (PRD) and relative reflectivity of the outer nuclear layer. Outcomes were correlated with best corrected visual acuity (BCVA) 12 months after surgery. Results: BCVA...

  1. Real-time computer-based visual feedback improves visual acuity in downbeat nystagmus ? a pilot study

    OpenAIRE

    Teufel, Julian; Bardins, S.; Spiegel, Rainer; Kremmyda, O.; Schneider, E.; Strupp, M.; Kalla, R.

    2016-01-01

    BACKGROUND Patients with downbeat nystagmus syndrome suffer from oscillopsia, which leads to an unstable visual perception and therefore impaired visual acuity. The aim of this study was to use real-time computer-based visual feedback to compensate for the destabilizing slow phase eye movements. METHODS The patients were sitting in front of a computer screen with the head fixed on a chin rest. The eye movements were recorded by an eye tracking system (EyeSeeCam®). We tested the vi...

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. A close eye on the eagle-eyed visual acuity hypothesis of autism.

    Science.gov (United States)

    Bölte, Sven; Schlitt, Sabine; Gapp, Volker; Hainz, Daniela; Schirman, Shella; Poustka, Fritz; Weber, Bernhard; Freitag, Christine; Ciaramidaro, Angela; Walter, Henrik

    2012-05-01

    Autism spectrum disorders (ASD) have been associated with sensory hypersensitivity. A recent study reported visual acuity (VA) in ASD in the region reported for birds of prey. The validity of the results was subsequently doubted. This study examined VA in 34 individuals with ASD, 16 with schizophrenia (SCH), and 26 typically developing (TYP). Participants with ASD did not show higher VA than those with SCH and TYP. There were no substantial correlations of VA with clinical severity in ASD or SCH. This study could not confirm the eagle-eyed acuity hypothesis of ASD, or find evidence for a connection of VA and clinical phenotypes. Research needs to further address the origins and circumstances associated with altered sensory or perceptual processing in ASD.

  8. 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

  9. Automated Measurement of Visual Acuity in Pediatric Ophthalmic Patients Using Principles of Game Design and Tablet Computers

    OpenAIRE

    Aslam, Tariq M; Tahir, Humza J; Parry, Neil R A; Murray, Ian J; Kwak, Kun; Heyes, Richard; Salleh, Mahani M; Czanner, Gabriela; Ashworth, Jane

    2016-01-01

    PURPOSE: To report on the utility of a computer tablet-based method for automated testing of visual acuity in children based on the principles of game design. We describe the testing procedure and present repeatability as well as agreement of the score with accepted visual acuity measures.DESIGN: Reliability and validity study.METHODS: Setting: Manchester Royal Eye Hospital Pediatric Ophthalmology Outpatients Department.PATIENT POPULATION: Total of 112 sequentially recruited patients.INTERVEN...

  10. Reliability and validity of an automated computerized visual acuity and stereoacuity test in children using an interactive video game.

    Science.gov (United States)

    Ma, Dae Joong; Yang, Hee Kyung; Hwang, Jeong-Min

    2013-07-01

    To evaluate the test-retest reliability and validity of the new automated computerized distance visual acuity and stereoacuity test for children, which uses an interactive video game. Retrospective, observational case series. A total of 102 children aged between 3 and 7 years underwent the Snellen visual acuity test, the Distance Randot Stereotest, and the new automated computerized distance visual acuity and stereoacuity test. The test-retest reliability and validity of the automated computerized tests were assessed and compared with the Snellen visual acuity test and the Distance Randot Stereotest with frequency distributions of the differences, Bland-Altman plots, and Deming regression. The automated computerized distance visual acuity test had high test-retest reliability (95% limits of agreement ±0.18 logMAR, 90.0% of the differences within 0.2 logMAR) and acceptable validity as compared with the Snellen visual acuity chart (95% limits of agreement ±0.27 logMAR, 81.3% of the differences within 0.2 logMAR). The automated computerized distance stereoacuity test had high test-retest reliability (95% limits of agreement ±0.29 log arc second, 95.1% of the differences within 0.3 log arc second) and acceptable validity as compared with the Distance Randot Stereotest (95% limits of agreement ±0.35 log arc second, 93.9% of the differences within 0.3 log arc second). The new automated computerized distance visual acuity and stereoacuity test, which uses an interactive video game, has good reliability and acceptable validity compared with the Snellen visual acuity chart and the Distance Randot Stereotest. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. Comparison of binocular through-focus visual acuity with monovision and a small aperture inlay

    Science.gov (United States)

    Schwarz, Christina; Manzanera, Silvestre; Prieto, Pedro M.; Fernández, Enrique J.; Artal, Pablo

    2014-01-01

    Corneal small aperture inlays provide extended depth of focus as a solution to presbyopia. As this procedure is becoming more popular, it is interesting to compare its performance with traditional approaches, such as monovision. Here, binocular visual acuity was measured as a function of object vergence in three subjects by using a binocular adaptive optics vision analyzer. Visual acuity was measured at two luminance levels (photopic and mesopic) under several optical conditions: 1) natural vision (4 mm pupils, best corrected distance vision), 2) pure-defocus monovision ( + 1.25 D add in the nondominant eye), 3) small aperture monovision (1.6 mm pupil in the nondominant eye), and 4) combined small aperture and defocus monovision (1.6 mm pupil and a + 0.75 D add in the nondominant eye). Visual simulations of a small aperture corneal inlay suggest that the device extends DOF as effectively as traditional monovision in photopic light, in both cases at the cost of binocular summation. However, individual factors, such as aperture centration or sensitivity to mesopic conditions should be considered to assure adequate visual outcomes. PMID:25360355

  12. 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 ...

  13. 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).

  14. Virtually controlled computerised visual acuity screening in a multilingual Indian population.

    Science.gov (United States)

    Sreelatha, Omana Keasry; Ramesh, S Ve; Jose, Judy; Devassy, Mredulla; Srinivasan, Krithica

    2014-01-01

    The efficacy of tele-based (virtually monitored) visual acuity (VA) examination in a hospital-based multilingual population was assessed based on subjects from the Outpatient Department of Optometry, School of Allied Health Sciences, Manipal University and Department of Ophthalmology, Kasturba Medical College, Manipal, India. Visual acuity measurement using a computerized VA chart (COMPlog) was done using a telemethod and face-to-face method in a randomized fashion for all subjects. Virtual (remotely operated) control of examination procedure and video-conferencing helped the optometrist positioned elsewhere (different physical location) to remotely operate the COMPlog VA chart and also interact with the subjects. The connection was facilitated using Lync software connected through local area network connections. During tele-examination, instructions were given on subject's language preference (Kannada, Malayalam or English). Mean age of 96 subjects (three language groups) was 40.3±14.1 years and a Bland-Altman plot showed good agreement with clinically acceptable limits of agreement. The mean difference in VA between the telemethod and face-to-face method was 0.00 logMAR (±0.16), p=0.844. Two methods had good intra-class correlation (0.912, 95% confidence interval 0.868-0.941) and had good agreement across the language groups (kappa>0.7). Visual acuity measurements using the telemethod along with native dialect was comparable to conventional face-to-face method in a hospital-based multilingual population. Digital VA testing systems along with communication in native dialect can be effectively integrated into a tele-eyecare model.

  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. 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.

  17. 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.

  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. Reduced response cluster size in early visual areas explains the acuity deficit in amblyopia.

    Science.gov (United States)

    Huang, Yufeng; Feng, Lixia; Zhou, Yifeng

    2017-05-03

    Focal visual stimulation typically results in the activation of a large portion of the early visual cortex. This spread of activity is attributed to long-range lateral interactions. Such long-range interactions may serve to stabilize a visual representation or to simply modulate incoming signals, and any associated dysfunction in long-range activation may reduce sensitivity to visual information in conditions such as amblyopia. We sought to measure the dispersion of cortical activity following local visual stimulation in a group of patients with amblyopia and matched normal. Twenty adult anisometropic amblyopes and 10 normal controls participated in this study. Using a multifocal stimulation, we simultaneously measured cluster sizes to multiple stimulation points in the visual field. We found that the functional MRI (fMRI) response cluster size that corresponded to the fellow eye was significantly larger as opposed to that corresponding to the amblyopic eye and that the fMRI response cluster size at the two more central retinotopic locations correlated with amblyopia acuity deficit. Our results suggest that the amblyopic visual cortex has a diminished long-range communication as evidenced by significantly smaller cluster of activity as measured with fMRI. These results have important implications for models of amblyopia and approaches to treatment.

  20. Automated Measurement of Visual Acuity in Pediatric Ophthalmic Patients Using Principles of Game Design and Tablet Computers.

    Science.gov (United States)

    Aslam, Tariq M; Tahir, Humza J; Parry, Neil R A; Murray, Ian J; Kwak, Kun; Heyes, Richard; Salleh, Mahani M; Czanner, Gabriela; Ashworth, Jane

    2016-10-01

    To report on the utility of a computer tablet-based method for automated testing of visual acuity in children based on the principles of game design. We describe the testing procedure and present repeatability as well as agreement of the score with accepted visual acuity measures. Reliability and validity study. Setting: Manchester Royal Eye Hospital Pediatric Ophthalmology Outpatients Department. Total of 112 sequentially recruited patients. For each patient 1 eye was tested with the Mobile Assessment of Vision by intERactIve Computer for Children (MAVERIC-C) system, consisting of a software application running on a computer tablet, housed in a bespoke viewing chamber. The application elicited touch screen responses using a game design to encourage compliance and automatically acquire visual acuity scores of participating patients. Acuity was then assessed by an examiner with a standard chart-based near ETDRS acuity test before the MAVERIC-C assessment was repeated. Reliability of MAVERIC-C near visual acuity score and agreement of MAVERIC-C score with near ETDRS chart for visual acuity. Altogether, 106 children (95%) completed the MAVERIC-C system without assistance. The vision scores demonstrated satisfactory reliability, with test-retest VA scores having a mean difference of 0.001 (SD ±0.136) and limits of agreement of 2 SD (LOA) of ±0.267. Comparison with the near EDTRS chart showed agreement with a mean difference of -0.0879 (±0.106) with LOA of ±0.208. This study demonstrates promising utility for software using a game design to enable automated testing of acuity in children with ophthalmic disease in an objective and accurate manner. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Clinical evaluation of dynamic visual acuity in subjects with unilateral vestibular hypofunction.

    Science.gov (United States)

    Dannenbaum, Elizabeth; Paquet, Nicole; Chilingaryan, Gevorg; Fung, Joyce

    2009-04-01

    The objectives of this study are threefold: 1) to examine the effect of frequency of head motion on the clinical dynamic visual acuity (DVA) score in subjects with unilateral vestibular hypofunction (UVH); 2) to compare DVA scores between subjects with UVH and subjects with a complete unilateral vestibular deficit; and 3) to establish whether a relationship exists between the extent of the vestibular deficit and the DVA score. Experimental study. Vestibular outpatient rehabilitation program. A convenience sample of 10 subjects with UVH. Dynamic visual acuity scores were recorded using 2 standard acuity charts: Snellen and E-chart. The DVA scores were obtained at slow (0.5 Hz), moderate (1 and 1.5 Hz), and fast (2.0 Hz) frequencies of head motion in the horizontal and the vertical planes. Percentage of caloric weakness was compared with DVA scores in each subject to test whether a relationship exists between the two. As the frequency of head motion increased, the number of UVH subjects with an abnormal DVA score increased. Subjects with an abnormal DVA score at 1 Hz had the same or higher score as the frequency of the head motion was increased. Spearman correlation analyses revealed low-correlation coefficients between percentage of vestibular paresis at the caloric test and DVA scores (horizontal direction: r = 0.31, p = 0.38 for Snellen chart and r = -0.33, p = 0.35 for the E-chart; vertical: r = 0.05, p = 0.91 for the Snellen chart and r = -0.28, p = 0.50 for the E-chart). Subjects with UVH manifest impaired DVA. The frequency of head motion has an impact on clinical DVA scores in UVH subjects.

  2. Feasibility of the clinical dynamic visual acuity test in typically developing preschoolers.

    Science.gov (United States)

    Verbecque, Evi; De Belder, Niels; Marijnissen, Tessa; Vereeck, Luc; Van de Heyning, Paul; Hallemans, Ann

    2018-02-28

    To determine the feasibility of the dynamic visual acuity test (DVA) in children who are preschoolers. Thirty-three preschoolers [3 years old (n = 11), 4 years old (n = 6), 5 years old (n = 8), and 6 years old (n = 8)], performed a static visual acuity test (SVA), a passive horizontal DVA (hDVA) at 1 and 2 Hz, and a DVA on treadmill at three age-specific walking speeds (slow/medium/high). The DVA scores, the difference between SVA and hDVA, were used to determine false positive results. The SVA was performed by 31/33 children, the hDVA and DVA on treadmill at slow and medium speed by 27/33 and the DVA on treadmill at high speed by 25/33. Except for one 5 years old, all drop-outs were 3 years old. The hDVA at 2 Hz was administered in only six children because of difficulties with focusing on reading the symbols at this frequency. False positive results for the hDVA at 1 Hz were found in 3/27 children, all 3 years old, and 2/6 for the hDVA at 2 Hz. The DVA on treadmill seems useful for preschoolers from age 5, but this should be further investigated in children with underlying pathologies.

  3. The effects of drift and displacement motion on Dynamic Visual Acuity

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    Scott Sinnett

    2005-01-01

    Full Text Available Dynamic Visual Acuity (DVA can be measured from two types of equivalently considered movement referred to as drifting-motion and displacement-motion. Displacement motion can be best described as the horizontal displacement of a stimulus, thus implying pursuit eye movements, and involves moving the stimulus from the fixation point of gaze towards the periphery. The drifting motion of a Gabor patch, for example, avoids pursuit eye movements, since the gaze is fixed in a point of the patch. Our data shows that in both types of movement visual acuity (VA, expressed in terms of spatial frequency, diminished as the velocity of the target increased. However, the slope of the regression equation indicated that this impairment is more than two-fold in the case of drifting-motion when compared to displacement motion. As the greater impairment took place when pursuit eye movements did not exist, our data suggests that these two types of motions correct differently for retinal slip. Retinal slip appears to be less efficiently compensated for in the case of drifting motion having adverse consequences on VA, while retinal slip has a higher tolerance in the case of displacement motion exhibited by the performance in VA.

  4. Long-term Visual Acuity, Strabismus, and Nystagmus Outcomes Following Multimodality Treatment in Group D Retinoblastoma Eyes.

    Science.gov (United States)

    Fabian, Ido D; Naeem, Zishan; Stacey, Andrew W; Chowdhury, Tanzina; Duncan, Catriona; Reddy, M Ashwin; Sagoo, Mandeep S

    2017-07-01

    To analyze the long-term visual acuity, strabismus, and nystagmus outcomes in Group D retinoblastoma following multimodality treatments in a national retinoblastoma referral center. Retrospective interventional case series. A 13-year retrospective chart review of Group D eyes treated initially with intravenous chemotherapy (IVC) and followed up for at least 1 year from last treatment. Risk factors for final visual acuity (VA) were analyzed, and rate of strabismus and nystagmus at last follow-up visit were calculated. One hundred and four Group D eyes (92 patients) presented to our center during the study period, of which 32 (27 patients) met the inclusion criteria. Following IVC (vincristine, etoposide, and carboplatin), adjuvant treatments included intraophthalmic artery chemotherapy in 5 (16%) eyes, plaque brachytherapy in 5 (16%), transpupillary thermotherapy (TTT) in 18 (56%), and cryotherapy in 24 (75%) eyes. On last examination, 64.41 ± 6.76 months from presentation, mean final VA was 20/283 (logMAR equivalent of 1.15 ± 0.15). On univariate analysis, presentation age, foveal retinoblastoma (at initial examination), use of TTT, and tumor-foveola distance (at last visit) were found to be significant risk factors for worse VA (P retinoblastoma eyes had <20/200 vision, with TTT being a risk factor for worse vision; 60% had strabismus; and 22% had nystagmus. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. 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

    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...

  6. "A retrospective cohort study for prognostic significance of visual acuity for near over that for distance in anisometropic amblyopia.".

    Directory of Open Access Journals (Sweden)

    Singh Vinita

    1992-01-01

    Full Text Available A cohort of 50 anisometropic amblyopes, between the ages of 2.5 to 10 years, was studied retrospectively to assess the prognostic significance of visual acuity for near over that for distance. There is ample evidence in the literature for a significantly lower accommodative response in the anisometropic amblyopic eye. It has been proposed that the efferent accommodative dysfunction may be a fundamental and causative factor in anisometropic amblyopia. A reduced visual acuity for near over that for distance was found in 17 [34%] patients and in 11 out of these the near vision improved after an addition of +3.0D sph. When a reduced visual acuity for near, was obtained it was difficult to determine whether the visual afferent system (due to insufficient visual input, or the accommodation efferent mechanism was responsible. However an improvement in corrected near vision by addition of +3.0D sph. suggested an accommodative dysfunction. In patients with reduced visual acuity for near over that for distance, not only was the final visual outcome poor but also the onset of visual improvement in response to amblyopia therapy was delayed.

  7. Cerebral Visual Impairment in Children: A Longitudinal Case Study of Functional Outcomes beyond the Visual Acuities

    Science.gov (United States)

    Lam, Fook Chang; Lovett, Fiona; Dutton, Gordon N.

    2010-01-01

    Damage to the areas of the brain that are responsible for higher visual processing can lead to severe cerebral visual impairment (CVI). The prognosis for higher cognitive visual functions in children with CVI is not well described. We therefore present our six-year follow-up of a boy with CVI and highlight intervention approaches that have proved…

  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. [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)

  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. Comparison of contrast sensitivity and visual acuity between deep anterior lamellar keratoplasty and penetrating keratoplasty in patients with keratoconus

    Directory of Open Access Journals (Sweden)

    Mehmet Orcun Akdemir

    2012-12-01

    Full Text Available AIM: To evaluate postoperative visual acuity and contrast sensitivity results following deep anterior lamellar keratoplasty (DALK and penetrating keratoplasty (PK in patients with keratoconus (KC. METHODS: All the patients’ records with KC who had PK or DALK surgery between May 2010 and May 2011 were retrospectively reviewed. Sixty patients who underwent successful corneal transplantation for KC: 30 eyes underwent DALK and 30 eyes underwent PK were included in this study. Preoperative and postoperative mean logarithm of the minimum angle of resolution (logMAR uncorrected visual acuity (UCVA, logMAR best spectacle-corrected visual acuity (BSCVA and intraocular pressure (IOP were evaluated. Contrast sensitivity tests (CS were done preoperative and 2 months after all sutures had removed. All surgeries were performed under regional anesthesia (retrobulbar anesthesia by 1 surgeon (B.K. who was experienced in penetrating and lamellar keratoplasty techniques.RESULTS: The mean age of the DALK group was 29.67±4.95 (range 18-40 years and the PK group was 28.7±3.53 (range 18-39 years. Preoperatively there was no significant difference in the logMAR UCVA, logMAR BSCVA and IOP between the DALK (1.281±0.56; 0.97±0.85; 12.07±2.12mmHg and PK (1.34±0.21; 0.98±0.21; 13±2.12mmHg groups. One-year after surgery there was no significant difference in the mean logMAR UCVA and IOP between the DALK (0.46±0.37; 11.73±2.1mmHg and PK (0.38±0.21; 12±2.12mmHg groups. The mean contrast sensitivity was evaluated by CC-100 Topcon LCD at 1.5, 2.52, 4.23, 7.10 and 11.91 cycles per degree (cs/deg spatial frequencies before and 2 months after the all sutures had removed. CONCLUSION: All patients with keratoconus in both DALK and PK groups performed good visual function postoperatively. The mean contrast sensitivity increased considerably at all spatial frequencies compared with preoperative levels in the DALK and PK groups. The mean post-operative evaluation of

  12. Visual Acuity Changes during Pregnancy and Postpartum: A Cross-Sectional Study in Iran

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    Khashayar Mehdizadehkashi

    2014-01-01

    Full Text Available In this research, we represent the changes in visual acuity during pregnancy and after delivery. Changes as myopic shift start during second trimester and will be stopped after delivery; however it is obtained that women will have the same refractive error as what they had in the first trimester, after postpartum. So, any change in their spectacle prescription during this period is forbidden. As a result, not only changing in hormones can cause myopic shift in vision, but also overweight has its retributive role. What we are trying to do is to notify gynecologists and optometrists to be aware of these changes, so as to leave spectacle prescription writing to the session after postpartum period.

  13. Visual acuity changes during pregnancy and postpartum: a cross-sectional study in Iran.

    Science.gov (United States)

    Mehdizadehkashi, Khashayar; Chaichian, Shahla; Mehdizadehkashi, Abolfazl; Jafarzadepour, Ebrahim; Tamannaie, Zeinab; Moazzami, Bahram; Pishgahroudsari, Mohaddeseh

    2014-01-01

    In this research, we represent the changes in visual acuity during pregnancy and after delivery. Changes as myopic shift start during second trimester and will be stopped after delivery; however it is obtained that women will have the same refractive error as what they had in the first trimester, after postpartum. So, any change in their spectacle prescription during this period is forbidden. As a result, not only changing in hormones can cause myopic shift in vision, but also overweight has its retributive role. What we are trying to do is to notify gynecologists and optometrists to be aware of these changes, so as to leave spectacle prescription writing to the session after postpartum period.

  14. 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

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

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    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. Test–retest reliability of contrast visual acuities in a clinical population

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    Anusha Y. Sukha

    2017-03-01

    Full Text Available Background: Previously, contrast visual acuities (VA have been evaluated as a potential screening, diagnostic and predictive tool in cases where standard visual acuity remains intact. Issues around contrast acuity sometimes make it difficult for clinicians to make appropriate clinical decisions and thus such tests have to be standardised and reliable. Aim: To investigate test–retest reliability of contrast VA in healthy adults in a clinical setting. Methods: Best compensated contrast VA at 100%, 10%, 5% and 2.5% of 155 patients (mean age 39.7 ± 12.2 years were measured using the computerised Thomson Test Chart 2000 Expert. For all participants and at each contrast level, two measurements per right eye were determined. Test–retest reliability for the four contrast levels were assessed using reliability coefficients and Bland–Altman plots. Participants were also divided into three age groups of young (18–39 years, n = 72, middle-age (40–49 years, n = 45 and elderly (50–67 years, n = 38 and reliability was assessed within and between age and gender groups. Results: For the whole-sample test and retest, measurements within each contrast level were not statistically different (p ≥ 0.05. Thus, test and retest measurements per participant were averaged and whole-sample mean-contrast VA and standard deviations for 100%, 10%, 5% and 2.5% were -0.146 ± 0.060, 0.050 ± 0.071, 0.135 ± 0.079 and 0.405 ± 0.115 logMAR, respectively. Significant differences were found between all pairs of contrast levels compared (p ≤ 0.0125. Mean-contrast VA within each age group were also significantly different across all contrast levels (p 0.05 but were statistically different between the young and elderly groups (p < 0.01. Only mean-contrast VA 10% was significantly different between the middle-age and elderly groups (p < 0.001. Also, mean-contrast VA for the four contrast levels within gender were significantly different (p ≤ 0.05 but not between

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

    Directory of Open Access Journals (Sweden)

    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.

  18. The Correlation of Age and Postoperative Visual Acuity for Age-Related Cataract

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    Xiaochun Li

    2016-01-01

    Full Text Available Purpose. Clinically, what is the best time for age-related cataract (ARC patients to receive surgeries and get the most benefits is important. We explored the relationship between age and presenting postoperative visual acuity (POVA in patients from rural China. Methods. Three Lifeline Express Hospital Eye-Train missions of Peking University People’s Hospital were chosen. At the first day after surgery, 3452 ARC eyes with the presenting POVA ≥ 6/60 were enrolled. The relationship between age and POVA was analyzed statistically. Results. In these three missions, there were more female patients than males; the ratio of females to males was 1.71. The average age of females was older than males. Overall, the percentages of patients with good visual outcomes (≥6/18 were significantly decreased with aging. Different regions had variations, but the trends were the same. There was weak linear correlation between age and POVA. The correlations of females were stronger than males in Yuncheng and Sanmenxia and weaker than males in Zhoukou. Conclusion. The good visual outcomes of presenting POVA were significantly decreased with aging and there were weak linear correlations between age and POVA in rural China. The linear correlation might be influenced by the difference of gender and region.

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

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    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.

  20. Improvement of visual acuity in children with anisometropic amblyopia treated with rotated prisms combined with near activity

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    Chao-Chyun Lin

    2013-08-01

    Full Text Available AIM: To evaluate the efficacy of a new modality for improving visual acuity (VA in pediatric patients with anisometropic amblyopia.METHODS: Retrospective and interventional case series. Medical records of 360 children with anisometropic amblyopia treated with a modality that included rotated prisms, lenses, and near activities from January 2008 to January 2012 were analyzed. Characteristics such as improvement of VA and contrast sensitivity in amblyopic eyes and resolution of amblyopia (VA≤0.1logMAR or a difference of ≤2 lines in logMAR between the eyes were assessed.RESULTS: Among the patients, the mean VA of the amblyopic eyes improved from 0.48logMAR (SD=0.16 to 0.12logMAR (SD=0.16 and the mean VA improvement was 0.36logMAR (SD=0.10, PP=0.437. We found that better baseline VA may be related to success and shorten the time to amblyopic resolution.CONCLUSION: VA and contrast sensitivity improved with rotated prisms, correcting lenses, and near activities in children with anisometropic amblyopia. The VA improvement by this modality was comparable to other methods. However, the time to resolution of amblyopia was shorter with this method than with other modalities. Rotated prisms combined with near acuity could provide an alternative treatment in children with anisometropic amblyopia who can’t tolerant traditional therapy method like patching.

  1. Visual acuity, amblyopia, and ocular pathology in 12- to 13-year-old children in Northern Mexico.

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    Ohlsson, Josefin; Villarreal, Gerardo; Sjöström, Anders; Cavazos, Humberto; Abrahamsson, Maths; Sjöstrand, Johan

    2003-02-01

    The aim of this study was to establish visual acuity (VA) and the prevalence of amblyopia and other ocular disorders in a population of 12- to 13-year-old children in Mexico who have not been vision screened. A total of 1,035 12- to 13-year-old children were examined in a field study. The examination included VA, stereopsis, cover testing, refractive retinoscopy, and examination of the red reflex and posterior pole. In cases with unexplained subnormal VA, visually evoked potential/visually evoked response was also performed. A >or=20/20 in at least one eye was found in 93% of the subjects. Bilateral VA albinism was found in 3 cases, whereas strabismus was found in 24 subjects (2.3%). There were very few ocular opacities or posterior pole abnormalities. The visual status in the Mexican 12- to 13-year-old children tested was good. The prevalence of amblyopia was similar to that in other unscreened populations.

  2. Visual acuity and intraocular pressure after Descemet's stripping endothelial keratoplasty in eyes with and without preexisting glaucoma.

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    Vajaranant, Thasarat S; Price, Marianne O; Price, Francis W; Gao, Weihua; Wilensky, Jacob T; Edward, Deepak P

    2009-09-01

    (1) To characterize the pattern of intraocular pressure (IOP) changes after Descemet's stripping endothelial keratoplasty (DSEK) in patients without preexisting glaucoma and in those with preexisting glaucoma, with and without prior glaucoma surgery. (2) To compare vision and IOP outcomes among the 3 groups. A retrospective chart review. A total of 805 DSEK cases performed in 641 patients by a single surgeon from December 2003 to August 2007 were available in the database. Only the first-treated eye of each patient with at least 1-year follow-up was included. Four hundred cases qualified: 315 eyes had no glaucoma (C); 64 eyes had glaucoma with no previous glaucoma surgery (G); and 21 eyes had prior glaucoma surgery (GS). Eyes with preexisting retinal problems were included in the analysis. Data analysis included calculation of incidence of postoperative IOP elevation. The study criteria for postoperative IOP elevation were IOP > or =24 mmHg or IOP increase > or =10 mmHg from baseline. Kruskal-Wallis test was used to compare visual acuity (VA) and IOP among the 3 groups preoperatively and at 1-, 3-, 6-, and 12-month postoperative visits. Visual acuity (Snellen) and IOP (millimeters of mercury). The incidence of postoperative IOP elevation by the study criteria was 35%, 45%, and 43% for groups C, G, and GS, respectively. Elevated IOP was medically managed by initiating or increasing glaucoma medications or reducing steroids in 27%, 44%, and 38% of the patients in groups C, G, and GS, respectively. A subsequent glaucoma procedure was performed in 0.3%, 5%, and 19% of patients in groups C, G, and GS, respectively. Only the control group had statistically significant IOP elevation at 12 months (median increase of 2 mmHg) when compared with baseline (Preferences.

  3. Prevalence and causes of reduced visual acuity among children aged three to six years in a metropolis in China.

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    Pan, Chen-Wei; Chen, Xuejuan; Gong, Yu; Yu, Jiajia; Ding, Hui; Bai, Jing; Chen, Ji; Zhu, Hui; Fu, Zhujun; Liu, Hu

    2016-03-01

    To determine the prevalence and possible causes for reduced visual acuity (VA) in preschool children in a metropolis in China. A school-based paediatric eye survey including 5862 preschool children aged three to 6 years was conducted from 2011 to 2012 in Yuhuatai District, Nanjing, China, using an age-stratified random sampling procedure. Clinical examinations including ocular alignment, ocular motility, visual acuity, prism cover test, cycloplegic refraction, stereopsis screening, slit lamp examination and fundus examination were performed by trained study ophthalmologists and optometrists. Reduced VA was defined as presenting VA of worse than 0.30 logMAR (Snellen 6/12 or 20/40), for both better and worse eyes. 5667 (94.8%) children with complete VA data were included in the data analyses. Among them, 208 and 93 had reduced VA in the worse and better eye, respectively. Reduced VA was detected in 3.7% (95% confidence interval [CI] 3.2%-4.2%) in the worse eye and 1.6% (95% CI 1.3%-2.0%) in the better eye. No significant age and gender differences in reduced VA were observed (p > 0.05). Refractive errors and amblyopia were the principal causes for reduced VA in the worse eye which accounted for 66.8% and 32.7% of the total cases with reduced VA, respectively. Astigmatism and hyperopia were the major types of refractive errors causing reduced VA. The burden of reduced VA in preschool children in China was similar to that of Asian children of similar ages in the United States. Uncorrected refractive error and amblyopia were the principal causes for reduced VA among preschoolers (aged three to 6 years) in China. © 2015 The Authors Ophthalmic & Physiological Optics © 2015 The College of Optometrists.

  4. Acute Macular Neuroretinopathy in a 15-Year-Old Boy: Optical Coherence Tomography and Visual Acuity Findings

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    Shinji Makino

    2014-01-01

    Full Text Available Purpose: To report a case of acute macular neuroretinopathy (AMN in a 15-year-old boy. Methods: Images were obtained with fundus photography and optical coherence tomography (OCT. Results: The patient complained of blurred vision and a small central scotoma in the left eye. Left visual acuity was 0.3. Fundus photographs revealed a small dark area in the fovea of the left eye. OCT showed attenuation of the photoreceptor inner segment (IS/outer segment (OS line and the OS/retinal pigment epithelium (RPE line in the left eye. One week after the initial visit, left visual acuity had improved to 0.6, and there was partial recovery of the IS/OS line with focal thinning of the OS/RPE line. One month later, left visual acuity had improved to 0.8, and OCT showed complete restoration of the IS/OS line and the OS/RPE line. Conclusions: To our knowledge, this is the youngest patient reported with a diagnosis of AMN. Changes in microstructural findings and visual acuity were analogous during recovery of AMN in our patient.

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

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    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.

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

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    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.

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

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    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.

  8. Ocular Manifestations, Conventional Fundus Fluorescein Angiographic Findings, and Relationship Between Angiographic Findings and Visual Acuity in Behçet's Disease.

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    Bazvand, Fatemeh; Zarei, Mohammad; Ebrahimiadib, Nazanin; Karkhaneh, Reza; Davoudi, Samaneh; Soleimanzadeh, Mahyar; Sharifian, Elaheh; Roohipoor, Ramak; Modjtahedi, Bobeck S

    2017-01-01

    Evaluating the ocular manifestation and fundus fluorescein angiography (FA) findings of patients with Behçet's disease as well as the relationship between visual acuity and angiographic findings. Retrospective chart review of patients with Behçet's disease seen at the Farabi Eye Hospital. Forty-six patients (92 eyes) with mean age of 33.41 ± 10.67 were included. The most frequent presenting symptom and sign were reduced vision (76%) and uveitis (87%), respectively. Panuveitis was the most frequent type of uveitis (76%). Among patients with FA, vasculitis was the most common finding (87%) and it was significantly more severe among patients with visual acuity less than 20/200. Macular leakage (P = 0.001), arterial narrowing (P = 0.000), and posterior retinal vasculitis (P = 0.002) on FA were all associated with worsening final visual acuity. The most common ocular findings in Behçet's disease were panuveitis and vasculitis. Location of vasculitis, arterial narrowing, and macular leakage on initial FA may predict visual prognosis.

  9. Effect of Cellular Mobile Phone Use and Cetrizine on Hand-Eye Coordination and Visual Acuity.

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    Gawit, Kalpita Ganpat; Tiwari, Smita Anand; Kasabe, Gauri Hari; Deshpande, Pradeep Kisanrao; Ghongane, Balasaheb Baburao

    2017-09-01

    Cellular mobile phones are a major cause of distraction especially while driving. The aggressive and inappropriate use of cellular mobile phones has increased the risk of accidents. Similar alerts are available in literature for certain substances and drugs (e.g. second generation anti H1 drug -Cetirizine) which also derange psychomotor performance and parameters of alertness. This study measured variations in hand-eye coordination and visual acuity due to use of cellular mobile phone in comparison to that of commonly used antihistaminic drug viz., single dose Cetirizine 10 mg. It was a single blind, single dose, interventional study, 100 healthy human volunteers divided into two groups. Baseline readings of all volunteers were noted. Group-I (n=50) was Cetirizine group (10mg orally stat), Group -II (n=50) Cellular mobile phone user group. Alertness was tested on hand- steadiness tester (Reaction Time Index = RTI) and on Flicker-fusion apparatus (visual acuity - Critical Flicker Fusion Frequency per second= CFFF/sec). Baseline readings of all volunteers were noted before intervention. Baseline was compared with readings at three hour post-intervention and was analysed by paired t-test. Inter-group comparison of parameters was also done and was analysed by unpaired t-test. The baseline RTI (95.46±41.74, 85.11±39.05) and CFF low and high (40.07±9.970, 40.76±9.309 and 40.42±9.035, 40.48±9.863) respectively, in Cetirizine group and Mobile user group were comparable. The RTI increased significantly (116.4±51.46, 102.8±49.26) in both the groups after intervention. However, there is no significant change in CFF intensity from baseline in either group post-intervention. Concurrent use of mobile phone while performing tasks, showed significant impairment of hand-steadiness which was comparable to that produced by single dose Cetirizine 10 mg and this may be one of the factors contributing to their close association with road traffic accidents.

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

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    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. Influence of visual acuity on anxiety, panic and depression disorders among young and middle age adults in the United States.

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    Loprinzi, Paul D; Codey, Kathleen

    2014-01-01

    Previous research, albeit limited, has demonstrated an association of visual acuity with depression and anxiety. However, these studies are limited in that they have focused on older adults, used a convenient sample, and/or used a subjective assessment of visual function. As a result, the purpose of this study was to examine the association of objectively-measured visual acuity with depression and anxiety (and panic disorder) among a national sample of young- and middle-age U.S. adults (20-39 years). Using data from the 2003-2004 NHANES (n=602), the presence of anxiety, depression, and panic disorders was assessed from a diagnostic interview. Visual acuity was assessed from a vision exam using the Nidek Auto Lensmeter Model (LM-990A) and expressed as LogMAR units. After adjusting for age, gender, race-ethnicity, body mass index, mean arterial pressure, cotinine, diabetes, and physical activity, visual acuity was not associated with panic disorder (p=0.71) or depression disorder (p=0.20), but for every 0.1 LogMAR unit change in vision, participants had a 14% (OR=1.14; p=0.04) higher odds of having an anxiety disorder. The main limitation of this study was the cross-sectional design. Young- and middle-age U.S. adults with worse visual function are at increased odds of having an anxiety disorder. Strategies to prevent and treat anxiety among those with worse visual function are needed. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. 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

  13. 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

  14. 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

  15. 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.

  16. Activity of daily living and its associated factors in war survivors with no visual acuity

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    Reza Amini

    2010-01-01

    Full Text Available Background: War is a known cause of tremendous physical injuries to different body organs, and eyes are not exceptions. War-related no visual acuity (NVA affects both the victim and the family. Activity of daily living (ADL can display personal life independency and is considered as a morbidity index. This study was designed to investigate the ADL profile of war survivors with NVA. Methods: This cross-sectional study was conducted in 2007 in Iran. In this study, 500 Iranian people with war related NVA were invited to take part in a camp in Mashhad city. ADL was evaluated using Barthel Index and demographic data were collected using a data sheet. Stepwise linear regression was used to determine the associates of ADL. Results: The overall response rate to the invitation was 50%. From the total 250 participants 96.5% were male with a mean age of 43 ± 8 years. Only 8.3% had no dependency in ADL and other 91.7% had some ranges of dependency in at least one of the daily living activities. ADL score was higher in highly educated participants, those younger than 50 years old, those with less co-morbid physical problems (hearing loss and those with regular physical exercises. According to regression analysis, age and duration of war related NVA were significant predictors of ADL. Conclusions: According to the results, both age and the time passed from war related NVA increase the dependency of people with war related NVA.

  17. 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.

  18. 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.

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

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    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.

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

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    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. Visual acuity, safe/unsafe practices and self-reported road traffic crash experiences among commuter bus drivers from two motor parks in Lagos, Nigeria.

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    Okafor, I P; Odeyemi, K A; Aribaba, O T; Dolapo, D C; Ogunyemi, A O

    2015-01-01

    Road Traffic injuries remain a significant public health problem with serious health and economic implications. This study was conducted to determine visual acuity, safety practices and road traffic crash (RTC) experiences of commercial bus drivers in Lagos, Nigeria. This cross-sectional study involved visual acuity screening and interviewer- administered questionnaire survey. Participating motor parks were selected by simple random sampling and all intercity, commercial minibus drivers were included. Data was analyzed with Epi info version 3.5.1. A total of 407 drivers participated with a mean age of 43.4 ± 10.8 years. A total of 68 (16.7%) of the drivers did not meet the minimum VA standard required for driving; 8.6% of them use mobile phones while driving; 97% fasten their seatbelt, out of which almost 98% do so always. Fourteen percent also admitted eating while driving. Sixty two (15.2%) of drivers had been involved in RTC in the past 5 years prior to interview. A proportion of commercial minibus drivers did not meet the minimum VA required for driving. Some of them also practiced distracted driving. Free visual acuity screening within the motor park is recommended for commercial drivers at least once a year. There should be awareness campaigns to enlighten commercial drivers on the dangers of distracted driving in addition to strict enforcement of regulations and Highway Code.

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

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    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

  3. 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

  4. Trends in visual acuity impairment in US adults: the 1986-1995 National Health Interview Survey.

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    Lee, David J; Gómez-Marín, Orlando; Lam, Byron L; Zheng, D Diane; Jané, Dulce M

    2004-04-01

    To assess 10-year trends in reported visual impairment. The National Health Interview Survey is a continuous multistage area probability survey of the US civilian noninstitutionalized population living at addressed dwellings. Adults within randomly selected households were administered a chronic conditions list that included questions about visual impairment. Proxy information on these conditions was obtained when household members were unavailable for interview. Complete data were available on 132 860 adults 18 years or older in survey years 1986 to 1995. Prevalence rates were adjusted for age and sample survey design. Annual age-adjusted rates of some visual impairment ranged from 3.6% to 4.6%. Rates of severe bilateral visual impairment ranged from 0.2% to 0.4%. There was some evidence for increasing rates of visual impairment among younger adults 18 to 39 years of age (annual increase, 0.03%; P =.03). However, there were no significant changes in reported visual impairment rates in older adults stratified into 10-year age groups. Data from the National Health Interview Survey provide no evidence that reported visual impairment rates are declining in the US noninstitutionalized population from 1986 to 1995. Additional treatment advances, greater use of existing treatments, including correcting refractive errors, and further reductions in risk factors for disabling eye diseases may be necessary before population-level reductions in visual impairment rates can be achieved.

  5. Visual Acuity, Retinal Sensitivity, and Macular Thickness Changes in Diabetic Patients without Diabetic Retinopathy after Cataract Surgery

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    Spela Stunf Pukl

    2017-01-01

    Full Text Available Aim. Functional and morphological macular study after cataract surgery in a group of diabetics without diabetic retinopathy compared to nondiabetics to evaluate the effect of surgical oxidative stress on diabetic retina. Methods. Prospective, comparative study. Preoperative eye exam, best corrected visual acuity (BCVA measured by ETDRS letters, and optical coherence tomography (OCT were followed by standard cataract surgery. The follow-up visits at 1, 3, and 6 months postoperatively included BCVA, OCT, and microperimetry, to analyze changes within and between the groups. Results. The BCVA improved significantly in diabetics and controls: 64.2 to 81.0 and 61.9 to 82.1 ETDRS at 6 months, respectively. The central macula at OCT significantly thickened in both groups, while the central 5 fields, corresponding to the microperimetry area, subclinically thickened from 284.20 to 291.18 μm at 6 months only in diabetics (p=0.026. A matching slight decrease in the microperimetry sensitivity from 1 to 6 months was found also only in diabetics, with mean average difference −0.75 dB (p=0.04. Conclusion. Underlying diabetes does not influence the surgical outcome in diabetics without diabetic retinopathy. However, slight thickening of wider macula and corresponding decrease in retinal sensitivity observed in diabetics 6 months postoperatively might influence visual function on long term.

  6. An evaluation of the M&S technologies smart system II for visual acuity measurement in young visually-normal adults.

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    McClenaghan, Neil; Kimura, Ayumi; Stark, Lawrence R

    2007-03-01

    To compare visual acuity measures obtained with the M&S Technologies Smart System II (SSII) and the revised Early Treatment of Diabetic Retinopathy Study (ETDRS) charts in terms of accuracy and test-retest repeatability. Monocular visual acuities were taken in 57 young, visually normal adults on two separate visits in which both the SSII system and the ETDRS charts were tested in random order by two masked examiners. The eye to be tested throughout was chosen randomly at the initial visit. Measurements were made through an optimal phoropter correction, determined by a noncycloplegic refraction for a 10-foot distance. Both charts were presented at 10 feet, and were matched closely for luminance. The mean visual acuity in the group was -0.16 log minimum angle of resolution (MAR) for the ETDRS chart and -0.18 log MAR for the SSII, a small but statistically significant difference. A 95% confidence interval for the mean difference in visual acuity between the two charts was -0.033 log MAR to -0.003 log MAR. The test-retest repeatability was not significantly different in the two tests. The 95% limits of agreement for test-retest repeatability were -0.13 log MAR to +0.17 log MAR for the SSII and -0.12 log MAR to +0.13 log MAR for the ETDRS charts. The SSII can provide an accurate (mean difference<0.033 log MAR) and repeatable alternative to the ETDRS charts for visual acuity measurement in young, visually normal, well-corrected individuals.

  7. Visual acuity and refraction after deep anterior lamellar keratoplasty with and without successful big-bubble formation.

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    Feizi, Sepehr; Javadi, Mohammad Ali; Rastegarpour, Ali

    2010-11-01

    To compare visual acuity and refractive outcomes after Anwar's deep anterior lamellar keratoplasty (DALK) between eyes with and without successful big-bubble formation. In this retrospective comparative study, keratoconic eyes undergoing DALK with the big-bubble technique were divided into 2 groups: group 1 in which a bared Descemet membrane (DM) was achieved and group 2 in which layer-by-layer manual dissection was performed because of the lack of big-bubble formation after several intrastromal air injections. The 2 groups were compared with respect to best spectacle-corrected visual acuity, keratometric astigmatism, and refractive error at months 1, 3, 6, and 12, and at least 3 months after complete suture removal. A total of 123 keratoconic eyes were enrolled. A bared DM was successfully achieved in 100 eyes (81.3%) (group 1), whereas in 23 eyes (18.7%) (group 2), some posterior stroma was left in place. The mean follow-up period was 21 ± 9 months in group 1 and 23 ± 9 months in group 2 (P = 0.37). Postoperative best spectacle-corrected visual acuity was significantly better in group 1 than in group 2 at months 1, 3, 6, and 12. But, at the final examinations, there was no significant difference between the study groups (0.24 ± 0.21 logarithm of the minimum angle of resolution in group 1 and 0.32 ± 0.14 logarithm of the minimum angle of resolution in group 2; P = 0.18). The 2 groups were comparable regarding keratometric astigmatism and spherical equivalent refractive error throughout the follow-up period. Retention of posterior corneal stroma delayed visual recovery after DALK using Anwar's technique, but the participants in this group ultimately reached the same levels of visual acuity as observed in the bared-DM group.

  8. A nationwide population-based survey on visual acuity, near vision, and self-reported visual function in the adult population in Finland.

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    Laitinen, Arja; Koskinen, Seppo; Härkänen, Tommi; Reunanen, Antti; Laatikainen, Leila; Aromaa, Arpo

    2005-12-01

    To estimate the prevalence rates of habitual visual acuity (VA) levels and visual impairment in Finland and to assess their correlation with self-reported visual function. Cross-sectional population-based study. Subjects were selected randomly from the Finnish population aged 30 years or older. Of 7979 eligible people, 7393 (93%) were interviewed, 6771 (85%) were examined, and 6663 (84%) had distance VA assessed. Participants underwent a home interview and a comprehensive examination including measuring binocular VA for distance and for near with the participants' current spectacles, if any. The level of VA for distance and for near with current spectacle correction. The self-reported capability to read newsprint and television text and the ability to move about without being restricted by reduced vision. The prevalence of good to moderate VA for distance (VA> or =0.5 [> or =20/40]) measured with current spectacles was 95.9%, and 87.4% had a VA level of 0.8 (20/25) or better. The prevalence of habitual visual impairment (VAvisual impairment increased significantly with age (Pvisually impaired and blind participants to the Finnish population (approximately 3 million aged 30 years or older), there were approximately 65000 (2.1%) visually impaired and 17000 (0.6%) blind adult persons in the country in 2000. The correlation between self-reported visual ability and measured visual function was moderate but statistically significant (r = 0.27-0.40; Pvisual impairment increased with age especially in the age group of 65 to 74 years and upward and was as prevalent in women as in men. The prevalence of people with reading difficulties has decreased considerably since 1980.

  9. Correlation of spectral domain optical coherence tomography findings in acute central serous chorioretinopathy with visual acuity

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    Nair U

    2012-11-01

    Full Text Available Unnikrishnan Nair,1 Sunil Ganekal,2 Manoj Soman,1 KGR Nair11Chaithanya Eye Hospital and Research Institute, Trivandrum, Kerala, India; 2Nayana Super Specialty Eye Hospital and Research Center, Davangere, Karnataka, IndiaPurpose: To evaluate the structural changes in the acute phase of central serous chorioretinopathy and after its resolution, using spectral domain optical coherence tomography, to correlate these tomographic changes with visual acuity (VA.Method: This was a prospective study of 100 consecutive patients with acute central serous chorioretinopathy. It was based on presenting the best-corrected VA, divided into three groups (Group 1, n = 36, VA 6/6; Group 2, n = 49, VA 6/9–6/18; Group 3, n = 15, VA > 6/18. All patients underwent fundus evaluation followed by fluorescein angiography and spectral domain optical coherence tomography.Results: The mean age of the patients was 40 ± 7.17 years. The mean log MAR VA was 0.176 ± 0.0185. Single pigment epithelial detachment (PED, and multiple discrete and multiple confluent PEDs were seen in 21%, 17%, and 32% of the eyes, respectively. The location of the PED was subfoveal in 35% of the eyes. The presence of subretinal fibrin and a rough undersurface of the neurosensory retina were noted in 61% and 64% of the eyes, respectively. On en-face scanning, a break in the walls of the PED and overlying fibrin were seen in 32.8% and 45% of the eyes, respectively. The mean subretinal fluid height at the fovea was 279.11 ± 148.78 µ. The mean outer nuclear layer thickness during the active stage was 95.10 µ and during the resolved stage, it was 77.69 µ (P = 0.012. The average photoreceptor lengths were 73.1 µ, 84.6 µ, and 94.9 µ in groups 1, 2, and 3, respectively, in the acute phase; and 69.5 µ, 70.8 µ, and 61.6 µ, respectively, after resolution (P = 0.013, P = 0.010, and P = 0.011.Conclusion: In the acute phase of the disease, poorer VA showed statistically significant association with

  10. Including Students with Visual Impairments: Softball

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    Brian, Ali; Haegele, Justin A.

    2014-01-01

    Research has shown that while students with visual impairments are likely to be included in general physical education programs, they may not be as active as their typically developing peers. This article provides ideas for equipment modifications and game-like progressions for one popular physical education unit, softball. The purpose of these…

  11. 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.

  12. Visual acuity outcomes after cataract surgery in patients with age-related macular degeneration: age-related eye disease study report no. 27.

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    Forooghian, Farzin; Agrón, Elvira; Clemons, Traci E; Ferris, Frederick L; Chew, Emily Y

    2009-11-01

    To evaluate visual acuity outcomes after cataract surgery in patients with varying degrees of age-related macular degeneration (AMD). Cohort study. A total of 4757 participants enrolled in the Age-Related Eye Disease Study (AREDS), a prospective, multicenter, epidemiological study of the clinical course of cataract and AMD and a randomized controlled trial of antioxidants and minerals. Standardized lens and fundus photographs, performed at baseline and annual visits, were graded by a centralized reading center using standardized protocols for severity of AMD and lens opacities. History of cataract surgery was obtained every 6 months. Analyses were conducted using multivariate logistic regression. The change in best-corrected visual acuity (BCVA) after cataract surgery compared with preoperative BCVA. Visual acuity results were analyzed for 1939 eyes that had cataract surgery during AREDS. The mean time from cataract surgery to measurement of postoperative BCVA was 6.9 months. After adjustment for age at surgery, gender, type, and severity of cataract, the mean change in visual acuity at the next study visit after the cataract surgery was as follows: Eyes without AMD gained 8.4 letters of acuity (P<0.0001), eyes with mild AMD gained 6.1 letters of visual acuity (P<0.0001), eyes with moderate AMD gained 3.9 letters (P<0.0001), and eyes with advanced AMD gained 1.9 letters (P = 0.04). The statistically significant gain in visual acuity after cataract surgery was maintained an average of 1.4 years after cataract surgery. On average, participants with varying severity of AMD benefited from cataract surgery with an increase in visual acuity postoperatively. This average gain in visual acuity persisted for at least 18 months.

  13. 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.

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

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    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.

  15. Comparison of gait velocity and center of mass during square and semicircular turning gaits between groups of elderly people with differing visual acuity.

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    Shin, Sun-Shil; An, Duk-Hyun; Yoo, Won-Gyu

    2015-02-01

    [Purpose] The purpose of this study was to investigate gait velocity and center of mass (COM) during square and semicircular turning gaits between two groups of elderly people with differing visual acuity. [Subjects] Twenty elderly Korean women who could walk independently and who lived in the community were recruited. [Methods] We measured gait velocity and COM using an accelerometer during two different turning gaits. [Results] The velocity during square and semicircular turning gaits of participants with good binocular visual acuity (GBVA) was significantly higher than that of participants with poor binocular visual acuity (PBVA). The COM during square and semicircular turning gaits of the GBVA group was significantly decreased compared with that of the PBVA group. [Conclusion] These findings suggest that visual acuity affects velocity and COM during square and semicircular turning gaits of elderly people.

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

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    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.

  17. 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

  18. Tabelas para medir acuidade visual com escala logarítmica: porque usar e como construir Logarithmic visual acuity charts: reasons to use and how to design it

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    André Messias

    2010-02-01

    Full Text Available A acuidade visual representa o inverso do ângulo visual, ou seja, da menor distância angular entre dois pontos que podem ser vistos como separados. Apesar de ser a medida da função visual mais comum na prática oftalmológica, é muitas vezes interpretada erroneamente, principalmente devido às inúmeras tabelas e diferentes sistemas de notações empregados na clínica. Este artigo revisa alguns conceitos sobre a quantificação da acuidade visual, suas principais notações e tabelas de medida, discutindo as vantagens do uso da escala logarítmica.Visual acuity represents the visual angle or the smallest distance between two points that allows their discrimination as separated points. Although it is the most common clinical measurement of visual function, it is often misunderstood, especially due to the variety of charts and different notation systems employed for its quantification. This article reviews some concepts about visual acuity measurement, the main notation systems, type of charts and discuss the advantages of using logarithmic scales.

  19. Comparing distance visual acuity measurement with a novel eye chart and the Landolt C chart in a population of children aged 6-18 years.

    Science.gov (United States)

    Gorham, John P; Bruce, Beau B; Hutchinson, Amy K

    2017-12-01

    The Handy Eye Chart™ is designed to assist in evaluating the visual acuity of patients with non-standard communication styles. The Handy Eye Chart™ has been previously validated against the early treatment diabetic retinopathy study (ETDRS) chart. The aim of this research is to compare visual acuity outcomes with The Handy Eye Chart™ against the international gold standard, the Landolt C chart, in a population of children. Sixty participants between the ages of 6 and 18 were recruited at the Pediatric Section of the Department of Ophthalmology at the Emory Eye Center. Visual acuity was evaluated using The Handy Eye Chart™ and the Landolt C Chart, altering the order of administration between charts. The visual acuity data were compared using t test, linear regression, and Bland-Altman analysis. The mean difference in visual acuity was 0.02 logMAR (CI 0.009-0.04, p = 0.002). The correlation coefficient was 0.98. The Bland-Altman analysis shows the 95% limits of agreement between the charts to be -0.14 to 0.09 logMAR. The Handy Eye Chart™ is a valid measure of visual acuity when compared with the international gold standard, the Landolt C Chart.

  20. Visual acuity thresholds associated with activity limitations in the elderly. The Pathologies Oculaires Liées à l'Age study.

    Science.gov (United States)

    Daien, Vincent; Peres, Karine; Villain, Max; Colvez, Alain; Carriere, Isabelle; Delcourt, Cécile

    2014-11-01

    Activity limitations, which induce loss of autonomy in the elderly, are a major public health problem. We investigated the associations between objectively determined visual impairments and activity limitations and assessed the visual acuity thresholds associated with these restrictions. The study sample consisted of 1887 people aged 63 years and over from a population-based cohort. Moderate to severe visual impairment was defined as presenting visual acuity lower than 20/70, according to the World Health Organization (WHO) definition. In addition, we studied mild visual impairment, defined as visual acuity [20/70-20/40]. Multivariate logistic regressions were used to estimate the associations between vision and instrumental activities of daily living (IADL) limitations. Using receiver-operating characteristic (ROC) curves, we identified visual acuity thresholds that maximized the Youden index ([sensitivity + specificity]-1) for predicting IADL limitations. After adjustment for potential confounders, moderate to severe visual impairment and mild visual impairment were strongly associated with IADL limitations (odds ratio [OR] = 3.49; 95% confidence interval [CI] = 1.93, 6.32 and OR = 1.77; 95% CI = 1.07, 2.91, respectively). Visual acuity was a strong predictor of IADL limitations, with an area under the ROC curve of 0.72 (95% CI = 0.68, 0.76). The best discrimination between subjects with or without IADL limitations (global, physical and cognitive) was obtained for visual acuities around 20/40-20/50. This study confirms major increased risk for IADL limitations in subjects with moderate to severe visual impairment. In addition, it suggests that milder visual impairments (in particular below 20/40) may also be related to an increased risk for IADL limitations and should be considered for early medical intervention, before the decline of the subject autonomy. © 2014 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  1. Rhegmatogenous retinal detachment surgery in elderly people over 70 years old: visual acuity, quality of life, and cost-utility values.

    Science.gov (United States)

    Ma, Yingyan; Ying, Xiaohua; Zou, Haidong; Xu, Xiaocheng; Liu, Haiyun; Bai, Lin; Xu, Xun; Zhang, Xi

    2014-01-01

    To evaluate the influence of rhegmatogenous retinal detachment (RRD) surgery on elderly patients in terms of visual acuity, vision-related quality of life and its cost-effectiveness. Elderly patients over 70 years old, who were diagnosed and underwent RRD surgery at Shanghai First People's Hospital, Shanghai Jiao Tong University, China, from January 1, 2009, through January 1, 2013. The participants received scleral buckling surgery and vitreous surgery with or without scleral buckling under retrobulbar anesthesia. We followed the patients for 1 year and collected best-corrected visual acuity (BCVA), vision-related quality of life, and direct medical costs data. Utility values elicited by time-trade-off were analyzed to determine the quality of life. Quality-adjusted life years (QALYs) gained in life expectancy were calculated and discounted at 3% annually. Costs per QALY gained were reported using the bootstrap method. Further analyses were made for two age groups, age 70-79 and age over 80 years. Sensitivity analyses were performed to test stability of the results. 98 patients were included in the study. The BCVA significantly improved by 0.53±0.44 (Logarithm of the Minimum Angle of Resolution (logMAR)) at the 1-year postoperative time point (plife expectancy. Costs per QALY gained from the RRD surgery were 33,186 Chinese Yuan (CNY) (5,276 US dollars (USD))/QALY; 24,535 CNY (3,901 USD)/QALY for the age group of 70-79 years and 71,240 CNY (11,326 USD)/QALY for the age group over 80 years. RRD surgery improved the visual acuity and quality of life in the elderly patients over 70 years old. According to the World Health Organization's recommendation, at a threshold of willingness to pay of 115,062 CNY (18,293 USD)/QALY, RRD surgery is cost effective in the elderly patients.

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

    Directory of Open Access Journals (Sweden)

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

    OpenAIRE

    Bu?i?, Mladen; Bjelo?, Mirjana; Petrove?ki, Mladen; Kuzmanovi? Elabjer, Biljana; Bosnar, Damir; Rami?, Senad; Mileti?, Daliborka; Andrija?evi?, Lidija; Kond?a Krstonijevi?, Edita; Jakovljevi?, Vid; Bi??an Tvrdi, Ana; Predovi?, Jurica; Kokot, Antonio; Bi??an, Filip; Kova?evi? Ljubi?, Mirna

    2016-01-01

    Aim To present and evaluate a new screening protocol for amblyopia in preschool children. Methods 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...

  4. 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.

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

    Science.gov (United States)

    Wu, Jian Feng; Bi, Hong Sheng; Wang, Shu Mei; Hu, Yuan Yuan; Wu, Hui; Sun, Wei; Lu, Tai Liang; Wang, Xing Rong; Jonas, Jost B

    2013-01-01

    To examine the prevalence of refractive errors and prevalence and causes of vision loss among preschool and school children in East China. 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. 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 (PPrevalence 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;Prefractive error (Prefractive error as cause in 1975 (32.9%) children. Amblyopia (BCVA ≤ 20/32) was detected in 44 (0.7%) children (11 children with bilateral amblyopia). In coastal East China, about 14% of the 17-years olds were highly myopic, and 80% were myopic. Prevalence of myopia increased with older age, female gender and urban region. About 0.7% of pre-school children and school children were amblyopic.

  6. 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

  7. Are individual differences in reading speed related to extrafoveal visual acuity and crowding?

    Science.gov (United States)

    Frömer, Romy; Dimigen, Olaf; Niefind, Florian; Krause, Niels; Kliegl, Reinhold; Sommer, Werner

    2015-01-01

    Readers differ considerably in their speed of self-paced reading. One factor known to influence fixation durations in reading is the preprocessing of words in parafoveal vision. Here we investigated whether individual differences in reading speed or the amount of information extracted from upcoming words (the preview benefit) can be explained by basic differences in extrafoveal vision--i.e., the ability to recognize peripheral letters with or without the presence of flanking letters. Forty participants were given an adaptive test to determine their eccentricity thresholds for the identification of letters presented either in isolation (extrafoveal acuity) or flanked by other letters (crowded letter recognition). In a separate eye-tracking experiment, the same participants read lists of words from left to right, while the preview of the upcoming words was manipulated with the gaze-contingent moving window technique. Relationships between dependent measures were analyzed on the observational level and with linear mixed models. We obtained highly reliable estimates both for extrafoveal letter identification (acuity and crowding) and measures of reading speed (overall reading speed, size of preview benefit). Reading speed was higher in participants with larger uncrowded windows. However, the strength of this relationship was moderate and it was only observed if other sources of variance in reading speed (e.g., the occurrence of regressive saccades) were eliminated. Moreover, the size of the preview benefit--an important factor in normal reading--was larger in participants with better extrafoveal acuity. Together, these results indicate a significant albeit moderate contribution of extrafoveal vision to individual differences in reading speed.

  8. 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).

  9. Visual acuity and patient satisfaction at varied distances and lighting conditions after implantation of an aspheric diffractive multifocal one-piece intraocular lens.

    Science.gov (United States)

    Chang, Daniel H

    2016-01-01

    The aim of the study is to evaluate the visual acuity and patient satisfaction at varied distances under photopic and mesopic lighting conditions in patients bilaterally implanted with aspheric diffractive multifocal one-piece intraocular lenses. In this retrospective-prospective study, 16 patients with a mean age of 66.2±9.2 years (range: 50-81 years) who had undergone bilateral phacoemulsification surgery with implantation of a Tecnis multifocal one-piece intraocular lens (ZMB00) were evaluated. Monocular and binocular uncorrected and distance-corrected visual acuities were measured at distance (20 ft), intermediate (70-80 cm), and near (35-40 cm) under photopic (85 cd/m(2)) and mesopic (3 cd/m(2)) lighting conditions and were compared using the paired t-test. All patients also completed a subjective questionnaire. At a mean follow-up of 9.5±3.9 months, distance, near, and intermediate visual acuity improved significantly from preoperative acuity. Under photopic and mesopic conditions, 93.8% and 62.5% of patients, respectively, had binocular uncorrected intermediate visual acuity of 20/40 or better, and 62.5% and 31.3% of patients had binocular uncorrected near visual acuity of 20/20 or better. All patients were satisfied with their overall vision without using glasses and/or contact lenses when compared with before surgery. A total of 87.5% of patients reported no glare and 68.8% of patients reported no halos around lights at night. Tecnis multifocal one-piece intraocular lenses provide good distance, intermediate, and near visual acuity under photopic as well as mesopic lighting conditions. High levels of spectacle independence with low levels of photic phenomenon were achieved, resulting in excellent patient satisfaction.

  10. Effect of Intraocular Forward Scattering and Corneal Higher-Order Aberrations on Visual Acuity after Descemet's Stripping Automated Endothelial Keratoplasty.

    Directory of Open Access Journals (Sweden)

    Kazutaka Kamiya

    Full Text Available To assess the relationship of intraocular forward scattering and corneal higher-order aberrations (HOAs with best spectacle corrected visual acuity (BSCVA after Descemet's stripping automated endothelial keratoplasty (DSAEK, and to compare these parameters between DSAEK and non-Descemet's stripping automated endothelial keratoplasty (n-DSAEK groups.This retrospective study enrolled thirty eyes of 30 consecutive patients who underwent standard DSAEK, and who underwent successful phacoemulsification with intraocular lens implantation before DSAEK. The mean age at the time of surgery was 71.7 ± 10.4 years. We quantitatively evaluated the objective scattering index (OSI using the double-pass instrument (OQAS II, Visiometrics and corneal HOAs using Hartmann-Shack aberrometry (KR-9000PW, Topcon 3 months postoperatively.The mean OSI, corneal HOAs, and logMAR BSCVA 3 months after DSAEK were 7.91 ± 3.58, 0.43 ± 0.27 μm, and 0.32 ± 0.25, respectively. We found a significant correlation between the OSI and logMAR BSCVA (Spearman correlation coefficient r=0.714, p0.05.Our pilot study demonstrated that the postoperative corrected visual acuity was significantly correlated with intraocular forward scattering, but not with corneal HOAs in post-DSAEK eyes, suggesting that intraocular forward scattering plays a more essential role in postoperative visual performance than corneal aberrations after DSAEK. The detailed visual performance, such as HOAs and intraocular scattering, after n-DSAEK appears to be essentially equivalent to that after DSAEK.

  11. The effect of intravitreal administration of bevacizumab on macular edema and visual acuity in age-related macular degeneration with subfoveolar choroidal neovascularisation

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    Ristić Dragana

    2013-01-01

    Full Text Available Background/Aim. Age-related macular degeneration (AMD is a leading cause of the loss of central visual acuity in population older than 70 years. We can distinguish wet and dry form of AMD. The aim of the study was to present our early results in treatment of the wet (neovascular form of AMD with intravitreal administration of bevacizumab. Methods. The study included 39 patients. Each patient underwent a complete ophthalmological examination, fluorescein angiography (FA and optical coherence tomography (OCT. All the patients received 1.25 mg of intravitreal bevacizumab (0.05 mL of commercial phial of Avastin®. The total of three doses was given with a one-month interval between doses. Results. Among 39 patients, 24 were women and 15 men. The average best corrected visual acuity (BCVA was improved from 0.09 before the therapy to 0.24 after the administration of all the three doses of bevacizumab (p < 0.001. The average central macular thickness (CMT measured by OCT was improved from 474 μm in the beginning to 341 μm after the administration of all the three doses of the drug (p < 0.001. There were no side effects. Conclusions. Our short-term experience indicates that intravitreal administration of three doses of bevacizumab in one-month intervals between the doses leads to a significant reduction of macular edema and improvement of BCVA in patients with neovascular AMD.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  13. 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.

  14. 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.

  15. Refractive errors and visual acuity impairment among self-selected Hispanic, white, and black adults examined by the UCLA Mobile Eye Clinic.

    Science.gov (United States)

    Macias, E P; Lee, D A; Oelrich, F O

    1999-11-01

    Occurrence of refractive errors and uncorrected visual acuity impairment among self-selected, indigent, medically underserved Hispanic, white, and black adults examined by the staff of the UCLA Mobile Eye Clinic (MEC) are described in this study and compared to population-based studies. The study sample consisted of all 2,970 Hispanic, 1,228 white, and 1,028 black participants, for a total of 5,226 self-selected adults, ages 25 to 74 years, who received vision screenings and eye examinations by the staff of the UCLA MEC from 1987 to 1997. Tests consisted of visual acuity, refractive error, intraocular pressure, retinoscopy, slit-lamp biomicroscopy, direct ophthalmoscopic examination, and indirect ophthalmoloscopy with pupillary dilation. Levels of visual acuity impairment were defined as mild (20/50-20/80), moderate (20/100), or severe (20/200 or worse) in either eye. Self-selected whites in this study had higher rates of astigmatism, anisometropia, and hyperopia, while myopia was higher among self-selected blacks. Myopia and hyperopia occurred more frequently among younger age groups for all ethnic groups. Whites had a higher occurrence of mild, moderate, and severe visual acuity impairment, as compared with Hispanics and blacks. Both refractive errors and impaired visual acuity of this self-selected sample are similar to those of adults from the National Health and Nutrition Examination Survey, Hispanic Health and Nutrition Examination Survey, and the Baltimore Eye Survey. The data presented in this study provide a crude estimate of the occurrence of refractive errors and impaired visual acuity among self-selected, medically underserved, indigent Hispanic, white, and black adults in the Los Angeles area.

  16. 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

  17. Correlation between macular ganglion cell-inner plexiform layer thickness and visual acuity after resolution of the macular edema secondary to central retinal vein occlusion

    Directory of Open Access Journals (Sweden)

    Hyun Ju Kim

    2018-02-01

    Full Text Available AIM: To examine the thickness of the ganglion cell-inner plexiform layer (GCIPL in eyes with resolved macular edema (ME in non-ischemic central retinal vein occlusion (CRVO, applying spectral-domain optical coherence tomography (SD-OCT, and its relationship with visual acuity. METHODS: The retrospective observational case-control study included 30 eyes of non-ischemic CRVO patients with resolved ME (ME eyes after treatment, and 30 eyes of non-ischemic CRVO patients without ME (non-ME eyes. The macular GCIPL thickness, peripapillary retinal nerve fiber layer (pRNFL thickness and central macular thickness (CMT were measured on a SD-OCT scan. Linear regression analyses were performed to determine the correlation between the thickness of each and the visual acuity (VA. RESULTS: No significant difference in average GCIPL thickness, mean pRNFL thickness and CMT were observed between ME group and non-ME group (P=0.296, 0.183, 0.846. But, minimum GCIPL thickness was reduced in ME eyes compared with non-ME eyes (P=0.022. Final VA significantly correlated with the minimum GCIPL thickness in ME eyes (r=-0.482, P=0.007, whereas no correlation was found with average GCIPL thickness, average pRNFL thickness and mean CMT. CONCLUSION: Minimum GCIPL thickness is reduced in ME eyes compared with non-ME eyes, and correlated with the VA in non-ischemic CRVO. These results propose that inner retinal damage occurring in patients with ME secondary to non-ischemic CRVO may lead to permanent visual defect after treatment.

  18. Grating resolution acuity in children with spatic cerebral palsy by the sweep visual evoked potential

    OpenAIRE

    Marcelo Fernandes da Costa

    2001-01-01

    Medimos a acuidade visual em crianças com paralisia cerebral do tipo espástica, classificadas em tetraplégicas, diplégicas e hemiplégicas, de acordo com o seu prejuízo motor, pelo método dos potenciais visuais evocados de varredura. Encontramos uma redução na acuidade visual em todos as crianças com tetraplegia e diplegia e em 94% das crianças com hemiplegia. Ambliopia foi identificada em 16% das crianças. Uma alta correlacão entre o prejuízo motor e a redução da acuidade visual foi encontrad...

  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...

  20. Stimulus Determinants of Dynamic Visual Acuity. I. Background and Exploratory Data.

    Science.gov (United States)

    1980-08-01

    of ceittral and peripheral visul functions and for coordination between visual and oculomotor mechanisms. The content valdity of DVA for assessing...stimuli. The literature provides little information regarding concurrent or predictive validities of any vision test with respect to measures of job...the latency of saccadic eye movements in response to positive contrast tagets decreased as the target luminance was increased. Initial information

  1. Speckle technologies and measurement of retinal visual acuity in cataract patients

    Science.gov (United States)

    Akchurin, Garif G.; Bakutkin, Valery V.; Radchenko, Elena Y.; Tuchin, Valery V.; Akchurin, Alexander G.

    2001-01-01

    Special features of speckle-modulated laser fields arising at in vitro measurements of different types of human cataractous lenses have been investigated experimentally. Computer analysis of digital images has allowed for estimation of destruction of the spatial coherence of a laser beam scattered by a turbid lens. Applied speckle-technologies have permitted the range of retinal angular resolution to be estimated with the help of laser retinometer at the stage of preoperative cataract diagnosis. An extent of laser retinometry at measuring visual acu9ity in patients with any type of cataract, and an incorrectness of its estimation by means of opto types charts have been set up.

  2. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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

  5. Complex for monitoring visual acuity and its application for evaluation of human psycho-physiological state

    Science.gov (United States)

    Sorokoumov, P. S.; Khabibullin, T. R.; Tolstaya, A. M.

    2017-01-01

    The existing psychological theories associate the movement of a human eye with its reactions to external change: what we see, hear and feel. By analyzing the glance, we can compare the external human response (which shows the behavior of a person), and the natural reaction (that they actually feels). This article describes the complex for detection of visual activity and its application for evaluation of the psycho-physiological state of a person. The glasses with a camera capture all the movements of the human eye in real time. The data recorded by the camera are transmitted to the computer for processing implemented with the help of the software developed by the authors. The result is given in an informative and an understandable report, which can be used for further analysis. The complex shows a high efficiency and stable operation and can be used both, for the pedagogic personnel recruitment and for testing students during the educational process.

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

    Directory of Open Access Journals (Sweden)

    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

  7. Delayed neurogenesis with respect to eye growth shapes the pigeon retina for high visual acuity.

    Science.gov (United States)

    Rodrigues, Tania; Krawczyk, Michal; Skowronska-Krawczyk, Dorota; Matter-Sadzinski, Lidia; Matter, Jean-Marc

    2016-12-15

    The macula and fovea located at the optical centre of the retina make primate visual perception unique among mammals. Our current understanding of retina ontogenesis is primarily based on animal models having no macula and no fovea. However, the pigeon retina and the human macula share a number of structural and functional properties that justify introducing the former as a new model system for retina development. Comparative transcriptome analysis of pigeon and chicken retinas at different embryonic stages reveals that the genetic programmes underlying cell differentiation are postponed in the pigeon until the end of the period of cell proliferation. We show that the late onset of neurogenesis has a profound effect on the developmental patterning of the pigeon retina, which is at odds with the current models of retina development. The uncoupling of tissue growth and neurogenesis is shown to result from the fact that the pigeon retinal epithelium is inhibitory to cell differentiation. The sum of these developmental features allows the pigeon to build a retina that displays the structural and functional traits typical of primate macula and fovea. © 2016. Published by The Company of Biologists Ltd.

  8. Change in visual acuity is well correlated with change in image-quality metrics for both normal and keratoconic wavefront errors.

    Science.gov (United States)

    Ravikumar, Ayeswarya; Marsack, Jason D; Bedell, Harold E; Shi, Yue; Applegate, Raymond A

    2013-11-26

    We determined the degree to which change in visual acuity (VA) correlates with change in optical quality using image-quality (IQ) metrics for both normal and keratoconic wavefront errors (WFEs). VA was recorded for five normal subjects reading simulated, logMAR acuity charts generated from the scaled WFEs of 15 normal and seven keratoconic eyes. We examined the correlations over a large range of acuity loss (up to 11 lines) and a smaller, more clinically relevant range (up to four lines). Nine IQ metrics were well correlated for both ranges. Over the smaller range of primary interest, eight were also accurate and precise in estimating the variations in logMAR acuity in both normal and keratoconic WFEs. The accuracy for these eight best metrics in estimating the mean change in logMAR acuity ranged between ±0.0065 to ±0.017 logMAR (all less than one letter), and the precision ranged between ±0.10 to ±0.14 logMAR (all less than seven letters).

  9. 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.

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

    Science.gov (United States)

    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.

  11. 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.

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

    Science.gov (United States)

    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 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 (p<0.001-p=0.031). The effect of speed was significant for both NearDVA (p=0.012) and FarDVA (p=0.014), however, there was no age group x speed interaction (FarDVA p=0.607, NearDVA p=0.343). The ICCs for Near and FarDVA ranged between 0.85- 0.88 and 0.71-0.87, respectively. CONCLUSIONS: Differences in DVA between the three age groups were detected by using both Near and FarDVA protocols irrespective of the walking speed. Therefore, age group-specific reference values should be used for detecting malfunction. Further, consistency in walking speed is critical for comparing between studies. NearDVA at all walking speeds and FarDVA at the speed of 1.2 m/s demonstrated excellent testretest reliability. FarDVA at 0.8 m/s and 1.0 m/s demonstrated good test-retest reliability (ICCs 0.71 and 0.77, respectively).

  13. Assessment of macular function, structure and predictive value of pattern electroretinogram parameters for postoperative visual acuity in patients with idiopathic epimacular membrane.

    Science.gov (United States)

    Lubiński, Wojciech; Gosławski, Wojciech; Krzystolik, Karol; Mularczyk, Maciej; Kuprjanowicz, Leszek; Post, Michał

    2016-08-01

    To evaluate macular function and structure before and after epimacular membrane surgery and to estimate the usefulness of pattern ERG test parameters in predicting the postoperative visual acuity. We evaluated 32 eyes of 32 patients (mean age 70.8 ± 6.7 years) before and 12 months after successful 25G pars plana vitrectomy with epimacular membrane removal and internal limiting membrane peeling. Distance best-corrected visual acuity (DBCVA-logMAR), foveal thickness (optical coherence tomography-OCT) and macular function [pattern electroretinogram-PERG (ISCEV standard): amplitudes (A) of P50- and N95-waves, implicit time (IT) of P50-wave] were assessed. To estimate the differences between the mean values of considered characteristics, the t test or Wilcoxon matched pair test was used. Correlation between preoperative data of PERG and preoperative and final DBCVA were investigated using Pearson correlation analysis. A receiver operating characteristic curve was constructed to obtain a cutoff value allowing prediction of visual prognosis. We tried to obtain the P50 and N95 amplitudes cutoff value in prediction of good visual outcome (DBCVA of 0.3 or less). Twelve months after surgery, mean of DBCVA significantly increased in comparison with preoperative value (0.31 ± 0.12 vs. 0.6 ± 0.15; p membranes with internal limiting membrane peeling not only provided increase in visual acuity and reduction in foveal thickness but also caused improvement of innermost retinal layer function in macular region. Pattern ERG test might be a valuable tool in predicting the postoperative visual acuity.

  14. Improvement of visual acuity based on optical coherence tomography patterns following intravitreal bevacizumab treatment in patients with diabetic macular edema

    Directory of Open Access Journals (Sweden)

    Haider R. Cheema

    2014-04-01

    Full Text Available AIM:To report the visual outcome based on various patterns of optical coherence tomography (OCT morphology in diabetic macular edema (DME, following treatment with anti-VEGF intravitreal bevacizumab (IVB injection.METHODS:Sixty-seven consecutive subjects with centre involving DME underwent intravitreal injection of Bevacizumab (1.25 mg/0.05 mL in this retrospective, comparative, non randomized study. The DME was classified into one of four categories:focal, diffuse, focal cystoid and neurosensory detachment based on OCT. Best corrected visual acuity (BCVA, macular appearance, and OCT findings were used to decide whether the subject should have a repeat injection of intravitreal bevacizumab. Outcome measures were a change in mean BCVA (Snellen converted to logMAR and central macular thickness (CMT in each group during the six month follow-up period.RESULTS:The mean BCVA improved to logMAR 0.23 at final follow-up from a baseline of 0.32 logMAR (P=0.040 in the focal group, logMAR 0.80 at final follow-up from a baseline of 0.82 logMAR (P=0.838 in the diffuse group, worsened to logMAR 0.53 at final follow-up from a baseline of 0.43 logMAR (P=0.276 in the focal cystoid group, and improved to logMAR 0.79 at final follow-up from a baseline of 0.93 logMAR (P=0.490 in the neurosensory detachment group. The mean CMT before treatment were 298.8±25.03 μm in the focal group, 310.8±40.6 μm in the diffuse group, 397.15±31.05 μm in the focal cystoid group and 401.03±75.1 μm in the neurosensory detachment group. A mean of 2.05 (range:1-5 injections in the focal group, 1.32 (range:1-2 in the diffuse group, 2.6 (range:1-6 in the focal cystoid group and 2.6 (range:1-6 in the neurosensory detachment group were performed during the six month follow-up period. Following intravitreal bevacizumab treatment, vision improved, remained unchanged or worsened in 11, 7 and 2 subjects in focal group; 11, 9 and 8 in diffuse group; 0, 2 and 4 in focal cystoid group and 5

  15. Torsional phacoemulsification: A pilot study to revise the "harm scale" evaluating the endothelial damage and the visual acuity after cataract surgery.

    Directory of Open Access Journals (Sweden)

    Francesco Saverio Sorrentino

    Full Text Available To study the effect of torsional phacoemulsification energy on corneal endothelium evaluating the relationship between changes of endothelial cells and postoperative visual acuity.This prospective clinical observational cohort study included 50 patients with cataract who underwent torsional phacoemulsification. Sequential quantitative and qualitative morphometric endothelial cell analyses of the cornea were performed four weeks preoperatively and six weeks postoperatively using noncontact specular microscopy.This work confirmed the strong relationship, described by a linear model (one-way ANOVA, R2 = 77.9%, P 85 letters from those with just a good/satisfied visual outcome (BCVA ≤ 85 letters. Within the 5-score harm scale, there was a significant correlation among phaco energy intraoperatively delivered and the average endothelial cell loss.This study confirms the validity of the 5-score harm scale first proposed by Sorrentino and colleagues in 2016. This time, the method categorizes cataracts taking into account nucleus hardness and phaco cumulative dissipated energy. Predicting the harm on corneal endothelium, we can discriminate patients with excellent BCVA and with just good/satisfied BCVA. With torsional phacoemulsification with respect to longitudinal, the percentage of patients who can reach excellent BCVA is remarkably increased.

  16. Development and testing of an automated computer tablet-based method for self-testing of high and low contrast near visual acuity in ophthalmic patients.

    Science.gov (United States)

    Aslam, Tariq M; Parry, Neil R A; Murray, Ian J; Salleh, Mahani; Col, Caterina Dal; Mirza, Naznin; Czanner, Gabriela; Tahir, Humza J

    2016-05-01

    Many eye diseases require on-going assessment for optimal management, creating an ever-increasing burden on patients and hospitals that could potentially be reduced through home vision monitoring. However, there is limited evidence for the utility of current applications and devices for this. To address this, we present a new automated, computer tablet-based method for self-testing near visual acuity (VA) for both high and low contrast targets. We report on its reliability and agreement with gold standard measures. The Mobile Assessment of Vision by intERactIve Computer (MAVERIC) system consists of a calibrated computer tablet housed in a bespoke viewing chamber. Purpose-built software automatically elicits touch-screen responses from subjects to measure their near VA for either low or high contrast acuity. Near high contrast acuity was measured using both the MAVERIC system and a near Landolt C chart in one eye for 81 patients and low contrast acuity using the MAVERIC system and a 25 % contrast near EDTRS chart in one eye of a separate 95 patients. The MAVERIC near acuity was also retested after 20 min to evaluate repeatability. Repeatability of both high and low contrast MAVERIC acuity measures, and their agreement with the chart tests, was assessed using the Bland-Altman comparison method. One hundred and seventy-three patients (96 %) completed the self- testing MAVERIC system without formal assistance. The resulting MAVERIC vision demonstrated good repeatability and good agreement with the gold-standard near chart measures. This study demonstrates the potential utility of the MAVERIC system for patients with ophthalmic disease to self-test their high and low contrast VA. The technique has a high degree of reliability and agreement with gold standard chart based measurements.

  17. Photobiomodulation reduces drusen volume and improves visual acuity and contrast sensitivity in dry age-related macular degeneration.

    Science.gov (United States)

    Merry, Graham F; Munk, Marion R; Dotson, Robert S; Walker, Michael G; Devenyi, Robert G

    2017-06-01

    To evaluate the efficacy of photobiomodulation (PBM) treatment for patients with dry age-related macular degeneration (AMD). Assessments on 42 eyes with dry AMD (age related eye disease study (AREDS) 2-4) were conducted. Multiwavelength light emitting diode (LED) light comprising of yellow (590 nm), red (670 nm) and near-infrared (790 nm) bandwidths was applied to subjects' eyes for a treatment course of 3 weeks. Outcome measures were changes in best-corrected visual acuity (BCVA), contrast sensitivity (CS), drusen volume and central drusen thickness. Significant improvement in mean BCVA of 5.90 letters (p < 0.001) was seen on completion of the 3-week treatment and 5.14 letters (p < 0.001) after 3 months. Contrast sensitivity improved significantly (log unit improvement of 0.11 (p = 0.02) at 3 weeks and 3 months (log unit improvement of 0.16 (p = 0.02) at three cycles per degree. Drusen volume decreased by 0.024 mm 3 (p < 0.001) and central drusen thickness was significantly reduced by a mean of 3.78 μm (p < 0.001), while overall central retinal thickness and retinal volume remained stable. This is the first study demonstrating improvements in functional and anatomical outcomes in dry AMD subjects with PBM therapy. These findings corroborate an earlier pilot study that looked at functional outcome measures. The addition of anatomical evidence contributes to the basis for further development of a non-invasive PBM treatment for dry AMD. © 2016 The Authors. Acta Ophthalmologica published by John Wiley & Sons Ltd on behalf of Acta Ophthalmologica Scandinavica Foundation.

  18. Comparison of gait velocity and center of mass during square and semicircular turning gaits between groups of elderly people with differing visual acuity

    OpenAIRE

    Shin, Sun-shil; An, Duk-hyun; Yoo, Won-gyu

    2015-01-01

    [Purpose] The purpose of this study was to investigate gait velocity and center of mass (COM) during square and semicircular turning gaits between two groups of elderly people with differing visual acuity. [Subjects] Twenty elderly Korean women who could walk independently and who lived in the community were recruited. [Methods] We measured gait velocity and COM using an accelerometer during two different turning gaits. [Results] The velocity during square and semicircular turning gaits of pa...

  19. Evaluation of various machine learning methods to predict vision-related quality of life from visual field data and visual acuity in patients with glaucoma.

    Science.gov (United States)

    Hirasawa, Hiroyo; Murata, Hiroshi; Mayama, Chihiro; Araie, Makoto; Asaoka, Ryo

    2014-09-01

    We investigated whether it was useful to use machine learning algorithms to predict patients' vision related quality of life (VRQoL) from visual field (VF) and visual acuity (VA). VRQoL was surveyed in 164 glaucomatous patients using the Sumi questionnaire. Their VRQoL score was predicted using machine learning algorithms (Random Forest, gradient boosting, support vector machine) based on total deviation (TD) values from integrated VF (IVF), VA, age and gender. For comparison, VRQoL score was predicted using standard linear regression with mean of IVF, TD values, and VA, and also the stepwise model selection by Akaike Information Criterion. Prediction error was calculated as root mean of the squared prediction error (RMSE) associated with the leave one out cross validation. RMSEs associated with general VRQoL score were smaller for the machine learning algorithms (1.99 to 2.21) compared with the standard linear model and the stepwise model selection (2.35 to 3.20). A similar tendency was found in each individual VRQoL task score. We found that it was advantageous to use machine learning methods to predict VRQoL accurately. These statistical methods could be used to help clinicians better understand patients' VRQoL without the need for extra tests other than standard VA and VF. 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.

  20. 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.

  1. Visual acuity after cataract surgery in patients with age-related macular degeneration: age-related eye disease study 2 report number 5.

    Science.gov (United States)

    Huynh, Nancy; Nicholson, Benjamin P; Agrón, Elvira; Clemons, Traci E; Bressler, Susan B; Rosenfeld, Philip J; Chew, Emily Y

    2014-06-01

    To evaluate visual acuity outcomes after cataract surgery in persons with varying degrees of severity of age-related macular degeneration (AMD). Cohort study. A total of 1232 eyes of 793 participants who underwent cataract surgery during the Age-Related Eye Disease Study 2, a prospective, multicenter, randomized controlled trial of nutritional supplements for treatment of AMD. Preoperative and postoperative characteristics of participants who underwent cataract extraction during the 5-year trial were analyzed. Both clinical data and standardized red-reflex lens and fundus photographs were obtained at baseline and annually. Photographs were graded by a centralized reading center for cortical and posterior subcapsular lens opacities and for AMD severity. Cataract surgery was documented at annual study visits or by history during the 6-month telephone calls. Analyses were conducted using multivariate repeated-measures regression. Change in best-corrected visual acuity (BCVA) after cataract surgery compared with preoperative BCVA. Adjusting for age at time of surgery, gender, interval between preoperative and postoperative visits, and type and severity of cataract, the mean changes in visual acuity were as follows: eyes with mild AMD (n = 30) gained 11.2 letters (95% confidence interval [CI], 6.9-15.5), eyes with moderate AMD (n = 346) gained 11.1 letters (95% CI, 9.1-13.2), eyes with severe AMD (n = 462) gained 8.7 letters (95% CI, 6.7-10.7), eyes with noncentral geographic atrophy (n = 70) gained 8.9 letters (95% CI, 5.8-12.1), and eyes with advanced AMD (central geographic atrophy, neovascular disease, or both; n = 324) gained 6.8 letters (95% CI, 4.9-8.8). The visual acuity gain across all AMD severity groups was statistically significant from preoperative values (P < 0.0001). Mean visual acuities improved significantly after cataract surgery across varying degrees of AMD severity. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier

  2. Correlation of neutrophil/lymphocyte and platelet/lymphocyte ratio with visual acuity and macular thickness in age-related macular degeneration

    Directory of Open Access Journals (Sweden)

    Elvan Alper Sengul

    2017-05-01

    Full Text Available AIM: To investigate the place of neutrophil-to-lymphocyte ratio (NLR and platelet-to-lymphocyte ratio (PLR in the diagnosis of and prognosis for neovascular age-related macular degeneration (AMD. METHODS: One hundred AMD patients and 100 healthy controls were included in the study. Blood samples were obtained from the venous blood, which is used for routine analysis, and these samples were subjected to complete blood count. NLR was defined as the neutrophil count divided by the number of lymphocytes, and PLR was defined as the platelet count divided by the number of lymphocytes. RESULTS: No statistically significant difference was observed between the two groups under consideration in terms of demographic features (P>0.05. The average NLR in the patient group was found to be significantly higher than that in the healthy control group (P<0.05. The average PLR was significantly higher in the patient group as compared to the control group (P<0.05. As best corrected visual acuity (BCVA increased, both NLR and PLR decreased (significant negative correlations at 49.8% and 63.0%, respectively, whereas as central macular thickness (CMT increased, both NLR and PLR increased (significant positive correlations at 59.3% and 70.0%, respectively. CONCLUSION: NLR and PLR levels are higher among neovascular AMD patients as compared to healthy control group. NLR and PLR levels were found to be inversely proportional to BCVA and directly proportional to CMT.

  3. Prevalência de baixa acuidade visual em escolares da rede pública, Sorocaba Prevalence of low visual acuity in public school's students from Brazil

    Directory of Open Access Journals (Sweden)

    Reinaldo José Gianini

    2004-04-01

    Full Text Available OBJETIVO: A baixa acuidade visual tem elevada prevalência e o diagnóstico precoce é necessário pelos danos que pode causar ao desenvolvimento e aprendizado infantis. O estudo realizado objetivou descrever e analisar a prevalência de baixa acuidade visual em escolares da rede de ensino fundamental. MÉTODOS: A partir do diagnóstico da acuidade visual, 9.640 escolares de primeira e quarta séries da rede pública de ensino fundamental de Sorocaba, Estado de São Paulo, no ano 2000, foram analisados e classificados seus registros segundo sexo, série, uso de óculos, área de residência e grau de acesso à assistência médica supletiva. Foram realizados testes de correlação de Pearson e análise de regressão linear. RESULTADOS: A população estudada apresentou prevalência de baixa acuidade visual de 13,1% (IC 95%=12,5-13,8%, sendo significantemente menor no sexo masculino (11,5% quando comparado ao feminino (14,9% - (RP=0,77; significantemente maior nos escolares de primeira série (14,1% quando comparados aos de quarta série (11,5% - (RP=1,22; e significantemente menor em não-usuários de óculos (12,1% quando comparados aos usuários (42,0% - (RP=0,29. Dentre os locais estudados, o bairro de Cajuru apresentou a menor prevalência de baixa acuidade visual (1,8% e o bairro de Vila Sabiá a maior prevalência (32,4%. Foi encontrada correlação positiva, segundo a área de residência entre a proporção de indivíduos que têm acesso à assistência médica supletiva e a proporção de usuários de óculos (r=0,64, pOBJECTIVE: Low visual acuity (VA is an important public health problem due to its high prevalence and because it needs early diagnosis in order to prevent damage in childhood development and apprenticeship. To describe and analyze low visual acuity (VA prevalence among school children METHODS: Once performed the VA test to 1st and 4th grades primary school children data were analyzed by separating students according to

  4. Knee muscle strength and visual acuity are the most important modifiable predictors of falls in patients after hip fracture surgery: a prospective study.

    Science.gov (United States)

    Yau, Dora T Y; Chung, Raymond C K; Pang, Marco Y C

    2013-03-01

    Our purpose was to identify risk factors for falls among older adults who had recently undergone hip fracture surgery. The subjects in this study were 69 older adults (aged 65 years or more) who had sustained a hip fracture and were admitted to an orthopedic rehabilitation ward after surgery. Potential fall risk factors were assessed using the physiological profile assessment, timed-up-and-go test, berg balance test, and activities-specific balance confidence scale at discharge from the hospital. Each individual was followed for a period of 6 months to obtain information on the incidence of falls. Receiver operating characteristic curves were constructed to determine the optimal cutoff score for each potential risk factor identified. Multivariate logistic regression was then used to identify the significant predictors of falls and their odds ratios (ORs). During the 6-month follow-up period, 10 of the 69 patients experienced one or more falls. The results showed that fallers were older than nonfallers (p=0.009). Fallers also had poorer performance in the high-contrast visual acuity test (p=0.015) and lower knee flexor (p=0.021) and knee extensor (p=0.005) muscle strength values. Multivariate logistic regression analysis showed that high-contrast visual acuity (cutoff score Z=-2.280, OR=6.14, 95% CI 1.13-33.29, p=0.035) and knee extensor muscle strength (cutoff score Z=-1.835, OR=4.81, 95% CI 1.04-22.33, p=0.045) were predictors of falls. Poor visual acuity and knee muscle weakness are modifiable predictors of falls and should be the key target areas in fall-prevention programs for older adults with hip fractures.

  5. 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

    2016-01-01

    Purpose To investigate whether suppression of blue light can improve visual function in patients with short tear break up time (BUT) dry eye (DE). Methods 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. Results 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), Conclusions 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. PMID:27045760

  6. 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. PMID:24504346

  7. 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.

  8. 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.

  9. Visual Impairments, "Including Blindness." NICHCY Disability Fact Sheet #13

    Science.gov (United States)

    National Dissemination Center for Children with Disabilities, 2012

    2012-01-01

    Vision is one of the five senses. Being able to see gives tremendous access to learning about the world around--people's faces and the subtleties of expression, what different things look like and how big they are, and the physical environments, including approaching hazards. When a child has a visual impairment, it is cause for immediate…

  10. Myopia prevention, near work, and visual acuity of college students: integrating the theory of planned behavior and self-determination theory.

    Science.gov (United States)

    Chan, Derwin King-Chung; Fung, Ying-Ki; Xing, Suxuan; Hagger, Martin S

    2014-06-01

    There has been little research examining the psychological antecedents of safety-oriented behavior aimed at reducing myopia risk. This study utilizes self-determination theory (SDT) and the theory of planned behavior (TPB) to understand the role of motivational and social-cognitive factors on individuals' near-work behavior. Adopting a prospective design, undergraduate students (n = 107) completed an initial questionnaire based on SDT in week 1, a second questionnaire containing measures of TPB variables in week 2, and objective measures of reading distance and visual acuity in week 6. The data were analyzed by variance-based structural equation modeling. The results showed that perceived autonomy support and autonomous motivation from SDT significantly predicted attitude, subjective norm, and perceived behavioral control from the TPB. These social-cognitive factors were significantly associated with intention and intention significantly predicted reading distance. The relationships in the model held when controlling for visual acuity. In conclusion, the integrated model of SDT and the TPB may help explain myopia-preventive behaviors.

  11. 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.

  12. 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

  13. 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)

  14. 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...

  15. Secular trends of reduced visual acuity from 1985 to 2010 and disease burden projection for 2020 and 2030 among primary and secondary school students in China.

    Science.gov (United States)

    Sun, Hong-Peng; Li, Ang; Xu, Yong; Pan, Chen-Wei

    2015-03-01

    Understanding the burden and trends of reduced visual acuity (VA), a proxy measure for myopia, is essential to guide future health care and clinical management in China. To describe the secular trends from 1985 to 2010, correlate the prevalence of reduced VA among children and adolescents with population density, and project the burden of reduced VA in China in 2020 and 2030. The National Survey on the Constitution and Health of Chinese Students conducted from 1985 to 2010, including 6 repeated surveys with a 3-stage clustering sampling strategy. Mainland China. Primary and secondary school students 7 to 18 years of age were randomly selected from 30 of 31 mainland provinces, excluding Tibet. Unaided distance VA was measured using a retroilluminated logMAR chart with tumbling-E optotypes. World Population Prospects data (the 2012 revision from the Population Division of the Department of Economic and Social Affairs of the United Nations) were used to project the number of people affected by reduced VA in 2020 and 2030. This analysis included 725 423, 142 655, 206 601, 219 663, 234 377, and 215 308 students in 1985, 1991, 1995, 2000, 2005, and 2010, respectively. The overall prevalence of reduced VA was 28.6% (95% CI, 28.4%-28.7%) in 1985, 38.6% (95% CI, 38.3%-38.8%) in 1991, 41.0% (95% CI, 40.8%-41.2%) in 1995, 38.5% (95% CI, 38.3%-38.7%) in 2000, 49.5% (95% CI, 49.3%-49.7%) in 2005, and 56.8% (95% CI, 56.6%-57.0%) in 2010. Girls were more susceptible than boys to having reduced VA (odds ratio, 1.38 [95% CI, 1.35-1.40]), and reduced VA was more prevalent in urban areas than in rural areas (odds ratio, 1.84 [95% CI, 1.81-1.87]). Reduced VA was not significantly associated with population density (P = .11). The projected numbers of cases with reduced VA are about 152.4 million (95% CI, 151.9-152.9 million) in 2020, increasing to 180.4 million (95% CI, 179.8-181.2 million) in 2030 among students who are 7 to 18 years of age in mainland China. There was

  16. 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.

  17. Avaliação da acuidade visual e da pressão intraocular no tratamento do edema macular diabético com triancinolona intravítrea Study of visual acuity and intraocular pressure in the treatment of macular diabetic edema with intravitreous triamcinolone

    Directory of Open Access Journals (Sweden)

    Marcussi Palata Rezende

    2010-04-01

    Full Text Available OBJETIVOS: Avaliar os efeitos do acetato de triancinolona intravítreo em pacientes com edema macular diabético difuso na acuidade visual e pressão intraocular. Relatar os possíveis efeitos adversos e analisar a possível relação da idade dos pacientes com as variações da acuidade visual e pressão intraocular. MÉTODOS: O ensaio clínico controlado incluiu 14 pacientes (28 olhos, sendo que 14 olhos receberam injeção de 4 mg de acetato de triancinolona intravítreo para o tratamento de edema macular diabético difuso. O grupo tratado foi comparado a um grupo controle de 14 olhos sem edema macular diabético difuso. O tempo de seguimento foi de três meses. RESULTADOS: Os picos de pressão intraocular >21 mmHg ocorreram em 28,57%, com diferença significante entre a pressão intraocular do grupo tratado com o grupo controle na primeira semana após o tratamento. A acuidade visual mostrou uma significativa melhora quando comparada com o grupo controle desde o segundo dia após o tratamento. Não houve associação entre a idade com as variações da acuidade visual e a pressão intraocular. CONCLUSÃO: O acetato de triancinolona intravítreo mostrou-se ser eficiente para melhorar a acuidade visual em pacientes com edema macular diabético difuso, nos primeiros três meses de tratamento. A incidência de hipertensão intraocular foi de 28,57%, podendo ser caracterizada como de fácil controle.PURPOSE: To evaluate the effect of intravitreal triamcinolone acetonide in patients with diffuse diabetic macular edema on the visual acuity and intraocular pressure. To report the potential adverse events and to analyze the potential relationship between age and visual acuity and intraocular pressure variability. METHODS: This clinical controlled study included 14 patients (28 eyes, 14 of the eyes received an intravitreal injection of 4 mg triamcinolone acetonide for the treatment of diabetic macular edema. The study group was compared to a control

  18. 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

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    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

  19. Assessment of visual disability using visual evoked potentials

    Directory of Open Access Journals (Sweden)

    Jeon Jihoon

    2012-08-01

    Full Text Available Abstract Background 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. Methods 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. Results 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

  20. 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

  1. Dynamic visual acuity (DVA) during locomotion for targets at near and far distances: effects of aging, walking speed and head-trunk coupling.

    Science.gov (United States)

    Deshpande, Nandini; Tourtillott, Brandon M; Peters, Brian T; Bloomberg, Jacob J

    2013-01-01

    This study examined effects of aging, head-trunk coupling (HTcoupling) and walking speed on dynamic visual acuity (DVA) at near and far viewing distances. Ten healthy participants were recruited in 3 groups; young: 20-33 years, Older1: 65-74 years, Older2: 75-85 years. The binocular DVA was measured while walking on a treadmill at 0.75 and 1.5 m/s speeds. The optotype display was placed at 0.5 m for NearDVA and at 3.0 m for FarDVA. On randomly selected trials, HTcoupling was achieved by using a collar. A mix-factor ANOVA (age-group x HTcoupling x speed) was performed separately for the Near and FarDVA. NearDVA declined with HTcoupling (p=0.021). Additionally, NearDVA worsened at the faster speed (p< 0.001). At 1.5 m/s speed the differences between Young and Older2 groups were significant (p=0.012) and those between Older1 and Older2 were marginal (p=0.085). FarDVA declined at the faster speed (p< 0.001) with no effect of HTcoupling or age-group. NearDVA is more sensitive to normal aging process. These age-related deficits become more apparent at higher walking speeds. Effect of HTcoupling on NearDVA suggests a possible additive effect of insufficient dampening of the vertical movement of the overall head-trunk complex and inability of the linear vestibulo-ocular reflex to compensate for the consequent high discrepancy.

  2. Local control and visual acuity following treatment of medium-sized ocular melanoma using a contact eye plaque: a single surgeon experience.

    Science.gov (United States)

    Karlovits, Brian; Trombetta, Mark G; Verstraeten, Thierry; Johnson, Mark; Wong, Michael; Karlovits, Stephen

    2011-01-01

    To evaluate the outcomes of choroidal melanoma in (CM) patients treated with (125)I episcleral plaque brachytherapy and to compare our single surgeon results with the multi-institutional Collaborative Ocular Melanoma Study (COMS). A review was performed of all CM patients treated with (125)I episcleral plaque brachytherapy by ophthalmologist in accordance with established COMS guidelines. The records of 35 patients were reviewed. The median longest basal tumor diameter and apical tumor height was 13.5 and 7.8mm, respectively. Median dose to the apex was 8609 cGy at a median dose rate of 92 cGy/h. At a median followup of 45 months, 35 patients had local control and 33 had successful organ preservation. At 5 years, the local control rate was 100%, and the eye preservation rate was 94%. Five patients developed hepatic metastasis at a median of 58 months, and 2 succumbed from disease. The 5-year survival rate was 84%, and the 5-year rate of death with histopathologically confirmed metastasis was 15%. Of the 22 patients with at least 3 years of followup, 68% had a visual acuity in the treated eye of 20/200 or worse. Excellent local control, eye preservation rates, and survival outcomes following (125)I episcleral plaque application for CM can be optimized by having an experienced ophthalmologist place the plaques. Additionally, hepatic metastasis can occur more than 5 years postimplant regardless of local control; therefore, longer systemic staging should be considered. Copyright © 2011 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  3. Reliability of visual acuity measurements taken with a notebook and a tablet computer in participants who were illiterate to Roman characters.

    Science.gov (United States)

    Ruamviboonsuk, Paisan; Sudsakorn, Napitchareeya; Somkijrungroj, Thanapong; Engkagul, Chayanee; Tiensuwan, Montip

    2012-03-01

    Electronic measurement of visual acuity (VA) has been proposed and adopted as a method of determining VA scores in clinical research. Characters (optotypes) are displayed on a monitor screen and the examinee selects a match and inputs his choice to another electronic device. Unfortunately, the optotypes, called Sloan letters, in the standard protocol are 10 Roman characters. This limits their practicabilityfor measuring VA of patients who are illiterate to these characters. The authors introduced a method of displaying the Sloan letters one by one on a notebook and all 10 Sloan letters on a tablet computer screen. The former is for testing the patients whereas the latter is for them to input their responses by tapping on a letter that matches the one on the notebook screen. To assess test-retest reliability of VA scores determined with this method. Participants without ocular abnormality were recruited to have their right eyes measured with the same VA measurement method twice, one week apart. Those who were illiterate to Roman characters were enrolled for the aforementioned method for measuring their VA (Tablet group). A 15-inch display notebook computer and a 9-inch display tablet computer (iPad) communicated via a local wireless data network provided by a Wi-Fi router. Those who understood Roman characters were enrolled to have measurements with a 17-inch desktop computer and an infrared wireless keyboard (Keyboard group). Both methods used the same protocols and software for VA measurements. Reliability of VA scores obtained from each group was assessed by the confidence interval (CI) of the difference of the scores from the test and retest. The t test was used to analyze differences in mean VA scores between the test and retest in each group with p international clinical trials without encountering a language barrier

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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

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

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    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.

  11. 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 ...

  12. Developing a Logarithmic Chinese Reading Acuity Chart.

    Science.gov (United States)

    Han, Qi-Ming; Cong, Lin-Juan; Yu, Cong; Liu, Lei

    2017-06-01

    An individual's reading ability cannot be reliably predicted from his/her letter acuity, contrast sensitivity, and visual field extent. We developed a set of Chinese reading acuity charts (C-READ) to assess the reading ability of Chinese readers, based on the collective wisdom of previously published reading acuity charts, especially the MNRead and the Radner Reading Charts. The C-READ consists of three charts. Each consists sixteen 12-character simplified Chinese sentences crafted from first- to third-grade textbooks. One hundred eighteen native Chinese-speaking college students (aged 22.1 ± 2.1 years) with normal or corrected to normal near vision (-0.26 ± 0.05 logMAR) were included in the study to develop the C-READ charts, to test the homogeneity of the three charts, and to validate the C-READ against the text paragraphs from the International Reading Speed Texts (IReST) with corrected and uncorrected near vision. The reading acuity, critical print size, and maximum reading speed for young normal native Chinese-speaking readers were 0.16 ± 0.05 logMAR, 0.24 ± 0.06 logMAR, and 273.44 ± 34.37 characters per minute (mean ± SD), respectively. The reliability test revealed no significant differences among the three C-READ charts and no significant test order effect in the three reading parameters. Regression analyses showed that the IReST reading speed could be reliably predicted by the C-READ maximum reading speed under the corrected near-vision condition (adjusted R = 0.72) and by C-READ maximum reading speed and critical print size under the uncorrected near-vision condition (adjusted R = 0.69). The three C-READ charts are very comparable to each other, and there is no significant order effect. Reading test results can accurately predict continuous text reading performance quantified by the IReST reading speed over a wide range of refractive errors. The C-READ is a reliable and valid clinical instrument for quantifying reading performance in simplified

  13. [Functional results of cryosurgical procedures in rhegmatogenous retinal detachment including macula region - our experience].

    Science.gov (United States)

    Chrapek, O; Sín, M; Jirková, B; Jarkovský, J; Rehák, J

    2013-10-01

    Aim of this study is to evaluate retrospectively functional results of cryosurgical treatment of uncomplicated, idiopathic rhegmatogenous retinal detachment including macula region in phakic patients operated on at the Department of Ophthalmology, Faculty Hospital, Palacký University, Olomouc, Czech Republic, E.U., during the period 2002 -2013, and to evaluate the significance of the macula detachment duration for the final visual acuity. In the study group were included 56 eyes of 56 patients operated in the years 2003 - 2012 at the Department of Ophthalmology, Faculty Hospital, Palacký University, Olomouc. All patients were phakic and in all of them, the retinal detachment including the macula region was diagnosed. The mean follow-up period of the patients was 8,75 months. The initial and final visual acuity testing were performed. Comparing the initial and final visual acuity we rated the level of the visual acuity change. The result was stated as improved, if the visual acuity improved by 1 or more lines on the ETDRS chart. The result was rated as stabilized, if the visual acuity remained the same or it changed by 1 line of the ETDRS chart only. The result was evaluated as worsened, if the visual acuity decreased by 1 or more lines of the ETDRS chart. In the followed-up group, the authors compared visual acuity levels in patients with the macula detachment duration 10 days and 11 days. For the statistical evaluation of achieved results, the Mann - Whitney U test was used. The visual acuity improved in 49 (87 %), did not changed in 5 (9 %) and worsened in 2 (4 %) patients. The patients with macula detachment duration 10 days achieved statistically significant better visual acuity than patients with macula detachment duration 11 days. Patients with macula detachment duration 10 days have better prognosis for functional result than patients with macula detachment duration 11 days.

  14. Analysis: including visually impaired participants in validation design studies of diabetes technology.

    Science.gov (United States)

    Uslan, Mark; Blubaugh, Morgan

    2010-09-01

    In an article in this issue of Journal of Diabetes Science and Technology, Sherwyn Schwartz, M.D., presents a study to validate the design of the ClikSTAR® insulin pen from sanofi-aventis and demonstrates that the device can be used correctly by participants with diabetes. Concern with this article lies with the selection of participants, which was meant to reflect the intended audience for the insulin pen device but does not address the inclusion of visually impaired individuals, who comprise over 20% of the adult diabetes population. Visually impaired individuals need to be included as part of the intended audience for insulin administration technology, and manufacturers of these devices need to design their products for safe use by all people, including those who are visually impaired. The study demonstrated successful use of the ClikSTAR insulin pen in a population that did not include subjects with severe visual impairment. We believe that future validation studies for insulin administration technology should also include samples of visually impaired users and that visually impaired patients will embrace the use of insulin pens designed with their needs in mind. © 2010 Diabetes Technology Society.

  15. 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.

  16. Effects of Reduced Acuity and Stereo Acuity on Saccades and Reaching Movements in Adults With Amblyopia and Strabismus.

    Science.gov (United States)

    Niechwiej-Szwedo, Ewa; Goltz, Herbert C; Colpa, Linda; Chandrakumar, Manokaraananthan; Wong, Agnes M F

    2017-02-01

    Our previous work has shown that amblyopia disrupts the planning and execution of visually-guided saccadic and reaching movements. We investigated the association between the clinical features of amblyopia and aspects of visuomotor behavior that are disrupted by amblyopia. A total of 55 adults with amblyopia (22 anisometropic, 18 strabismic, 15 mixed mechanism), 14 adults with strabismus without amblyopia, and 22 visually-normal control participants completed a visuomotor task while their eye and hand movements were recorded. Univariate and multivariate analyses were performed to assess the association between three clinical predictors of amblyopia (amblyopic eye [AE] acuity, stereo sensitivity, and eye deviation) and seven kinematic outcomes, including saccadic and reach latency, interocular saccadic and reach latency difference, saccadic and reach precision, and PA/We ratio (an index of reach control strategy efficacy using online feedback correction). Amblyopic eye acuity explained 28% of the variance in saccadic latency, and 48% of the variance in mean saccadic latency difference between the amblyopic and fellow eyes (i.e., interocular latency difference). In contrast, for reach latency, AE acuity explained only 10% of the variance. Amblyopic eye acuity was associated with reduced endpoint saccadic (23% of variance) and reach (22% of variance) precision in the amblyopic group. In the strabismus without amblyopia group, stereo sensitivity and eye deviation did not explain any significant variance in saccadic and reach latency or precision. Stereo sensitivity was the best clinical predictor of deficits in reach control strategy, explaining 23% of total variance of PA/We ratio in the amblyopic group and 12% of variance in the strabismus without amblyopia group when viewing with the amblyopic/nondominant eye. Deficits in eye and limb movement initiation (latency) and target localization (precision) were associated with amblyopic acuity deficit, whereas changes in

  17. 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).

  18. Effect of 1% Inspired CO2 During Head-Down Tilt on Ocular Structures, Cerebral Blood Flow, and Visual Acuity in Healthy Human Subjects

    Science.gov (United States)

    Laurie, S. S.; Hu, X.; Lee, S. M. C.; Martin, D. S.; Phillips, T. R.; Ploutz-Snyder, R.; Smith, S. M.; Stenger, M. B.; Taibbi, G.; Zwart, S. R.; hide

    2016-01-01

    The cephalad fluid shift induced by microgravity has been hypothesized to elevate intracranial pressure (ICP) and contribute to the development of the visual impairment/intracranial pressure (VIIP) syndrome experienced by many astronauts during and after long-duration space flight. In addition, elevated ambient partial pressure of carbon dioxide (PCO2) on the International Space Station (ISS) has also been hypothesized to contribute to the development of VIIP. We seek to determine if an acute, mild CO2 exposure, similar to that occurring on the ISS, combined with the cephalad fluid shift induced by head-down tilt will induce ophthalmic and ICP changes consistent with the VIIP syndrome.

  19. Enhanced visual acuity with echogenic needles in ultrasound-guided axillary brachial plexus block: a randomized, comparative, observer-blinded study.

    Science.gov (United States)

    Abbal, B; Choquet, O; Gourari, A; Bouic, N; Massone, A; Biboulet, P; Bringuier, S; Capdevila, X

    2015-04-01

    We prospectively evaluated the effect of insertion angle on the visibility of echogenic and nonechogenic needles in phantoms and in axillary nerve blocks in patients. Conventional and echogenic needles were studied in phantoms at insertion angles of 0-30°, 30-45°, and ≥ 45°. Operators rated comfort and image quality during the procedure and experts blinded to the needle groups randomly analyzed videos for tip and shaft visibility, surrounding tissue visibility, sharpness of the needle surface, and percentage of time with the needle completely visible. Patients scheduled for axillary nerve block were prospectively enrolled in the clinical study. Needle insertion angles were 0-30° for the median nerve approach, 30-45° for the radial nerve, and ≥ 45° for the musculocutaneous nerve. The same needle parameters were analyzed during the procedure and on videos. Physician comfort and image quality were significantly better for echogenic needles for phantoms and patients at 30-45° and ≥ 45° insertion angles. Needle tip and shaft visibility at 30-45° and ≥ 45° insertion angles in phantoms and for the musculocutaneous nerve in patients were significantly improved, as well as the percentage with complete needle visualization during the procedure. Tissue visibility and needle sharpness were significantly superior for conventional needles. There were no differences concerning block parameters and adverse events. Needles with enhanced echogenicity improved physician comfort, image quality, needle visibility, and visualization time of the needle during ultrasound-guided procedures in phantoms and axillary nerve blocks using insertion angles of 30-45° and ≥ 45°.

  20. 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.

  1. 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

  2. Merging Psychophysical and Psychometric Theory to Estimate Global Visual State Measures from Forced-Choices

    Science.gov (United States)

    Massof, Robert W.; Schmidt, Karen M.; Laby, Daniel M.; Kirschen, David; Meadows, David

    2013-09-01

    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.

  3. Spine surgeon's kinematics during discectomy, part II: operating table height and visualization methods, including microscope.

    Science.gov (United States)

    Park, Jeong Yoon; Kim, Kyung Hyun; Kuh, Sung Uk; Chin, Dong Kyu; Kim, Keun Su; Cho, Yong Eun

    2014-05-01

    Surgeon spine angle during surgery was studied ergonomically and the kinematics of the surgeon's spine was related with musculoskeletal fatigue and pain. Spine angles varied depending on operation table height and visualization method, and in a previous paper we showed that the use of a loupe and a table height at the midpoint between the umbilicus and the sternum are optimal for reducing musculoskeletal loading. However, no studies have previously included a microscope as a possible visualization method. The objective of this study is to assess differences in surgeon spine angles depending on operating table height and visualization method, including microscope. We enrolled 18 experienced spine surgeons for this study, who each performed a discectomy using a spine surgery simulator. Three different methods were used to visualize the surgical field (naked eye, loupe, microscope) and three different operating table heights (anterior superior iliac spine, umbilicus, the midpoint between the umbilicus and the sternum) were studied. Whole spine angles were compared for three different views during the discectomy simulation: midline, ipsilateral, and contralateral. A 16-camera optoelectronic motion analysis system was used, and 16 markers were placed from the head to the pelvis. Lumbar lordosis, thoracic kyphosis, cervical lordosis, and occipital angle were compared between the different operating table heights and visualization methods as well as a natural standing position. Whole spine angles differed significantly depending on visualization method. All parameters were closer to natural standing values when discectomy was performed with a microscope, and there were no differences between the naked eye and the loupe. Whole spine angles were also found to differ from the natural standing position depending on operating table height, and became closer to natural standing position values as the operating table height increased, independent of the visualization method

  4. 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.

  5. Cerebral versus Ocular Visual Impairment: The Impact on Developmental Neuroplasticity

    OpenAIRE

    Mart?n, Maria B. C.; Santos-Lozano, Alejandro; Mart?n-Hern?ndez, Juan; L?pez-Miguel, Alberto; Maldonado, Miguel; Baladr?n, Carlos; Bauer, Corinna M.; Merabet, Lotfi B.

    2016-01-01

    Cortical/cerebral visual impairment (CVI) is clinically defined as significant visual dysfunction caused by injury to visual pathways and structures occurring during early perinatal development. Depending on the location and extent of damage, children with CVI often present with a myriad of visual deficits including decreased visual acuity and impaired visual field function. Most striking, however, are impairments in visual processing and attention which have a significant impact on learning,...

  6. 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.

  7. Acuity Assessment in Obstetrical Triage.

    Science.gov (United States)

    Gratton, Robert J; Bazaracai, Neila; Cameron, Ian; Watts, Nancy; Brayman, Colleen; Hancock, Gregg; Twohey, Rachel; AlShanteer, Suhair; Ryder, Jennifer E; Wodrich, Kathryn; Williams, Emily; Guay, Amélie; Basso, Melanie; Smithson, David S

    2016-02-01

    A five-category Obstetrical Triage Acuity Scale (OTAS) was developed with a comprehensive set of obstetrical determinants. The purposes of this study were: (1) to compare the inter-rater reliability (IRR) in tertiary and community hospital settings and measure the intra-rater reliability (ITR) of OTAS; (2) to establish the validity of OTAS; and (3) to present the first revision of OTAS from the National Obstetrical Triage Working Group. To assess IRR, obstetrical triage nurses were randomly selected from London Health Sciences Centre (LHSC) (n = 8), Stratford General Hospital (n = 11), and Chatham General Hospital (n= 7) to assign acuity levels to clinical scenarios based on actual patient visits. At LHSC, a group of nurses were retested at nine months to measure ITR. To assess validity, OTAS acuity level was correlated with measures of resource utilization. OTAS has significant and comparable IRR in a tertiary care hospital and in two community hospitals. Repeat assessment in a cohort of nurses demonstrated significant ITR. Acuity level correlated significantly with performance of routine and second order laboratory investigations, point of care ultrasound, nursing work load, and health care provider attendance. A National Obstetrical Triage Working Group was formed and guided the first revision. Four acuity modifiers were added based on hemodynamics, respiratory distress, cervical dilatation, and fetal well-being. OTAS is the first obstetrical triage scale with established reliability and validity. OTAS enables standardized assessments of acuity within and across institutions. Further, it facilitates assessment of patient care and flow based on acuity. Copyright © 2016 Society of Obstetricians and Gynaecologists of Canada. Published by Elsevier Inc. All rights reserved.

  8. Prevalence of visual impairment and uncorrected refractive error - report from a Canadian urban population-based study.

    Science.gov (United States)

    Robinson, Barbara; Feng, Yunwei; Woods, Craig A; Fonn, Desmond; Gold, Deborah; Gordon, Keith

    2013-06-01

    The prevalence of visual impairment due to uncorrected refractive error has not been previously studied in Canada. A population-based study was conducted in Brantford, Ontario. The target population included all people 40 years of age and older. Study participants were selected using a randomized sampling strategy based on postal codes. Presenting distance and near visual acuities were measured with habitual spectacle correction, if any, in place. Best corrected visual acuities were determined for all participants who had a presenting distance visual acuity of less than 20/25. Population weighted prevalence of distance visual impairment (visual acuity refraction. Population weighted prevalence of near visual impairment (visual acuity refraction. Multivariable adjusted analysis showed that the odds of having distance visual impairment was independently associated with increased age (odds ratio, OR, 3.56, 95% CI 1.22-10.35; ≥65 years compared to those 39-64 years), and time since last eye examination (OR 4.93, 95% CI 1.19-20.32; ≥5 years compared to ≤2 years). The same factors appear to be associated with increased prevalence of near visual impairment but were not statistically significant. The majority of visual impairment found in Brantford was due to uncorrected refractive error. Factors that increased the prevalence of visual impairment were the same for distance and near visual acuity measurements.

  9. Visual Symptoms in Parkinson's Disease

    OpenAIRE

    R. A. Armstrong

    2011-01-01

    Parkinson’s disease (PD) is a common disorder of middle-aged and elderly people in which degeneration of the extrapyramidal motor system causes significant movement problems. In some patients, however, there are additional disturbances in sensory systems including loss of the sense of smell and auditory and/or visual problems. This article is a general overview of the visual problems likely to be encountered in PD. Changes in vision in PD may result from alterations in visual acuity, contrast...

  10. Results of Screening in Schools for Visually Impaired Children.

    Science.gov (United States)

    Bingöl Kızıltunç, Pınar; İdil, Aysun; Atilla, Hüban; Topalkara, Ayşen; Alay, Cem

    2017-08-01

    The aim of this study was to identify the causes of visual impairment in children attending schools for students with visual impairment and to identify children suitable for treatment and rehabilitation. All students were examined in our department by a pediatric ophthalmologist and an ophthalmologist experienced in low vision and visual rehabilitation. The children's medical histories were recorded. All children underwent ophthalmological examination including visual acuity measurement, anterior segment and dilated fundus evaluation, retinoscopy with cycloplegia, and intraocular pressure measurement. The causes of visual impairment were grouped as avoidable and unavoidable. Children with residual visual acuity better than 20/1250 were included in the low vision rehabilitation programme. A total of 120 patients were evaluated and 79.2% were legally blind (visual acuity less than 0.05), 18.4% had low vision (visual acuity between 0.05 and 0.3), and 0.8% had normal vision (>0.3). The main causes of visual impairment were retinal dystrophies (24.2%) and retinopathy of prematurity (17.5%). Of all diseases related to visual impairment, 27.6% were avoidable. Improvement in visual acuity was achieved with low vision aids in 57.5% of all patients. The incidence of visual impairment due to avoidable causes can be decreased by ophthalmic screening. Treatment of these children in the early stages of visual development can improve visual acuity. Even in cases with delayed diagnosis, low vision aids are important for visual and neurobehavioral development, and these programmes may improve quality of life and education in these children.

  11. Results of Screening in Schools for Visually Impaired Children

    Directory of Open Access Journals (Sweden)

    Pınar Bingöl Kızıltunç

    2017-08-01

    Full Text Available Objectives: The aim of this study was to identify the causes of visual impairment in children attending schools for students with visual impairment and to identify children suitable for treatment and rehabilitation. Materials and Methods: All students were examined in our department by a pediatric ophthalmologist and an ophthalmologist experienced in low vision and visual rehabilitation. The children’s medical histories were recorded. All children underwent ophthalmological examination including visual acuity measurement, anterior segment and dilated fundus evaluation, retinoscopy with cycloplegia, and intraocular pressure measurement. The causes of visual impairment were grouped as avoidable and unavoidable. Children with residual visual acuity better than 20/1250 were included in the low vision rehabilitation programme. Results: A total of 120 patients were evaluated and 79.2% were legally blind (visual acuity less than 0.05, 18.4% had low vision (visual acuity between 0.05 and 0.3, and 0.8% had normal vision (>0.3. The main causes of visual impairment were retinal dystrophies (24.2% and retinopathy of prematurity (17.5%. Of all diseases related to visual impairment, 27.6% were avoidable. Improvement in visual acuity was achieved with low vision aids in 57.5% of all patients. Conclusion: The incidence of visual impairment due to avoidable causes can be decreased by ophthalmic screening. Treatment of these children in the early stages of visual development can improve visual acuity. Even in cases with delayed diagnosis, low vision aids are important for visual and neurobehavioral development, and these programmes may improve quality of life and education in these children.

  12. A biologically inspired neural model for visual and proprioceptive integration including sensory training.

    Science.gov (United States)

    Saidi, Maryam; Towhidkhah, Farzad; Gharibzadeh, Shahriar; Lari, Abdolaziz Azizi

    2013-12-01

    Humans perceive the surrounding world by integration of information through different sensory modalities. Earlier models of multisensory integration rely mainly on traditional Bayesian and causal Bayesian inferences for single causal (source) and two causal (for two senses such as visual and auditory systems), respectively. In this paper a new recurrent neural model is presented for integration of visual and proprioceptive information. This model is based on population coding which is able to mimic multisensory integration of neural centers in the human brain. The simulation results agree with those achieved by casual Bayesian inference. The model can also simulate the sensory training process of visual and proprioceptive information in human. Training process in multisensory integration is a point with less attention in the literature before. The effect of proprioceptive training on multisensory perception was investigated through a set of experiments in our previous study. The current study, evaluates the effect of both modalities, i.e., visual and proprioceptive training and compares them with each other through a set of new experiments. In these experiments, the subject was asked to move his/her hand in a circle and estimate its position. The experiments were performed on eight subjects with proprioception training and eight subjects with visual training. Results of the experiments show three important points: (1) visual learning rate is significantly more than that of proprioception; (2) means of visual and proprioceptive errors are decreased by training but statistical analysis shows that this decrement is significant for proprioceptive error and non-significant for visual error, and (3) visual errors in training phase even in the beginning of it, is much less than errors of the main test stage because in the main test, the subject has to focus on two senses. The results of the experiments in this paper is in agreement with the results of the neural model

  13. the evaluation of vision in children using monocular vision acuity ...

    African Journals Online (AJOL)

    INTRODUCTION. Monocular visual acuity (VA) is a direct method of detecting amblyopia, a leading cause of monocular vision loss in the 2 to 7years age group . Binocular vision is fully established by 6 moths of age, while fusion is consistently strengthened until the age of 6 years when it is fully developed . It was observed ...

  14. Gender differences in episodic memory and visual working memory including the effects of age.

    Science.gov (United States)

    Pauls, Franz; Petermann, Franz; Lepach, Anja Christina

    2013-01-01

    Analysing the relationship between gender and memory, and examining the effects of age on the overall memory-related functioning, are the ongoing goals of psychological research. The present study examined gender and age group differences in episodic memory with respect to the type of task. In addition, these subgroup differences were also analysed in visual working memory. A sample of 366 women and 330 men, aged between 16 and 69 years of age, participated in the current study. Results indicate that women outperformed men on auditory memory tasks, whereas male adolescents and older male adults showed higher level performances on visual episodic and visual working memory measures. However, the size of gender-linked effects varied somewhat across age groups. Furthermore, results partly support a declining performance on episodic memory and visual working memory measures with increasing age. Although age-related losses in episodic memory could not be explained by a decreasing verbal and visuospatial ability with age, women's advantage in auditory episodic memory could be explained by their advantage in verbal ability. Men's higher level visual episodic memory performance was found to result from their advantage in visuospatial ability. Finally, possible methodological, biological, and cognitive explanations for the current findings are discussed.

  15. Prevalence of visual impairment in the United States.

    Science.gov (United States)

    Vitale, Susan; Cotch, Mary Frances; Sperduto, Robert D

    2006-05-10

    The prevalence of visual impairment in the US public has not been surveyed nationally in several decades. To estimate the number of US individuals aged 12 years or older who have impaired distance vision due to uncorrected refractive error. The National Health and Nutrition Examination Survey (NHANES), using a multistage probability sampling design, included a vision evaluation in a mobile examination center. Visual acuity data were obtained from 13,265 of 14,203 participants (93.4%) who visited the mobile examination center in 1999-2002. Visual impairment was defined as presenting distance visual acuity of 20/50 or worse in the better-seeing eye. Visual impairment due to uncorrected refractive error was defined as (presenting) visual impairment that improved, aided by automated refraction results, to 20/40 or better in the better-seeing eye. Presenting distance visual acuity (measured with usual corrective lenses, if any) and distance visual acuity after automated refraction. Overall, 1190 study participants had visual impairment (weighted prevalence, 6.4%; 95% confidence interval [CI], 6.0%-6.8%), and of these, 83.3% could achieve good visual acuity with correction (95% CI, 80.9%-85.8%). Extrapolating these findings to the general US population, approximately 14 million individuals aged 12 years or older have visual impairment (defined as distance visual acuity of 20/50 or worse), and of these, more than 11 million individuals could have their vision improved to 20/40 or better with refractive correction. Visual impairment due to uncorrected refractive error is a common condition in the United States. Providing appropriate refractive correction to those individuals whose vision can be improved is an important public health endeavor with implications for safety and quality of life.

  16. Repeatability of Monocular Acuity Testing in Adults with and without Down Syndrome.

    Science.gov (United States)

    Ravikumar, Ayeswarya; Benoit, Julia S; Morrison, Kelsie B; Marsack, Jason D; Anderson, Heather A

    2018-03-01

    Individuals with Down syndrome may experience greater difficulty reliably performing visual acuity (VA) tests because of intellectual disability and limitations in visual quality. This study evaluated the repeatability of acuity (Bailey-Lovie [BL] and HOTV) in subjects with and without Down syndrome. High-contrast VA was measured in both eyes of 30 subjects with Down syndrome (mean, 30 years; range, 18 to 50 years) and 24 control subjects without Down syndrome (mean, 29 years; range, 18 to 50 years). In the Down syndrome group, 23 subjects performed BL, and 7 subjects performed HOTV. All control subjects performed both BL and HOTV, but for HOTV analysis, only seven age-matched control subjects were included. For each eye, subjects performed VA three times on different charts (computer controlled, single-line display) until five total letters were missed on each chart. A repeated-measure ANOVA was used to compare the acuity measures between groups. The average logMAR VA for subjects with Down syndrome was approximately six lines worse than the control subjects (BL: Down syndrome = right eye: 0.51 ± 0.16, left eye: 0.53 ± 0.18; control = right eye: -0.06 ± 0.06, left eye: -0.06 ± 0.08, P Down syndrome = right eye: 0.47 ± 0.19, left eye: 0.46 ± 0.16; control: right eye = -0.11 ± 0.09, left eye: -0.07 ± 0.07, P Down syndrome and 0.09 logMAR (4.5 letters) for control subjects. HOTV VA repeatability was 0.16 logMAR (eight letters) for both Down syndrome and control subjects. Despite poorer acuity in individuals with Down syndrome, repeatability of VA measurements was comparable to control subjects for both BL and HOTV techniques.

  17. 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.

  18. 45 CFR 1308.13 - Eligibility criteria: Visual impairment including blindness.

    Science.gov (United States)

    2010-10-01

    ... correction, adversely affects a child's learning. The term includes both blind and partially seeing children... OF HUMAN DEVELOPMENT SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES THE ADMINISTRATION FOR CHILDREN, YOUTH AND FAMILIES, HEAD START PROGRAM HEAD START PROGRAM PERFORMANCE STANDARDS ON SERVICES FOR...

  19. Evolutionary analysis of vision genes identifies potential drivers of visual differences between giraffe and okapi

    OpenAIRE

    Ishengoma, Edson; Agaba, Morris; Cavener, Douglas R.

    2017-01-01

    Background The capacity of visually oriented species to perceive and respond to visual signal is integral to their evolutionary success. Giraffes are closely related to okapi, but the two species have broad range of phenotypic differences including their visual capacities. Vision studies rank giraffe’s visual acuity higher than all other artiodactyls despite sharing similar vision ecological determinants with many of them. The extent to which the giraffe’s unique visual capacity and its diffe...

  20. Accommodation, acuity, and their relationship to emmetropization in infants.

    Science.gov (United States)

    Mutti, Donald O; Mitchell, G Lynn; Jones, Lisa A; Friedman, Nina E; Frane, Sara L; Lin, Wendy K; Moeschberger, Melvin L; Zadnik, Karla

    2009-06-01

    To evaluate the relationship between accommodation, visual acuity, and emmetropization in human infancy. Defocus at distance and near (57 cm) was assessed using Mohindra and dynamic retinoscopy, respectively, in 262 normal birthweight infants at 3, 9, and 18 months of age. Preferential looking provided acuity data at the same ages. The spherical equivalent refractive error was measured by cycloplegic retinoscopy (cyclopentolate 1%). Univariate linear regression analyses showed no associations between the change in refractive error and defocus at distance or near. Change in refractive error was linearly related to the accommodative response at distance (R = 0.17, p < 0.0001) and near (R = 0.13, p < 0.0001). The ten subjects with the poorest emmetropization relative to the change predicted by the linear effects of their refractive error had higher average levels of hyperopic defocus at distance and near (p < 0.043). Logistic regression showed a decrease in the odds of reaching +2.00 diopter or less hyperopia by 18 months with increasing levels of hyperopia at 3 months, or if Mohindra retinoscopy was myopic combined with acuity better than the median level of 1.25 logMAR [area under the receiver operating characteristic curve = 0.78 (95% CI = 0.68 to 0.88)]. The level of cycloplegic refractive error was the best single factor for predicting emmetropization by 18 months of age, with smaller contributions from visual acuity and Mohindra retinoscopy. The lack of correlation between defocus and change in refractive error does not support a simple model of emmetropization in response to the level of hyperopic defocus. Infants were capable of maintaining accurate average levels of accommodation across a range of moderate hyperopic refractive errors at 3 months of age. The association between the change in refractive error and accommodative response suggests that accommodation is a plausible visual signal for emmetropization.

  1. Age-specific prevalence and causes of blindness and visual impairment in an older population: the Rotterdam Study

    NARCIS (Netherlands)

    Klaver, C. C.; Wolfs, R. C.; Vingerling, J. R.; Hofman, A.; de Jong, P. T.

    1998-01-01

    To study the prevalence and causes of blindness and visual impairment in various age categories of a large population-based study. For the study, 6775 subjects aged 55 years or older underwent an extensive ophthalmologic screening examination, including measurements of visual acuity and the visual

  2. Visual rehabilitation and outcomes for ectasia after corneal refractive surgery.

    Science.gov (United States)

    Woodward, Maria A; Randleman, J Bradley; Russell, Buddy; Lynn, Michael J; Ward, Michael A; Stulting, R Doyle

    2008-03-01

    To analyze the visual outcomes and method of final visual correction in eyes with corneal ectasia after laser in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK). Emory University Department of Ophthalmology and Emory Vision, Atlanta, Georgia, USA. This retrospective review comprised 74 eyes of 45 patients with corneal ectasia after LASIK (72 eyes) or PRK (2 eyes). Outcomes included postoperative uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), best corrected visual acuity (BCVA), and refraction; method of final visual correction; and time to rigid gas-permeable (RGP) contact lens failure. Corneal ectasia developed a mean of 19.2 months after surgery. Postoperatively, the mean UCVA was 20/400 and the mean BSCVA before ectasia management was 20/108. After ectasia management, the mean BCVA was 20/37 and the final BCVA was 20/40 or better in 78% of eyes. Final visual correction was achieved with RGP lenses in 77% of eyes, spectacles in 9%, collagen crosslinking in 3%, intracorneal ring segments in 1%, and penetrating keratoplasty (PKP) in 8%. Two eyes with intracorneal ring segments required segment explantation and subsequent PKP. One eye that had PKP had a graft-rejection episode; there were no graft failures. Two eyes (3%) did not require a visual device to improve visual acuity. The mean time for successful RGP lens wear was 24.8 months; 80% of cases initially managed with RGP lenses were successful with this form of treatment. The majority of eyes developing postoperative corneal ectasia achieved functional visual acuity with RGP lens wear and did not require further intervention. Penetrating keratoplasty can usually be postponed or avoided by alternative methods of visual rehabilitation; however, PKP, when necessary, can provide good visual outcomes.

  3. Visual Impairment, Including Blindness

    Science.gov (United States)

    ... explores its dimensions—let us say, a stuffed animal, a dog, a salt shaker, or a CD ... tests, treatments, surgery, diseases and conditions, and the anatomy of the eye. The glossary’s online at: http:// ...

  4. Visual Quality Assessment of Posterior Capsule Opacification Using Optical Quality Analysis System (OQAS

    Directory of Open Access Journals (Sweden)

    Hui Zhang

    2017-01-01

    Full Text Available Objective. To evaluate intraocular scattering in eyes with posterior capsule opacification by means of an objective scatter index (OSI obtained from double-pass images of optical quality assessment system (OQAS TM II and to determine the indication for laser capsulotomy when patients report visual disturbances without decreased visual acuity. Methods. In this prospective, observational, and nonconsecutive case series study, a total of 32 eyes of 29 patients are diagnosed with posterior capsule opacification after age-associated cataract were analyzed. Patient examination included age, the period after cataract surgery, logMAR best corrected visual acuity (BCVA, and OSI. Results. We found a significant decrease in the BCVA and increase in the OSI with the development of posterior capsule opacification. The decrease of BCVA was statistically correlated with the increase of OSI (r=0.812, P<0.01. In patients who reported visual disturbances without decreased visual acuity, OSI decreased to <1.3 and subjective symptoms were resolved in all cases although there was no significant improvement in visual acuity after laser capsulotomy. Conclusions. The results of our study showed that OSI is also a useful parameter for objectively evaluating posterior capsule opacification. OSI may help predict laser capsulotomy in patients who report visual disturbances without decreased visual acuity.

  5. Cortical Neural Activity Predicts Sensory Acuity Under Optogenetic Manipulation.

    Science.gov (United States)

    Briguglio, John J; Aizenberg, Mark; Balasubramanian, Vijay; Geffen, Maria N

    2018-02-21

    Excitatory and inhibitory neurons in the mammalian sensory cortex form interconnected circuits that control cortical stimulus selectivity and sensory acuity. Theoretical studies have predicted that suppression of inhibition in such excitatory-inhibitory networks can lead to either an increase or, paradoxically, a decrease in excitatory neuronal firing, with consequent effects on stimulus selectivity. We tested whether modulation of inhibition or excitation in the auditory cortex of male mice could evoke such a variety of effects in tone-evoked responses and in behavioral frequency discrimination acuity. We found that, indeed, the effects of optogenetic manipulation on stimulus selectivity and behavior varied in both magnitude and sign across subjects, possibly reflecting differences in circuitry or expression of optogenetic factors. Changes in neural population responses consistently predicted behavioral changes for individuals separately, including improvement and impairment in acuity. This correlation between cortical and behavioral change demonstrates that, despite the complex and varied effects that these manipulations can have on neuronal dynamics, the resulting changes in cortical activity account for accompanying changes in behavioral acuity. SIGNIFICANCE STATEMENT Excitatory and inhibitory interactions determine stimulus specificity and tuning in sensory cortex, thereby controlling perceptual discrimination acuity. Modeling has predicted that suppressing the activity of inhibitory neurons can lead to increased or, paradoxically, decreased excitatory activity depending on the architecture of the network. Here, we capitalized on differences between subjects to test whether suppressing/activating inhibition and excitation can in fact exhibit such paradoxical effects for both stimulus sensitivity and behavioral discriminability. Indeed, the same optogenetic manipulation in the auditory cortex of different mice could improve or impair frequency discrimination

  6. Radio Transmitters and Tower Locations, Layer includes all towers identified visually and include cellular and other communication towers., Published in 2008, 1:1200 (1in=100ft) scale, Noble County Government.

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Radio Transmitters and Tower Locations dataset current as of 2008. Layer includes all towers identified visually and include cellular and other communication towers..

  7. Gender differences in adapting driving behavior to accommodate visual health limitations.

    Science.gov (United States)

    Sarkin, Andrew J; Tally, Steven R; Wooldridge, Jennalee S; Choi, Kyle; Shieh, Marian; Kaplan, Robert M

    2013-12-01

    This study investigated whether men and women are equally likely to adapt their driving behaviors in response to visual limitations. Participants were 376 (222 women and 154 men) pre-surgical cataract patients from the Shiley Eye Center in La Jolla, California. All participants completed the National Eye Institute Visual Functioning Questionnaire, which assesses self-reported visual symptoms, functional limitations, and behaviors including driving during the day, at night, or in difficult conditions. Visual acuity was assessed using the log of the minimal angle of resolution (LogMAR) scale. There were no significant differences in LogMAR visual acuity between men and women who reported either that they stopped driving at night because of visual impairment or reported having no difficulty driving at night. Of participants who reported having difficulty driving at night, mean weighted LogMAR scores indicated significantly better visual acuity for women than men. There were no significant differences in LogMAR visual acuity between women and men in any of the difficult driving condition categories. Significantly more women than men reported that they stopped driving in difficult conditions because of eyesight, despite the lack of gender differences in visual acuity for this sample. We found no evidence that cataract disease had different effects on the visual acuity of older adult men and women. However, there was a significant difference between genders in self-reported driving behavior. It is possible that some women are more cautious or have less need to drive. However, failing to adapt driving behaviors to accommodate visual limitations may represent a potential behavioral public health risk for men.

  8. Visual loss after use of intraocular silicone oil associated with thinning of inner retinal layers

    DEFF Research Database (Denmark)

    Christensen, Ulrik C; la Cour, Morten

    2012-01-01

    Purpose: To investigate the incidence and cause of severe visual loss following use and removal of intraocular silicone oil (SiO) after uncomplicated vitrectomy and SiO injection for primary rhegmatogenous retinal detachment (RRD). Methods: Consecutive case series of 216 patients operated...... visual acuity =6/12 before surgery, where SiO had been removed, cataract surgery performed and no re-detachment had occurred. Examinations included best-corrected visual acuity (BCVA) and high-definition optical coherence tomography (OCT) of the macular area. Results: Preoperative characteristics were...

  9. 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.

  10. Training Improves Vibrotactile Spatial Acuity and Intensity Discrimination on the Lower Back Using Coin Motors.

    Science.gov (United States)

    Stronks, H Christiaan; Walker, Janine; Parker, Daniel J; Barnes, Nick

    2017-11-01

    Tactile vision substitution devices are assistive technologies for the blind that redirect visual information to the tactile sense. They typically include a tactile display that conveys visual information to the skin. Two important parameters that determine the maximum information bandwidth of tactile displays are the spatial acuity of the skin, and the ability of the user to discriminate between stimulus intensities. These two parameters were investigated by determining the two-point discrimination (TPD) threshold and the just-noticeable intensity difference (JND) using coin motors on the lower back. Coin motors are eccentric rotating-mass motors that are affordable, energy-efficient, and easy to implement. The lower back was chosen because it is a discreet place to wear assistive technology. It is generally available for use, as it is usually not critically involved in activities of daily living. Rehabilitation with sensory substitution devices often requires training by professional occupational therapists, because the user needs to extract visual information from sparse information presented through an alternative channel such as the skin. In this study they determined whether short, automated training sessions of 5 min each could improve the TPD threshold and JND. It was found that 10 min of computer-assisted training improved the vibrotactile TPD threshold on the lower back by 36%, and that 18 min of training improved the just-noticeable intensity difference (JND) by 44%. It was concluded that short, automated training sessions could provide a fast and inexpensive means to improve people's basic spatial acuity and intensity discrimination skills with coin motors. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  11. 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.

  12. 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.

  13. 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.

  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. iStimulation: Apple iPad Use with Children Who Are Visually Impaired, Including Those with Multiple Disabilities

    Science.gov (United States)

    Campaña, Laura V.; Ouimet, Donald A.

    2015-01-01

    Since its creation in the early 1980s, Light Box, a product developed by the American Printing House for the Blind (APH) that is designed for working on functional vision tasks with children who have visual impairments or multiple disabilities, has been an effective tool to help teach children with visual impairments to locate and track items…

  16. Visual impairment in the hearing impaired students.

    Science.gov (United States)

    Gogate, Parikshit; Rishikeshi, Nikhil; Mehata, Reshma; Ranade, Satish; Kharat, Jitesh; Deshpande, Madan

    2009-01-01

    Ocular problems are more common in children with hearing problems than in normal children. Neglected visual impairment could aggravate educational and social disability. To detect and treat visual impairment, if any, in hearing-impaired children. Observational, clinical case series of hearing-impaired children in schools providing special education. Hearing-impaired children in selected schools underwent detailed visual acuity testing, refraction, external ocular examination and fundoscopy. Ocular motility testing was also performed. Teachers were sensitized and trained to help in the assessment of visual acuity using Snellen's E charts. Refractive errors and squint were treated as per standard practice. Excel software was used for data entry and SSPS for analysis. The study involved 901 hearing-impaired students between four and 21 years of age, from 14 special education schools. A quarter of them (216/901, 24%) had ocular problems. Refractive errors were the most common morbidity 167(18.5%), but only 10 children were using appropriate spectacle correction at presentation. Fifty children had visual acuity less than 20/80 at presentation; after providing refractive correction, this number reduced to three children, all of whom were provided low-vision aids. Other common conditions included strabismus in 12 (1.3%) children, and retinal pigmentary dystrophy in five (0.6%) children. Ocular problems are common in hearing-impaired children. Screening for ocular problems should be made mandatory in hearing-impaired children, as they use their visual sense to compensate for the poor auditory sense.

  17. The association between various visual function tests and low fragility hip fractures among the elderly: a Malaysian experience.

    Science.gov (United States)

    Chew, Fiona L M; Yong, Chee-Khuen; Mas Ayu, S; Tajunisah, I

    2010-03-01

    hip fractures are an increasing source of morbidity and mortality in older people. The role of visual function tests such as visual impairment, stereopsis, contrast sensitivity and visual field defects in low fragility hip fractures in Asian populations is not well understood. to determine the association between various visual function tests and low fragility hip fractures in an Asian population. case-control study. University Malaya Medical Centre, Kuala Lumpur, Malaysia. 108 cases aged > or = 55 years admitted with low fragility fractures and 108 controls (matched for age, gender and race). both cases and controls underwent a detailed ophthalmological examination, which included visual acuity, stereopsis, contrast sensitivity and visual field testing. poorer visual acuity (odds ratio, OR = 4.08; 95% confidence interval, CI: 1.44, 11.51), stereopsis (OR = 3.60, 95% CI: 1.55, 8.38), contrast sensitivity (OR = 3.34, 95% CI: 1.48, 7.57) and visual field defects (OR = 11.60, 95% CI: 5.21, 25.81) increased the risk of fracture. Increased falls were associated with poorer visual acuity (OR = 2.30, 95% CI: 1.04, 5.13), stereopsis (OR = 2.11, 95% CI: 1.03, 4.32), contrast sensitivity (OR = 2.12, 95% CI: 1.05, 4.30) and visual field defects (OR = 3.40, 95% CI: 1.69, 6.86). impaired visual acuity, stereopsis, contrast sensitivity and visual field defects are associated with an increased risk of low fragility hip fractures. We recommend that all patients aged > or = 55 should have an annual ophthalmological examination that includes visual acuity, contrast sensitivity, stereopsis and visual field testing to assess the risks for falls and low fragility fractures.

  18. 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 (pamblyopia 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/.

  19. 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.

  20. Relationship between Clinical Presentation and Visual Outcome in Postoperative and Posttraumatic Endophthalmitis in South Central India

    Directory of Open Access Journals (Sweden)

    Das Taraprasad

    2005-03-01

    Full Text Available PURPOSE: To determine risk factors for poor visual outcome in postoperative and posttraumatic endophthalmitis in a large referral center in south central India. METHODS: In this prospective observational series the authors examined 388 patients of postoperative (n= 206 and posttraumatic (n= 182 endophthalmitis at the L V Prasad Eye Institute in Hyderabad, India between 1991 and 1997.The analysis was confined to 236 patients-128 (62.1% postoperative and 108 (59.3% posttraumatic patients who were followed for a minimum period of 3 months. A detailed protocol was followed. Chi-square and logistic regression analysis were used to determine risk factors for visual outcome worse than 6/18 and worse than 6/120. RESULTS: Postoperative endophthalmitis: In univariate analysis the features associated with poor visual acuity (grouped as < 6/18 and < 6/120 included intracapsular cataract surgery, poor presenting visual acuity, presence of vitreous cells, inability to visualise the optic disc on indirect ophthalmoscopy, presence of vitreous membranes on ultrasonography, and a culture-positive vitreous biopsy. In the multivariate analysis, visual acuity of < light perception (LP at presentation was associated with a 3-month postoperative visual acuity of < 6/18, with an odds ratio of 5.85 [ 1.25 - 27.42, 95% CI], and vitreous membranes seen on ultrasonography was associated with a final visual acuity of < 6/120, with an odds ratio of 2.47 [1.05 - 5.83, 95% CI]. Posttraumatic endophthalmitis: In univariate analysis the features associated with poor visual acuity (grouped as < 6/18 and < 6/120 included a retained intraocular foreign body (IOFB, trauma by needle (hypodermic or sewing, poor presenting visual acuity, inability to visualise the optic disc on indirect ophthalmoscopy, presence of vitreous membranes on ultrasonography, and a culture-positive vitreous biopsy. In multivariate analysis, IOFB was associated with a 3-month follow-up visual acuity of < 6

  1. Practice makes perfect: the neural substrates of tactile discrimination by Mah-Jong experts include the primary visual cortex

    Directory of Open Access Journals (Sweden)

    Honda Manabu

    2006-12-01

    Full Text Available Abstract Background It has yet to be determined whether visual-tactile cross-modal plasticity due to visual deprivation, particularly in the primary visual cortex (V1, is solely due to visual deprivation or if it is a result of long-term tactile training. Here we conducted an fMRI study with normally-sighted participants who had undergone long-term training on the tactile shape discrimination of the two dimensional (2D shapes on Mah-Jong tiles (Mah-Jong experts. Eight Mah-Jong experts and twelve healthy volunteers who were naïve to Mah-Jong performed a tactile shape matching task using Mah-Jong tiles with no visual input. Furthermore, seven out of eight experts performed a tactile shape matching task with unfamiliar 2D Braille characters. Results When participants performed tactile discrimination of Mah-Jong tiles, the left lateral occipital cortex (LO and V1 were activated in the well-trained subjects. In the naïve subjects, the LO was activated but V1 was not activated. Both the LO and V1 of the well-trained subjects were activated during Braille tactile discrimination tasks. Conclusion The activation of V1 in subjects trained in tactile discrimination may represent altered cross-modal responses as a result of long-term training.

  2. Practice makes perfect: the neural substrates of tactile discrimination by Mah-Jong experts include the primary visual cortex.

    Science.gov (United States)

    Saito, Daisuke N; Okada, Tomohisa; Honda, Manabu; Yonekura, Yoshiharu; Sadato, Norihiro

    2006-12-05

    It has yet to be determined whether visual-tactile cross-modal plasticity due to visual deprivation, particularly in the primary visual cortex (V1), is solely due to visual deprivation or if it is a result of long-term tactile training. Here we conducted an fMRI study with normally-sighted participants who had undergone long-term training on the tactile shape discrimination of the two dimensional (2D) shapes on Mah-Jong tiles (Mah-Jong experts). Eight Mah-Jong experts and twelve healthy volunteers who were naïve to Mah-Jong performed a tactile shape matching task using Mah-Jong tiles with no visual input. Furthermore, seven out of eight experts performed a tactile shape matching task with unfamiliar 2D Braille characters. When participants performed tactile discrimination of Mah-Jong tiles, the left lateral occipital cortex (LO) and V1 were activated in the well-trained subjects. In the naïve subjects, the LO was activated but V1 was not activated. Both the LO and V1 of the well-trained subjects were activated during Braille tactile discrimination tasks. The activation of V1 in subjects trained in tactile discrimination may represent altered cross-modal responses as a result of long-term training.

  3. Visual deficits in Nepalese patients with oculocutaneous albinism

    Directory of Open Access Journals (Sweden)

    Safal Khanal

    2016-04-01

    Conclusion: Patients with OCA present with a broad spectrum of visual deficits that impair the visual functions. Significant improvement in visual acuity following optical correction serves as an impetus to the reduction of visual disabilities in individuals with albinism.

  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. Comparison of the development of the communicative competence of the blind and visually impaired in institutions and including schooling

    Directory of Open Access Journals (Sweden)

    Mateja Forte

    2015-06-01

    Full Text Available The article is a research, belonging to the domain of practical/usable linguistics. The basis of the presented content is the communicative competence and the issue of its development by blind and visually impaired children. The methodology, used in the research, consists of primary and secondary materials. The secondary ones are theoretical, from: linguistics, psychology, medicine, pedagogies and special pedagogies. The primary materials can be divided in two sections. The first one is a comparison of two educational models for blind and visually impaired children, one from mainstream schools and the other from specialized institutions. The second part consists of four structured interviews, the analysis of which gives us the answer about the difference in the development of the communicative competence of the blind and the visually impaired in consideration of the chosen model of schooling.

  6. Unilateral visual impairment in an urban population in Southern India

    Directory of Open Access Journals (Sweden)

    Dandona Lalit

    2000-01-01

    Full Text Available This study assessed the prevalence and causes of unilateral visual impairment in the urban population of Hyderabad city as part of the Andhra Pradesh Eye Disease Study. Stratified, random, cluster, systematic sampling was used to select 2,954 subjects from 24 clusters representative of the population of Hyderabad. Eligible subjects underwent detailed eye examination including logMAR visual acuity, refraction, slitlamp biomicroscopy, applanation tonometry, gonioscopy, dilatation, cataract grading, and stereoscopic evaluation of fundus. Automated threshold visual fields and slitlamp and fundus photography were done when indicated by standardised criteria. Unilateral visual impairment was defined as presenting distance visual acuity <6/18 in the worse eye and ≥6/12 in the better eye, which was further divided into unilateral blindness (visual acuity <6/60 in the worse eye and unilateral moderate visual impairment (visual acuity <6/18-6/60 in the worse eye. A total of 2,522 subjects (85.4% of eligible, including 1,399 ≥30 years old, participated in the study. In addition to the 1% blindness and 7.2% moderate visual impairment (based on bilateral visual impairment criteria reported earlier in this sample, 139 subjects had unilateral visual impairment, an age-gender-adjusted prevalence of 3.8% (95% confidence interval 2.7-4.9%. The major causes of this visual impairment 39.9% were refractive error (42.9%, cataract (14.4%, corneal disease (11.5%, and retinal disease (11.2%. Of this unilateral visual impairment was blindness. The major causes of unilateral blindness were corneal disease (23.2%, cataract (22.5%, retinal disease (18%, and optic atrophy (12.9%. On the other hand, the predominant cause of unilateral moderate visual impairment was refractive error (67% followed by cataract (9%. Of the total unilateral visual impairment, 34.3% was present in those <30 years old and 36.2% in those 30-49 years old. Unilateral visual

  7. Spatial frequency interference effects and interpolation in vernier acuity.

    Science.gov (United States)

    Morgan, M J; Watt, R J

    1984-01-01

    Discrete spatial sampling of sinusoidal gratings has a detrimental effect upon vernier acuity for such stimuli if the sampling rate is less than 20 c/deg. We have examined the possibility that interpolation failure is due to masking by spatial frequency components near to the signal frequency. In an explicit masking paradigm, vernier acuity for a sine wave grating was found to be adversely affected by the presence of a masking grating falling within a critical band of frequencies near the test target. In the sampled stimulus, removal of sampling replicas similar in frequency to the test improved acuity, but the extent of the residual interference by high frequency components could not be predicted from the masking data. The high frequency interference effect depended on fixed phase relations between frequency components, creating narrow bright bars in the spatial luminance profile, and was greatly reduced by phase randomizing the sampling replicas. Various explanations of this nonlinear behaviour are discussed, including the Marr-Hildreth theory of edge detection.

  8. Teacher-Made Tactile Science Materials with Critical and Creative Thinking Activities for Learners Including Those with Visual Impairments

    Science.gov (United States)

    Teske, Jolene K.; Gray, Phyllis; Kuhn, Mason A.; Clausen, Courtney K.; Smith, Latisha L.; Alsubia, Sukainah A.; Ghayoorad, Maryam; Rule, Audrey C.; Schneider, Jean Suchsland

    2014-01-01

    Gifted students with visual impairments are twice exceptional learners and may not evidence their advanced science aptitudes without appropriate accommodations for learning science. However, effective tactile science teaching materials may be easily made. Recent research has shown that when tactile materials are used with "all" students…

  9. The National Agenda for the Education of Children and Youths with Visual Impairments, Including Those with Multiple Disabilities.

    Science.gov (United States)

    Corn, Anne L.; And Others

    This monograph identifies and discusses eight goals for students with visual impairments, which are intended to be integrated with educational reform efforts called for by the Individuals with Disabilities Education Act, the Goals 2000 program, and the School to Work initiatives. The goals are: (1) students and their families will be referred to…

  10. 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.

  11. 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.

  12. Assessment and Management of Children with Visual Impairment

    OpenAIRE

    Labib, Taha A.; El Sada, Mohamed A.; Mohamed, Boshra; Sabra, Neveen M.; Abdel Aleem, Hanan M.

    2009-01-01

    Purpose: The aim of this work was to evaluate the role of low vision aids in improving visual performance and response in children with low vision. Study Design: Prospective clinical case series. Materials and Methods: This study was conducted on 50 patients that met the international criteria for a diagnosis of low vision. Their ages ranged from 5 to 15 years. Assessment of low vision included distance and near visual acuity assessment, color vision and contrast sensitivity function. Lo...

  13. Survey on Visual Impairment and Refractive Errors on Ta′u Island, American Samoa

    Directory of Open Access Journals (Sweden)

    Shawn S Barnes

    2011-01-01

    Full Text Available Purpose: To assess the prevalence of presenting visual impairment and refractive errors on the isolated island of Ta′u, American Samoa. Methods: Presenting visual acuity and refractive errors of 124 adults over 40 years of age (55 male and 69 female were measured using the Snellen chart and an autorefractometer. This sample represented over 50% of the island′s eligible population. Results: In this survey, all presenting visual acuity (VA was uncorrected. Of the included sample, 10.5% presented with visual impairment (visual acuity lower than 6/18, but equal to or better than 3/60 in the better eye and 4.8% presented with VA worse than 6/60 in the better eye. Overall, 4.0% of subjects presented with hyperopia (+3 D or more, 3.2% were myopic (‑1 D or less, and 0.8% presented with high myopia (‑5 D or less. There was no significant difference between genders in terms of visual impairment or refractive errors. Conclusion: This study represents the first population-based survey on presenting visual acuity and refractive errors in American Samoa. In addition to providing baseline data on vision and refractive errors, we found that the prevalence of myopia and hyperopia was much lower than expected.

  14. Visual complications in diabetes mellitus: beyond retinopathy.

    Science.gov (United States)

    Khan, A; Petropoulos, I N; Ponirakis, G; Malik, R A

    2017-04-01

    Diabetic retinopathy is the most common cause of vision loss in people with diabetes mellitus; however, other causes of visual impairment/loss include other retinal and non-retinal visual problems, including glaucoma, age-related macular degeneration, non-arteritic anterior ischaemic optic neuropathy and cataracts. Additionally, when a person with diabetes complains of visual disturbance despite a visual acuity of 6/6, abnormalities in refraction, contrast sensitivity, straylight and amplitude of accommodation should be considered. We review and highlight these visual problems for physicians who manage people with diabetes to ensure timely referral and treatment to limit visual disability, which can have a significant impact on daily living, especially for those participating in sports and driving. © 2016 Diabetes UK.

  15. Acuity and case management: a healthy dose of outcomes, part III.

    Science.gov (United States)

    Huber, Diane L; Craig, Kathy

    2007-01-01

    draft and final tools for evaluator concordance, b testing for content accuracy and appropriateness, and representative sample size testing were done. Expert panel reviews occurred at multiple junctures along the development pathway, including the 5 critical points after initial tool draft and both before and after b-test (n = 5) and pilot-test (n = 28) evaluations. The pilot testing body (n = 33) consisted of a team of case managers (n = 28) along with quality analysts (n = 2), supervisory personnel (n = 2), and the lead product analyst (the developer). Product evaluation included monitoring weekly reports of open cases for the 28 case managers for 3 months (June-August 2000). The Acuity Tools Suite was used to calculate individual case acuity, overall caseload acuity profiles, case length, and acuity differentials. Normal distributions and outliers were analyzed and the results were used for internal quality improvement and outcomes monitoring. To show value, case managers need to access the evidence base for practice, use tools to capture quantities of intervention intensity, and precisely specify the activities that produce better outcomes. Acuity and dosage can help case managers explore and fully describe their own practice in ways that can be measured, and thus provide data and evidence that contributes to the accumulating body of definitive proof regarding the exceptional worth of CM. Proving business and professional worth in CM through EBP is a clarion call that case managers must heed and an innovation that all case managers can practice.

  16. Acuity and case management: a healthy dose of outcomes, part II.

    Science.gov (United States)

    Craig, Kathy; Huber, Diane L

    2007-01-01

    development, interrater reliability testing of draft and final tools for evaluator concordance, beta (beta) testing for content accuracy and appropriateness, and representative sample size testing were done. Expert panel reviews occurred at multiple junctures along the development pathway, including the 5 critical points after initial tool draft and both before and after beta-test (n = 5) and pilot-test (n = 28) evaluations. The pilot testing body (n = 33) consisted of a team of case managers (n = 28) along with quality analysts (n = 2), supervisory personnel (n = 2), and the lead product analyst (the developer). Product evaluation included monitoring weekly reports of open cases for the 28 case managers for 3 months (June-August 2000). The Acuity Tools suite was used to calculate individual case acuity, overall caseload acuity profiles, case length, and acuity differentials. Normal distributions and outliers were analyzed and the results used for internal quality improvement and outcomes monitoring. To show value, case managers need to access the evidence base for practice, use tools to capture quantities of intervention intensity, and specify precisely the activities that produce better outcomes. Acuity and dosage can help case managers explore and fully describe their own practice in ways that can be measured. This data-driven evidence contributes to the accumulating body of definitive proof regarding the exceptional worth of CM. Proving business and professional worth in CM though evidence-based practice is a clarion call that case managers must heed and an innovation that all case managers can practice.

  17. Analysis of the National Health and Nutrition Examination Survey. Comment on "Prevalence of visual impairment in the United States", by S Vitale, MF Cotch, and RD Sperduto. JAMA 295:2158-63, 2006.

    Science.gov (United States)

    Carden, Susan M

    2006-01-01

    The prevalence of visual impairment in the U.S. public has not been surveyed nationally in several decades. To estimate the number of U.S. individuals aged 12 years or older who have impaired distance vision due to uncorrected refractive error. The National Health and Nutrition Examination Survey (NHANES), using a multistage probability sampling design, included a vision evaluation in a mobile examination center. Visual acuity data were obtained from 13,265 of 14,203 participants (93.4%) who visited the mobile examination center in 1999-2002. Visual impairment was defined as presenting distance visual acuity of 20/50 or worse in the better-seeing eye. Visual impairment due to uncorrected refractive error was defined as (presenting) visual impairment that improved, aided by automated refraction results, to 20/40 or better in the better-seeing eye. Presenting distance visual acuity (measured with usual corrective lenses, if any) and distance visual acuity after automated refraction. Overall, 1,190 study participants had visual impairment (weighted prevalence, 6.4%; 95% confidence interval [CI], 6.0-6.8%), and of these, 83.3% could achieve good visual acuity with correction (95% CI, 80.9-85.8%). Extrapolating these findings to the general U.S. population, approximately 14 million individuals aged 12 years or older have visual impairment (defined as distance visual acuity of 20/50 or worse), and of these, more than 11 million individuals could have their vision improved to 20/40 or better with refractive correction. Visual impairment due to uncorrected refractive error is a common condition in the United States. Providing appropriate refractive correction to those individuals whose vision can be improved is an important public health endeavor with implications for safety and quality of life.

  18. Intraocular pressure and visual acuity across the phases of the ...

    African Journals Online (AJOL)

    Context: Available literature suggests that the pattern of variation in intraocular pressure (IOP) in different phases of the menstrual cycle is inconsistent. Results from studies on the effects of oestrogen and progesterone alone or in combination, on IOP have been conflicting. Aim: To determine the pattern of changes in IOP ...

  19. on visual acuity in age related macular degeneration

    African Journals Online (AJOL)

    marine origin) in the treatment of age related macular degeneration (AMD). In a randomized double blind clinical trial 280 eyes of 280 (157 F, 123 M) patients with wet and dry AMD were randomly assigned in treatment or placebo groups. Patients in ...

  20. Acuity and case management: a healthy dose of outcomes, part I.

    Science.gov (United States)

    Huber, Diane L; Craig, Kathy

    2007-01-01

    final tools for evaluator concordance, beta (beta) testing for content accuracy and appropriateness, and representative sample size testing were done. Expert panel reviews occurred at several junctures along the development pathway, including after initial tool draft and both before and after beta-tests (n = 5) and pilot tests (n = 28). The pilot testing body (n = 33) consisted of a team of case managers (n = 28) along with quality analysts (n = 2), supervisory personnel (n = 2), and the lead product analyst (the developer). Product evaluation included monitoring weekly reports of open cases for the 28 case managers for 3 months (June to August 2000). Positive results generated approval from the expert review panel to apply the suite of acuity tools beyond (1) the initial draft phase, (2) the test population phase, and then (3) at a national CM organization level. This article defines and discusses acuity and dosage as two practical conceptual tools that successfully unite clinical quality and business practices and measure and analyze CM activities. The CM Acuity Tool(c) is a master conceptual framework in three dimensions that synthesizes key components of CM practice, organized into indicators, drivers, and subdrivers. To show value, case managers need to access the evidence base for practice, use tools to capture quantities of intervention-intensity, and specify the activities that produce better outcomes.

  1. 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

  2. Visual impairment and multimorbidity in a representative sample of the Spanish population.

    Science.gov (United States)

    Garin, Noe; Olaya, Beatriz; Lara, Elvira; Moneta, Maria Victoria; Miret, Marta; Ayuso-Mateos, Jose Luis; Haro, Josep Maria

    2014-08-08

    In the context of population aging, visual impairment has emerged as a growing concern in public health. However, there is a need for further research into the relationship between visual impairment and chronic medical conditions in the elderly. The aim of our study was to examine the relationship between visual impairment and three main types of co-morbidity: chronic physical conditions (both at an independent and additive level), mental health and cognitive functioning. Data were collected from the COURAGE in Europe project, a cross-sectional study. A total of 4,583 participants from Spain were included. Diagnosis of chronic medical conditions included self-reported medical diagnosis and symptomatic algorithms. Depression and anxiety were assessed using CIDI algorithms. Visual assessment included objective distance/near visual acuity and subjective visual performance. Descriptive analyses included the whole sample (n = 4,583). Statistical analyses included participants aged over 50 years (n = 3,625; mean age = 66.45 years) since they have a significant prevalence of chronic conditions and visual impairment. Crude and adjusted binary logistic regressions were performed to identify independent associations between visual impairment and chronic medical conditions, physical multimorbidity and mental conditions. Covariates included age, gender, marital status, education level, employment status and urbanicity. The number of chronic physical conditions was found to be associated with poorer results in both distance and near visual acuity [OR 1.75 (CI 1.38-2.23); OR 1.69 (CI 1.27-2.24)]. At an independent level, arthritis, stroke and diabetes were associated with poorer distance visual acuity results after adjusting for covariates [OR 1.79 (CI 1.46-2.21); OR 1.59 (CI 1.05-2.42); OR 1.27 (1.01-1.60)]. Only stroke was associated with near visual impairment [OR 3.01 (CI 1.86-4.87)]. With regard to mental health, poor subjective visual acuity was associated with depression

  3. Visual Function in Asymptomatic Patients With Homozygous Sickle Cell Disease and Temporal Macular Atrophy.

    Science.gov (United States)

    Martin, Gilles C; Dénier, Charlotte; Zambrowski, Olivia; Grévent, David; Bruère, Lenaïc; Brousse, Valentine; de Montalembert, Mariane; Brémond-Gignac, Dominique; Robert, Matthieu P

    2017-10-01

    Temporal macular involvement in sickle cell disease can now easily be detected by optical coherence tomography (OCT). However, while recent studies have demonstrated its high prevalence, little is known about its potential consequences on visual function. To assess the visual function of patients with sickle cell disease with no visual symptoms despite temporal macular atrophy. This retrospective case series included data collection and explorations made in a single referral center for sickle cell disease in 2016. Three patients with sickle cell disease exhibiting preserved visual acuity but showing temporal macular retinal atrophy were included. Patients underwent the following explorations: best-corrected distance and near visual acuity evaluation; dilated fundus examination; OCT with 12 × 6-mm thickness map; horizontal, vertical, and en face sections; OCT angiography of the 6 × 6-mm perifoveal retina; 30° and 12° central visual fields; Lanthony 15-hue color vision test; automated static contrast sensitivity test; and global electroretinography. The OCT thickness maps were checked for areas of retinal thinning, appearing as blue patches. When present, these areas were compared with the areas of superficial and deep capillary flow loss on OCT angiography and with the scotomas on visual fields. Contrast sensitivity and color vision loss were quantified. All 3 patients included had homozygous sickle cell disease. They presented with a 20/20 distance visual acuity, and Parinaud 1,5 near visual acuity in both eyes. They were all followed up for a severe cerebral vasculopathy related to sickle cell disease. The areas of atrophy involved the inner retinal layers and were associated with an absence of signal in the deep capillary plexuses in OCT angiography. These patches of retinal thinning were also matching with scotomas in the automated visual fields. Color vision ability and contrast sensitivity were impaired in all patients. Global electroretinography

  4. Visual impairment in school children in Southern India

    Directory of Open Access Journals (Sweden)

    Kalikivayi Venkataramana

    1997-01-01

    Full Text Available This study was done to determine the prevalence of visual impairment due to refractive errors and ocular diseases in lower middle class school children of Hyderabad, India. A total of 4,029 children, which included 2,348 males and 1,681 females, in the age range of 3 to 18 years from 9 schools were screened with a detailed ocular examination protocol. Among 3,669 children in whom visual acuity could be recorded, on presentation 115 (3.1% had visual acuity < 6/18 in the better eye (equivalent to visual impairment, while 41 (1.1% had visual acuity of 6/60 in the better eye (equivalent to legal blindness out of which 18 (0.5% had visual acuity < 6/60 in the better eye (equivalent to economic blindness. Of 115 children who presented with initial visual acuity < 6/18, vision improved to ≥6/18 with refraction in 109 (94.8%. No child was legally or economically blind after refractive correction. Prevalence of hyperopia was 22.6%, myopia 8.6% and astigmatism 10.3%. The prevalence of myopia was significantly higher among children ≥10 years of age (P<0.001. The maximum, mean and median values for myopia were 10.00, 1.35 and 0.75 D in the better eye. For hyperopia these values were 8.50, 0.65 and 0.50 D. The major causes for best corrected visual acuity < 6/9 in the worse eye for 51 (1.4% children included amblyopia in 40 (1.1%, corneal diseases in 5 (0.1%, cataract in 2 (0.05% and others in 4 (0.1%. Out of the total, 30 (0.7% children had strabismus. These data support the assumption that vision screening of school children in developing countries could be useful in detecting correctable causes of decreased vision, especially refractive errors, and in minimising long term permanent visual disability.

  5. Visual symptoms in Parkinson's disease.

    Science.gov (United States)

    Armstrong, R A

    2011-01-01

    Parkinson's disease (PD) is a common disorder of middle-aged and elderly people in which degeneration of the extrapyramidal motor system causes significant movement problems. In some patients, however, there are additional disturbances in sensory systems including loss of the sense of smell and auditory and/or visual problems. This paper is a general overview of the visual problems likely to be encountered in PD. Changes in vision in PD may result from alterations in visual acuity, contrast sensitivity, colour discrimination, pupil reactivity, eye movements, motion perception, visual field sensitivity, and visual processing speeds. Slower visual processing speeds can also lead to a decline in visual perception especially for rapidly changing visual stimuli. In addition, there may be disturbances of visuospatial orientation, facial recognition problems, and chronic visual hallucinations. Some of the treatments used in PD may also have adverse ocular reactions. The pattern electroretinogram (PERG) is useful in evaluating retinal dopamine mechanisms and in monitoring dopamine therapies in PD. If visual problems are present, they can have an important effect on the quality of life of the patient, which can be improved by accurate diagnosis and where possible, correction of such defects.

  6. Visual Symptoms in Parkinson's Disease

    Directory of Open Access Journals (Sweden)

    R. A. Armstrong

    2011-01-01

    Full Text Available Parkinson's disease (PD is a common disorder of middle-aged and elderly people in which degeneration of the extrapyramidal motor system causes significant movement problems. In some patients, however, there are additional disturbances in sensory systems including loss of the sense of smell and auditory and/or visual problems. This paper is a general overview of the visual problems likely to be encountered in PD. Changes in vision in PD may result from alterations in visual acuity, contrast sensitivity, colour discrimination, pupil reactivity, eye movements, motion perception, visual field sensitivity, and visual processing speeds. Slower visual processing speeds can also lead to a decline in visual perception especially for rapidly changing visual stimuli. In addition, there may be disturbances of visuospatial orientation, facial recognition problems, and chronic visual hallucinations. Some of the treatments used in PD may also have adverse ocular reactions. The pattern electroretinogram (PERG is useful in evaluating retinal dopamine mechanisms and in monitoring dopamine therapies in PD. If visual problems are present, they can have an important effect on the quality of life of the patient, which can be improved by accurate diagnosis and where possible, correction of such defects.

  7. Associations of Anisometropia with Unilateral Amblyopia, Interocular Acuity Difference and Stereoacuity in Preschoolers

    Science.gov (United States)

    Ying, Gui-shuang; Huang, Jiayan; Maguire, Maureen; Quinn, Graham; Kulp, Marjean Taylor; Ciner, Elise; Cyert, Lynn; Orel-Bixler, Deborah

    2012-01-01

    Purpose To evaluate the relation of anisometropia with unilateral amblyopia, interocular acuity difference (IAD) and stereoacuity, among Head Start preschoolers, using both clinical notation and vector notation analyses. Design Multicenter, cross-sectional study. Participants 3- to 5-year-old participants in the Vision In Preschoolers (VIP) Study (N=4040). Methods Secondary analysis of VIP data from participants who had comprehensive eye examinations including monocular visual acuity (VA) testing, stereoacuity testing, and cycloplegic refraction. VA was retested with full cycloplegic correction when retest criteria were met. Unilateral amblyopia was defined as IAD ≥2 lines in logarithm of the Minimum Angle of Resolution (logMAR). Anisometropia was defined as ≥0.25 D (diopter) difference in spherical equivalent (SE) or in cylinder power, and also two approaches using power vector notation. The percentage with unilateral amblyopia, mean IAD, and mean stereoacuity were compared between anisometropic and isometropic children. Main Outcomes Measures The percentage with unilateral amblyopia, mean IAD, and mean stereoacuity. Results Compared with isometropic children, anisometropic children had a higher percentage of unilateral amblyopia (8% vs. 2%), larger mean IAD (0.07 vs. 0.05 logMAR) and worse mean stereoacuity (145 vs.117 arc sec) (all pamblyopia, larger IAD, and worse stereoacuity (trend pamblyopia was significantly increased with spherical equivalent (SE) anisometropia >0.5 D, cylindrical anisometropia >0.25 D, the vertical/horizontal meridian (J0) or oblique meridian (J45) >0.125 D, or vector dioptric distance (VDD) >0.35 D (all pamblyopia than cylinder, SE, J0 and J45 (pamblyopia, larger IAD and worse stereoacuity. The threshold level of anisometropia at which unilateral amblyopia becomes significant was lower than current guidelines. VDD is more accurate than spherical equivalent anisometropia or cylindrical anisometropia in identifying preschoolers with

  8. Visual Survey of Infantry Troops. Part 1. Visual Acuity, Refractive Status, Interpupillary Distance and Visual Skills

    Science.gov (United States)

    1989-06-01

    prevalence of refractive error types among infantrymen .............................. 35 15. 2ercentages of refractive errors by sphere and cylinder...not prescribing for a minimum amount. Table 14. Classification and prevalence of refractive error types among infantrymen Prevalence Refractive...with a 10 mm IPD difference was probably an accommodative esotrope. This five-plus diopter hyperope demonstrated left-eye amblyopia , 4 prism diopters

  9. The prevalence and causes of visual impairment in seven-year-old children.

    Science.gov (United States)

    Ghaderi, Soraya; Hashemi, Hassan; Jafarzadehpur, Ebrahim; Yekta, Abbasali; Ostadimoghaddam, Hadi; Mirzajani, Ali; Khabazkhoob, Mehdi

    2017-11-22

    To report the prevalence and causes of visual impairment in seven-year-old children in Iran and its relationship with socio-economic conditions. In a cross-sectional population-based study, first-grade students in the primary schools of eight cities in the country were randomly selected from different geographic locations using multistage cluster sampling. The examinations included visual acuity measurement, ocular motility evaluation, and cycloplegic and non-cycloplegic refraction. Using the definitions of the World Health Organization (presenting visual acuity less than or equal to 6/18 in the better eye) to estimate the prevalence of vision impairment, the present study reported presenting visual impairment in seven-year-old children. Of 4,614 selected students, 4,106 students participated in the study (response rate 89 per cent), of whom 2,127 (51.8 per cent) were male. The prevalence of visual impairment according to a visual acuity of 6/18 was 0.341 per cent (95 per cent confidence interval 0.187-0.571); 1.34 per cent (95 per cent confidence interval 1.011-1.74) of children had visual impairment according to a visual acuity of 6/18 in at least one eye. Sixty-six (1.6 per cent) and 23 (0.24 per cent) children had visual impairment according to a visual acuity of 6/12 in the worse and better eye, respectively. The most common causes of visual impairment were refractive errors (81.8 per cent) and amblyopia (14.5 per cent). Among different types of refractive errors, astigmatism was the main refractive error leading to visual impairment. According to the concentration index, the distribution of visual impairment in children from low-income families was higher. This study revealed a high prevalence of visual impairment in a representative sample of seven-year-old Iranian children. Astigmatism and amblyopia were the most common causes of visual impairment. The distribution of visual impairment was higher in children from low-income families. Cost

  10. Five-year visual outcome among people with correctable visual impairment: the Liwan Eye Study.

    Science.gov (United States)

    Wang, Lanhua; Zhao, Yanzhi; Han, Xiaotong; Huang, Wenyong; Huang, Guofu; He, Mingguang

    2017-12-07

    Longitudinal data on visual outcome of correctable visual impairments (VI) are of paramount importance for decision-maker to estimate burden and demand to treat avoidable VI. To assess the 5-year visual outcome among participants with correctable VI and to identify associated risk factors. Population-based longitudinal cohort study. Participants with correctable VI at baseline attended the 5-year follow-up visit of the Liwan Eye Study. Presenting visual acuity (PVA) with habitual refractive correction was assessed using an Early Treatment Diabetic Retinopathy Study (ETDRS) chart. Then participants with PVA visual acuity. Correctable VI was defined as having a PVA of visual outcome among participants with correctable VI. Among 1405 participants at baseline examination, 188 (13.4%) had correctable VI, of whom 118 (62.8%) were re-examined at the 5-year follow-up, including 39 (33.9%) who progressed to non-correctable VI, 43 (37.4%) who had persistent correctable VI and 33 (28.7%) who were converted to normal vision. In multivariate logistic regression, compared with participants who were no longer visual impaired, significant risk factors for participants with persistent VI were older, had income <1000 RMB/month, and more myopia spherical equivalent. Over two of three participants with correctable VI remained to have VI after 5 years, among whom 50% are correctable by spectacles, highlighting the need to improve the refractive care accessibility to treat avoidable VI in China. © 2017 Royal Australian and New Zealand College of Ophthalmologists.

  11. Visual impairment in the hearing impaired students

    Directory of Open Access Journals (Sweden)

    Gogate Parikshit

    2009-01-01

    Full Text Available Background : Ocular problems are more common in children with hearing problems than in normal children. Neglected visual impairment could aggravate educational and social disability. Aim : To detect and treat visual impairment, if any, in hearing-impaired children. Setting and Design : Observational, clinical case series of hearing-impaired children in schools providing special education. Materials and Methods : Hearing-impaired children in selected schools underwent detailed visual acuity testing, refraction, external ocular examination and fundoscopy. Ocular motility testing was also performed. Teachers were sensitized and trained to help in the assessment of visual acuity using Snellen′s E charts. Refractive errors and squint were treated as per standard practice. Statistical Analysis : Excel software was used for data entry and SSPS for analysis. Results : The study involved 901 hearing-impaired students between four and 21 years of age, from 14 special education schools. A quarter of them (216/901, 24% had ocular problems. Refractive errors were the most common morbidity 167(18.5%, but only 10 children were using appropriate spectacle correction at presentation. Fifty children had visual acuity less than 20/80 at presentation; after providing refractive correction, this number reduced to three children, all of whom were provided low-vision aids. Other common conditions included strabismus in 12 (1.3% children, and retinal pigmentary dystrophy in five (0.6% children. Conclusion : Ocular problems are common in hearing-impaired children. Screening for ocular problems should be made mandatory in hearing-impaired children, as they use their visual sense to compensate for the poor auditory sense.

  12. Visual disability rates in a ten-year cohort of patients with anterior visual pathway meningiomas.

    Science.gov (United States)

    Bor-Shavit, Elite; Hammel, Naama; Nahum, Yoav; Rappaport, Zvi Harry; Stiebel-Kalish, Hadas

    2015-01-01

    To examine the visual outcome of anterior visual pathway meningioma (AVPM) patients followed for at least one year. Data were collected on demographics, clinical course and management. Visual disability was classified at the first and last examination as follows: I--no visual disability; II--mild visual defect in one eye; III--mild visual defect in both eyes; IV--loss of driver's license; V--legally blind. Eight-one AVPM patients had their tumor originate in the clinoid process in 23 (28%), sphenoid-wing area in 18 (22%), cavernous sinus in 15 (19%), tuberculum sellae in 8 (10%), and mixed in 17 (21%). On last examination, 46 patients (57%) had good visual acuity in one or both eyes (Class I or II) and 17 (21%) were mildly affected in both eyes. The rate of Class IV disability was 16%, and Class V disability was 6%. Attention needs to be addressed to the considerable proportion of patients with AVPM (22% in this study) who may lose their driver's license or become legally blind. Occupational therapists should play an important role in the multidisciplinary management of those patients to help them adapt to their new physical and social situation. Anterior visual pathway meningiomas (AVPMs) are commonly not life-threatening but they can lead to profound visual disability, especially when the tumor originates in the tuberculum sellae and cavernous sinus. Particular attention should be paid to visual acuity and visual field deficits, as these can profoundly affect the patient's quality of life including ability to drive and activities of daily living. The interdisciplinary management of patients with AVPM should include the neurosurgeon, neuro-ophthalmologist and occupational therapist. Also, early intervention by the occupational therapist can help patients adapt to their current physical and social situation and return to everyday tasks more rapidly.

  13. Visual dysfunction, neurodegenerative diseases, and aging.

    Science.gov (United States)

    Jackson, Gregory R; Owsley, Cynthia

    2003-08-01

    The four most common sight-threatening conditions in older adults in North America are cataract, ARM, glaucoma, and diabetic retinopathy. Even in their moderate stages, these conditions cause visual sensory impairments and reductions in health-related quality of life, including difficulties in daily tasks and psychosocial problems. Many older adults are free from these conditions, yet still experience a variety of visual perceptual problems resulting from aging-related changes in the optics of the eye and degeneration of the visual neural pathways. These problems consist of impairments in visual acuity, contrast sensitivity, color discrimination, temporal sensitivity, motion perception, peripheral visual field sensitivity, and visual processing speed. PD causes a progressive loss of dopaminergic cells predominantly in the retina and possibly in other areas of the visual system. This retinal dopamine deficiency produces selective spatial-temporal abnormalities in retinal ganglion cell function, probably arising from altered receptive field organization in the PD retina. The cortical degeneration characteristics of AD, including neurofibrillary tangles and neuritic plaques, also are present in the visual cortical areas, especially in the visual association areas. The most prominent electrophysiologic change in AD is a delay in the P2 component of the flash VEP. Deficits in higher-order visual abilities typically are compromised in AD, including problems with visual attention, perceiving structure from motion, visual memory, visual learning, reading, and object and face perception. There have been reports of a visual variant of AD in which these types of visual problems are the initial and most prominent signs of the disease. Visual sensory impairments (e.g., contrast sensitivity or achromatopsia) also have been reported but are believed more reflective of cortical disturbances than of AD-associated optic neuropathy.

  14. Evaluation of visual evoked potentials in post-trauma eyes

    Directory of Open Access Journals (Sweden)

    Xin Zhou

    2013-10-01

    Full Text Available AIM: To analyze the visual evoked potentials(VEPof 189 eyes subjected to traumatic injury, and to explore the feasibility and method to applying VEP technology to the evaluation of visual acuity after eye trauma. METHODS: All the objects were volunteers who were grouped according to a random examination with the international standard visual acuity chart. The study determined spatial frequency in stimulation mode, P100 amplitude and latency. Then, the lowest spatial frequency(LSFwas analyzed and its relationship with visual acuity were studied. Finally this study discussed about the way to evaluate visual acuity with VEP and also compared the VEP evaluation results with the visual acuity chart. RESULTS: The LSF of 22', 11', 5', and 3' corresponded respectively to vision of 0.1-0.2, 0.3-0.5, 0.6-1.0, 1.2-1.5. There was a significant difference in P100 amplitude between eyes with different visual acuity, but there was no significant difference in P100 latency between these eyes. The random evaluation results of VEP combined with LSF and P100 amplitude were highly consistent with the results with international standard visual acuity chart. CONCLUSION: It is practicable to evaluate these volunteers' visual acuity with the VEP technology.

  15. Changes in neurophysiologic markers of visual processing following beneficial anti-VEGF treatment in macular degeneration

    Directory of Open Access Journals (Sweden)

    Vottonen P

    2013-02-01

    Full Text Available Pasi Vottonen,1 Kai Kaarniranta,1,2 Ari Pääkkönen,3 Ina M Tarkka41Department of Ophthalmology, Kuopio University Hospital, Kuopio, Finland; 2Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland; 3Department of Clinical Neurophysiology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland; 4Department of Health Sciences, University of Jyväskylä, Jyväskylä, FinlandPurpose: Antivascular endothelial growth factor (VEGF agents have been shown to improve visual acuity and prevent vision loss in exudative age-related macular degeneration. As the vision improves relatively quickly in response to intravitreal injections, we wanted to know whether this improvement is reflected in electrophysiological markers of visual cortical processing.Patients and methods: Our interventional case series included six elderly patients who underwent injection treatment to the affected eye. Their visual acuity, tomographic images of retinal thickness, and visual evoked potentials (VEP were assessed before treatment and six weeks after the last injection.Results: All patients showed improved visual acuity and reduced retinal fluid after the treatment. All but one patient showed increased VEP P100 component amplitudes and/or shortened latencies in the treated eye. These VEP changes were consistent with improved vision while the untreated eyes showed no changes.Conclusions: Our results indicate that antivascular endothelial growth factor injections improved visual function of the treated eyes both in the level of the retina and in the level of visual cortical processing.Keywords: age-related eye diseases, exudative age-related macular degeneration, visual evoked potentials, scalp-recorded EEG, visual acuity

  16. 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.

  17. 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.

  18. Comparison of ACUITY and CRUSADE Scores in Predicting Major Bleeding during Acute Coronary Syndrome

    Directory of Open Access Journals (Sweden)

    Luis C. L. Correia

    2015-07-01

    Full Text Available Background:The ACUITY and CRUSADE scores are validated models for prediction of major bleeding events in acute coronary syndrome (ACS. However, the comparative performances of these scores are not known.Objective:To compare the accuracy of ACUITY and CRUSADE in predicting major bleeding events during ACS.Methods:This study included 519 patients consecutively admitted for unstable angina, non-ST-elevation or ST-elevation myocardial infarction. The scores were calculated based on admission data. We considered major bleeding events during hospitalization and not related to cardiac surgery, according to the Bleeding Academic Research Consortium (BARC criteria (type 3 or 5: hemodynamic instability, need for transfusion, drop in hemoglobin ≥ 3 g, and intracranial, intraocular or fatal bleeding.Results:Major bleeding was observed in 31 patients (23 caused by femoral puncture, 5 digestive, 3 in other sites, an incidence of 6%. While both scores were associated with bleeding, ACUITY demonstrated better C-statistics (0.73, 95% CI = 0.63 - 0.82 as compared with CRUSADE (0.62, 95% CI = 0.53 - 0.71; p = 0.04. The best performance of ACUITY was also reflected by a net reclassification improvement of + 0.19 (p = 0.02 over CRUSADE’s definition of low or high risk. Exploratory analysis suggested that the presence of the variables ‘age’ and ‘type of ACS’ in ACUITY was the main reason for its superiority.Conclusion:The ACUITY Score is a better predictor of major bleeding when compared with the CRUSADE Score in patients hospitalized for ACS.

  19. Peripheral Vision of Youths with Low Vision: Motion Perception, Crowding, and Visual Search

    Science.gov (United States)

    Tadin, Duje; Nyquist, Jeffrey B.; Lusk, Kelly E.; Corn, Anne L.; Lappin, Joseph S.

    2012-01-01

    Purpose. Effects of low vision on peripheral visual function are poorly understood, especially in children whose visual skills are still developing. The aim of this study was to measure both central and peripheral visual functions in youths with typical and low vision. Of specific interest was the extent to which measures of foveal function predict performance of peripheral tasks. Methods. We assessed central and peripheral visual functions in youths with typical vision (n = 7, ages 10–17) and low vision (n = 24, ages 9–18). Experimental measures used both static and moving stimuli and included visual crowding, visual search, motion acuity, motion direction discrimination, and multitarget motion comparison. Results. In most tasks, visual function was impaired in youths with low vision. Substantial differences, however, were found both between participant groups and, importantly, across different tasks within participant groups. Foveal visual acuity was a modest predictor of peripheral form vision and motion sensitivity in either the central or peripheral field. Despite exhibiting normal motion discriminations in fovea, motion sensitivity of youths with low vision deteriorated in the periphery. This contrasted with typically sighted participants, who showed improved motion sensitivity with increasing eccentricity. Visual search was greatly impaired in youths with low vision. Conclusions. Our results reveal a complex pattern of visual deficits in peripheral vision and indicate a significant role of attentional mechanisms in observed impairments. These deficits were not adequately captured by measures of foveal function, arguing for the importance of independently assessing peripheral visual function. PMID:22836766

  20. Intensive Math Training Does not Affect Approximate Number Acuity: Evidence From a Three-Year Longitudinal Curriculum Intervention

    Directory of Open Access Journals (Sweden)

    Jessica Sullivan

    2016-08-01

    Full Text Available Does nonverbal, approximate number acuity predict mathematics performance? Some studies report a correlation between acuity of representations in the Approximate Number System (ANS and early math achievement, while others do not. Few previous reports have addressed (1 whether reported correlations remain when other domain-general capacities are considered, and (2 whether such correlations are causal. In the present study, we addressed both questions using a large (N = 204 3-year longitudinal dataset from a successful math intervention, which included a wide array of non-numerical cognitive tasks. While we replicated past work finding correlations between approximate number acuity and math success, these correlations were very small when other domain-general capacities were considered. Also, we found no evidence that changes to math performance induced changes to approximate number acuity, militating against one class of causal accounts.

  1. The Pakistan national blindness and visual impairment survey--research design, eye examination methodology and results of the pilot study.

    Science.gov (United States)

    Bourne, Rupert; Dineen, Brendan; Jadoon, Zahid; Lee, Pak S; Khan, Aman; Johnson, Gordon J; Foster, Allen; Khan, Daud

    2005-10-01

    To establish age- and sex-specific prevalence rates and causes of blindness and low vision in children aged 10 to 15 years and adults aged 30 years and older in Pakistan. Multi-stage, stratified (rural/urban), cluster random sampling, with probability proportional-to-size procedures, was utilised to select a cross-sectional, nationally representative sample of adults (16,600 subjects) and children (6,000 subjects). Each subject underwent: interview, visual acuity (logMAR), autorefraction and optic disc examination. Those that saw visual acuity and dilated posterior segment examination. The results of a pilot survey are reported in this paper. In the two rural pilot sites, 159 subjects (including 47 children) were examined; 50% were male. Thirty seven adults (23.3%) but no children saw worse than 6/12 in either eye. Two subjects were blind (corrected visual acuity) in the better eye, and 11 were visually impaired. Refractive error was the main cause (in 22 eyes (39% of the total of 56 eyes)) of visual acuity, followed by cataract (12 eyes), uncorrected aphakia (6 eyes) and age-related macular disease (3 eyes). The pilot survey demonstrated that the proposed examination process for the main survey is feasible. Particular strengths of this survey include the use of logMAR visual acuity testing and autorefraction of all subjects, a dilated posterior segment examination, and the use of a 'less than 6/12' threshold for further examination. This lower threshold addresses the burden of refractive error, which, with cataract, are two of the diseases specifically targeted by Vision 2020.

  2. Quality of Life Related to Visual Function in Three Young Adults with Mucopolysaccharidoses

    Directory of Open Access Journals (Sweden)

    Katherine L. Bergwerk

    2003-01-01

    Full Text Available The systemic mucopolysaccharidoses are complex syndromes, which may include corneal clouding as a mechanism leading to decreased vision and hence decreased quality of life. This study presents three young adult patients with mucopolysaccharidoses in order to compare their visual status through retrospective chart review, including patient and guardian interview, history, and examination, including a modified form of the VF-14 questionnaire (visual function with 14 questions.When the visual acuity and VF-14 results of the three patients were compared, the results of the VF-14 correlated with the patients� visual acuity status. The two patients who retained clear corneas or underwent penetrating keratoplasty had a wider range of social and physical activities, and an overall better quality of life than did the patient with decreased vision due to opacified corneas.We conclude that close monitoring of the ocular health of patients with storage syndromes that may compromise visual acuity must be stressed, and intervention to insure good vision is of the utmost importance to maintaining a good quality of life for these patients, especially as new therapies assist these patients to achieve increased longevity with better health.

  3. Visual problems associated with traumatic brain injury.

    Science.gov (United States)

    Armstrong, Richard A

    2018-02-28

    Traumatic brain injury (TBI) and its associated concussion are major causes of disability and death. All ages can be affected but children, young adults and the elderly are particularly susceptible. A decline in mortality has resulted in many more individuals living with a disability caused by TBI including those affecting vision. This review describes: (1) the major clinical and pathological features of TBI; (2) the visual signs and symptoms associated with the disorder; and (3) discusses the assessment of quality of life and visual rehabilitation of the patient. Defects in primary vision such as visual acuity and visual fields, eye movement including vergence, saccadic and smooth pursuit movements, and in more complex aspects of vision involving visual perception, motion vision ('akinopsia'), and visuo-spatial function have all been reported in TBI. Eye movement dysfunction may be an early sign of TBI. Hence, TBI can result in a variety of visual problems, many patients exhibiting multiple visual defects in combination with a decline in overall health. Patients with chronic dysfunction following TBI may require occupational, vestibular, cognitive and other forms of physical therapy. Such patients may also benefit from visual rehabilitation, including reading-related oculomotor training and the prescribing of spectacles with a variety of tints and prism combinations. © 2018 Optometry Australia.

  4. 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.

  5. Visual processing in migraine

    OpenAIRE

    OHare, Louise; Hibbard, Paul

    2016-01-01

    Background Migraine is a common neurological condition that often involves differences in visual processing. These sensory processing differences provide important information about the underlying causes of the condition, and for the development of treatments. Review of Psychophysical Literature Psychophysical experiments have shown consistent impairments in contrast sensitivity, orientation acuity, and the perception of global form and motion. They have also established ...

  6. Evaluation of objective visual quality after corneal cross-linking using double-pass analysis system

    Directory of Open Access Journals (Sweden)

    Meng-Meng Wang

    2016-06-01

    Full Text Available AIM: To evaluate the objective visual quality of patients who underwent corneal cross-linking for the keratoconus using double-pass analysis system. METHODS: Advanced keratoconus patients who underwent UV-riboflavin corneal cross-linking from January to July 2015 were included.The outcomes of their objective scattering index(OSI, predicted visual acuity(VA, the cut-off frequency of modulation transfer function(MTF cut-off, the Strehl ratio(SRwere compared before and 6mo after corneal cross-linking. RESULTS: A total of 13 patients(16 eyeswere included. There was no statistically significant difference between pre- and 6mo postoperative data in uncorrected visual acuity,best corrected visual acuity,refractions and mean value of Sim-k(P>0.05. Non-invasive average tear film break up time(NIAvg-BUTdetected by the Sirius system decreased after corneal cross-linking(PP>0.05. Tear Film Analysis Mean OSI increased at 6mo postoperatively(PCONCLUSION: The subjective visual quality isn't effected by corneal cross-linking. The tear stabilities of patients are influenced by these operations at 6mo postoperatively. More observations on long-term effect are needed to be taken in the future.

  7. Visual symptoms in Parkinson's disease and Parkinson's disease dementia.

    Science.gov (United States)

    Archibald, Neil K; Clarke, Mike P; Mosimann, Urs P; Burn, David J

    2011-11-01

    Visual symptoms are common in PD and PD dementia and include difficulty reading, double vision, illusions, feelings of presence and passage, and complex visual hallucinations. Despite the established prognostic implications of complex visual hallucinations, the interaction between cognitive decline, visual impairment, and other visual symptoms remains poorly understood. Our aim was to characterize the spectrum of visual symptomatology in PD and examine clinical predictors for their occurrence. Sixty-four subjects with PD, 26 with PD dementia, and 32 age-matched controls were assessed for visual symptoms, cognitive impairment, and ocular pathology. Complex visual hallucinations were common in PD (17%) and PD dementia (89%). Dementia subjects reported illusions (65%) and presence (62%) more frequently than PD or control subjects, but the frequency of passage hallucinations in PD and PD dementia groups was equivalent (48% versus 69%, respectively; P = 0.102). Visual acuity and contrast sensitivity was impaired in parkinsonian subjects, with disease severity and age emerging as the key predictors. Regression analysis identified a variety of factors independently predictive of complex visual hallucinations (e.g., dementia, visual acuity, and depression), illusions (e.g., excessive daytime somnolence and disease severity), and presence (e.g., rapid eye movement sleep behavior disorder and excessive daytime somnolence). Our results demonstrate that different "hallucinatory" experiences in PD do not necessarily share common disease predictors and may, therefore, be driven by different pathophysiological mechanisms. If confirmed, such a finding will have important implications for future studies of visual symptoms and cognitive decline in PD and PD dementia. Copyright © 2011 Movement Disorder Society.

  8. Pattern-reversal visual evoked potentials as a diagnostic tool for ocular malingering.

    Science.gov (United States)

    Soares, Tarciana de Souza; Sacai, Paula Yuri; Berezovsky, Adriana; Rocha, Daniel Martins; Watanabe, Sung Eun Song; Salomão, Solange Rios

    2016-01-01

    To investigate the contributions of transient pattern-reversal visual evoked potentials in the diagnosis of ocular malingering at a Brazilian university hospital. Adult patients with suspected malingering in one or both eyes were referred for visual evoked potential testing. Data from patients' medical records were reviewed and analyzed retrospectively. Data analysis included the distance optotype visual acuity based on a ETDRS retro-illuminated chart and the transient pattern-reversal visual evoked potential parameters of latency (milliseconds) and amplitude (microvolts) for the P100 component, using checkerboards with visual subtenses of 15' and 60'. Motivations for malingering were noted. The 20 subjects included 11 (55%) women. Patient ages ranged from 21 to 61 years (mean= 45.05 ± 11.76 years; median= 49 years). In 8 patients (6 women), both eyes exhibited reduced visual acuity with normal pattern-reversal visually evoked potential parameters (pure malingerers). The remaining 12 patients (7 men) exhibited reduced vision in only 1 eye, with simulated reduced vision in the contralateral eye (exaggerators). Financial motivation was noted in 18 patients (9 men). Normal pattern-reversal visually evoked potential parameters with suspected ocular malingering were observed in a 20 patient cohort. This electrophysiological technique appeared to be useful as a measure of visual pathway integrity in this specific population.

  9. 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...

  10. Visual outcomes in relation to time to treatment in neovascular age-related macular degeneration

    DEFF Research Database (Denmark)

    Rasmussen, Annette; Bloch, Sara Brandi; Fuchs, Josefine

    2015-01-01

    PURPOSE: To study the relation between the interval from diagnosis to initiation of intravitreal injection therapy and visual outcome in neovascular age-related macular degeneration (nAMD) and to report changes over time in fellow-eye status. METHODS: Retrospective chart review. The study included...... 1185 eyes in 1099 patients who began vascular endothelial growth factor inhibitor treatment for nAMD during four separate periods in 2007, 2009, 2011 and 2012 using a fixed loading-dose regimen of three ranibizumab injections. RESULTS: Mean best-corrected visual acuity (BCVA) at presentation remained....... CONCLUSION: In this study, 2-week-earlier injection was associated with the equivalent of a 5-Early Treatment Diabetic Retinopathy Study letter-gain in mean visual acuity at 3 months after presentation. The difference is larger than expected from the 2-week-longer duration of disease at the study end...

  11. Influence of uncorrected refractive error and unmet refractive error on visual impairment in a Brazilian population.

    Science.gov (United States)

    Ferraz, Fabio H; Corrente, José E; Opromolla, Paula; Schellini, Silvana A

    2014-06-25

    The World Health Organization (WHO) definitions of blindness and visual impairment are widely based on best-corrected visual acuity excluding uncorrected refractive errors (URE) as a visual impairment cause. Recently, URE was included as a cause of visual impairment, thus emphasizing the burden of visual impairment due to refractive error (RE) worldwide is substantially higher. The purpose of the present study is to determine the reversal of visual impairment and blindness in the population correcting RE and possible associations between RE and individual characteristics. A cross-sectional study was conducted in nine counties of the western region of state of São Paulo, using systematic and random sampling of households between March 2004 and July 2005. Individuals aged more than 1 year old were included and were evaluated for demographic data, eye complaints, history, and eye exam, including no corrected visual acuity (NCVA), best corrected vision acuity (BCVA), automatic and manual refractive examination. The definition adopted for URE was applied to individuals with NCVA > 0.15 logMAR and BCVA ≤ 0.15 logMAR after refractive correction and unmet refractive error (UREN), individuals who had visual impairment or blindness (NCVA > 0.5 logMAR) and BCVA ≤ 0.5 logMAR after optical correction. A total of 70.2% of subjects had normal NCVA. URE was detected in 13.8%. Prevalence of 4.6% of optically reversible low vision and 1.8% of blindness reversible by optical correction were found. UREN was detected in 6.5% of individuals, more frequently observed in women over the age of 50 and in higher RE carriers. Visual impairment related to eye diseases is not reversible with spectacles. Using multivariate analysis, associations between URE and UREN with regard to sex, age and RE was observed. RE is an important cause of reversible blindness and low vision in the Brazilian population.

  12. Repeated mobility testing for later artificial visual function evaluation

    Science.gov (United States)

    Velikay-Parel, M.; Ivastinovic, D.; Koch, M.; Hornig, R.; Dagnelie, G.; Richard, G.; Langmann, A.

    2007-03-01

    The study investigates the utility of a newly designed mobility test for repeated testing of visual function in patients with severe visual impairment and future application in evaluating functional progress in patients with artificial vision. Ten subjects divided into three groups based on visual acuity (VA) ranging from light perception to 20/200 and reduced visual field (VF) were included in the study. The mobility test consisted of using a set of four different but structurally similar and relatively short mazes having a constant number of obstacles of various sizes. The subjects, divided into three groups by acuity, passed through each course several times. In general, the patients with better VA had a larger extent of VF. Average speed and number of contacts were recorded as measures of performance. The average passing times of the groups through the courses were significantly different (p = 0.03), which was influenced by VA and VF. There was no significant difference in average number of contacts between the groups (p = 0.15). The mobility test proved to be appropriate for gaining statistically relevant results in repeated individual testing of patients with severe vision impairment. Results show promise for use this mobility test as a tool for assessing visual function of patients undergoing implantation of a visual prosthesis for artificial vision.

  13. Cerebral versus Ocular Visual Impairment: The Impact on Developmental Neuroplasticity

    Science.gov (United States)

    Martín, Maria B. C.; Santos-Lozano, Alejandro; Martín-Hernández, Juan; López-Miguel, Alberto; Maldonado, Miguel; Baladrón, Carlos; Bauer, Corinna M.; Merabet, Lotfi B.

    2016-01-01

    Cortical/cerebral visual impairment (CVI) is clinically defined as significant visual dysfunction caused by injury to visual pathways and structures occurring during early perinatal development. Depending on the location and extent of damage, children with CVI often present with a myriad of visual deficits including decreased visual acuity and impaired visual field function. Most striking, however, are impairments in visual processing and attention which have a significant impact on learning, development, and independence. Within the educational arena, current evidence suggests that strategies designed for individuals with ocular visual impairment are not effective in the case of CVI. We propose that this variance may be related to differences in compensatory neuroplasticity related to the type of visual impairment, as well as underlying alterations in brain structural connectivity. We discuss the etiology and nature of visual impairments related to CVI, and how advanced neuroimaging techniques (i.e., diffusion-based imaging) may help uncover differences between ocular and cerebral causes of visual dysfunction. Revealing these differences may help in developing future strategies for the education and rehabilitation of individuals living with visual impairment. PMID:28082927

  14. Cerebral versus Ocular Visual Impairment: The Impact on Developmental Neuroplasticity.

    Science.gov (United States)

    Martín, Maria B C; Santos-Lozano, Alejandro; Martín-Hernández, Juan; López-Miguel, Alberto; Maldonado, Miguel; Baladrón, Carlos; Bauer, Corinna M; Merabet, Lotfi B

    2016-01-01

    Cortical/cerebral visual impairment (CVI) is clinically defined as significant visual dysfunction caused by injury to visual pathways and structures occurring during early perinatal development. Depending on the location and extent of damage, children with CVI often present with a myriad of visual deficits including decreased visual acuity and impaired visual field function. Most striking, however, are impairments in visual processing and attention which have a significant impact on learning, development, and independence. Within the educational arena, current evidence suggests that strategies designed for individuals with ocular visual impairment are not effective in the case of CVI. We propose that this variance may be related to differences in compensatory neuroplasticity related to the type of visual impairment, as well as underlying alterations in brain structural connectivity. We discuss the etiology and nature of visual impairments related to CVI, and how advanced neuroimaging techniques (i.e., diffusion-based imaging) may help uncover differences between ocular and cerebral causes of visual dysfunction. Revealing these differences may help in developing future strategies for the education and rehabilitation of individuals living with visual impairment.

  15. Joint engagement in infants and its relationship to their visual impairment measurements.

    Science.gov (United States)

    Urqueta Alfaro, Andrea; Morash, Valerie S; Lei, Daisy; Orel-Bixler, Deborah

    2018-02-01

    Coordination of attention between a social partner and an external focus of shared interest, called joint engagement, is associated with positive developmental outcomes such as better language, socio-emotional, and theory of mind skills in sighted infants. Current measures of joint engagement rely on an infant's visual behaviors, making it difficult to study joint engagement in infants with low or no vision. In a naturalistic observational study, 20 infants with various levels of visual impairments - mean ages: 1.08 years (N=9) and 1.62 years (N=18), were videotaped during 30-min free play sessions with their caregivers. Seven infants were tested at both ages. Videos were coded to determine the percentage of time the dyads participated in joint engagement. Results showed that all visually impaired infants participated in joint engagement, with a significant increase between earlier and later ages. Infants' visual impairment levels were described in terms of visual acuity and contrast sensitivity as measured using both visual evoked potential and preferential looking techniques. Of the visual measurements, infants' reduction in contrast sensitivity measured with preferential looking, alone, predicted the infants' percentage of time in joint engagement across ages. Contrary to prior research that exclusively focused on visual acuity, this finding supports the need to include contrast sensitivity measurements in studies with visually impaired infants. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Prevalence and causes of visual impairment in low-middle income school children in Sao Paulo, Brazil.

    Science.gov (United States)

    Salomão, Solange R; Cinoto, Rafael W; Berezovsky, Adriana; Mendieta, Luana; Nakanami, Célia R; Lipener, César; Muñoz, Emílio de Haro; Ejzenbaum, Fabio; Belfort, Rubens; Pokharel, Gopal P; Ellwein, Leon B

    2008-10-01

    Assess prevalence and causes of vision impairment among low-middle income school children in São Paulo. Cluster sampling was used to obtain a random sample of children ages 11 to 14 years from public schools (grades 5-8) in three districts from June to November 2005. The examination included visual acuity testing, ocular motility, and examination of the external eye, anterior segment, and media. Cycloplegic refraction and fundus examination were performed in children with uncorrected visual acuity 20/40 or worse in either eye. A principal cause of visual impairment was determined for eyes with uncorrected visual acuity of 20/40 or worse. A total of 2825 children were enumerated and 2441 (86.4%) were examined. The prevalence of uncorrected, presenting, and best-corrected visual acuity 20/40 or worse in the better eye was 4.82%, 2.67%, and 0.41%, respectively. Spectacles were used by 144 (5.9%) children. Refractive error was a cause in 76.8% of children with visual impairment in one or both eyes; amblyopia, 11.4%; retinal disorders, 5.9%; other causes, 2.7%; and unexplained causes, 7.7%. Myopic visual impairment (spherical equivalent -0.50 D in one or both eyes) was not associated with age or grade level, but female sex was marginally significant (P = 0.070). Hyperopic visual impairment (+2.00 D or more) was not associated with age, grade level, or sex. The prevalence of reduced vision in low-middle income urban São Paulo school children was low, most of it because of uncorrected refractive error. Cost-effective strategies are needed to address this easily treated cause of vision impairment.

  17. Age-Specific Prevalence of Visual Impairment and Refractive Error in Children Aged 3-10 Years in Shanghai, China.

    Science.gov (United States)

    Ma, Yingyan; Qu, Xiaomei; Zhu, Xiaofeng; Xu, Xun; Zhu, Jianfeng; Sankaridurg, Padmaja; Lin, Senlin; Lu, Lina; Zhao, Rong; Wang, Ling; Shi, Huijing; Tan, Hui; You, Xiaofang; Yuan, Hong; Sun, Sifei; Wang, Mingjin; He, Xiangui; Zou, Haidong; Congdon, Nathan

    2016-11-01

    We assessed changes in age-specific prevalence of refractive error at the time of starting school, by comparing preschool and school age cohorts in Shanghai, China. A cross-sectional study was done in Jiading District, Shanghai during November and December 2013. We randomly selected 7 kindergartens and 7 primary schools, with probability proportionate to size. Chinese children (n = 8398) aged 3 to 10 years were enumerated, and 8267 (98.4%) were included. Children underwent distance visual acuity assessment and refraction measurement by cycloplegic autorefraction and subjective refraction. The prevalence of uncorrected visual acuity (UCVA), presenting visual acuity, and best-corrected visual acuity in the better eye of ≤20/40 was 19.8%, 15.5%, and 1.7%, respectively. Among those with UCVA ≤ 20/40, 93.2% could achieve visual acuity of ≥20/32 with refraction. Only 28.7% (n = 465) of children with UCVA in the better eye of ≤20/40 wore glasses. Prevalence of myopia (spherical equivalent ≤-0.5 diopters [D] in at least one eye) increased from 1.78% in 3-year-olds to 52.2% in 10-year-olds, while prevalence of hyperopia (spherical equivalent ≥+2.0 D) decreased from 17.8% among 3-year-olds to 2.6% by 10 years of age. After adjusting for age, attending elite "high-level" school was statistically associated with greater myopia prevalence. The prevalence of myopia was lower or comparable to that reported in other populations from age 3 to 5 years, but increased dramatically after 6 years, consistent with a strong environmental role of schooling on myopia development.

  18. Comparison of visual outcomes and subjective visual quality after bilateral implantation of a diffractive trifocal intraocular lens and blended implantation of apodized diffractive bifocal intraocular lenses

    Directory of Open Access Journals (Sweden)

    Gundersen KG

    2016-05-01

    Full Text Available Kjell G Gundersen,1 Rick Potvin21IFocus Øyeklinikk AS, Haugesund, Norway; 2Science in Vision, Akron, NY, USAPurpose: To compare the visual acuity (VA and quality of vision between bilateral implantation of a trifocal intraocular lens (IOL and blended bifocal IOLs with an intermediate add in the dominant eye and a near add in the nondominant eye.Patients and methods: Patients with either trifocal or blended bifocal IOLs implanted were recruited after surgery. Subjects returned for a single diagnostic visit between 3 and 24 months after surgery. VA was tested at various distances, including low-contrast acuity and acuity at their preferred reading distance. A binocular defocus curve was obtained, and subjective visual function and quality of vision were evaluated.Results: Twenty-five trifocal subjects and 30 blended bifocal subjects were enrolled. There were no significant differences in low-contrast acuity, preferred reading distance, or acuity at that reading distance. Binocular vision at 4 m, 60 cm, and 40 cm was not statistically significantly different. The trifocal provided statistically significantly better visual acuity (P<0.05 at vergences from -0.5 to -1.5 D (from 2 m to 67 cm viewing distance, P<0.05. There was no statistically significant difference in the near vision subscale scores of the 39-question National Eye Institute Visual Function Questionnaire or the overall scores of the Quality of Vision questionnaire, though significantly more trifocal subjects reported that the observed visual disturbances were “bothersome” (P<0.05.Conclusion: Both lens modalities provided subjects with excellent binocular near and distance vision, with similar low rates of visual disturbances and good reported functional vision. The trifocal IOL provided significantly better intermediate VA in the viewing distance range of 2 m to 67 cm, corresponding to viewing things such as a car dashboard or grocery shelf. VA was similar between groups at

  19. Visual impairment and spectacle use in schoolchildren in rural and urban regions in Beijing.

    Science.gov (United States)

    Guo, Yin; Liu, Li Juan; Xu, Liang; Lv, Yan Yun; Tang, Ping; Feng, Yi; Meng, Lei; Jonas, Jost B

    2014-01-01

    To determine prevalence and associations of visual impairment and frequency of spectacle use among grade 1 and grade 4 students in Beijing. This school-based, cross-sectional study included 382 grade 1 children (age 6.3 ± 0.5 years) and 299 grade 4 children (age 9.4 ± 0.7 years) who underwent a comprehensive eye examination including visual acuity, noncycloplegic refractometry, and ocular biometry. Presenting visual acuity (mean 0.04 ± 0.17 logMAR) was associated with younger age (p = 0.002), hyperopic refractive error (pvisual impairment (presenting visual acuity ≤20/40 in the better eye) was found in 44 children (prevalence 6.64 ± 1.0% [95% confidence interval (CI) 4.74, 8.54]). Mean best-corrected visual acuity (right eyes -0.02 ± 0.04 logMAR) was associated with more hyperopic refractive error (p = 0.03) and rural region of habitation (pvisual impairment (best-corrected visual acuity ≤20/40 in the better eye) was 2/652 (0.30 ± 0.21% [95% CI 0.00, 0.72]). Undercorrection of refractive error was present in 53 children (7.99 ± 1.05%) and was associated with older age (p = 0.003; B 0.53; OR 1.71 [95% CI 1.20, 2.42]), myopic refractive error (p = 0.001; B -0.72; OR 0.49 [95% CI 0.35, 0.68]), and longer axial length (p = 0.002; B 0.74; OR 2.10 [95% CI 1.32, 3.32]). Spectacle use was reported for 54 children (8.14 ± 1.06%). Mean refractive error of the worse eyes of these children was -2.09 ± 2.88 D (range -7.38 to +7.25 D). Factors associated with presenting visual impairment were older age, myopic refractive error, and higher maternal education level. Despite a prevalence of myopia of 33% in young schoolchildren in Greater Beijing, prevalence of best-corrected visual impairment (0.30% ± 0.21%), presenting visual impairment (6.64% ± 1.0%), and undercorrection of refractive error (7.99% ± 1.05%) were relatively low.

  20. Visual Fields at Presentation and after Trans-sphenoidal Resection of Pituitary Adenomas

    Directory of Open Access Journals (Sweden)

    Renu Dhasmana

    2011-01-01

    Full Text Available Purpose: To evaluate visual field changes in patients with pituitary adenomas following trans-sphenoidal surgery. Methods: Eighteen patients with pituitary adenomas underwent a complete ophthalmic assessment and visual field analysis using the Humphrey Field Analyzer 30-2 program before and after trans-sphenoidal surgical resection at the Himalayan Institute of Medical Sciences over a one year period. Visual acuity, duration of symptoms, optic nerve head changes, pattern of visual field defects, and variables such as mean deviation and visual field index were compared. Results: Thirty-six eyes of 18 patients including 10 male and 8 female subjects with mean age of 35.1±9.9 years and histologically proven pituitary adenoma were included. Mean visual acuity at presentation was 0.29 logMAR which improved to 0.21 logMAR postoperatively (P = 0.305. Of 36 eyes, 24 (66.7% had visual field defects including temporal defects in 12 eyes (33.3%, non-specific defects in 10 eyes (27.8%, and peripheral field constriction in 2 eyes (5.6%. Mean deviation of visual fields at presentation was -14.28 dB which improved to -11.32 dB postoperatively. The visual field index improved from 63.5% to 75% postoperatively. Favorable visual field outcomes were correlated with shorter duration of symptoms and absence of optic nerve head changes at presentation. Conclusion: Visual field defects were present in two thirds of patients at presentation. An overall improvement in vision and visual fields was noted after surgical resection. An inverse correlation was found between the duration of symptoms and postoperative visual field recovery, signifying the importance of early surgical intervention.

  1. Oculo-Visual Dysfunction in Parkinson’s Disease

    Science.gov (United States)

    Armstrong, R.A.

    2015-01-01

    This review describes the oculo-visual problems likely to be encountered in Parkinson’s disease (PD) with special reference to three questions: (1) are there visual symptoms characteristic of the prodromal phase of PD, (2) is PD dementia associated with specific visual changes, and (3) can visual symptoms help in the differential diagnosis of the parkinsonian syndromes, viz. PD, progressive supranuclear palsy (PSP), dementia with Lewy bodies (DLB), multiple system atrophy (MSA), and corticobasal degeneration (CBD)? Oculo-visual dysfunction in PD can involve visual acuity, dynamic contrast sensitivity, colour discrimination, pupil reactivity, eye movement, motion perception, and visual processing speeds. In addition, disturbance of visuo-spatial orientation, facial recognition problems, and chronic visual hallucinations may be present. Prodromal features of PD may include autonomic system dysfunction potentially affecting pupil reactivity, abnormal colour vision, abnormal stereopsis associated with postural instability, defects in smooth pursuit eye movements, and deficits in visuo-motor adaptation, especially when accompanied by idiopathic rapid eye movement (REM) sleep behaviour disorder. PD dementia is associated with the exacerbation of many oculo-visual problems but those involving eye movements, visuo-spatial function, and visual hallucinations are most characteristic. Useful diagnostic features in differentiating the parkinsonian symptoms are the presence of visual hallucinations, visuo-spatial problems, and variation in saccadic eye movement dysfunction. PMID:26599301

  2. INFLUENCE OF CHOLINE ALFOSCERATE ON VISUAL PERCEPTION IN PATIENTS WITH AMBLYOPIA

    OpenAIRE

    I.E. Aznauryan; I.S. Bagrova

    2006-01-01

    Amblyopia is a frequent disorder in pediatric ophthalmology. The term of amblyopia refers to reduced vision caused by limited visual sensory stimulation (visual deprivation) at a time of visual system development, so the vision can not be improved by proper sunglasses. Apparatus treatment of amblyopia have limited effect in rehabilitation of children with moderate (lens corrected visual acuity between 0.2 and 0.3) and severe (lens corrected visual acuity below 0.2) amblyopia. Novel data conce...

  3. 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.

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

    Science.gov (United States)

    Winslow, Brent D; Nguyen, Nam; Venta, Kimberly E

    2017-01-01

    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.

  5. Spatial acuity and prey detection in weakly electric fish.

    Directory of Open Access Journals (Sweden)

    David Babineau

    2007-03-01

    Full Text Available It is well-known that weakly electric fish can exhibit extreme temporal acuity at the behavioral level, discriminating time intervals in the submicrosecond range. However, relatively little is known about the spatial acuity of the electrosense. Here we use a recently developed model of the electric field generated by Apteronotus leptorhynchus to study spatial acuity and small signal extraction. We show that the quality of sensory information available on the lateral body surface is highest for objects close to the fish's midbody, suggesting that spatial acuity should be highest at this location. Overall, however, this information is relatively blurry and the electrosense exhibits relatively poor acuity. Despite this apparent limitation, weakly electric fish are able to extract the minute signals generated by small prey, even in the presence of large background signals. In fact, we show that the fish's poor spatial acuity may actually enhance prey detection under some conditions. This occurs because the electric image produced by a spatially dense background is relatively "blurred" or spatially uniform. Hence, the small spatially localized prey signal "pops out" when fish motion is simulated. This shows explicitly how the back-and-forth swimming, characteristic of these fish, can be used to generate motion cues that, as in other animals, assist in the extraction of sensory information when signal-to-noise ratios are low. Our study also reveals the importance of the structure of complex electrosensory backgrounds. Whereas large-object spacing is favorable for discriminating the individual elements of a scene, small spacing can increase the fish's ability to resolve a single target object against this background.

  6. Binocular visual function of myopic pseudophakic monovision.

    Science.gov (United States)

    Hayashi, Ken; Yoshida, Motoaki; Sasaki, Hiroshi; Hirata, Akira

    2018-02-20

    To compare binocular visual function of myopic pseudophakic patients with myopic monovision to patients without monovision. Randomized comparative study METHODS: Sixty patients were randomized to one of two groups: patients whose refraction was targeted to -2.75 diopters (D) in the dominant eye and -1.75D in the nondominant eye (myopic monovision group), and patients whose refraction was targeted to -2.75D bilaterally (non-monovision group). Binocular uncorrected and corrected visual acuity at various distances was measured using an all-distance vision tester, and contrast visual acuity and near stereoacuity were examined. In the myopic monovision group mean refraction was -2.74D in the dominant eyes and -1.94D in the nondominant eyes, and in the non-monovision group it was -2.96D bilaterally. Mean binocular uncorrected distance (UDVA) and intermediate visual acuity (UIVA) from 0.5 m to 5.0 m were significantly better in the myopic monovision group than in the non-monovision group (P≤ 0.0134), while binocular uncorrected near visual acuity (UNVA) at 0.3 m did not differ significantly between groups. The distribution of UIVA and UDVA was significantly better in the myopic monovision group (P≤ 0.0035). Corrected visual acuity at any distance, photopic and mesopic contrast visual acuity, and stereoacuity did not differ significantly between groups. Patients with myopic monovision exhibited significantly better binocular UIVA and UDVA than those without monovision, while UNVA, corrected visual acuity, contrast sensitivity, and stereoacuity were comparable between groups, suggesting that this method is useful for patients who want to see near and intermediate distances without spectacles.

  7. Visual impairment in children with congenital Zika syndrome.

    Science.gov (United States)

    Ventura, Liana O; Ventura, Camila V; Lawrence, Linda; van der Linden, Vanessa; van der Linden, Ana; Gois, Adriana L; Cavalcanti, Milena M; Barros, Eveline A; Dias, Natalia C; Berrocal, Audina M; Miller, Marilyn T

    2017-08-01

    To describe the visual impairment associated with ocular and neurological abnormalities in a cohort of children with congenital Zika syndrome (CZS). This cross-sectional study included infants with microcephaly born in Pernambuco, Brazil, from May to December 2015. Immunoglobulin M antibody capture enzyme-linked immunosorbent assay for the Zika virus on the cerebrospinal fluid samples was positive for all infants. Clinical evaluation consisted of comprehensive ophthalmologic examination including visual acuity, visual function assessment, visual developmental milestone, neurologic examination, and neuroimaging. A total of 32 infants (18 males [56%]) were included. Mean age at examination was 5.7 ± 0.9 months (range, 4-7 months). Visual function and visual developmental milestone could not be tested in 1 child (3%). Visual impairment was detected in 32 infants (100%). Retinal and/or optic nerve findings were observed in 14 patients (44%). There was no statistical difference between the patients with ocular findings and those without (P = 0.180). All patients (100%) demonstrated neurological and neuroimaging abnormalities; 3 (9%) presented with late-onset of microcephaly. Children with CZS demonstrated visual impairment regardless of retina and/or optic nerve abnormalities. This finding suggests that cortical/cerebral visual impairment may be the most common cause of blindness identified in children with CZS. Copyright © 2017 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

  8. Significant improvements in near vision, reading speed, central visual field and related quality of life after ranibizumab treatment of wet age-related macular degeneration.

    Science.gov (United States)

    Frennesson, Christina; Nilsson, Ulla L; Peebo, Beatrice B; Nilsson, Sven E G

    2010-06-01

    To investigate the effects on near visual acuity, reading speed, central visual field and related quality of life of ranibizumab treatment of wet age-related macular degeneration (AMD). The study was a prospective, non-comparative consecutive case series, followed for 3 months and investigator-driven. Thirty eyes of 30 patients with wet AMD were included, mean age 75 years (range 69-95 years). In addition to a full ophthalmological examination--including best-corrected visual acuity (BCVA; Early Treatment Diabetic Research Study chart), fundus biomicroscopy, fundus photography, fluorescein angiography, indocyanine green angiography (occult cases) and ocular coherence tomography--near visual acuity, reading speed, central visual field and quality of life for related activities were also investigated at baseline and at 3 months after ranibizumab treatment. Mean BCVA increased from 62 +/- 11 to 66 +/- 14 letters at 3 months (7%; p = 0.018). Near vision improved from 9 +/- 5 to 6 +/- 3 points (33%; p = 0.0006) and reading speed increased from 59 +/- 40 to 85 +/- 50 words/min (44%; p Reading newspaper text in the group in which the better eye was treated showed the highest increase in quality of life score of all: 116%. The increase in BCVA after ranibizumab treatment is well established. The present study also showed significant improvements in other important visual qualities, such as near visual acuity, reading speed, central visual field and several activities influencing quality of life. The improvement was greater for near activities than for distance activities. Therefore, the beneficial effects of ranibizumab treatment shown here are more extensive than those reported previously.

  9. The Tribal Odisha Eye Disease Study (TOES) 1: prevalence and causes of visual impairment among tribal children in an urban school in Eastern India.

    Science.gov (United States)

    Warkad, Vivekanand U; Panda, Lapam; Behera, Pradeep; Das, Taraprasad; Mohanta, Bikash C; Khanna, Rohit

    2018-03-16

    To estimate the prevalence and causes of visual impairment and other ocular comorbidities among tribal children in an urban school population in eastern India. In this cross-sectional study, vision screening tests were administered to tribal school children. Demographic data, including name, age, sex, home district, height, and weight of each child, and examination data, including unaided and pinhole visual acuity, external eye examination with a flashlight, slit-lamp examination, intraocular pressure (IOP) measurement, and undilated fundus photography, were collected. Children with visual acuity of less than 20/20, abnormal anterior or posterior segment findings, and IOP of >21 mm Hg were referred to for further evaluation. Of 10,038 children (5,840 males [58.2%]) screened, 335 (median age, 9 years; range, 6-17 years) were referred. Refractive error was the most common cause of visual impairment (59.52%; 95% CI, 51.97-66.65) followed by amblyopia (17.2%; 95% CI, 12.3-23.6) and posterior segment anomaly (14.88%; 95% CI, 10.2-21.0). The prevalence of best-corrected visual acuity of 20/40 was 0.13%. The prevalence of blindness was 0.03%. Visual impairment among tribal children in this residential school is an uncommon but important disability. Copyright © 2018 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

  10. The Effectiveness of Combining Tangible Symbols with the Picture Exchange Communication System to Teach Requesting Skills to Children with Multiple Disabilities Including Visual Impairment

    Science.gov (United States)

    Ali, Emad

    2009-01-01

    The Picture Exchange Communication System (PECS) is an augmentative and alternative communication program (Frost & Bondy, 2002). Although PECS has been effectively used to teach functional requesting skills for children with autism, mental retardation, visual impairment, and physical disabilities (e.g., Anderson, Moore, & Bourne, 2007; Chambers &…

  11. The occurrence of visual and cognitive impairment, and eye diseases in the super-elderly in Japan: a cross-sectional single-center study.

    Science.gov (United States)

    Fukuoka, Hideki; Nagaya, Masahiro; Toba, Kenji

    2015-10-29

    The current state of eye diseases and treatments in the elderly as well as the relationships between dementia and systemic diseases remain unclear. Therefore, this study evaluated the prevalence of eye diseases, visual impairment, cognitive impairment, and falls (which are an important health issue and are considered one of the Geriatric Giants) in super-elderly people in Japan. The subjects were 31 elderly people (62 eyes; mean age: 84.6 ± 8.8 years; age range 61-98 years) who were admitted to a geriatric health services facility. Eye treatment status, systemic diseases, dementia, and recent falls were investigated. Eye examinations including vision and intraocular pressure measurement, and slit-lamp biomicroscopy were conducted. Mean best corrected visual acuity (logMAR) was 0.51 ± 0.56, and mean intraocular pressure was 13.7 ± 3.5 mmHg. Approximately half of the subjects exhibited excavation of the optic nerve head including cataracts and glaucoma. Ten subjects had visual impairment (i.e., visual acuity of the eye with the better vision visually impaired and non-visually impaired groups were 10.2 ± 6 and 16 ± 8 points, respectively (p visual impairment experienced a fall in the past year compared to 48% of those without visual impairment, although the difference was not significant. Regarding systemic diseases, there were 6, 5, and 15 cases of diabetes, hyperlipidemia, and hypertension, respectively. There was no significant difference between these systemic diseases and visual function after adjusted for age and gender. The percentages of patients with age-related eye diseases and poor visual acuity in a geriatric health services facility were extremely high. Compared to those without visual impairment, those with visual impairment had lower dementia scores and a higher rate of falls.

  12. Visual outcome of traumatic cataract surgery in Ibadan, Nigeria.

    Science.gov (United States)

    Bekibele, C O; Fasina, O

    2008-12-01

    To review the visual outcome of traumatic cataracts operated at the University College Hospital, Ibadan with the view to making recommendations for improved outcome. All patients operated at the University College Hospital Ibadan, Nigeria between May 1999 and April 2004 with traumatic cataract were reviewed retrospectively to determine visual outcome and main causes of poor visual outcome notes of patients 32 patients, age range 2 to 71 years, mean age 25.6 +/- SD 16.1 years were reviewed. 22 (68.8%) were males while 10 (31.2%) were females. Causes of traumatic cataract included wood/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%) noted.

  13. 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.

  14. Therapeutic interventions for macular diseases show characteristic effects on near and distance visual function.

    Science.gov (United States)

    Munk, Marion; Kiss, Christopher; Huf, Wolfgang; Sulzbacher, Florian; Bolz, Matthias; Sayegh, Ramzi; Eisenkölbl, Stefan; Simader, Christian; Schmidt-Erfurth, Ursula

    2013-10-01

    To compare therapy-induced reading and distance visual acuity (dVA) increases in neovascular age-related macular degeneration (nAMD) and uveitis-associated cystoid macular edema. This longitudinal study included 68 treatment-naive eyes: 39 subfoveal nAMD eyes with disrupted photoreceptor layers treated with monthly ranibizumab and 29 uveitis-associated cystoid macular edema eyes with intact photoreceptor layer treated with 1 triamcinolone injection. Patients were examined with high-definition optical coherence tomography, Early Treatment Diabetic Retinopathy Study dVA (logarithm of the minimum angle of resolution), reading acuity (logRADscore), and maximum reading speed (words per minute) over 3 months of therapy. In uveitis-associated cystoid macular edema, logarithm of the minimum angle of resolution and logRADscore improved 1 day post treatment, from 0.49 ± 0.28 to 0.39 ± 0.3 (P = 0.018) and 0.71 ± 0.53 to 0.56 ± 0.49 (P = 0.012), respectively. In nAMD, logarithm of the minimum angle of resolution improved 1 week after anti-vascular endothelial growth factor therapy from 0.59 ± 0.29 to 0.49 ± 0.24 (P = 0.002), with no change in logRADscore. One month after treatment, logRADscore improved from 1.09 ± 0.65 to 0.90 ± 0.60 (P = 0.002). In uveitis-associated cystoid macular edema, the recovery course of reading and dVA was comparable, and in nAMD, reading acuity recovery was delayed. Irrespective of disease, a small reduction in dVA resulted in a larger reading acuity decrease. Cystoid macular edema resolution was associated with rapid synchronous reading and dVA improvement, whereas nAMD was followed by faster recovery of distance than reading acuity. In both conditions, reading acuity expressed by critical angular resolution was more suppressed by active disease and recovered relatively more than distance acuity. These discrepancies indicate that reading acuity might be a more sensitive measure for vision decrease in macular diseases than dVA. Reading

  15. 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.

  16. Arithmetic Training Does Not Improve Approximate Number System Acuity.

    Science.gov (United States)

    Lindskog, Marcus; Winman, Anders; Poom, Leo

    2016-01-01

    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-min 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 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.

  17. AutO&Mobility: safe driving with a visual impairment in a European setting

    NARCIS (Netherlands)

    van Damme, Wim; Bredewoud, Ruud; Heutink, Joost; Melis-Dankers, Bart

    2015-01-01

    Background: European legislation prohibits driving a passenger car when visual acuity is below 0.50 or visual field is less than 120 degrees horizontal. However insufficient acuity might be compensated using a bioptic telescope, and people with hemianopia might learn to use compensatory saccadic eye

  18. 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.

  19. Comparing performance on the MNREAD iPad application with the MNREAD acuity chart.

    Science.gov (United States)

    Calabrèse, Aurélie; To, Long; He, Yingchen; Berkholtz, Elizabeth; Rafian, Paymon; Legge, Gordon E

    2018-01-01

    Our purpose was to compare reading performance measured with the MNREAD Acuity Chart and an iPad application (app) version of the same test for both normally sighted and low-vision participants. Our methods included 165 participants with normal vision and 43 participants with low vision tested on the standard printed MNREAD and on the iPad app version of the test. Maximum Reading Speed, Critical Print Size, Reading Acuity, and Reading Accessibility Index were compared using linear mixed-effects models to identify any potential differences in test performance between the printed chart and the iPad app. Our results showed the following: For normal vision, chart and iPad yield similar estimates of Critical Print Size and Reading Acuity. The iPad provides significantly slower estimates of Maximum Reading Speed than the chart, with a greater difference for faster readers. The difference was on average 3% at 100 words per minute (wpm), 6% at 150 wpm, 9% at 200 wpm, and 12% at 250 wpm. For low vision, Maximum Reading Speed, Reading Accessibility Index, and Critical Print Size are equivalent on the iPad and chart. Only the Reading Acuity is significantly smaller (I. E., better) when measured on the digital version of the test, but by only 0.03 logMAR (p = 0.013). Our conclusions were that, overall, MNREAD parameters measured with the printed chart and the iPad app are very similar. The difference found in Maximum Reading Speed for the normally sighted participants can be explained by differences in the method for timing the reading trials.

  20. Modeling Visual Symptoms and Visual Skills to Measure Functional Binocular Vision

    Science.gov (United States)

    Powers, M. K.; Fisher, W. P., Jr.; Massof, R. W.

    2016-11-01

    Obtaining a clear image of the world depends on good eye coordination (“binocular vision”). Yet no standard exists by which to determine a threshold for good vs poor binocular vision, as exists for the eye chart and visual acuity. We asked whether data on the signs and symptoms related to binocular vision are sufficiently consistent with children's self-reported visual symptoms to substantiate a construct model of Functional Binocular Vision (FBV), and then whether that model can be used to aggregate clinical and survey observations into a meaningful diagnostic measure. Data on visual symptoms from 1,100 children attending school in Los Angeles were obtained using the Convergence Insufficiency Symptom Survey (CISS); and for more than 300 students in that sample, 35 additional measures were taken, including acuity, cover test near and far, near point of convergence, near point of accommodation, accommodative facility, vergence ranges, tracking ability, and oral reading fluency. A preliminary analysis of data from the 15-item, 5-category CISS and 15 clinical variables from 103 grade school students who reported convergence problems (CISS scores of 16 or higher) suggests that the clinical and survey observations will be optimally combined in a multidimensional model.

  1. Reading Acquisition, Cognitive and Visual Development, and Self-Esteem in Four Children with Cerebral Visual Impairment

    Science.gov (United States)

    Ek, Ulla; Fellenius, Kerstin; Jacobson, Lena

    2003-01-01

    During a longitudinal in-depth study of the reading acquisition and cognitive and visual development of four children with cerebral visual impairment, the children's visual acuity improved, but their full-scale IQs declined, mostly because of difficulties in abstract thinking, visual cognitive organization, and extremely low processing speed. The…

  2. Age related macular degeneration and visual disability.

    Science.gov (United States)

    Christoforidis, John B; Tecce, Nicola; Dell'Omo, Roberto; Mastropasqua, Rodolfo; Verolino, Marco; Costagliola, Ciro

    2011-02-01

    Age-related macular degeneration (AMD) is the leading cause of central blindness or low vision among the elderly in industrialized countries. AMD is caused by a combination of genetic and environmental factors. Among modifiable environmental risk factors, cigarette smoking has been associated with both the dry and wet forms of AMD and may increase the likelihood of worsening pre-existing AMD. Despite advances, the treatment of AMD has limitations and affected patients are often referred for low vision rehabilitation to help them cope with their remaining eyesight. The characteristic visual impairment for both forms of AMD is loss of central vision (central scotoma). This loss results in severe difficulties with reading that may be only partly compensated by magnifying glasses or screen-projection devices. The loss of central vision associated with the disease has a profound impact on patient quality of life. With progressive central visual loss, patients lose their ability to perform the more complex activities of daily living. Common vision aids include low vision filters, magnifiers, telescopes and electronic aids. Low vision rehabilitation (LVR) is a new subspecialty emerging from the traditional fields of ophthalmology, optometry, occupational therapy, and sociology, with an ever-increasing impact on the usual concepts of research, education, and services for visually impaired patients. Relatively few ophthalmologists practise LVR and fewer still routinely use prismatic image relocation (IR) in AMD patients. IR is a method of stabilizing oculomotor functions with the purpose of promoting better function of preferred retinal loci (PRLs). The aim of vision rehabilitation therapy consists in the achievement of techniques designed to improve PRL usage. The use of PRLs to compensate for diseased foveae has offered hope to these patients in regaining some function. However, in a recently published meta-analysis, prism spectacles were found to be unlikely to be of

  3. Cerebrospinal fluid neurofilament light chain levels predict visual outcome after optic neuritis

    DEFF Research Database (Denmark)

    Modvig, Signe; Degn, M; Sander, B

    2016-01-01

    BACKGROUND: Optic neuritis is a good model for multiple sclerosis relapse, but currently no tests can accurately predict visual outcome. OBJECTIVE: The purpose of this study was to examine whether cerebrospinal fluid (CSF) biomarkers of tissue damage and remodelling (neurofilament light chain (NF......-L), myelin basic protein, osteopontin and chitinase-3-like-1) predict visual outcome after optic neuritis. METHODS: We included 47 patients with optic neuritis as a first demyelinating episode. Patients underwent visual tests, optical coherence tomography (OCT), magnetic resonance imaging (MRI) and lumbar...... puncture. Biomarkers were measured in CSF by enzyme-linked immunosorbent assay (ELISA). Patients were followed up six months after onset and this included visual tests and OCT. Outcome measures were inter-ocular differences in low contrast visual acuity (LCVA), retinal nerve fibre layer (RNFL) and ganglion...

  4. Development and validation of the Greek version of the MNREAD acuity chart.

    Science.gov (United States)

    Mataftsi, Asimina; Bourtoulamaiou, Areti; Haidich, Anna-Bettina; Antoniadis, Antonis; Kilintzis, Vassilis; Tsinopoulos, Ioannis T; Dimitrakos, Stavros

    2013-01-01

    The aim of this study was to develop MNREAD acuity charts in the Greek language (MNREAD-GR) and establish their repeatability in a normal-sighted population. One hundred and eighty Greek sentences were constructed based on the design principles of the Minnesota Low Vision Reading Test. The software used to validate them for width was adjusted to the parameters of the non-Latin characters used in the Greek language (MNTest-GR) and width-validated sentences were then checked for literacy by two language teachers. Pilot testing followed in 20 adults and two groups of 20 children. Subsequently, three versions of the MNREAD-GR chart were printed and validated for repeatability: 20 adults read MNREAD-GR charts 1, 2 and 3 in random order over two sessions. A linear mixed-model analysis was performed for near visual acuity (VA), maximum reading speed and critical print size to identify the contribution of each source (individual subject, session, chart and residual error) to the total variance. Subject variance determined the intraclass correlation coefficient. One hundred of the initial 180 sentences were validated with MNTest-GR and approved for literacy correctness. Of those, 57 sentences were selected after pilot testing, and used in the final printed chart in random distribution among three versions. The intraclass correlation coefficients were 0.72 for VA, 0.87 for maximum reading speed and 0.46 for critical print size. The between-charts within-session within-subject component accounted for a maximum five per cent of the variance. The between-sessions within-subject component had a maximum of one per cent. The coefficient of repeatability was 0.08 logMAR for VA, 46.96 words per minute for maximum reading speed and 0.10 logMAR for critical print size. The created MNREAD-GR acuity chart is a standardised clinical test that can be used reliably to measure near acuity, reading speed and critical print size in Greek-speaking literate patients of all ages. © 2012 The

  5. Lumbar position sense acuity during an electrical shock stressor

    Directory of Open Access Journals (Sweden)

    Fallentin Nils

    2005-07-01

    Full Text Available Abstract Background Optimal motor control of the spine depends on proprioceptive input as a prerequisite for co-ordination and the stability of the spine. Muscle spindles are known to play