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Sample records for preoperative visual acuity

  1. THE SIGNIFICANCE OF TESTING PREOPERATIVE VISUAL FUNCTION IN CATARACT USING LASER INTERFEROMETRIC VISUAL ACUITY AND ERG

    Institute of Scientific and Technical Information of China (English)

    1991-01-01

    Tests of preoperative visual function and prediction of postoperative E chart visual acuity(ECVA) using laser interferometric visual acuity(LIVA) and electroretinogram(ERG) were performed in 16 cases(19 eyes) of cataract. The results showed that the coincident rate between preoperative LIVA and postoperative ECVA was 63.2%, and there was a parallel correlation between preoperative amplitude of photopic ERG b-wave and postoperative ECVA in 79.0% of the eyes. Comparing these two methods, the test of LIVA ...

  2. Preoperative factors predictive of postoperative decimal visual acuity ≥ 1.0 following surgical treatment for idiopathic epiretinal membrane

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    Hiroshi Kunikata

    2011-02-01

    Full Text Available Hiroshi Kunikata1, Toshiaki Abe2, Jiro Kinukawa1, Kohji Nishida1,31Department of Ophthalmology and Visual Science, Tohoku University Graduate School of Medicine, Sendai, Japan; 2Division of Clinical Cell Therapy, Tohoku University Graduate School of Medicine, Sendai, Japan; 3Department of Ophthalmology, Osaka University Medical School, Suita, JapanPurpose: To report the preoperative best-corrected visual acuity (BCVA and foveal thickness (FT values that lead to a postoperative decimal BCVA of ≥ 1.0 after surgical removal of an idiopathic epiretinal membrane (ERM.Methods: This is a retrospective case series of 73 eyes that underwent surgery for removal of an idiopathic ERM. All eyes had been treated by a single surgeon using a 25-gauge transconjunctival sutureless vitrectomy and indocyanine green-assisted internal limiting membrane peel. The BCVA and FT were measured at baseline and 6 months postoperatively.Results: A postoperative decimal BCVA ≥ 1.0 was obtained in eyes with a preoperative decimal BCVA ≥ 0.3 but not in those with a preoperative decimal BCVA ≤ 0.2. The incidence of obtaining a postoperative decimal BCVA ≥ 1.0 was significantly (P = 0.002 higher in eyes with a preoperative decimal BCVA ≥ 0.5 (50% than in eyes with a preoperative decimal BCVA < 0.5 (11%. Additionally, a postoperative decimal BCVA of ≥ 1.0 was obtained in 51% of the eyes that had a preoperative FT < 400 µm, compared with only 21% of eyes with a preoperative FT ≥ 400 µm (P = 0.01. The incidence of obtaining a postoperative decimal BCVA ≥ 1.0 was significantly higher in eyes with preoperative decimal BCVA ≥ 0.5 and FT < 400 µm (60% than in eyes with preoperative decimal BCVA ≥ 0.5 and FT ≥ 400 µm (20%; P = 0.03 or preoperative BCVA < 0.5 and FT ≥ 400 µm (7%; P < 0.001.Conclusions: These findings indicate that eyes with both preoperative BCVA ≥ 0.5 and FT < 400 µm have a significantly better chance of obtaining a postoperative decimal

  3. 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 ...

  4. [Snellen visual acuity evaluation].

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    Zapparoli, Marcio; Klein, Fernando; Moreira, Hamilton

    2009-01-01

    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. 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. 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. 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 and approaches the theoretical values recommended by Herman Snellen in 1862.

  5. The neurology of visual acuity.

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    Frisén, L

    1980-09-01

    A series of patients with well defined lesions of various parts of the visual pathways was studied in an attempt to iluminate the neuropathophysiology of visual acuity. Acuity was found to remain normal in all cases with unilateral retrochiasmal lesions, including those of the optic tract. Bilateral retrochiasmal lesions involving the foveal nerve fibres on both sides impaired acuity to the same degree in both eyes. Lateral chiasmal lesions regularly produced impaired acuity in the ipsilateral eye. Midchiasmal lesions commonly led to an impairment of visual acuity in both eyes, usually asymmetrically, and roughly proportionate to the severity of the visual field defect. Compression optic neuropathy was found to reduce acuity in rough proportion to the severity of compression. It was concluded that acuity remains normal as long as either the crossing or the non-crossing neural outflow from the retinal fovea remains intact: acuity fails only when both sets of nerve fibres are compromised. A properly executed acuity test seems to be a powerful tool for detecting such conditions. The lower limit of normal acuity should never be set below 1.0 or 20/20: even this level is clearly subnormal in many subjects.

  6. 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... distance and near vision using Snellen's test type or its equivalent. (b) Evaluation of visual acuity. (1) Evaluate central visual acuity on the basis of corrected distance vision with central fixation, even if...

  7. Grating visual acuity with Teller cards compared with Snellen visual acuity in literate patients.

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    Kushner, B J; Lucchese, N J; Morton, G V

    1995-04-01

    To determine the usefulness of Teller Acuity Cards for detecting three levels of vision deficit, the cutoff for amblyopia (20/40 or poorer), vision impairment (20/70), or legal blindness (20/200). We compared grating visual acuity with the Teller cards with Snellen visual acuity (our gold standard) in 69 literate patients with amblyopia or other cause of vision loss in a prospective masked study. Teller card visual acuity and distance Snellen visual acuity correlated significantly (r = .508, P Snellen visual acuity. Teller card visual acuity had a low sensitivity for detecting vision deficit of 20/40 or poorer (58%), vision deficit of 20/70 or poorer (39%), or legal blindness (24%), but somewhat more accurately reflected near Snellen visual acuity than distance visual Snellen acuity. Teller cards had a higher positive predictive value--80% for 20/70 visual acuity and 43% for legal blindness, as determined by near Snellen visual acuity. Specificity of Teller cards was 88% for detecting visual acuity loss of 20/70 and 98% for legal blindness. Negative predictive value of Teller cards for detecting visual acuity loss of 20/70 was 50% and for legal blindness was 71%. Teller Acuity Cards may underestimate the presence of amblyopia of all types, legal blindness, and a specified level of vision impairment (20/70). Even in the presence of normal visual acuity measurements with Teller cards, significant visual loss as assessed by standard Snellen optotypes may be anticipated in many patients.

  8. Adaptive Rendering Based on Visual Acuity Equations

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new method of adaptable rendering for interaction in Virtual Environment(VE) through different visual acuity equations is proposed. An acuity factor equation of luminance vision is first given. Secondly, five equations which calculate the visual acuity through visual acuity factors are presented, and adaptive rendering strategy based on different visual acuity equations is given. The VE system may select one of them on the basis of the host's load, hereby select LOD for each model which would be rendered. A coarser LOD is selected where the visual acuity is lower, and a better LOD is used where it is higher. This method is tested through experiments and the experimental results show that it is effective.

  9. Visual Acuity Reporting in Clinical Research Publications.

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    Tsou, Brittany C; Bressler, Neil M

    2017-06-01

    Visual acuity results in publications typically are reported in Snellen or non-Snellen formats or both. A study in 2011 suggested that many ophthalmologists do not understand non-Snellen formats, such as logarithm of the Minimum Angle of Resolution (logMAR) or Early Treatment Diabetic Retinopathy Study (ETDRS) letter scores. As a result, some journals, since at least 2013, have instructed authors to provide approximate Snellen equivalents next to non-Snellen visual acuity values. To evaluate how authors currently report visual acuity and whether they provide Snellen equivalents when their reports include non-Snellen formats. From November 21, 2016, through December 14, 2016, one reviewer evaluated visual acuity reporting among all articles published in 4 ophthalmology clinical journals from November 2015 through October 2016, including 3 of 4 journals that instructed authors to provide Snellen equivalents for visual acuity reported in non-Snellen formats. Frequency of formats of visual acuity reporting and frequency of providing Snellen equivalents when non-Snellen formats are given. The 4 journals reviewed had the second, fourth, fifth, and ninth highest impact factors for ophthalmology journals in 2015. Of 1881 articles reviewed, 807 (42.9%) provided a visual acuity measurement. Of these, 396 (49.1%) used only a Snellen format; 411 (50.9%) used a non-Snellen format. Among those using a non-Snellen format, 145 (35.3%) provided a Snellen equivalent while 266 (64.7%) provided only a non-Snellen format. More than half of all articles in 4 ophthalmology clinical journals fail to provide a Snellen equivalent when visual acuity is not in a Snellen format. Since many US ophthalmologists may not comprehend non-Snellen formats easily, these data suggest that editors and publishing staff should encourage authors to provide Snellen equivalents whenever visual acuity data are reported in a non-Snellen format to improve ease of understanding visual acuity measurements.

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

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    Grković Desanka

    2013-01-01

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

  11. The importance of measuring dynamic visual acuity

    National Research Council Canada - National Science Library

    Muzdalo, Natasa Vujko

    2013-01-01

    .... Beside good eyesight, drivers also have to have good reflexes and short reaction span. The aim of this study was to compare dynamic and static visual acuity in order to observe how they vary among individuals...

  12. Estimating visual acuity by character counting using the Snellen visual acuity chart.

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    Levy, A H; McCulley, T J; Lam, B L; Feuer, W J

    2005-06-01

    This study examines visual acuity estimation with character counting, which can be used in subjects with nonorganic visual loss. The right eyes of 35 healthy subjects were fogged with plus lenses and tested with the Snellen visual acuity chart (Reichert 11180). Visual acuity and counting level were assessed under various degrees of fogging, up to a maximal fogged acuity of 20/200. Counting level was defined as the smallest line that subjects could count the number of characters correctly. For each counting level, the visual acuity that 95% of subjects could see equal to or better than was determined. A counting level of 20/10 estimates (ie 95% chance) a visual acuity equal to or better than 20/30. Counting levels 20/15, 20/20, and 20/25 estimate visual acuities of at least 20/50, 20/80, and 20/80, respectively. Counting levels 20/30-20/60 estimate a visual acuity of at least 20/200. Character counting appears to be a useful technique of obtaining a rough estimate of visual acuity in subjects unable to be tested by standard methods, such as those with non-organic visual loss.

  13. [Some basic aspects in statistical analysis of visual acuity data].

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    Ren, Ze-Qin

    2007-06-01

    All visual acuity charts used currently have their own shortcomings. Therefore, it is difficult for ophthalmologists to evaluate visual acuity data. Many problems present in the use of statistical methods for handling visual acuity data in clinical research. The quantitative relationship between visual acuity and visual angle varied in different visual acuity charts. The type of visual acuity and visual angle are different from each other. Therefore, different statistical methods should be used for different data sources. A correct understanding and analysis of visual acuity data could be obtained only after the elucidation of these aspects.

  14. Development of visual acuity in children with cerebral visual impairment.

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    Lim, Mira; Soul, Janet S; Hansen, Ronald M; Mayer, D Luisa; Moskowitz, Anne; Fulton, Anne B

    2005-09-01

    To study the development of visual acuity in term-born children with cerebral visual impairment and a history of neonatal hypoxic-ischemic encephalopathy. We studied 19 term-born children, aged 6 months to 6 years, with moderate to severe neonatal hypoxic-ischemic encephalopathy and behaviors indicative of cerebral visual impairment. Longitudinal measures of grating acuity were obtained using preferential looking (PL) and visual evoked potential (VEP) procedures. Visual acuities at first and last visits were compared. The courses of acuity development in the 9 children who underwent both VEP and PL acuity assessment at 4 or more ages were compared with normal development. All children had measurable PL and VEP acuity, despite poor visual behavior. In nearly all, both PL and VEP acuity were below normal for age. For both PL and VEP measures, acuity at the last visit was, on average, 1 octave better than at the first visit, with a rate of improvement lower than normal. Although parallel courses of PL and VEP development occurred in many, substantial disparities in PL and VEP acuity were observed in others. Modest increases in PL and VEP grating acuity occur during early childhood in many of these patients. The rate of increase is lower than normal.

  15. VISUAL ACUITY IN DIFFERENT INTENSITIES OF LIGHT

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    Shruthi

    2014-12-01

    Full Text Available : BACKGROUND: Visual acuity is the resolving power of eyes which enables to distinguish the details and shapes of the objects. It is influenced by the intensity (illumination of light falling on the object. Measuring visual acuity is a simple test in assessing-health of the eyes, the pathway and visual brain. Intact normal vision is mandatory for selection of posts related to driving and traffic services. Intactness of visual acuity is influenced by a number of factors and one among them is intensity of ambient light. Hence, this study is undertaken to assess optimum light intensity for better visual perception. AIM: To evaluate the association between visual acuity and intensity of light and the optimum intensity of light to carry out for better perception of vision. MATERIALS AND METHODS: 100 literate subjects - 50 males and 50 females between 15-45 years, act both as cases and controls. Subjects, instructed to read alphabets and numbers from Snellen chart in 15 watts, 20 watts, 40 watts, 60 watts, 100 watts, 200 watts were considered as the study group and the same subjects in this study in day light as controls. Chart was placed at 6m distance. Both right and left eyes were tested separately in dark room illuminated with controlled light intensities. Number of correct characters read were noted for different illuminations and compared with that of controls. RESULTS: Reduced illumination significantly increased the no of incorrect choices and was statistically significant (P < 0.05 between 15 - 100 W. Visual acuity was best in 200 W in comparison with day light but was not statistically significant. However Visual acuity showed no significant difference between males and females for different intensities of light.

  16. How to measure distance visual acuity

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    Janet Marsden

    2014-04-01

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

  17. New standardized visual acuity charts in hindi and gujarati

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    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.

  18. New standardized visual acuity charts in Hindi and Gujarati.

    Science.gov (United States)

    Khamar, B M; Vyas, U H; Desai, T M

    1996-09-01

    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.

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

    Science.gov (United States)

    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…

  20. THE VISUAL ACUITY OF THE HONEY BEE.

    Science.gov (United States)

    Hecht, S; Wolf, E

    1929-07-20

    1. Bees respond by a characteristic reflex to a movement in their visual field. By confining the field to a series of parallel dark and luminous bars it is possible to determine the size of bar to which the bees respond under different conditions and in this way to measure the resolving power or visual acuity of the eye. The maximum visual acuity of the bee is lower than the lowest human visual acuity. Under similar, maximal conditions the fineness of resolution of the human eye is about 100 times that of the bee. 2. The eye of the bee is a mosaic composed of hexagonal pyramids of variable apical angle. The size of this angle determines the angular separation between adjacent ommatidia and therefore sets the structural limits to the resolving power of the eye. It is found that the visual angle corresponding to the maximum visual acuity as found experimentally is identical with the structural angular separation of adjacent ommatidia in the region of maximum density of ommatidia population. When this region of maximum ommatidia population is rendered non-functional by being covered with an opaque paint, the maximum visual acuity then corresponds to the angular separation of those remaining ommatidia which now constitute the maximum density of population. 3. The angular separation of adjacent ommatidia is much smaller in the vertical (dorso-ventral) axis than in the horizontal (anterio-posterior) axis. The experimentally found visual acuity varies correspondingly. From this and other experiments as well as from the shape of the eye itself, it is shown that the bee's eye is essentially an instrument for uni-directional visual resolution, functional along the dorso-ventral axis. The resolution of the visual pattern is therefore determined by the vertical angular separation of those ocular elements situated in the region of maximum density of ommatidia population. 4. The visual acuity of the bee varies with the illumination in much the same way that it does for the human

  1. Confiabilidade da previsão da acuidade visual pós-operatória de catarata mediante medição da acuidade visual pré-operatória utilizando o retinômetro Heine Lambda 100 Reliability of predictable postoperative visual acuity of cataracts as measured by Heine Lambda 100 retinometer preoperatively

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    Guilherme Novoa Colombo-Barboza

    2010-06-01

    , from April to July, 2009. In the preoperative period, Heine retinometer test was performed under mydriasis and its results were compared to postoperative best corrected visual acuity three months after surgery and correlated with the morphological classification of cataracts, being considered a satisfactory result those who did not vary more than two lines in Snellen chart. Results: The satisfactory cases found in our study were 86.78%, with results of visual acuity with Heine retinometer equal to the postoperative visual acuity in 34.7% of the cases. Predominant nuclear opacity N1+ has a higher reliability than N2+ and N3+ (50%, 31.3% and 26.7%, respectively. Regarding all studied eyes, statistical significance was noted (p<0.0001. Conclusion: In most cases Heine retinometer underestimated or maintained best corrected visual acuity 3 months postoperatively in patients who underwent cataract surgery. With respect to the morphological classification of cataracts, the higher the opacity of the nuclear lens, the greater the visual acuity underestimation.

  2. [The best corrected presenting distance visual acuity in forensic medicine].

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    Liu, Rui-Jue

    2011-06-01

    At present the sight impairment evaluation in forensic medicine of China is based on the international classification of disease by WHO in 1973. The main measured indicator is "best corrected visual acuity". It is different from "presenting distance visual acuity" in some situations. In the new blindness and vision loss classification made by WHO in 2003, "presenting distance visual acuity" took the place of the "best corrected visual acuity". In the practice of forensic medicine, "presenting distance visual acuity" can not reflect the real visual acuity duo to the exaggeration or disguise of the wounded. We suggest to use "the best corrected presenting distance visual acuity" instead of "presenting distance visual acuity" in order to avoid the influences of the exaggeration or disguise of the wounded.

  3. [Fidelity of the potential acuity meter in the postoperative visual acuity of cataract surgery].

    Science.gov (United States)

    Chiacchio, Brenda Biagio; Sato, Ricardo Mitsuo; Siqueira, Roberta Bianca Peres; Marques, Frederico França

    2008-01-01

    To evaluate the correlation between the preoperative visual acuity (VA) obtained by the potential acuity meter (PAM) and the postoperative VA in a patient submitted to cataract surgery, as well as its correlation with the dominant morphologic classification of the cataract. This is a prospective study performed at the Hospital Monumento Study Center. Sixty-three eyes of 45 patients submitted to phacoemulsification with intraocular lens implantation were enrolled in this study and 1 eye had been excluded. Besides the complete examination in the preoperative period, PAM was used and its results were compared with the VA at the third postoperative month and correlated with the dominant morphologic cataract classification. The result was called satisfactory when the variation was equal to or less than two lines at the Snellen chart. We transformed the AV into logMAR for comparison with the literature. The mean age was 45.3 years with a mean VA of 0.64 logMAR by the PAM. At the third postoperative month, the mean best corrected visual acuity (BCVA) was 0.09 logMAR. The PAM overestimated the BCVA in 8 eyes (13%), underestimated it in 41 eyes (66%) and in 13 eyes (21%) the BCVA were the same. The satisfactory results regarding nuclear cataract were reduced in cases of higher density (1+/4 with 75.5% e 4+/4 with 33.3%) and increased in the posterior subcapsular cataracts (85.7%). PAM revealed an underestimation or maintenance of the BCVA in most cases (87%). Its fidelity was inversely proportional in the nuclear cataracts (1+/4 with 75.5% e 4+/4 with 33.3%) and higher in the posterior subcapsular cataracts.

  4. Dynamic Visual Acuity Training in Cricket Players

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    Renee Edgar, B.Optom

    2015-04-01

    Full Text Available Background: Dynamic visual acuity (DVA is the ability of an observer to correctly identify details of a moving target and is considered to be important for tasks like driving. Dynamic Visual Acuity is better in athletes involved in sports such as basketball and baseball; however, no previous studies have considered the sport of cricket. We conducted a study to determine whether there was any difference in DVA between cricket and non-cricket players. Method: Dynamic visual acuity was measured by asking subjects to identify the orientation of the gap of a moving Landolt C target as a four-alternative forced-choice task. The Landolt C targets had confusion bars surrounding them. The participants in the study were tested twice with a break of seven weeks. In between the two measurements, participants underwent two training sessions (similar to the testing sessions, each three weeks apart. Results: The initial mean DVA for cricket players was 107.7 deg/sec, and the mean DVA for non-cricket players was 105.5 deg/sec, with a target size of 6/15. The subjects who participated in training (cricketers and non-cricketers improved in DVA by 41 deg/sec in contrast to the improvement in the non-training subjects of 18 deg/sec (p=0.0032. The cricketers who participated in the training improved in DVA by 44 deg/sec, whereas the cricketers who did not participate in the training improved by 19 deg/sec (p=0.0167. Conclusions: We found no significant difference in initial DVA between the cricket players and the non-cricket players. The training resulted in an extremely significant improvement in DVA performance by both the cricketers and non-cricketers.

  5. 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.

  6. Bayesian model of Snellen visual acuity

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    Nestares, Oscar; Navarro, Rafael; Antona, Beatriz

    2003-07-01

    A Bayesian model of Snellen visual acuity (VA) has been developed that, as far as we know, is the first one that includes the three main stages of VA: (1) optical degradations, (2) neural image representation and contrast thresholding, and (3) character recognition. The retinal image of a Snellen test chart is obtained from experimental wave-aberration data. Then a subband image decomposition with a set of visual channels tuned to different spatial frequencies and orientations is applied to the retinal image, as in standard computational models of early cortical image representation. A neural threshold is applied to the contrast responses to include the effect of the neural contrast sensitivity. The resulting image representation is the base of a Bayesian pattern-recognition method robust to the presence of optical aberrations. The model is applied to images containing sets of letter optotypes at different scales, and the number of correct answers is obtained at each scale; the final output is the decimal Snellen VA. The model has no free parameters to adjust. The main input data are the eyes optical aberrations, and standard values are used for all other parameters, including the StilesCrawford effect, visual channels, and neural contrast threshold, when no subject specific values are available. When aberrations are large, Snellen VA involving pattern recognition differs from grating acuity, which is based on a simpler detection (or orientation-discrimination) task and hence is basically unaffected by phase distortions introduced by the optical transfer function. A preliminary test of the model in one subject produced close agreement between actual measurements and predicted VA values. Two examples are also included: (1) application of the method to the prediction of the VA in refractive-surgery patients and (2) simulation of the VA attainable by correcting ocular aberrations. 2003 Optical Society of America

  7. Potential acuity meter for predicting visual acuity after Nd:YAG posterior capsulotomy

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    Smiddy, W.E.; Radulovic, D.; Yeo, J.H.; Stark, W.J.; Maumenee, A.E.

    1986-03-01

    We studied 30 patients with opacifications of the posterior capsule to determine if the potential acuity meter (PAM) could accurately predict final visual outcome after Nd:YAG discussion. The final visual acuity was within one line of the PAM prediction in 22 of 30 patients (73%), better by two or more lines in seven patients (23%), and worse in one patient (4%) by two lines. Although in thicker capsules the final acuity was occasionally better than the PAM prediction, the rates of false negative and false positive predictions were very low. Mild cystoid macular edema (3 patients), age-related macular degeneration (3 patients), intraocular lens status, and level of initial acuity did not diminish PAM accuracy. The PAM effectively predicts final visual acuity after YAG posterior capsulotomy, when used in a patient, unhurried manner.

  8. An Association between Poor Eyesight and Work Efficiency: Far Visual Acuity and Near Visual Acuity and Work Efficiency

    OpenAIRE

    高橋, ひとみ; 北村, 佳子; 衞藤, 隆

    2012-01-01

    While the number of people engaging in VDT work increases, "The summary of new VDT work guidelines" was announced (H 12.4) by the Ministry of Health, Labor and Welfare , and far visual acuity test and near visual acuity test are now obligatory. Early detection and early treatment of poor eyesight can increase efficiency and can promote work in a comfortable state. On October 31, 2011, we carried out tests for visual acuity and near visual acuity (using an NV-300 automatic eyesight measuring d...

  9. Novel method for analyzing snellen visual acuity measurements.

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    Gregori, Ninel Z; Feuer, William; Rosenfeld, Philip J

    2010-01-01

    Most retrospective reviews convert Snellen visual acuity measurements obtained during routine clinic visits to logarithm of the minimum angle of resolution (logMAR) units so that statistical manipulations can be performed. However, visual acuity measurements expressed as logMAR units are not intuitively interpretable by clinicians. A more intuitive approach is presented here which uses the conversion of Snellen visual acuity fractions to Early Treatment Diabetic Retinopathy Study (ETDRS) letter scores for statistical manipulations. Snellen visual acuity measurements were converted to approximate ETDRS (approxETDRS) letter scores for statistical manipulations and then converted back to Snellen equivalent fractions. The formula to convert Snellen visual acuity measurements to approxETDRS letter scores is 85 + 50 x log (Snellen fraction), which may be rounded to the nearest letter. A linear relationship exists between true ETDRS letter scores, approxETDRS letter scores, and logMAR units. The interconversion between Snellen visual acuity measurements, logMAR units, and approxETDRS letter scores was prepared in a tabular form for easy reference. The same outcomes (in Snellen fractions) were obtained with statistical manipulation of either approxETDRS letter scores or logMAR conversions. Conversion of Snellen visual acuity fractions to approxETDRS letter scores for the purpose of performing statistical manipulations provides more readily interpretable outcomes compared with the current strategy of converting Snellen visual acuity fractions to logMAR units.

  10. Psychophysics of prosthetic vision: I. Visual scanning and visual acuity.

    Science.gov (United States)

    Chen, S C; Hallum, L E; Suaning, G J; Lovell, N H

    2006-01-01

    Recipients of vision prosthesis prototypes have reported electrically elicited visual perceptions as discrete dots of light (phosphenes). Phosphenes construct the scenery in discontinuous small isolated patches, resulting in visual information deficit to a large portion of the visual field. Visual scanning therefore plays an important role in the utility of prosthetic vision. In a psychophysical study, normally sighted subjects undertook a visual acuity task in a simulation of prosthetic vision with scanning facilitated by head movements. Subjects who adopted the circular scanning technique (4/12) correctly identified >60% of the test items, compared to subjects with no particular scanning patterns (3/12) with <50%. Increased head movement velocity was correlated to increased performance; at optimal scanning velocities, we estimated a 50% increase in identification rate or a two-fold improvement in visual acuity threshold compared to otherwise complete lack of scanning movement. Improved performance likely resulted from positive interactions with the temporal processes of the human visual system, which may as much as double the spatial information of that originally afforded by the phosphene lattice.

  11. Comparison of Snellen and interferometer visual acuity in an aging noncataractous population.

    Science.gov (United States)

    Geddes, L A; Patel, B J; Bradley, A

    1990-05-01

    Using standard clinical procedures we have compared visual acuity (VA) estimates made with a hand-held white light interferometer to those obtained with a Snellen acuity chart. Fifty noncataractous patients with a mean age of 45 years (SD = 18) were tested. Snellen and interferometric acuity measures were obtained with and without refractive correction. On average, aided Snellen VA's were better (decimal acuity = 0.98) than the unaided interferometric VA's (decimal acuity = 0.67). Although we found a statistically significant p less than 0.01) correlation between unaided interferometric and aided Snellen VA's, the correlation was poor (r = 0.36). This poor correlation may account for the often observed failure to estimate postoperative aided Snellen VA with preoperative interferometric VA in cataract patients.

  12. Visual acuity and X-linked color blindness.

    Science.gov (United States)

    Jägle, Herbert; de Luca, Emanuela; Serey, Ludwig; Bach, Michael; Sharpe, Lindsay T

    2006-04-01

    Optimal sampling for visual acuity requires a fine array of cones with identical sensitivity. Thus, dichromats, whose inner fovea is made up of cones having the same spectral sensitivity, may have better than normal visual acuity. We investigated this by comparing the visual acuities of trichromats and X-linked dichromats, while taking into account the different molecular genetics underlying the disorder. Our subjects were age- and refraction-matched groups of normals (n=8) and X-linked dichromats (n=13). The dichromats (four protanopes and nine deuteranopes) were genotyped and classified according to whether they carried a single (n=6) or multiple (n=7) visual pigment genes on their X-chromosome. Visual acuity was measured in both eyes with the Freiburger Visual Acuity Test. Normal trichromats and ungenotyped dichromats do not significantly differ in visual acuity, nor do ungenotyped protanopes and deuteranopes. However, multi-gene dichromats, who possess more than one photopigment gene in the array, all of which encode for the same long- or middle-wavelength sensitive photopigment, have significantly higher visual acuity than either normal trichromats or dichromats who have only a single-gene. Multi-gene dichromats may benefit from a reduction in chromatic aberration and chromatic noise in the high acuity channel, normally a consequence of combining signals from different cone photoreceptor types and of cone-specific patterns of retinal image defocus and blur. Single-gene dichromats may not share in the advantage because of other molecular differences that influence the development of the retinal mosaic and/or its visual pathways.

  13. To Further the Near-vision Visual Acuity Test (1) : The Necessity of Near-vision Visual Acuity Testing from the Purpose of the Visual Acuity Tests of the School(Special Issue Dedicated to Professor TAKENAKA Teruo)

    OpenAIRE

    高橋, ひとみ; 川端, 秀仁; 衛藤, 隆

    2014-01-01

    Children are given visual acuity tests at school. The purpose of the tests is to facilitate school education. There are two types of visual acuity: far- and near-vision visual acuity. Far-vision visual acuity is required, for example, when reading something written on a whiteboard in a classroom. On the other hand, near-vision visual acuity is needed when reading textbooks, notebooks, or when looking at computer screens. However, only far-vision visual acuity tests are typically included in m...

  14. Visual acuity in mammals: effects of eye size and ecology.

    Science.gov (United States)

    Veilleux, Carrie C; Kirk, E Christopher

    2014-01-01

    Previous comparative research has attributed interspecific variation in eye size among mammals to selection related to visual acuity. Mammalian species have also been hypothesized to differ in visual acuity partly as a result of differences in ecology. While a number of prior studies have explored ecological and phylogenetic effects on eye shape, a broad comparative analysis of the relationships between visual acuity, eye size and ecology in mammals is currently lacking. Here we use phylogenetic comparative methods to explore these relationships in a taxonomically and ecologically diverse sample of 91 mammal species. These data confirm that axial eye length and visual acuity are significantly positively correlated in mammals. This relationship conforms to expectations based on theoretical optics and prior analyses of smaller comparative samples. Our data also demonstrate that higher visual acuity in mammals is associated with: (1) diurnality and (2) predatory habits once the effects of eye size and phylogeny have been statistically controlled. These results suggest that interspecific variation in mammalian visual acuity is the result of a complex interplay between phylogenetic history, visual anatomy and ecology.

  15. Changes in the clinical measurement of visual acuity

    Science.gov (United States)

    Bailey, I. L.; Jackson, A. J.

    2016-11-01

    In 1862, Hermann Snellen introduced his letter chart for the clinical measurement of visual acuity. His chart presented letters,or optotypes, arranged in a progressively diminishing size sequence, and the visual acuity was determined by the smallest letters that could read at a specified distance. Numerous modifications of the design of the optotypes, the progression of size and the chart layout were suggested, and in 1976, Bailey and Lovie published a set of design principles that made the visual task the same at all size levels, so that size become the only significant variable. This required the same number of letters at each size level, fixed spacing ratios and a logarithmic progression of size. This facilitates more precise quantification of visual acuity by giving credit for every letter read correctly, and this gives clinicians tighter confidence limits for determining changes or differences in visual acuity. However, optotype choices, and associated spacing arrangements can have significant effects on visual acuity scores as can viewing conditions and testing protocols. Computer based visual acuity tests are becoming more commonplace, there will be more variety in test charts and procedures which will create some problems for making comparisons between tests.

  16. Factors affecting visual acuity after accelerated crosslinking in patients with progressive keratoconus

    Directory of Open Access Journals (Sweden)

    Ahmet Kırgız

    2016-06-01

    Full Text Available ABSTRACT Purpose: The present study aimed to report the outcomes of patients with progressive keratoconus who were treated via accelerated crosslinking (CXL 6 months earlier and to determine the factors that promoted improved visual acuity after treatment. Methods: This retrospective study included 35 eyes of 34 patients with progressive keratoconus who underwent CXL. Topographical measurements were obtained preoperatively and in the first, third, and sixth months postoperatively using a rotating Scheimpflug camera. The uncorrected visual acuity (UCVA, best-corrected visual acuity (BCVA, flat keratometry (K value (K1, steep K value (K2, average K value (avgK, topographic cylindrical value (Cyl, apical keratoscopy front (AKf, apical keratoscopy back (AKb, symmetry index front (SIf, symmetry index back (SIb, and thinnest point of the cornea (ThkMin were recorded. Results: At the 6-month follow-up, the mean UCVA and BCVA values were improved, and the K values remained stable. Statistically significant decreases in AKf (p=0.04 and the thinnest point of the cornea (p=0.001 and a statistically significant increase in AKb (p=0.01 were observed. A correlation analysis revealed that the preoperative BCVA, UCVA, K1, K2, avgK, AKf, and AKb values significantly affected visual acuity at the 6-month follow-up. Conclusions: Accelerated CXL is an effective treatment for the prevention or even reversal of keratoconus progression. The preoperative K values and apexes of the anterior and posterior cornea were found to affect visual acuity at 6 months after accelerated CXL. Both AKb steepening and AKf flattening appear to be important factors in the stabilization of keratometric values and improvement of visual outcomes.

  17. Infant Visual Assessment: Using Eye Tracking to Measure Visual Acuity

    Directory of Open Access Journals (Sweden)

    Eliza Burton

    2012-05-01

    Full Text Available A technique commonly used to assess infants' visual acuity is forced-choice preferential looking, which relies on the propensity of infants to look at patterned stimuli over uniform grey. Existing tests use trained examiners to judge where an infant fixates; however, eye trackers offer the opportunity to measure eye movements quickly and automatically. In the present study infants' visual acuity was measured using a remote Tobii eye tracker (Tobii T120. Thirteen infants aged 4–8 months were seated before a screen and presented with a preferential looking task. On each trial a black and white chequerboard of variable spatial frequency was displayed on half of the screen, while uniform grey was displayed elsewhere. Eye tracking data were used to determine whether the infant fixated the chequerboard and to update the spatial frequency on subsequent trials according to a weighted up-down staircase targeting the 75% threshold. This initial study showed data in line with age norms are consistent across two testing sessions for some infants. Others yielded poor data or inconsistent performance. Future modifications will aim to make the test more engaging and to optimise its power and speed. These will provide a basis for a full assessment of the test's accuracy and reliability.

  18. Comparison of Applicability of Different Visual Acuity Charts for Pediatric Outpatient Visual Tests

    Institute of Scientific and Technical Information of China (English)

    Haili Fang; Hongxing Diao; Linxing Chen; Junwen Zeng

    2014-01-01

    Purpose: To evaluate the applicability of different visual acu-ity charts for outpatient pediatric visual tests. Methods: Fifty-three children (53 eyes) aged 4-8 years un-dergoing visual acuity tests as outpatients were randomly se-lected for this study. The best corrected visual acuity (BCVA) of the eye with better visual acuity was measured for each child using the digital LogMAR visual chart,.the ETDRS vi-sual chart,.and a new standard logarithm visual chart;.all measurements were repeated twice and the BCVA was record-ed. Paired comparisons were made between the LogMAR vi-sual acuity chart and ETDRS chart measurements or between the ETDRS chart and logarithm visual acuity chart measure-ments for statistical analysis of the differences in measurement of visual acuity..The results of different measurements by the same chart were compared to evaluate the consistency of the measurement results..Bland-Altman analysis was employed to evaluate the most suitable chart for outpatient measurement of visual acuity in children. Results:.Bland-Altman analysis revealed that the mean visual acuity measured was. (0.447 ±0.017 LogMAR).by the digital LogMAR chart,.(0.301±0.024 LogMAR).by the standard log-arithm visual acuity chart, and (0.309 ±0.018 LogMAR) by the ETDRS visual acuity chart. The BCVA was significantly lower when measured by the LogMAR visual acuity chart than by the ETDRS chart (P0.05)..The Bland-Altman plot showed that the high-est consistency was obtained with the digital LogMAR chart, with a difference between two repeated measurements of 0.068 LogMAR,.compared to 0.090 and 0.072 LogMAR for the logarithm and ETDRS visual acuity charts, respectively. Conclusion: All three types of visual acuity charts are appli-cable for outpatient measurement of pediatric visual acuity. The ETDRS and logarithm visual acuity charts have a higher consistency, but the LogMAR visual acuity chart shows better reproducibility..Consequently,.it is difficult to identify and

  19. 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

  20. Comparing Visual Acuity Measured by Lea Symbols and Patti Pics.

    Science.gov (United States)

    Singman, Eric L; Matta, Noelle S; Tian, Jing; Silbert, David I

    2015-01-01

    There is little data validating most illiterate eye charts. Lea Symbols®, however, have been well validated in numerous studies. In this study, we compare the assessment of visual acuity employing both the Lea Symbol hanging wall Early Treatment Diabetic Retinopathy Study (ETDRS)-style chart and a similar Patti Pics® ETDRS-style chart in order to determine whether the two charts provide clinically similar data. We tested the vision of the right eyes of fifty-two consecutive patients. Patients were cooperative children or adults between the ages of 3 and 88 years (mean 58 years). We alternated the order of the chart used first. Patients were also categorized by age and by visual acuity. The visual acuities measured by the two charts were equal for 83% of the measurements (forty-three eyes). In 8% of eyes (four eyes), the visual acuity measured with the Lea Symbols was one line better than that measured by the Patti Pics; in 9% of eyes (five eyes), the acuity from the Patti Pics chart measured one line better than the Lea Symbols. There was no difference in measurements for either adults or children or among patients with different visual acuities. We believe this study will serve to provide useful information when choosing an eye chart to assess visual acuity in a clinic setting. Patti Pics performed similarly to Lea Symbols in adults and children tested in a multi-specialty ophthalmology practice. We suspect that it would also perform similarly in the primary care and school settings. © 2015 Board of regents of the University of Wisconsin System, American Orthoptic Journal, Volume 65, 2015, ISSN 0065-955X, E-ISSN 1553-4448.

  1. 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.

  2. The Effect of Zeaxanthin on the Visual Acuity of Zebrafish.

    Directory of Open Access Journals (Sweden)

    Eric A Saidi

    Full Text Available Oral supplementation of carotenoids such as zeaxanthin or lutein which naturally occur in human retina have been shown to improve vision and prevent progression of damage to advanced AMD in some studies. The zebrafish eye shares many physiological similarities with the human eye and is increasingly being used as model for vision research. We hypothesized that injection of zeaxanthin into the zebrafish eye would improve the visual acuity of the zebrafish over time. Visual acuity, calculated in cycles per degree, was measured in adult zebrafish to establish a consistent baseline using the optokinetic response. Zeaxanthin dissolved into phosphate buffered saline (PBS or PBS only was injected into the anterior chamber of the right and left eyes of the Zebrafish. Visual acuities were measured at 1 week and 3, 8 and 12 weeks post-injection to compare to baseline values. Repeated measures ANOVA was used to compare visual acuities between fish injected with PBS and zeaxanthin. A significant improvement in visual acuity, 14% better than before the injection (baseline levels, was observed one week after injection with zeaxanthin (p = 0.04. This improvement peaked at more than 30% for some fish a few weeks after the injection and improvement in vision persisted at 3 weeks after injection (p = 0.006. The enhanced visual function was not significantly better than baseline at 8 weeks (p = 0.19 and returned to baseline levels 12 weeks after the initial injection (p = 0.50. Zeaxanthin can improve visual acuity in zebrafish eyes. Further studies are required to develop a better understanding of the role zeaxanthin and other carotenoids play during normal visual function.

  3. The Effect of Zeaxanthin on the Visual Acuity of Zebrafish.

    Science.gov (United States)

    Saidi, Eric A; Davey, Pinakin Gunvant; Cameron, D Joshua

    2015-01-01

    Oral supplementation of carotenoids such as zeaxanthin or lutein which naturally occur in human retina have been shown to improve vision and prevent progression of damage to advanced AMD in some studies. The zebrafish eye shares many physiological similarities with the human eye and is increasingly being used as model for vision research. We hypothesized that injection of zeaxanthin into the zebrafish eye would improve the visual acuity of the zebrafish over time. Visual acuity, calculated in cycles per degree, was measured in adult zebrafish to establish a consistent baseline using the optokinetic response. Zeaxanthin dissolved into phosphate buffered saline (PBS) or PBS only was injected into the anterior chamber of the right and left eyes of the Zebrafish. Visual acuities were measured at 1 week and 3, 8 and 12 weeks post-injection to compare to baseline values. Repeated measures ANOVA was used to compare visual acuities between fish injected with PBS and zeaxanthin. A significant improvement in visual acuity, 14% better than before the injection (baseline levels), was observed one week after injection with zeaxanthin (p = 0.04). This improvement peaked at more than 30% for some fish a few weeks after the injection and improvement in vision persisted at 3 weeks after injection (p = 0.006). The enhanced visual function was not significantly better than baseline at 8 weeks (p = 0.19) and returned to baseline levels 12 weeks after the initial injection (p = 0.50). Zeaxanthin can improve visual acuity in zebrafish eyes. Further studies are required to develop a better understanding of the role zeaxanthin and other carotenoids play during normal visual function.

  4. 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.

  5. 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

  6. Visual acuity in larval zebrafish: behavior and histology

    Directory of Open Access Journals (Sweden)

    Mueller Kaspar P

    2010-03-01

    Full Text Available Abstract Background Visual acuity, the ability of the visual system to distinguish two separate objects at a given angular distance, is influenced by the optical and neuronal properties of the visual system. Although many factors may contribute, the ultimate limit is photoreceptor spacing. In general, at least one unstimulated photoreceptor flanked by two stimulated ones is needed to perceive two objects as separate. This critical interval is also referred to as the Nyquist frequency and is according to the Shannon sampling theorem the highest spatial frequency where a pattern can be faithfully transmitted. We measured visual acuity in a behavioral experiment and compared the data to the physical limit given by photoreceptor spacing in zebrafish larvae. Results We determined visual acuity by using the optokinetic response (OKR, reflexive eye movements in response to whole field movements of the visual scene. By altering the spatial frequency we determined the visual acuity at approximately 0.16 cycles/degree (cpd (minimum separable angle = 3.1°. On histological sections we measured the retinal magnification factor and the distance between double cones, that are thought to mediate motion perception. These measurements set the physical limit at 0.24 cpd (2.1°. Conclusion The maximal spatial information as limited by photoreceptor spacing can not be fully utilized in a motion dependent visual behavior, arguing that the larval zebrafish visual system has not matured enough to optimally translate visual information into behavior. Nevertheless behavioral acuity is remarkable close to its maximal value, given the immature state of young zebrafish larvae.

  7. Causes of suboptimal corrected visual acuity following phacoemulsification in a teaching university hospital.

    Science.gov (United States)

    Fathallah, Mohammed; Eltanamly, Rasha M; Saadeldin, Hala; Elnahry, Gehad H

    2017-03-10

    Cataract is the leading cause of reversible blindness in developing countries, with variable visual outcome following surgery. This work aims at assessing the outcomes of cataract surgery at Kasr Al Ainy Hospital and identifying the reasons for borderline and poor outcome in the studied group. A total of 150 eyes of patients with cataract and no other ocular pathology were included in this study. Uncorrected visual acuity (UCVA) and corrected visual acuity (CVA), complete ocular examination using slit-lamp, applanation tonometry, and ophthalmoscopy were performed for all patients. Biometry for intraocular lens power calculation and operative data were recorded. Patients were followed for 6 weeks; UCVA, CVA, and any complications were noted. Mean preoperative CVA was 0.16 ± 0.16 (SD) and mean postoperative CVA was 0.66 ± 0.33 (pteaching hospital where most surgeons were in their learning periods.

  8. Alcohol and marijuana effects on static visual acuity.

    Science.gov (United States)

    Adams, A J; Brown, B; Flom, M C; Jones, R T; Jampolsky, A

    1975-11-01

    Static visual acuity was measured at two contrast levels (12 and 49%) in ten subjects in a double blind experiment involving five drug conditions of alcohol and marijuana (0.5 ml and 1.0 ml/kg body weight of 95% ethanol, 8 and 15 mg delta-9-tetrahydrocannabinol (THC), and a placebo). We found no statistically significant change in static visual acuity for any of the dose levels at any of the measurement time up to six hours following drug ingestion; this is sharply contrasted with the marked decrements in acuity which were found in the same subjects under the same drug conditions when the targets were in motion and required corrdinated eye movements for their resolution.

  9. 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

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

    Science.gov (United States)

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

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

  11. Evaluation of visual acuity with Gen 3 night vision goggles

    Science.gov (United States)

    Bradley, Arthur; Kaiser, Mary K.

    1994-01-01

    Using laboratory simulations, visual performance was measured at luminance and night vision imaging system (NVIS) radiance levels typically encountered in the natural nocturnal environment. Comparisons were made between visual performance with unaided vision and that observed with subjects using image intensification. An Amplified Night Vision Imaging System (ANVIS6) binocular image intensifier was used. Light levels available in the experiments (using video display technology and filters) were matched to those of reflecting objects illuminated by representative night-sky conditions (e.g., full moon, starlight). Results show that as expected, the precipitous decline in foveal acuity experienced with decreasing mesopic luminance levels is effectively shifted to much lower light levels by use of an image intensification system. The benefits of intensification are most pronounced foveally, but still observable at 20 deg eccentricity. Binocularity provides a small improvement in visual acuity under both intensified and unintensified conditions.

  12. Effects of Horizontal Acceleration on Human Visual Acuity and Stereopsis

    Directory of Open Access Journals (Sweden)

    Chi-Ting Horng

    2015-01-01

    Full Text Available 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 (< and >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 in the X- or Y-axis did not affect dynamic vision and stereopsis. Vision decreased (mean from 0.02 logMAR to 0.25 logMAR and stereopsis declined significantly (mean from 40 s to 60.2 s of arc when Gx > 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.

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

    Science.gov (United States)

    Kemp, Addison D; Christopher Kirk, E

    2014-04-01

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

  14. Hypoxia impairs visual acuity in snapper (Pagrus auratus).

    Science.gov (United States)

    Robinson, Esme; Jerrett, Alistair; Black, Suzanne; Davison, William

    2013-07-01

    We investigated the effect of environmental hypoxia on vision in snapper (Pagrus auratus). Juvenile snapper inhabit estuarine environments where oxygen conditions fluctuate on a seasonal basis. Optomotor experiments demonstrated that visual acuity is impaired by environmental hypoxia, but not until levels approach the critical oxygen tension (P crit) of this species (around 25% air-saturated seawater). In 100, 80, and 60% air-saturated seawater, a positive optomotor response was present at a minimum separable angle (M SA) of 1°. In 40% air-saturated seawater, vision was partially impaired with positive responses at M SAs of 2° and above. However, in 25% air-saturated seawater, visual acuity was seriously impaired, with positive responses only present at M SAs of 6° and above. Snapper were found to possess a choroid rete, facilitating the maintenance of high ocular oxygen partial pressures (PO2) during normoxia and moderate hypoxia (PO2, between 269 and 290 mmHg). However, at 40 and 25% water oxygen saturation, ocular PO2 was reduced to below 175 mmHg, which is perhaps linked to impairment of visual acuity in these conditions. The ability to preserve visual function during moderate hypoxia is beneficial for the maintenance of a visual lifestyle in the fluctuating oxygen environments of estuaries.

  15. NEW DEFINITIONS OF KINETIC VISUAL ACUITY AND KINETIC VISUAL FIELD AND THEIR AGING EFFECTS

    Directory of Open Access Journals (Sweden)

    Jinglong WU

    2009-01-01

    However, traditional kinetic visual acuity and kinetic visual field measurements do not factor in the effects of individual differences in simple reaction times. This study identifies problems with the traditional method employed to define kinetic visual acuity and kinetic visual fields, and proposes new definitions of kinetic visual acuity and kinetic visual fields that measure simple reaction times and their aging effects. Simple reaction time tests reveal that simple reaction times of senior citizens are longer than those of younger people. The results of appraisal tests between traditional and new kinetic visual acuity definitions demonstrate the appropriateness of the new kinetic visual acuity definition. The study also takes a quantitative look at the aging effects of kinetic visual fields, measuring kinetic visual field characteristics of senior citizens while assessing space dependence, light dependence and index speed dependence of young people. The results obtained show that kinetic visual field ranges decrease with age, particularly in upward visual fields rather than downward visual fields in all target conditions. Visual field angle reductions in the temple sides of upward visual fields were of particular note.

  16. 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.

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

    NARCIS (Netherlands)

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

    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 w

  18. 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.N.

    2013-01-01

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

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

    NARCIS (Netherlands)

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

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

    Directory of Open Access Journals (Sweden)

    Kai-jian CHEN

    2011-04-01

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

  1. 2009-2013年中国白内障手术患者白内障类型和术前视力分析%Types of cataract and the preoperative visual acuity of surgerical patients in China in 2009-2013

    Institute of Scientific and Technical Information of China (English)

    徐笑; 杨梅; 安磊; 詹磊磊; 赵家良

    2015-01-01

    目的:通过分析2009年7月1日至2013年12月31日期间全国白内障复明手术信息报告系统中手术患者的白内障类型和术前视力,来了解我国白内障类型的构成特点,以及白内障手术适应证掌握情况。方法数据分析。资料来源于全国白内障手术信息报送系统,纳入分析数据5013694条。术眼白内障类型根据出院诊断分为年龄相关性、先天性、并发性、外伤性以及未分类的白内障共5种。手术适应证的判断主要为术前矫正视力。对数据采用字2检验、Spearman 相关进行分析。结果2009-2013年报送的手术信息逐年递增。在接受白内障手术的眼中,以年龄相关性白内障最多,占手术眼总数的90.83%;其次是并发性白内障,占5.40%,外伤性白内障占1.12%,先天性白内障最少,仅占0.80%。接受手术患者≥50岁最多,占93.88%,10~49岁占5.59%,<10岁的患者仅占0.53%。此外,男、女性分别占42.11%和57.89%,女性患者明显多于男性。接受白内障手术的眼大多数是盲眼和低视力眼,分别为46.88%和35.00%。但是18.66%的术眼术前最佳矫正视力≥0.3,特别是7.17%的术眼术前最佳矫正视力≥0.5。结论我国的白内障手术患者以年龄相关性白内障为主。大部分接受白内障手术的眼为盲或低视力眼,但有相当一部分患眼术前矫正视力较好,因此在大规模的白内障复明手术中要严格掌握手术适应证。%Objective To acquire the composing features of cataract types in China and the knowledge of surgical indications by analyzing the cataract types and preoperative visual acuities of cataract surgical patients nationwide from July 1st,2009 to December 31st, 2013, for promoting the large-scale cataract-extraction work in China. Methods The data comes from the national cataract surgery information reporting system , including 5 013 694 items. Based on the discharge diagnosis , there

  2. 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.

  3. The Development and Validation of a Smartphone Visual Acuity Test (Peek Acuity) for Clinical Practice and Community-Based Fieldwork

    Science.gov (United States)

    Bastawrous, Andrew; Rono, Hillary; Livingstone, Iain AT; Weiss, Helen A.; Jordan, Stewart; Kuper, Hannah; Burton, Matthew

    2017-01-01

    Importance Visual acuity is the most frequently performed measure of visual function in clinical practice and the majority of people worldwide living with visual impairment are living in low and middle-income countries Objective To design and validate a smartphone-based visual acuity test that is not dependent on familiarity with symbols or letters commonly used in the English language. Design Validation study comparing results from smartphone Peek Acuity to Snellen Acuity (clinical normal) and the Early Treatment Diabetic Retinopathy Study (ETDRS) LogMAR chart (reference standard). Setting This study was nested within the six-year follow-up of the Nakuru Eye Disease Cohort in central Kenya. Participants Three hundred adults aged 55 years and above, recruited consecutively from the Nakuru Eye Disease Cohort Study.. Main Outcome(s) and Measure(s) Outcome measures were monocular logarithm of the minimum angle of resolution (LogMAR) visual acuity scores for each test: ETDRS LogMAR, Snellen and Peek. Peek was compared, in terms of test-retest variability (TRV) and measurement time, with that of the Snellen and ETDRS LogMAR chart in participants’ homes and temporary clinic settings in rural Kenya in 2013/2014. Results The 95% confidence limits for TRV of smartphone acuity data were +/-0.033 LogMAR. The mean difference between smartphone and ETDRS and smartphone and Snellen acuity data was 0.07 (95%CI: 0.05-0.09) and 0.08 (95%CI: 0.06-0.10) LogMAR respectively indicating that smartphone acuities agreed well with those of the ETDRS chart and Snellen. The agreement of Peek and ETDRS was greater than Snellen with ETDRS, p=0.08 (95%CI 0.05 to 0.10). The local Kenyan community health care workers readily accepted the Peek Acuity smartphone test; it required minimal training and took no longer than Snellen; 77s vs. 82s (95%CI: 71 – 84s vs. 73 – 91s, p=0.13). Conclusions The study demonstrated that the Peek Acuity smartphone test is capable of accurate and repeatable

  4. 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.

  5. 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.

  6. Relationship of Visual Cortex Function and Visual Acuity in Anisometropic Amblyopic Children

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    Chuanming Li, Lin Cheng, Qiongwu Yu, Bing Xie, Jian Wang

    2012-01-01

    Full Text Available Purpose: To detect the functional deficit of the visual cortex in anisometropic amblyopia children using functional magnetic resonance imaging (fMRI technique, and investigate the relationship between visual acuity and visual cortex function.Methods: Blood oxygenation level-dependent fMRI (BOLD-fMRI was performed in ten monocular anisometropic amblyopia children and ten normal controls. fMRI images were acquired in two runs with visual stimulation delivered separately through the sound and amblyopic eyes. Measurements were performed in cortical activation of striate and extrastriate areas at the occipital lobe. The relationship between cortex function and visual acuity was analyzed by Pearson partial analysis.Results: The activation areas of both the striate and extrastriate cortices in the amblyopic eyes were significantly lower than that of the sound fellow eyes. No relationship was found between the striate and extrastriate cortex activation. No relationship was found between the visual cortical activation of striate, extrastriate areas and visual acuity of anisometropic amblyopes.Conclusions: BOLD-fMRI revealed the independent striate and extrastriate cortical deficits in anisometropic amblyopes. In addition, the visual acuity lesion and the striate and extrastriate cortical deficits were not parallel, and results of fMRI examination have much potential value in the evaluation of amblyopia.

  7. Visual acuity in an opportunistic raptor, the chimango caracara (Milvago chimango).

    Science.gov (United States)

    Potier, Simon; Bonadonna, Francesco; Kelber, Almut; Duriez, Olivier

    2016-04-01

    Raptors are always considered to have an extraordinary resolving power of their eyes (high visual acuity). Nevertheless, raptors differ in their diet and foraging tactics, which could lead to large differences in visual acuity. The visual acuity of an opportunist bird of prey, the Chimango caracara (Mivalgo chimango) was estimated by operant conditioning. Three birds were trained to discriminate two stimuli, a positive grey uniform pattern and a negative grating pattern stimulus. The visual acuity range from 15.08 to 39.83 cycles/degrees. When compared to other birds, they have a higher visual acuity than non-raptorial birds, but they have the lowest visual acuity found in bird of prey so far. We discuss this result in the context of the ecology of the bird, with special focus on it is foraging tactic.

  8. The effect of preoperative keratometry on visual outcomes after moderate myopic LASIK.

    Science.gov (United States)

    Christiansen, Steven M; Neuffer, Marcus C; Sikder, Shameema; Semnani, Rodmehr T; Moshirfar, Majid

    2012-01-01

    To evaluate visual outcomes in moderately myopic eyes with flat and steep corneas (preoperatively) that have been treated with laser-assisted in situ keratomileusis (LASIK). Records of ninety-six eyes with average preoperative keratometry (K) values between 39.9 and 42.0 diopters (D) (flat) were matched with 103 eyes with preoperative K values between 46.0 and 47.2 D (steep) that underwent LASIK between March 2007 and March 2010 for moderate myopia, and were retrospectively reviewed. The primary outcome measures used to determine the effect of preoperative keratometry on visual prognosis were refraction, visual acuity, change in keratometry (ΔK), and change in spherical equivalent (ΔSE), measured at 1, 3, 6, and 12 months postoperatively. Significant differences were found at 6 months postoperatively between the flat group and steep group in SE (P = 0.029), sphere (P = 0.018), ΔK (P = 0.002), percentage of eyes achieving SE of -0.25 to + 0.25 D (P = 0.0125), -0.26 to -0.50 D (P = 0.003), -0.51 to -1.00 D (P = 0.044), and the percentage of eyes achieving uncorrected distance visual acuity of 20/15 or better (P = 0.0006). Moderately myopic eyes with flatter corneas preoperatively have better visual prognosis following LASIK compared with moderately myopic eyes with steeper corneas.

  9. Sensitivity of The Dynamic Visual Acuity Test To Sensorimotor Change

    Science.gov (United States)

    Cohen, Helen; Bloomberg, Jacob; Elizalde, Elizabeth; Fregia, Melody

    1999-01-01

    Post-flight astronauts, acutely post-vestibular nerve section patients, and patients with severe chronic bilateral vestibular deficits have oscillopsia caused by reduced vestibulocular reflex gains and decreased postural stability. Therefore, as previous work has shown, a test of dynamic visual acuity (DVA), in which the subject must read numbers from a computer screen while standing still or walking in place provides a composite measure of sensorimotor integration. This measure may be useful for determining the level of recovery, post-flight, post-operatively, or after vestibular rehabilitation. To determine the sensitivity of DVA to change in impaired populations we have tested patients with acoustic neuromas before and during the first post-operative week after resection of the tumors, and with bilaterally labyrinthine deficient subjects before and after six weeks of balance rehabilitation therapy.

  10. ASTIGMATISM IN PRIMARY PTERYGIUM AND ITS EFFECT ON VISUAL ACUITY

    Directory of Open Access Journals (Sweden)

    Devika

    2015-09-01

    Full Text Available BACKGROUND: Pterygium is a fairly common condition in a tropical country like India with average incidence being 5.2%. Surgery being offered as a treatment for pterygium does not, at present, have a universally accepted indication based on the size. This study was done to make an attempt to define the indication for surgical exicision of pterygium. AIMS: To find out an association between increasing size of pterygium and degree of induced corneal astigmatism and to assess if corneal astigmatism induced by pterygium affects best corrected visual acuity (BCVA and thus making it an indication for pterygium excision surgery. SETTINGS AND DESIGN: Hospital Out Patient Departmen t (OPD based prospective clinical cross sectional study on patients with unilateral pterygium. METHODS AND MATERIAL : 33 patients were included in this study who had unilateral pterygium of varying sizes. Evaluation was done using slit - lamp beam for size o f pterygium in millimetre from the limbus, ketatometry using Bausch and Lomb keratometer, autorefractometer objective refraction readings, visual acuity and BCVA using Snellens chart. STATISTICAL ANALYSIS USED: Chi - square - test, Karl - Pearson correlation coe fficient, Kruskal - Wallis - co - efficient using SPSS statistics 22.0 . RESULTS: 33 people having unilateral pterygium were divided into three groups on the basis of size of the pterygium - ≤2mm, 2.1 - 3mm, >3mm. The co - relation coefficient between the astigmatism induced to BCVA was maximum for the 3rd group with pterygium size >3mm and was statistically significant. CONCLUSION: Pterygium induces ‘with the rule’ astigmatism. Surgery is indicated in patients of pterygium size >3mm as the astigmatism induced affects the BCVA

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

    Science.gov (United States)

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

    2013-09-17

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

  12. Predictive factors for postoperative visual acuity in idiopathic epiretinal membrane: a systematic review.

    Science.gov (United States)

    Scheerlinck, Laura M E; van der Valk, Rikkert; van Leeuwen, Redmer

    2015-05-01

    The aim of this study was to review the literature on predictive factors for postoperative visual acuity (VA) in surgery for idiopathic epiretinal membrane (ERM). A systematic review of the literature in the databases of PubMed and Embase was performed. The risk of bias was assessed based on predefined criteria and the results were summarized. In total, 1927 studies were retrieved of which 35 were potentially eligible. Nineteen studies were of adequate quality in terms of bias. Preoperative VA, central foveal thickness (CFT) and inner segment/outer segment (IS/OS) integrity on optical coherence tomography (OCT) were most extensively studied. Other preoperative factors studied were severity of metamorphopsia, several OCT parameters, fundus autofluorescence and multifocal electroretinogram. In the current literature, preoperative VA is the only variable consistently associated with postoperative VA. IS/OS integrity on OCT is probably associated, and the severity of metamorphopsia, cone outer segment tips integrity and fundus autofluorescence are possibly associated with postoperative VA. CFT is not associated with postoperative VA. Further studies with adequate methodological quality are needed to confirm these findings. Therefore, an overall prediction model, including different parameters, is still awaited.

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

    Institute of Scientific and Technical Information of China (English)

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

    2012-01-01

    Objective To systemically explore the range of visual angles that affect visual acuity,and to establish the relationship between the P 1 component (peak latency ~100 ms) of the pattern-reversal visual-evoked potential (PRVEP) and the visual acuity at particular visual angles.Methods 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.Results (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.Diferences 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 P 1 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.Conclusion (1) Visual angle should be taken into consideration when exploring the function of the visual pathway,especially visual acuity.A visual angle

  14. 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....

  15. Comparison of Dynamic Visual Acuity between Water Polo Players and Sedentary Students

    Science.gov (United States)

    Quevedo-Junyent, Lluisa; Aznar-Casanova, Jose Antonio; Merindano-Encina, Dolores; Cardona, Genis; Sole-Forto, Joan

    2011-01-01

    In this study, we examined differences in dynamic visual acuity between elite and subelite water polo players and sedentary students. To measure dynamic visual acuity binocularly, we asked participants to indicate the orientation of a broken ring, similar to the Landolt C, which increased in size as it moved across a computer screen. Two different…

  16. Comparison of Dynamic Visual Acuity between Water Polo Players and Sedentary Students

    Science.gov (United States)

    Quevedo-Junyent, Lluisa; Aznar-Casanova, Jose Antonio; Merindano-Encina, Dolores; Cardona, Genis; Sole-Forto, Joan

    2011-01-01

    In this study, we examined differences in dynamic visual acuity between elite and subelite water polo players and sedentary students. To measure dynamic visual acuity binocularly, we asked participants to indicate the orientation of a broken ring, similar to the Landolt C, which increased in size as it moved across a computer screen. Two different…

  17. Initial findings on visual acuity thresholds in an African elephant (Loxodonta africana).

    Science.gov (United States)

    Shyan-Norwalt, Melissa R; Peterson, Jeff; Milankow King, Barbara; Staggs, Timothy E; Dale, Robert H I

    2010-01-01

    There are only a few published examinations of elephant visual acuity. All involved Asian elephants (Elephas maximus) and found visual acuity to be between 8' and 11' of arc for a stimulus near the tip of the trunk, equivalent to a 0.50 cm gap, at a distance of about 2 m from the eyes. We predicted that African elephants (Loxodonta africana) would have similarly high visual acuity, necessary to facilitate eye-trunk coordination for feeding, drinking and social interactions. When tested on a discrimination task using Landolt-C stimuli, one African elephant cow demonstrated a visual acuity of 48' of arc. This represents the ability to discriminate a gap as small as 2.75 cm in a stimulus 196 cm from the eye. This single-subject study provides a preliminary estimate of the visual acuity of African elephants.

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

    Science.gov (United States)

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

    2017-04-01

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

  19. Visual acuity and pattern of visual field loss at presentation in pituitary adenoma.

    Science.gov (United States)

    Ogra, Siddharth; Nichols, Andrew D; Stylli, Stanley; Kaye, Andrew H; Savino, Peter J; Danesh-Meyer, Helen V

    2014-05-01

    Our purpose was to analyse the demographics, prevalence and pattern of visual field defects in patients with pituitary adenoma. We prospectively recruited 103 consecutive patients (206 eyes) presenting to a neurosurgical unit with pituitary adenoma. Ophthalmological examination and standard automated perimetry (Humphrey, 24-2 threshold) was performed. Severity of visual field defects was also assessed. The mean population age was 53.9 years (standard deviation=15). Visual loss was the most common reason for presentation (39%) followed by endocrine abnormality (21%) and headache (15%). Patients with endocrine abnormality on presentation were 10.9 years younger than those presenting with visual loss (p=0.001). Bitemporal defects were the most prevalent pattern (n=22, 41%) followed by homonymous defects (n=7, 13%). Of the patients with visual field loss, 33% had unilateral visual field defects. The mean visual acuity in those with bitemporal defects was 6/7.5 with half of these patients having 6/6 vision in both eyes. In conclusion, the majority of patients with pituitary adenoma have visual acuity better than 6/7.5 despite having visual field defects. While a bitemporal pattern of visual field loss is the most common, a significant proportion of patients had unilateral and altitudinal defects. Assessment of the visual field is essential to rule out chiasmal compression.

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

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    Khajenasiri F.

    2007-11-01

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

  1. Acuity-independent effects of visual deprivation on human visual cortex.

    Science.gov (United States)

    Hou, Chuan; Pettet, Mark W; Norcia, Anthony M

    2014-07-29

    Visual development depends on sensory input during an early developmental critical period. Deviation of the pointing direction of the two eyes (strabismus) or chronic optical blur (anisometropia) separately and together can disrupt the formation of normal binocular interactions and the development of spatial processing, leading to a loss of stereopsis and visual acuity known as amblyopia. To shed new light on how these two different forms of visual deprivation affect the development of visual cortex, we used event-related potentials (ERPs) to study the temporal evolution of visual responses in patients who had experienced either strabismus or anisometropia early in life. To make a specific statement about the locus of deprivation effects, we took advantage of a stimulation paradigm in which we could measure deprivation effects that arise either before or after a configuration-specific response to illusory contours (ICs). Extraction of ICs is known to first occur in extrastriate visual areas. Our ERP measurements indicate that deprivation via strabismus affects both the early part of the evoked response that occurs before ICs are formed as well as the later IC-selective response. Importantly, these effects are found in the normal-acuity nonamblyopic eyes of strabismic amblyopes and in both eyes of strabismic patients without amblyopia. The nonamblyopic eyes of anisometropic amblyopes, by contrast, are normal. Our results indicate that beyond the well-known effects of strabismus on the development of normal binocularity, it also affects the early stages of monocular feature processing in an acuity-independent fashion.

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

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    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.

  3. The usage of interference fringe visual acuity for examination of pre-operation of high myopia with cataract%干涉条纹视力测定在高度近视者白内障术前检查的应用

    Institute of Scientific and Technical Information of China (English)

    李会芳; 白洁; 谢芳; 张璐; 林宏彬; 刘平

    2011-01-01

    Objective To assess the reliability and value of interference fringe visual acuity (IVA) in predicting potential visual acuity after cataract surgery in cataract patients with high myopia. Design Prospective case series. Participants 71 eyes of 49 cataract patiems (the axial≥26.00 mm) with high myopia. Methods We measured the IVA in all patients before cataract surgery. Lens opacity was divided into grade Ⅰ-Ⅴ according to LOCSII standard. Croup 1(60 eyes): lens opacity grade Ⅰ-Ⅲ , Group 2( 10 eyes): lens opacity grade Ⅳ , Group 3( 1 eye): lens opacity grade Ⅴ. According to preoperative IVA, patients were divided into group A(IVA≥0.4) and group B (IVA<0.4 ). The best corrected visual acuity (BCVA) was compared with IVA, and correlation analysis and chi-square test were used for statistical analysis. Main Outcome Measures IVA, lens opacity and BCVA. Result The accuracy of the IVA for predicting BCVA after cataract surgery was 71.8%. The IVA was significantly correlated with posloperative BCVA in patients with lens nuclear hardness of grade Ⅳ or below ( r=0.677, P=0.000). The IVA and post-operative BCVA of group B (IVA≤0.4) was significantly different from group A (IVA≥0.4) (x2=9.906,P=0.002). Conclusion The IVA can accurately predict the post-operative BCVA in cataract patients with high myopia, especially in those with lens nuclear hardness of gradeⅣ and below and IVA more than 0.4.%目的 评价激光干涉条纹视力(IVA)检测在预测高度近视者白内障术后潜在视力的可靠性及应用价值.设计 前瞻性病例系列.研究对象 49例(71眼)高度近视白内障患者(眼轴长度≥26.00mm).方法 所有患者术前进行IVA检测,按LOCSII标准依晶状体核硬度将患者分为,甲组(60眼):晶状体核Ⅰ-Ⅲ级,乙组(10眼):晶状体核IV级,丙组(1眼):晶状体核Ⅴ级;根据术前IVA值分为,A组(51眼):IVA≥0.4,B组(20眼):IVA<0.4.检测结果与患者术后1个月最佳矫止视力(BCVA)进行相关

  4. 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.

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

    Directory of Open Access Journals (Sweden)

    Shu-Guo Yin

    2014-12-01

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

  6. The Eye Phone Study: reliability and accuracy of assessing Snellen visual acuity using smartphone technology.

    Science.gov (United States)

    Perera, C; Chakrabarti, R; Islam, F M A; Crowston, J

    2015-07-01

    Smartphone-based Snellen visual acuity charts has become popularized; however, their accuracy has not been established. This study aimed to evaluate the equivalence of a smartphone-based visual acuity chart with a standard 6-m Snellen visual acuity (6SVA) chart. First, a review of available Snellen chart applications on iPhone was performed to determine the most accurate application based on optotype size. Subsequently, a prospective comparative study was performed by measuring conventional 6SVA and then iPhone visual acuity using the 'Snellen' application on an Apple iPhone 4. Eleven applications were identified, with accuracy of optotype size ranging from 4.4-39.9%. Eighty-eight patients from general medical and surgical wards in a tertiary hospital took part in the second part of the study. The mean difference in logMAR visual acuity between the two charts was 0.02 logMAR (95% limit of agreement -0.332, 0.372 logMAR). The largest mean difference in logMAR acuity was noted in the subgroup of patients with 6SVA worse than 6/18 (n=5), who had a mean difference of two Snellen visual acuity lines between the charts (0.276 logMAR). We did not identify a Snellen visual acuity app at the time of study, which could predict a patients standard Snellen visual acuity within one line. There was considerable variability in the optotype accuracy of apps. Further validation is required for assessment of acuity in patients with severe vision impairment.

  7. CHARACTERISTICS OF MACULAR REGION AND VISUAL ACUITY IN GLAUCOMA PATIENTS AFTER PHACOEMULSIFICATION CATARACT SURGERY

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    E. N. Mityaeva

    2015-01-01

    Full Text Available Background: To improve safety of phacoemulsification cataract surgery, innovative technologies have been developed. Assessment of macular region status after the use of routine and innovative phaco technologies is of great interest. Aim: To compare effects of different phaco technologies on macular retina, visual acuity and intraocular pressure in patients with compensated glaucoma after uncomplicated phaco with intraocular lens implantation. Materials and methods: Phacoemulsification of immature cataract was performed in 52  patients (52 eyes using Oertli machine and uniform method. Patients were divided into 3 groups. Group 1 included 20  patients (20  eyes with simple (primary openangle glaucoma (POAG after phaco using easyPhaco technology. Group 2 included 20  POAG patients (20  eyes after phaco using routine technology. Group  3 included 12  patients without glaucoma after routine phaco. EasyPhaco technology involves using of the new Oertli machine parameters, phaco tip with new geometry, flow rate/vacuum setting of 1:10. Preoperatively, in all 40 patients with glaucoma, normal values of intraocular pressure were achieved using antiglaucomatous therapies. Visual acuity, intraocular pressure and macular thickness by optical coherent tomography were measured before the surgery, in 1 and 6 weeks after the procedure. Results: Increase of macular thickness (by 12–30  mcm compared to baseline was observed postoperatively in patients with and without glaucoma. After 1 week, mean macular thickness was significantly less in the easyPhaco group compared to routine phaco groups with and without glaucoma (221.5±15.4;238.3 ± 11.5 and 229.3 ± 16.9 mcm,respectively, p < 0.05. In the groups 1 and 3, macular thickness returned to preoperative values after 6 weeks (group 1: 210.5 ± 13.8 and 209.7 ± 16.3 mcm; group  3: 211.1 ± 14.4 and 211.1 ± 15.8  mcm,respectively. By contrast, after routine phaco technology in POAG

  8. Visual Acuity Using Head-fixed Displays During Passive Self and Surround Motion

    Science.gov (United States)

    Wood, Scott J.; Black, F. Owen; Stallings, Valerie; Peters, Brian

    2007-01-01

    The ability to read head-fixed displays on various motion platforms requires the suppression of vestibulo-ocular reflexes. This study examined dynamic visual acuity while viewing a head-fixed display during different self and surround rotation conditions. Twelve healthy subjects were asked to report the orientation of Landolt C optotypes presented on a micro-display fixed to a rotating chair at 50 cm distance. Acuity thresholds were determined by the lowest size at which the subjects correctly identified 3 of 5 optotype orientations at peak velocity. Visual acuity was compared across four different conditions, each tested at 0.05 and 0.4 Hz (peak amplitude of 57 deg/s). The four conditions included: subject rotated in semi-darkness (i.e., limited to background illumination of the display), subject stationary while visual scene rotated, subject rotated around a stationary visual background, and both subject and visual scene rotated together. Visual acuity performance was greatest when the subject rotated around a stationary visual background; i.e., when both vestibular and visual inputs provided concordant information about the motion. Visual acuity performance was most reduced when the subject and visual scene rotated together; i.e., when the visual scene provided discordant information about the motion. Ranges of 4-5 logMAR step sizes across the conditions indicated the acuity task was sufficient to discriminate visual performance levels. The background visual scene can influence the ability to read head-fixed displays during passive motion disturbances. Dynamic visual acuity using head-fixed displays can provide an operationally relevant screening tool for visual performance during exposure to novel acceleration environments.

  9. The impact of visual acuity on age-related differences in neural markers of early visual processing.

    Science.gov (United States)

    Daffner, Kirk R; Haring, Anna E; Alperin, Brittany R; Zhuravleva, Tatyana Y; Mott, Katherine K; Holcomb, Phillip J

    2013-02-15

    The extent to which age-related differences in neural markers of visual processing are influenced by changes in visual acuity has not been systematically investigated. Studies often indicate that their subjects had normal or corrected-to-normal vision, but the assessment of visual acuity seems to most frequently be based only on self-report. Consistent with prior research, to be included in the current study, subjects had to report normal or corrected-to-normal vision. Additionally, visual acuity was formally tested using a Snellen eye chart. Event-related potentials (ERPs) were studied in young adults (18-32years old), young-old adults (65-79years old), and old-old adults (80+ years old) while they performed a visual processing task involving selective attention to color. Age-related differences in the latency and amplitude of ERP markers of early visual processing, the posterior P1 and N1 components, were examined. All results were then re-analyzed after controlling for visual acuity. We found that visual acuity declined as a function of age. Accounting for visual acuity had an impact on whether older and younger adults differed significantly in the size and latency of the posterior P1 and N1 components. After controlling for visual acuity, age-related increases in P1 and N1 latency did not remain significant, and older adults were found to have a larger P1 amplitude than young adults. Our results suggest that until the relationship between age-associated differences in visual acuity and early ERPs is clearly established, investigators should be cautious when interpreting the meaning of their findings. Self-reports about visual acuity may be inaccurate, necessitating formal measures. Additional investigation is needed to help establish guidelines for future research, especially of very old adults.

  10. 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.

  11. 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.

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

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    Chang DH

    2016-08-01

    Full Text Available Daniel H Chang Empire Eye and Laser Center, Bakersfield, CA, USA Purpose: 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. Methods: 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/m2 and mesopic (3 cd/m2 lighting conditions and were compared using the paired t-test. All patients also completed a subjective questionnaire. Results: 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. Conclusion: 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. Keywords: Tecnis multifocal one-piece IOL, photopic visual acuity, mesopic visual acuity, intermediate visual

  13. Comparing visual acuity in preschool children using the Lea symbols and Sheridan Gardiner charts

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    Aghafekokhian B. Osaiyuwu

    2015-03-01

    Full Text Available Visual acuity measurement is a vital part of an optometric examination. The purpose of the present study was to compare visual acuity in preschool children using two charts – the Lea symbols chart and the Sheridan Gardiner chart. One hundred and fifty-three preschool children (72 boys and 81 girls between the ages of 3 and 5 years (mean age and standard deviation 4.23 ± 0.78 years were recruited from five randomly selected nursery schools. Distance visual acuity was measured monocularly and binocularly after a pre-test was done. An interval of 5 minutes was allowed for testing with both charts. The ages and sexes of each child were documented. Results showed a statistical difference in visual acuities using both charts (p < 0.05. There was also a statistical difference in both charts regarding age. There was no significant gender difference between the results from each chart.

  14. Night vision goggle visual acuity assessment: results of an interagency test

    Science.gov (United States)

    Task, H. Lee

    2001-08-01

    There are several parameters that are used to characterize the quality of a night vision goggle (NVG) such as resolution, gain, field-of-view, visual acuity, etc. One of the primary parameters is visual acuity or resolution of the NVG. These two terms are often used interchangeably primarily because of the measurement methods employed. The objectives of this paper are to present: (1) an argument as to why NVG visual acuity and resolution should be considered as distinctly different parameters, (2) descriptions of different methods of measuring visual acuity and resolution, and (3) the results of a blind test by several agencies to measure the resolution of the same two NVGs (four oculars).

  15. The effect of preoperative keratometry on visual outcomes after moderate myopic LASIK

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    Christiansen SM

    2012-03-01

    Full Text Available Steven M Christiansen1, Marcus C Neuffer1, Shameema Sikder2, Rodmehr T Semnani1, Majid Moshirfar11John A Moran Eye Center, University of Utah, Salt Lake City, UT, 2Wilmer Eye Institute, Johns Hopkins University, Baltimore, MA, USAPurpose: To evaluate visual outcomes in moderately myopic eyes with flat and steep corneas (preoperatively that have been treated with laser-assisted in situ keratomileusis (LASIK.Patients and methods: Records of ninety-six eyes with average preoperative keratometry (K values between 39.9 and 42.0 diopters (D (flat were matched with 103 eyes with preoperative K values between 46.0 and 47.2 D (steep that underwent LASIK between March 2007 and March 2010 for moderate myopia, and were retrospectively reviewed. The primary outcome measures used to determine the effect of preoperative keratometry on visual prognosis were refraction, visual acuity, change in keratometry (ΔK, and change in spherical equivalent (ΔSE, measured at 1, 3, 6, and 12 months postoperatively.Results: Significant differences were found at 6 months postoperatively between the flat group and steep group in SE (P = 0.029, sphere (P = 0.018, ΔK (P = 0.002, percentage of eyes achieving SE of −0.25 to + 0.25 D (P = 0.0125, −0.26 to −0.50 D (P = 0.003, −0.51 to −1.00 D (P = 0.044, and the percentage of eyes achieving uncorrected distance visual acuity of 20/15 or better (P = 0.0006.Conclusion: Moderately myopic eyes with flatter corneas preoperatively have better visual prognosis following LASIK compared with moderately myopic eyes with steeper corneas.Keywords: keratometry, cornea, LASIK, refractive surgery

  16. A new Gujarati language logMAR visual acuity chart: Development and validation

    OpenAIRE

    Ananth Sailoganathan; John Siderov; Ebi Osuobeni

    2013-01-01

    Aims: Gujarati is the main spoken language of a large proportion of the population of India. The aim of this study was to develop and validate a new Minimum Angle of Resolution (logMAR) visual acuity chart in the Gujarati language. Materials and Methods: A new Gujarati visual acuity chart was designed to logMAR specifications using Gujarati optotypes experimentally selected to have similar relative letter legibility under spherical and cylindrical defocus. The chart validation study was carri...

  17. The Effect of Signal-to-Noise Ratio on Visual Acuity Through Night Vision Goggles

    Science.gov (United States)

    1991-02-01

    subjects in visuLal acuity performance with NVGs, it was concluded that further research should be conducted to examine the correlation between visual...the image intensifier tuho. Tile image intensifier tube is basically a light amplifier that is sensitive over tho spectral region of about 600nm to... excellent means of getting a sensitive measure of visual acuity. 2 Method 2.1 Subje;cts Twelve male volunteers participated in this study. ’he subjects

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

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    Ai-Hong Chen

    2012-01-01

    Full Text Available 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 ranging between plano and −7.75D, astigmatism ranging from plano to −1.75D, anisometropia less than 1.00D and with no history of ocular injury or pathology. Right eye visual acuity (recorded in logMAR unit was measured with Snellen letter chart (Snellen, wall mounted letter chart (WM and projected letter chart (PC under two ambient room illuminations, room light on and room light off. Results: Visual acuity estimates showed no statistically significant difference when measured with the room light on and with the room light off (F1,372 = 0.26, P = 0.61. Post-hoc analysis with Tukey showed that visual acuity estimates were significantly different between the Snellen and PC (P = 0.009 and between Snellen and WM (P = 0.002. Conclusions: Different levels of ambient room illumination had no significant effect on visual acuity estimates. However, the discrepancies in estimates of visual acuity noted in this study were purely due to the type of letter chart used.

  19. 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.

  20. Crowding and visual acuity measured in adults using paediatric test letters, pictures and symbols.

    Science.gov (United States)

    Lalor, Sarah J H; Formankiewicz, Monika A; Waugh, Sarah J

    2016-04-01

    Crowding refers to the degradation of visual acuity for target optotypes with, versus without, surrounding features. Crowding is important clinically, however the effect of target-flanker spacing on acuity for symbols and pictures, compared to letters, has not been investigated. Five adults with corrected-to-normal vision had visual acuity measured for modified single target versions of Kay Pictures, Lea Symbols, HOTV and Cambridge Crowding Cards, tests. Single optotypes were presented in isolation and with surrounding features placed 0-5 stroke-widths away. Visual acuity measured with Kay Picture optotypes is 0.13-0.19logMAR better than for other test optotypes and varies significantly across picture. The magnitude of crowding is strongest when the surrounding features abut, or are placed 1 stroke-width away from the target optotype. The slope of the psychometric function is steeper in the region just beyond maximum crowding. Crowding is strongest and the psychometric function steepest, with the Cambridge Crowding Cards arrangement, than when any single optotype is surrounded by a box. Estimates of crowding extent are less variable across test when expressed in units of stroke-width, than optotype-width. Crowding for single target presentations of letters, symbols and pictures used in paediatric visual acuity tests can be maximised and made more sensitive to change in visual acuity, by careful selection of optotype, by surrounding the target with similar flankers, and by using a closer target-flanker separation than half an optotype-width.

  1. 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

    Purpose 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. Methods 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/m2) and mesopic (3 cd/m2) lighting conditions and were compared using the paired t-test. All patients also completed a subjective questionnaire. Results 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. Conclusion 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. PMID:27536061

  2. 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

  3. Effects of molting on the visual acuity of the blue crab, Callinectes sapidus.

    Science.gov (United States)

    Baldwin, Jamie; Johnsen, Sönke

    2011-09-15

    In crustaceans with compound eyes, the corneal lens of each facet is part of the exoskeleton and thus shed during molting. Here we used an optomotor assay to evaluate the impact of molting on visual acuity (as measured by the minimum resolvable angle, α(min)) in the female blue crab, Callinectes sapidus. We found that visual acuity decreases substantially in the days prior to molting and is gradually recovered after molting. Four days prior to molting, α(min) was 1.8 deg (N=5), a value approximating the best possible acuity in this species. In the 24 h before ecdysis occurred, α(min) increased to 15.0 deg (N=12), corresponding to an eightfold drop in visual acuity. Within 6 days after molting, α(min) returned to the pre-molting value. Micrographs of C. sapidus eyes showed that a gap between the corneal lens and the crystalline cone first appeared approximately 5 days prior to shedding and increased in width as the process progressed. This separation was likely responsible for the loss of visual acuity observed in behavioral tests. In blue crabs, mating is limited to the period of the female's pubertal molt, and a reduction in acuity during this time may have an effect on the sensory cues used in female mate choice. The results described here may be broadly applicable to all arthropods that molt and have particular importance for crustaceans that molt multiple times in their lifetime or have mating cycles that are paired with molting.

  4. A new Gujarati language logMAR visual acuity chart: development and validation.

    Science.gov (United States)

    Sailoganathan, Ananth; Siderov, John; Osuobeni, Ebi

    2013-10-01

    Gujarati is the main spoken language of a large proportion of the population of India. The aim of this study was to develop and validate a new Minimum Angle of Resolution (logMAR) visual acuity chart in the Gujarati language. A new Gujarati visual acuity chart was designed to logMAR specifications using Gujarati optotypes experimentally selected to have similar relative letter legibility under spherical and cylindrical defocus. The chart validation study was carried out using 153 adult subjects in a large clinical setting in India. Subjects who were literate in English and Gujarati participated in the study. Visual acuity was measured with the new Gujarati logMAR chart and a modified Early Treatment of Diabetic Retinopathy Study-(m-ETDRS) logMAR chart. The method of presentation was randomized between the charts. Repeat visual acuity was measured on a subsequent day with a second version of the Gujarati logMAR chart. The Gujarati chart correlated highly with the m-ETDRS logMAR chart (r² = 0.974). The mean visual acuity difference (Gujarati - m-ETDRS logMAR) was equal to three letters (-0.06 logMAR). The Gujarati logMAR chart also proved to be highly repeatable (r² = 0.994, test-retest) with 95% CI of ± 0.04 logMAR. The new Gujarati logMAR visual acuity chart provides a valid and repeatable tool for the measurement of visual acuity in native Gujarati language speakers.

  5. A new Gujarati language logMAR visual acuity chart: Development and validation

    Directory of Open Access Journals (Sweden)

    Ananth Sailoganathan

    2013-01-01

    Full Text Available Aims: Gujarati is the main spoken language of a large proportion of the population of India. The aim of this study was to develop and validate a new Minimum Angle of Resolution (logMAR visual acuity chart in the Gujarati language. Materials and Methods: A new Gujarati visual acuity chart was designed to logMAR specifications using Gujarati optotypes experimentally selected to have similar relative letter legibility under spherical and cylindrical defocus. The chart validation study was carried out using 153 adult subjects in a large clinical setting in India. Subjects who were literate in English and Gujarati participated in the study. Visual acuity was measured with the new Gujarati logMAR chart and a modified Early Treatment of Diabetic Retinopathy Study-(m-ETDRS logMAR chart. The method of presentation was randomized between the charts. Repeat visual acuity was measured on a subsequent day with a second version of the Gujarati logMAR chart. Results: The Gujarati chart correlated highly with the m-ETDRS logMAR chart (r2 = 0.974. The mean visual acuity difference (Gujarati - m-ETDRS logMAR was equal to three letters (-0.06 logMAR. The Gujarati logMAR chart also proved to be highly repeatable (r2 = 0.994, test-retest with 95% CI of ± 0.04 logMAR. Conclusions: The new Gujarati logMAR visual acuity chart provides a valid and repeatable tool for the measurement of visual acuity in native Gujarati language speakers.

  6. Modelling Cost Effectiveness in Neovascular Age-Related Macular Degeneration: The Impact of Using Contrast Sensitivity vs. Visual Acuity.

    OpenAIRE

    Butt, T.; Patel,P J; Tufail, A; Rubin, G. S.

    2014-01-01

    The cost utility of treatments of age-related macular degeneration (AMD) is commonly assessed using health state transition models defined by levels of visual acuity. However, there is evidence that another measure of visual function, contrast sensitivity, may be better associated with utility than visual acuity. This paper investigates the difference in cost effectiveness resulting from models based on visual acuity and contrast sensitivity using the example of bevacizumab (Avastin) for neov...

  7. Through the Neural Magnifying Glass: Visual Acuity and Motion-Aftereffect

    Directory of Open Access Journals (Sweden)

    S.C Boyle

    2014-08-01

    Full Text Available A Sloan- or Snellen-type visual acuity chart is commonly used for routine eye examination. This test serves as a benchmark for visual acuity where observers read out letters of decreasing size at a recommended viewing distance. The smallest readable letter size is typically used as a measure of visual acuity. For example, vision of 20/20 and 10/10 describe the ability to resolve letters that subtend 5 minutes of arc at a viewing distance of 20 (6m and 10 feet (3m, respectively. Here we show that adaptation to a rotating spiral and the ensuing motion aftereffect (MAE significantly alters visual acuity in normal observers. In one group 44 observers adapted to contracting motion and in a second group 30 observers adapted to expanding motion. The results clearly demonstrate that the expanding MAE facilitated subsequent letter recognition whereas the contracting MAE impaired letter recognition. We conclude that illusory expansion enlarges the apparent size of letters thereby increasing perceptual fields and number of feature detectors. Illusory contraction on the other hand reduces the apparent size of the letters thereby decreasing perceptual fields and number of feature detectors. It is an astonishing characteristic of the visual system that motion adaptation can improve visual acuity – a measure that is typically related to the optics of the eye rather than feature recognition and cognitive inference

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

    Science.gov (United States)

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

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

  9. 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.

  10. Comparison of visual acuity measured with Allen figures and Snellen letters using the B-VAT II monitor.

    Science.gov (United States)

    Lueder, G T; Garibaldi, D

    1997-11-01

    Allen figure optotypes commonly are used to measure visual acuity in young children. Children with normal acuity measured with Allen figures sometimes are found to have unsuspected amblyopia that is detected when they are tested with Snellen letters. The correlation between visual acuities measured with these two optotype charts has not been well studied. The authors compared visual acuities measured with Allen figure and Snellen letter optotypes using the Mentor B-VAT II monitor. The study design was a nonrandomized, comparative clinical trial. The study was composed of 12 adult subjects. Visual acuities were measured using both Allen figure and Snellen letter optotypes using the B-VAT II monitor. The images were progressively blurred using plus lenses. Visual acuity was measured. At visual acuity levels of 20/60 or better, Allen figure testing averaged 1.5 lines better than Snellen letter testing; between 20/70 and 20/200 visual acuities, the difference was 2.5 lines. Allen figure testing with the B-VAT II monitor overestimates visual acuity compared with testing with Snellen letters. This appears to result primarily from the construction of the optotypes. This discrepancy should be considered when visual acuity is measured in young children.

  11. Single spot PDT in patients with circumscribed choroidal haemangioma and near normal visual acuity

    NARCIS (Netherlands)

    F.D. Verbraak; R.O. Schlingemann; M.D. de Smet; J.E.E. Keunen

    2006-01-01

    Background: In circumscribed choroidal hemangiomas (CCH) a long observation period and decreased visual acuity before treatment are risk factors for poor visual outcome. Therefore, we studied the use of limited, single spot photodynamic therapy (PDT) with Visudyne for the timely treatment of CCH. Me

  12. Single spot PDT in patients with circumscribed choroidal haemangioma and near normal visual acuity.

    NARCIS (Netherlands)

    Verbraak, F.D.; Schlingemann, R.O.; Smet, M.D. de; Keunen, J.E.E.

    2006-01-01

    BACKGROUND: In circumscribed choroidal hemangiomas (CCH) a long observation period and decreased visual acuity before treatment are risk factors for poor visual outcome. Therefore, we studied the use of limited, single spot photodynamic therapy (PDT) with Visudyne for the timely treatment of CCH. ME

  13. Screening for Impaired Visual Acuity in Older Adults : US Preventive Services Task Force Recommendation Statement

    NARCIS (Netherlands)

    Calonge, Ned; Petitti, Diana B.; DeWitt, Thomas G.; Dietrich, Allen J.; Gregory, Kimberly D.; Grossman, David; Isham, George; LeFevre, Michael L.; Leipzig, Rosanne M.; Marion, Lucy N.; Melnyk, Bernadette; Moyer, Virginia A.; Ockene, Judith K.; Sawaya, George F.; Schwartz, J. Sanford; Wilt, Timothy

    2009-01-01

    Description: Update of the 1996 U. S. Preventive Services Task Force (USPSTF) recommendation statement on screening for visual impairment. Methods: The USPSTF reviewed evidence published since its last review on screening adults 65 years or older in the primary care setting for visual acuity impairm

  14. Screening for Impaired Visual Acuity in Older Adults : US Preventive Services Task Force Recommendation Statement

    NARCIS (Netherlands)

    Calonge, Ned; Petitti, Diana B.; DeWitt, Thomas G.; Dietrich, Allen J.; Gregory, Kimberly D.; Grossman, David; Isham, George; LeFevre, Michael L.; Leipzig, Rosanne M.; Marion, Lucy N.; Melnyk, Bernadette; Moyer, Virginia A.; Ockene, Judith K.; Sawaya, George F.; Schwartz, J. Sanford; Wilt, Timothy

    2009-01-01

    Description: Update of the 1996 U. S. Preventive Services Task Force (USPSTF) recommendation statement on screening for visual impairment. Methods: The USPSTF reviewed evidence published since its last review on screening adults 65 years or older in the primary care setting for visual acuity impairm

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Bevacizumab injection in patients with age-related macular degeneration associated with poor initial visual acuity.

    Science.gov (United States)

    El Matri, Leila; Bouraoui, Rym; Chebil, Ahmed; Kort, Fedra; Bouladi, Mejda; Limaiem, Rym; Landoulsi, Hana

    2012-01-01

    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 (P = 0.001) and at 12 months was 1.22 logMar ±  0.33 (P = 0.004). Mean baseline central retinal thickness was 431 μm ±  159.7 at 6 months was 293.43 μm  ±  122.79 (P = 10(-4)) and at 12 months was 293.1 μm  ±  130 (P = 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.

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

    African Journals Online (AJOL)

    olayemitoyin

    Summary: This study assessed the gender and environmental influences on visual ... Visual disability together with other ... prevalence of reduced VA was higher among ametropics and rural dwellers. ... Health education on diet, drug use.

  18. Effect of air and sulfur hexafluoride (SF6) tamponade on visual acuity after epiretinal membrane surgery: a pilot study.

    Science.gov (United States)

    Chabot, Guillaume; Bourgault, Serge; Cinq-Mars, Benoit; Tourville, Éric; Caissie, Mathieu

    2017-06-01

    The aim of this study was to compare visual acuity improvement after epiretinal membrane (ERM) surgery using air and sulfur hexafluoride (SF6) tamponade. Secondary objectives were to evaluate Visual Function Questionnaire (VFQ) scores and central retinal thickness (CRT) changes. This was a prospective, randomized study. Thirty-two patients were prospectively randomized, 19 to the air group and 13 to the SF6 group. This study has enrolled patients with ERM from clinical practice of 4 vitreoretinal surgeons. Preoperative and postoperative data included best-corrected visual acuity (BCVA) with the use of the Early Treatment Diabetic Retinopathy Study (ETDRS) chart, VFQ scores, CRT, and cataract staging. Pars plana vitrectomy with ERM peeling was performed on all patients, either with partial air tamponade or with complete SF6 tamponade. Mean BCVA improved by 0.07 logMAR (3.5 ETDRS letters) in the air group and by 0.09 logMAR (4.5 ETDRS letters) in the SF6 group (p = 0.58). There was no statistically significant difference between the groups with regard to BCVA, VFQ scores, and CRT. The groups had similar rates of cataract progression and adverse events. ERM peeling with partial air tamponade or with complete SF6 tamponade have similar outcomes in terms of BCVA, VFQ scores, CRT, cataract development, and adverse events. Copyright © 2017 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    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

  20. 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. 

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

    Science.gov (United States)

    Janky, Kristen; Givens, Diane

    2016-01-01

    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. Objectives 1) determine if age-related changes in peripheral vestibular tests occur; 2) quantify peripheral vestibular function in children with normal hearing (CNH) and CCI; 3) determine if amount of vestibular loss predicts visual acuity and balance performance. Design Eleven CCI and 12 CNH completed the following tests of vestibular function: ocular and cervical vestibular evoked myogenic potential (VEMP) to assess utricle and saccule function, and the video head impulse test (vHIT) 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. Results 1) There were no significant age-related changes in peripheral vestibular testing with the exception of the n23 cervical VEMP 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. Conclusions 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. PMID:26182202

  2. Change of Visual Acuity and Related Factors in Idiopathic Optic Neuritis

    Institute of Scientific and Technical Information of China (English)

    Changxian Yi; Linjie Guo; Jiexiong Ou; Hong Yan; Qiang Yu

    2001-01-01

    Purpose : To study the change of visual acuity and related factors in idiopathic optic neuritis. Methods: Retrospectively studying 136 cases (210 eyes) of idiopathic optic neuritis hospitalized in our department during last 5 years. The data was analyzed with the methods of multivariate stepwise regression analysis by SPSS statistic package. Results: The final visual acuity was very strongly related positively to the initial visual acuity at the time point of starting treatment and negatively to the time span beginning the treatment to the time showing improvement, age of patient and the duration from onset of the disorder to the time point of treatment beginning. Conclusions: Promptly right treatment can significantly change the natural course and the final vision of optic neuritis. Severe visual loss, old age, longer time without right therapy and slow improvement after the treatment may indicate an unfavorable final visual recovery. The different dosages of steroid applied in this study was not significant in view of the final visual acuity. Eye Sience 2001; 17: 46 ~ 49.

  3. 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.

  4. Effects of Dilation on Electronic-ETDRS Visual Acuity in Diabetic Patients

    OpenAIRE

    Sun, Jennifer Katherine; Aiello, Lloyd Paul; Stockman, Margaret; Cavallerano, Jerry D.; Kopple, Ann; Eagan, Sharon; Qin, Haijing; Kollman, Craig; Beck, Roy W.; Glassman, Adam R.

    2009-01-01

    Objectives: To evaluate the effect of pupillary dilation on electronic-ETDRS visual acuity (EVA) in diabetic subjects and to assess post-dilation EVA as a surrogate for pre-dilation visual acuity (VA). Methods and Design: DRCR.net-protocol refraction and EVA were measured pre- and post-dilation in diabetic subjects by independent, masked examiners. Results: In 129 eyes of 66 subjects, median [25th, 75th percentiles] pre-dilation EVA score was 69 [54, 86] (Snellen-equivalent 20/40-1 [20/80-1, ...

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

    OpenAIRE

    Leila El Matri; Rym Bouraoui; Ahmed Chebil; Fedra Kort; Mejda Bouladi; Rym Limaiem; Hana Landoulsi

    2012-01-01

    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 . 3 3 , at 6 months was 1.14 logMAR ± 0 . 3 7 ( = 0 . 0 0 1 ) and ...

  6. Patient with Macular Disease, Good Visual Acuity, and Central Visual Field Disruption and Significant Difficulties with Activities of Daily Living

    Science.gov (United States)

    Fletcher, Donald C.; Schuchard, Ronald A.; Walker, Joseph P.; Raskauskas, Paul A.

    2008-01-01

    It is generally appreciated that patients with macular disease frequently experience reduced visual acuity. It is not as widely appreciated that they often have significant central visual field disruption, which, by itself, can cause significant problems with activities of daily living, such as reading and driving, even when they maintain good…

  7. Patient with Macular Disease, Good Visual Acuity, and Central Visual Field Disruption and Significant Difficulties with Activities of Daily Living

    Science.gov (United States)

    Fletcher, Donald C.; Schuchard, Ronald A.; Walker, Joseph P.; Raskauskas, Paul A.

    2008-01-01

    It is generally appreciated that patients with macular disease frequently experience reduced visual acuity. It is not as widely appreciated that they often have significant central visual field disruption, which, by itself, can cause significant problems with activities of daily living, such as reading and driving, even when they maintain good…

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

    Science.gov (United States)

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

    2010-01-01

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

  9. To Further the Near-Vision Visual Acuity Tests (2) : The Necessity of Near-Vision Visual Acuity Testing from the Results of a Detailed Examination of Children's Visual Acuity Carried Out in an Ophthalmology Clinic(Special Issue Dedicated to Professor HASHIUCHI Takeshi)

    OpenAIRE

    高橋, ひとみ; 川端, 秀仁; 衞藤, 隆

    2014-01-01

    After carrying out far-vision visual acuity tests, near-vision visual acuity tests, refraction tests, and ciliary muscle function tests at A elementary-school, we stressed the need for school medical checkups to be followed up by consultation at an ophthalmology clinic in the case of children with poor far-vision visual acuity, poor near-vision visual acuity, or eye control dysfunction. 155 children were seen in an ophthalmology clinic and given a detailed examination. We carried out an in-de...

  10. Evaluation of vestibular and dynamic visual acuity in adults with congenital deafness.

    Science.gov (United States)

    Nakajima, Yukinori; Kaga, Kimitaka; Takekoshi, Hideki; Sakuraba, Keisyoku

    2012-10-01

    This study compared vestibular and dynamic visual acuity in 19 adult athletes with deafness participating in Deaflympics to those of 25 young adults with normal hearing. Balance capability was evaluated using a one-leg standing test with eyes open and stabilometry. Caloric tests and vestibular evoked myogenic potential tests were conducted to test vestibular function. Visual function was evaluated using a dynamic visual acuity test. No significant difference was found between results of the one-leg standing test with eyes open and stabilometry with eyes open. Athletes with deafness performed better than normal hearing young adults with eyes closed. The caloric test indicated hypofunction of the lateral semicircular canal function in 5 of the 19 athletes with deafness. Balance-function tests showed normal results for both groups. The results for athletes with deafness on visual acuity were better than those of controls. Young Deaflympics athletes with deafness can adjust their balance function as well as or better than normal hearing young adults using dynamic visual acuity.

  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

    Abstract 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. PMID:27610269

  12. 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 < 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.

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

    Science.gov (United States)

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

    2016-05-04

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

  14. 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.

  15. 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.

  16. 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

  17. Association between alcohol consumption and diabetic retinopathy and visual acuity-the AdRem Study

    NARCIS (Netherlands)

    Lee, C. C.; Stolk, R. P.; Adler, A. I.; Patel, A.; Chalmers, J.; Neal, B.; Poulter, N.; Harrap, S.; Woodward, M.; Marre, M.; Grobbee, D. E.; Beulens, J. W.

    2010-01-01

    Aims We investigated the association between alcohol consumption and diabetic retinopathy and deterioration of visual acuity in individuals with Type 2 diabetes. Methods We conducted a cohort analysis of 1239 participants with Type 2 diabetes aged 55-81 years enrolled in the AdRem study, a sub-study

  18. 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 di

  19. The Effects of Drift and Displacement Motion on Dynamic Visual Acuity

    Science.gov (United States)

    Aznar-Casanova, J. Antonio; Quevedo, Lluisa; Sinnett, Scott

    2005-01-01

    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…

  20. Predictive factors for postoperative visual acuity in idiopathic epiretinal membrane : A systematic review

    NARCIS (Netherlands)

    Scheerlinck, Laura M E; van der Valk, Rikkert; van Leeuwen, Redmer

    2015-01-01

    The aim of this study was to review the literature on predictive factors for postoperative visual acuity (VA) in surgery for idiopathic epiretinal membrane (ERM). A systematic review of the literature in the databases of PubMed and Embase was performed. The risk of bias was assessed based on predefi

  1. The role of white light interferometry in predicting visual acuity following posterior capsulotomy.

    Science.gov (United States)

    Hanna, I T; Sigurdsson, H; Baines, P S; Roxburgh, S T

    1989-01-01

    White light interferometry was performed on 21 eyes of 19 patients presenting for posterior capsulotomy following uncomplicated extracapsular cataract surgery. The white light interferometer was able to predict post-operative visual acuity to within one Snellen line in 56 per cent of eyes and to within two Snellen lines in 76 per cent of eyes.

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

    Directory of Open Access Journals (Sweden)

    Monika Jasielska

    2017-05-01

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

  3. Changes in ocular flow induced by hypo- and hypercapnia relate to static visual acuity in humans

    Directory of Open Access Journals (Sweden)

    Nami Someya

    2011-06-01

    Full Text Available We investigated whether the change in ocular blood flow, induced by hypo- and hypercapnia, is related to static visual acuity. Eleven healthy subjects (26±5 years underwent three treatments. A three-treatment three-period crossover design was used. In the hypocapnia treatment (HYPO, the subjects controlled their minute ventilation (VE to a target of 25 L/min for 6 min. In the hypercapnia treatment (HYPER, the subjects inspired high-fraction CO2 gas (FICO2 = 4% for 6 min. In the control treatment (CON, VE was not manipulated. We measured choroidal and retinal blood flow by laser speckle flowmetry as ocular blood flow, and static visual acuity using the Landolt C chart. End-tidal partial pressure of CO2 differed significantly among HYPO, HYPER and CON (21±1, 48±1, and 42±1 mmHg, respectively. Retinal blood flow decreased significantly from the baseline in HYPO (-22±5%, but increased significantly in HYPER (+3±9% compared to CON. Decimal visual acuity was significantly lower in HYPO than in the CON (0.21±0.1 vs. 0.24±0.1 P<0.05. These results suggest that changes in ocular blood flow induced by changes in arterial CO2 partial pressure influences visual acuity.

  4. Association between alcohol consumption and diabetic retinopathy and visual acuity-the AdRem Study

    NARCIS (Netherlands)

    Lee, C. C.; Stolk, R. P.; Adler, A. I.; Patel, A.; Chalmers, J.; Neal, B.; Poulter, N.; Harrap, S.; Woodward, M.; Marre, M.; Grobbee, D. E.; Beulens, J. W.

    2010-01-01

    Aims We investigated the association between alcohol consumption and diabetic retinopathy and deterioration of visual acuity in individuals with Type 2 diabetes. Methods We conducted a cohort analysis of 1239 participants with Type 2 diabetes aged 55-81 years enrolled in the AdRem study, a sub-study

  5. Short-term visual deprivation, tactile acuity, and haptic solid shape discrimination.

    Science.gov (United States)

    Crabtree, Charles E; Norman, J Farley

    2014-01-01

    Previous psychophysical studies have reported conflicting results concerning the effects of short-term visual deprivation upon tactile acuity. Some studies have found that 45 to 90 minutes of total light deprivation produce significant improvements in participants' tactile acuity as measured with a grating orientation discrimination task. In contrast, a single 2011 study found no such improvement while attempting to replicate these earlier findings. A primary goal of the current experiment was to resolve this discrepancy in the literature by evaluating the effects of a 90-minute period of total light deprivation upon tactile grating orientation discrimination. We also evaluated the potential effect of short-term deprivation upon haptic 3-D shape discrimination using a set of naturally-shaped solid objects. According to previous research, short-term deprivation enhances performance in a tactile 2-D shape discrimination task - perhaps a similar improvement also occurs for haptic 3-D shape discrimination. The results of the current investigation demonstrate that not only does short-term visual deprivation not enhance tactile acuity, it additionally has no effect upon haptic 3-D shape discrimination. While visual deprivation had no effect in our study, there was a significant effect of experience and learning for the grating orientation task - the participants' tactile acuity improved over time, independent of whether they had, or had not, experienced visual deprivation.

  6. 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.

  7. Forward light scatter and visual acuity before and after intrastromal corneal ring segment implantation at different stages of keratoconus.

    Science.gov (United States)

    Puell, María Cinta; Carballo-Álvarez, Jesús

    2016-12-01

    To assess forward light scatter (stray light) before and after intrastromal corneal ring segment (ICRS) implantation at different stages of keratoconus and to examine correlation between postoperative stray light and visual acuity (VA). In 27 eyes of 27 subjects with keratoconus, stray light was determined using the compensation comparison technique before and 6 months after ICRS implantation. Monocular corrected distance VA (CDVA) was measured using a high-contrast logMAR letter chart. Corneal higher-order aberrations (HOAs), contrast sensitivity (CS) and minimum corneal thickness (CT) were also measured. Mean CDVA was 0.42 ± 0.28 preoperatively and 0.24 ± 0.15 logMAR postoperatively (p  0.05) for stage I, 0.13 ± 0.14 (p = 0.013) for stage II and 0.18 ± 0.21 (p = 0.023) for stage III. Significant positive correlation (r = 0.47, p = 0.01) was detected between postoperative stray light and postoperative CDVA such that as stray light increased, CDVA worsened (higher logMAR values). Postoperative stray light was neither associated with HOAs, CS nor minimum CT. Stray light values in these patients with keratoconus were higher than normal preoperatively. In eyes with stage II and III keratoconus, stray light increased 6 months after ICRS placement. Higher postoperative stray light was correlated with a worse visual acuity outcome. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  8. 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.

  9. Theoretical and applied aspects of night vision goggle resolution and visual acuity assessment

    Science.gov (United States)

    Task, H. Lee; Pinkus, Alan R.

    2007-04-01

    The image quality of night vision goggles is often expressed in terms of visual acuity, resolution or modulation transfer function. The primary reason for providing a measure of image quality is the underlying assumption that the image quality metric correlates with the level of visual performance that one could expect when using the device, for example, target detection or target recognition performance. This paper provides a theoretical analysis of the relationships between these three image quality metrics: visual acuity, resolution and modulation transfer function. Results from laboratory and field studies were used to relate these metrics to visual performance. These results can also be applied to non-image intensifier based imaging systems such as a helmet-mounted display coupled to an imaging sensor.

  10. Visual Acuity and Reaction Time in Navy Fighter Pilots,

    Science.gov (United States)

    1986-12-01

    10. SOUR CW 0FUHND"N NUmIRs Naval Medical Research & Development Command PRGKOM POX ~JCT TASK WORK UNITI IIAMET NO Ný CESSION NO.NMC, National Capital...8. Stimulus sizes were specified in minutes of visual angle ( mva ), and target exposure time was 3 seconds. 2 kdditiotwl details concerning these...This test required the subject to press the joystick iWmmeiately at the appearance of a swrathreshold spot target (2 mva 4iame-. ter). Target

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

    NARCIS (Netherlands)

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

    2008-01-01

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

  12. Assessment of Visual Acuity, Refraction Changes, and Proptosis in Different Ages of Patients with Thyroid Diseases

    Directory of Open Access Journals (Sweden)

    J. Jankauskiene

    2012-01-01

    Full Text Available Objective. The aim of the study was to assess visual acuity, refractive status, and eye proptosis in children and young adults with Graves’ disease. Material and Methods. We have done investigations of visual acuity, refraction, and eye proptosis in 16 children, 14 teenagers, and 49 adults with Graves’ disease at Eye Clinic of Lithuanian University of Health Sciences Medical Academy. Data were compared with 14 children, 14 teenagers, and 35 adults of similar age without the same diseases (control group. Results. In the present study we observed a significant decrease of visual acuity in teenagers (0.73±0.18, P=0.001 and adults (0.7±0.16, P=0.001 with Graves’ disease. Myopia was ascertained more frequent in teenagers (42.8 percent and adults (44.9 percent with Graves’ disease. In our study exophthalmometer values were higher in children (15.94±1.98 mm, P=0.003, teenagers (17.28±2.99 mm, P=0.01, and adults (18.05±2.91 mm, P=0.001 in comparison with the controls. Conclusions. The data we have found suggest that Graves’ disease in children, teenagers, and adults has influence on vision acuity, refraction, and eye proptosis.

  13. Interferometer assessment of potential visual acuity before YAG capsulotomy: relative performance of three instruments.

    Science.gov (United States)

    Strong, N

    1992-01-01

    The accuracy of white light and laser interferometers in predicting visual acuity after YAG laser capsulotomy was compared. 42 eyes of 41 patients were tested with both a Haag-Streit (Lotmar) white light interferometer and a Rodenstock laser interferometer, and 14 were also tested with a Site white light machine. The laser interferometer predicted a final visual acuity to within one line of that actually achieved in 93%, and to within two lines in 98%, whereas for the Haag-Streit these figures were 64% and 81%, and for the Site 77% and 92%. In patients with poor initial visual acuity, the difference in the relative performance of the two instruments was increased further. When interferometry was repeated after capsulotomy, the values obtained with all instruments agreed closely with Snellen acuity. This difference in predictive accuracy shows that capsular thickening causes a greater degree of optical degradation of the image produced by a white light interferometer than occurs when a laser interferometer is employed.

  14. Comparison of the visual function index to the Snellen Visual Acuity Test in predicting older adult self-restricted driving.

    Science.gov (United States)

    Lotfipour, Shahram; Patel, Bhakti Harishchandra; Grotsky, Thomas Aaron; Anderson, Craig L; Carr, Erin M; Ahmed, Suleman Syed; Chakravarthy, Bharath; Fox, John Christian; Vaca, Federico E

    2010-10-01

    In this observational study, a modified version of the Visual Function Index (VF-14) and the Snellen Visual Acuity Test were compared in how well they correlated with self-restricted driving habits in older adults. The VF-14 was originally designed to assess vision in cataract patients; however, in this study, a modified version (mVF-14) was evaluated as a tool for predicting self-restricted driving in older drivers. During a 3-month period, 151 drivers over the age of 65 were screened at the local senior center. In addition to the Snellen Visual Acuity Test and mVF-14, each participant was given a questionnaire about their driving habits, previously used in self-restriction studies. Out of 151 total participants, 134 were included and 7 nondrivers and 10 subjects who did not complete all questionnaires were excluded. One hundred one participants exhibited normal visual acuity of 20/40 or better (75%), and 110 scored over 90 on the mVF-14 (82%). Spearman's rank sum correlation coefficient was used to analyze the data and showed significant negative correlation of the mVF-14 and Snellen with self-restricted driving. Individuals with normal vision (20/40 or better on the Snellen eye test) had both high and low mVF-14 scores. The study shows that poor vision, as indicated by the Snellen scale and low mVF-14 scores, correlates to self-imposed driving limitations. The mVF-14 showed further distinctions of self-restriction between individuals in the same Snellen Visual Acuity category. Therefore, using the mVF-14 in addition to the Snellen Visual Acuity Test can be helpful to further differentiate visual ability within older drivers who appear to have normal vision.

  15. 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.

  16. VISUAL ACUITY AND MULTIFOCAL ELECTRORETINOGRAPHIC CHANGES AFTER ARTERIOVENOUS CROSSING SHEATHOTOMY FOR MACULAR EDEMA ASSOCIATED WITH BRANCH RETINAL VEIN OCCLUSION

    Science.gov (United States)

    Chung, Eun Jee; Freeman, William R.; Koh, Hyoung Jun

    2009-01-01

    Purpose To evaluate the influence of arteriovenous (AV) sheathotomy on retinal function with central multifocal electroretinography (mfERG) in eyes with macular edema secondary to branch retinal vein occlusion (BRVO). Methods Fifteen patients (15 eyes) who underwent AV sheathotomy for macular edema secondary to BRVO were included in the study. Best-corrected visual acuity and mfERG responses from the most central seven hexagons were analyzed before and 6 months after the operation. Results The mean preoperative Early Treatment Diabetic Retinopathy Study (ETDRS) score ± SD was 34.1 ± 12.7 letters (Snellen equivalent, 20/50) and significantly improved up to 40.5 ± 10.9 letters (Snellen equivalent, 20/40) at 6 months after AV sheathotomy (P = 0.027, Wilcoxon signed rank test). The mean preoperative P1 amplitude ± SD of the most central 7 hexagons was 39.30 ± 10.86 nV/deg2 for the affected eye versus 47.72 ± 6.67 nV/deg2 for the normal fellow (control) eye (P = 0.013, Mann–Whitney U test) and significantly increased up to 50.71 ± 15.58 nV/deg2 at 6 months after the operation (P = 0.014, Wilcoxon signed rank test). Significant correlations between preoperative and postoperative ETDRS score and preoperative P1 amplitude were present (r = 0.929, P < 0.001; r = 0.768, P = 0.001; respectively [Spearman correlation]). Conclusions AV sheathotomy improved macular function and anatomical outcome as measured by ETDRS score and mfERG responses in patients with macular edema due to BRVO. PMID:18301026

  17. 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.

  18. [Correctly evaluate the role of visual acuity in age-related macular degeneration treatment].

    Science.gov (United States)

    Zhang, Feng

    2012-02-01

    Age-related macular degeneration (AMD) is the leading cause of irreversible visual loss in aged population. As the aging of population, the prevalence of AMD increases gradually. Anti-VEGF medication intravitreal injection, which can obtain good therapeutic efficiency and is relatively safe, becomes the main therapy for neovascular AMD. However, high-frequency repeated treatment increases the intravitreal injections risk, as well as the costs. In clinical practice, to pursue the best-corrected visual acuity, high-frequency repeated injections are implemented and inflict psychological pressure and economic burden on patients. The author believes that to pursue the best corrected visual acuity is the ultimate aim but not the only one for every ophthalmologist and patient. The activity of lesions should be overall evaluated with fundus imaging technologies. Being people-oriented is the principle in clinical medicine. A treatment plan is made according to the patients' sickness and economy and to coordinate the relation between the best corrected visual acuity and the numbers of treatment. Based on the stabilized lesion, patient should be benefited at the lowest risk and cost with the best effect.

  19. The exact estimation of visual acuity by VEP technology: a report of 726 cases of eye injury.

    Science.gov (United States)

    Rao, Guangxun; Wu, Bingwei; Zhang, Lingli

    2010-02-01

    This study explored the accuracy of using visual evoked potentials (VEP) technology for visual acuity estimation. The enrolled 726 patients with post-traumatic unilateral decrease in visual acuity included the injured eyes served as the experimental group, and the healthy eyes as the control group. The least signal visual angle (LSVA), and amplitude and latency of P(100) were chosen as test indexes. The results under different experimental conditions were recorded by PRVEP technology. All data collected were processed and analyzed by SPSS software. The results showed that the coincidence between subjective and VEP visual acuity was 96.7% in control group, but there was very significant difference in experimental group. It was concluded that with the regression formulation for the amplitude of P(100) and vision under LSVA, visual acuity can be estimated more accurately and impartially.

  20. 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.

  1. Peculiarities of vernier monocular and binocular visual acuity in the retinal orthogonal meridians in patients with hypermetropic astigmatism

    Directory of Open Access Journals (Sweden)

    Владимир Александрович Коломиец

    2015-06-01

    Full Text Available It was carried out an examination of meridional vernier visual acuity in 100 patients 7-25 years old with a simple and compound hypermetropic astigmatism and refractive ambyiopia. An astigmatic component of refraction was in range 0,5- 2,5 dptr. Visual acuity on the sighting eyes after correction was 0,9- 1,0, on eyes with amblyopia 0,4 - 0,85 relative units.Methods. Visual acuity was defined by the Landolt rings of Sivtsev table. Vernier visual acuity was defined in seconds of arc from 5 km, using special computer program.Result. It was demonstrated that in patients with the simple hypertropic astigmatism diagnosis of meridional amblyopia can be specified by the comparison of data of monocular and binocular vernier visual acuity in orthogonal meridians of retinas.Conclusions. An effect of the rise of meridional binocular visual acuity in one of meridians and its absence in another one allows define selective meridional disturbances of the visual acuity

  2. Correlation between Ocular Manifestations and Their Complications as Opposed to Visual Acuity and Treatment in Behcet's Disease

    Directory of Open Access Journals (Sweden)

    Jelena Paovic

    2013-01-01

    Full Text Available The aim of this study was to analyze ocular manifestations, their complications, and treatment in a sample of 40 patients with confirmed Behcet’s disease. Results. Serofibrinous iridocyclitis was the most common form of uveitis (60%. Retinal periphlebitis manifested in 92.5% of cases, and periphlebitis in conjunction with periarteritis was diagnosed in 72.5% of cases. Macular edema was the most frequent complication on the posterior segment (60% and it correlated with periphlebitis (P=0.45 and periphlebitis associated with periarteritis (P=0.51. Cyclosporine A and corticosteroids were used in the majority of cases (67%. Following six months of therapy, a significant improvement of visual acuity occurred in patients with initial visual acuity >0.5 on both eyes. Level of visual acuity before and after treatment had a strong significant correlation coefficient with various ocular complications. Previously proven significant increase of visual acuity in patients with macular edema depicts effectiveness of treatment in these types of ocular manifestations of Behcet’s disease. Conclusions. Significant improvement of visual acuity occurred in patients with initial visual acuity >0.5 on both eyes. The highest increase in visual acuity was achieved by laser photocoagulation in combination with triamcinolone acetonide P=0.038<0.050.

  3. Effect of aspheric multifocal toric IOL implantation on visual acuity and contrast sensitivity in patients with cataract

    Directory of Open Access Journals (Sweden)

    Ling-Ling Zhang

    2016-07-01

    Full Text Available AIM: To observe the effect of intraocular lens(IOLimplantation on visual acuity and contrast sensitivity in patients with cataract.METHODS: Fifty-eight cases(72 eyescataract patients with regular cornel astigmatism, in our hospital from May 2014 to May 2015 were randomly divided into two groups to undergo phacoemulsification and IOL implantation: the observation group: 29 cases(36 eyesreceived multifocal toric IOL implantation; the control group: 29 cases(36 eyesreceived monofocal toric IOL implantation. Uncorrected distance visual acuity(UCDVA, uncorrected near visual acuity(UCNVA, best corrected distance visual acuity(BCDVA, the best corrected near visual acuity(BCNVA, total eye astigmatism, and the dark contrast sensitivity were observed for these patients at 1 and 6mo after cataract surgery. RESULTS: There were no statistical significant difference between the two groups at postoperative 1, 6mo on UCDVA, BCNVA, BCDVA and total eye astigmatism(P>0.05. UCNVA of observation group at 1 and 6mo were better than those of control group(PPCONCLUSION: Both monofocal toric IOL implantation, and aspheric multifocal toric IOL implantation for cataract with regular corneal astigmatism are effective to improve visual acuity. But the latter treatment would contribute to the improvement of uncorrected near visual acuity and the dark contrast sensitivity.

  4. Hierarchical linear modeling of visual acuity change over time: rate of functional recovery after macular hole surgery.

    Science.gov (United States)

    Wittich, Walter; Overbury, Olga; Kapusta, Michael A; Watanabe, Donald H

    2007-09-01

    To examine acuity recovery rate after Macular Hole (MH) surgery, using Hierarchical Linear Modeling (HLM) with linear and curvilinear regression analysis. Preoperative MH diameter (OCT) and acuity (ETDRS) were recorded in 20 eyes. Acuities were tested during follow-up (6 to 23 months), with three to eight measurements per eye. The resulting 95 acuities were analyzed using HLM. Variability at the level of the person was explained by change over time, using a natural logarithm conversion. Across patients, MH diameter was used to predict slopes and intercepts at the level of the individual. MH diameter was able to account for significant amounts of variability in preoperative acuity (intercept) and significantly influenced rate of functional recovery (slope). A nonlinear approach to the data accounted for the largest amount of variance. Participants with larger MHs recovered relatively more acuity sooner while eyes with smaller MHs had better absolute acuity outcome. HLM provides important insight into the recovery process after MH surgery and is more flexible with follow-up data. In the context of MH treatment, most recuperation occurred during the initial 6 months.

  5. DEVELOPMENT OF RETINAL STRUCTURE AND VISUAL ACUITY IN JAPANESE FLOUNDER (PARALICHTHYS OLIVACEUS)

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The retinal structure and visual acuity in Japanese flounder Paralichthys olivaceus at different stages of development were examined by light microscopy. The resolving power of the retina, the visual axis and the best visual field were estimated based on the distribution of cone cells in the retina. The visual system of the larvae appears poorly developed at hatching. The larvae with total length (TL) of less than 10 mm, have single cones only and the eyes were well pigmented. At 10-11 mm TL, most single cones fused to form double cones, with the single and double cones forming a mosaic pattern. From larvae to early juvenile the retina stretches, the cones increase in diameter and rods increase in number. Based on the highest density of the cones in the ventro-temporal region, the visual axis was orientated up-forward. The resolving power of the retina in 40-530 mm TL Japanese flounder was found to range from 25.1 to 11.5 min. The results indicated continual improvements in the visual system of the growing fish towards higher resolving power, visual acuity and sensitivity.

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

    Science.gov (United States)

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

    2016-04-28

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

  7. Measurement of night vision goggle (NVG) visual acuity with the NVG resolution chart.

    Science.gov (United States)

    DeVilbiss, C A; Antonio, J C

    1994-09-01

    Night vision goggles (NVG) operations are characterized as stressful with high task loading. Any reduction in goggle or visual performance which goes undetected can have a serious effect on flight safety and operational capability. The NVG Test Lane, with its resolution chart, provides an effective cost-efficient method for aircrew members to quickly evaluate the correct positioning and focusing of their NVG's prior to each mission. This evaluation validated the ability of the NVG resolution chart to produce the same performance results as a more detailed psychophysical procedure. NVG visual acuity was measured for five subjects (four pilots and one non-pilot) with two different night vision goggles. The results supported that there is no statistical difference between the results obtained with the individual target format and the 3 x 3 format. Additionally, the pilots with current NVG experience were able to obtain a significantly better acuity level than were those without current NVG experience.

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

    Energy Technology Data Exchange (ETDEWEB)

    Miyao, Yoko; Tada, Rei; Koizumi, Noriko; Yamada, Hideaki; Kinoshita, Shigeru [Kyoto Prefectural Univ. of Medicine (Japan); Ikeda, Tsunehiko

    2000-05-01

    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)

  9. 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.

  10. Omega 3 fatty acids on child growth, visual acuity and neurodevelopment

    OpenAIRE

    Campoy, C.; Escolano-Margarit, MV; Anjos, T.; Szajewska, H.; Uauy, R

    2012-01-01

    The aim of this review is to evaluate the effects of omega-3 long chain polyunsaturated fatty acids (n-3 LCPUFA) supplementation in pregnant and lactating women and infants during postnatal life, on the visual acuity, psychomotor development, mental performance and growth of infants and children. Eighteen publications (11 sets of randomized control clinical trial [RCTs]) assessed the effects of the n-3 LCPUFA supplementation during pregnancy on neurodevelopment and growth, in the same subject...

  11. [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.

  12. CORRELATION OF MICROVASCULAR STRUCTURES ON OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY WITH VISUAL ACUITY IN RETINAL VEIN OCCLUSION.

    Science.gov (United States)

    Kang, Joon-Won; Yoo, Romi; Jo, Youn Hye; Kim, Hyung Chan

    2017-09-01

    To analyze the correlation of superficial and deep capillary plexuses using optical coherence tomography (OCT) angiography with visual acuity in eyes with retinal vein occlusion (RVO). We retrospectively reviewed the medical records of 33 patients with retinal vein occlusion (RVO; branch retinal vein occlusion in 21 patients, central retinal vein occlusion in 12 patients) and included 33 healthy subjects as a control group, who were evaluated by OCT angiography. The OCT angiography was performed on a 3 mm × 3-mm region centered on the fovea and parafoveal area. The foveal avascular zone (FAZ), and foveal and parafoveal vascular density (VD) in superficial and deep vascular plexuses were analyzed using OCT angiography. The area of superficial and deep FAZ in eyes with RVO were larger than those in fellow eyes and control eyes (P = 0.034, P = 0.018). The superficial and deep parafoveal VDs in eyes with RVO were significantly lower than those in fellow eyes and control eyes (P = 0.001, Pretinal vein occlusion (85.7%) showed a high concordance rate with respect to the location of branch retinal vein occlusion and the lowest parafoveal VD area. The multivariate analysis showed that the deep parafoveal VD was associated with best-corrected visual acuity. The OCT angiography allows to detect FAZ enlargement, increased parafoveal capillary nonperfusion, and decreased parafoveal VD in eyes with RVO. The area of superficial FAZ and the parafoveal VD are correlated with best-corrected visual acuity in eyes with RVO.

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

    Directory of Open Access Journals (Sweden)

    Lisa O'Donoghue

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

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

    Directory of Open Access Journals (Sweden)

    Jun-Hua Li

    2014-02-01

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

  15. Osteological evidence for the evolution of activity pattern and visual acuity in primates.

    Science.gov (United States)

    Kay, R F; Kirk, E C

    2000-10-01

    Examination of orbit size and optic foramen size in living primates reveals two adaptive phenomena. First, as noted by many authors, orbit size is strongly correlated with activity pattern. Comparisons of large samples of extant primates consistently reveal that nocturnal species exhibit proportionately larger orbits than diurnal species. Furthermore, nocturnal haplorhines (Tarsius and Aotus) have considerably larger orbits than similar-sized nocturnal strepsirrhines. Orbital hypertrophy in Tarsius and Aotus accommodates the enormously enlarged eyes of these taxa. This extreme ocular hypertrophy seen in extant nocturnal haplorhines is an adaptation for both enhanced visual acuity and sensitivity in conditions of low light intensity. Second, the relative size of the optic foramen is highly correlated with the degree of retinal summation and inferred visual acuity. Diurnal haplorhines exhibit proportionately larger optic foramina, less central retinal summation, and much higher visual acuity than do all other primates. Diurnal strepsirrhines exhibit a more subtle but significant parallel enlargement of the optic foramen and a decrease in retinal summation relative to the condition seen in nocturnal primates. These twin osteological variables of orbit size and optic foramen size may be used to draw inferences regarding the activity pattern, retinal anatomy, and visual acuity of fossil primates. Our measurements demonstrate that the omomyiforms Microchoerus, Necrolemur, Shoshonius, and Tetonius, adapiform Pronycticebus, and the possible lorisiform Plesiopithecus were likely nocturnal on the basis of orbit diameter. The adapiforms Leptadapis, Adapis, and Notharctus, the phylogenetically enigmatic Rooneyia, the early anthropoids Proteopithecus, Catopithecus, and Aegyptopithecus, and early platyrrhine Dolichocebus were likely diurnal. The activity pattern of the platyrrhine Tremacebus is obscure. Plesiopithecus, Pronycticebus, Microchoerus, and Necrolemur probably had

  16. 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, Roger

    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...

  17. 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.

  18. 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

  19. Analysis of risk factors for visual acuity and visual field impairments in patients with pituitary adenoma%垂体腺瘤患者视力视野受损的危险因素分析

    Institute of Scientific and Technical Information of China (English)

    周文剑龙; 牛国栋; 管修东; 赵敏; 马顺昌; 刘祥祥; 李德岭; 贾桂军; 贾旺

    2016-01-01

    Objective To investigate the risk factors for visual acuity and visual field impairments,and the effect on their prognoses.Methods The clinical data of 637 patients with pituitary adenoma operated at the Department of Neurosurgery,Beijing Tiantan Hospital,Capital Medical University from January 2008 to December 2013 were analyzed retrospectively.The patients were followed up at 3 years after procedure.Receiver operating characteristic (ROC) curve was used to obtain the optimal critical value of the risk factors for affecting visual acuity and visual field impairments and postoperative recovery.The round numbers were taken to group.Results In 637 patients,436 (68.4%) experienced visual acuity and visual field impairments,414 of them had decreased vision,and 292 had visual field defect.Receiver operating characteristic (ROC) curve showed that (1) the suprasellar extension height of tumors < 12.5 mm tended to cause less visual acuity and visual field impairments in patients.There was significant difference in whether the preoperative visual acuity and visual field were impaired and the degree of visual impairment between the ≤ 10 mm group and the > 10 mm group (all P < 0.01);(2) the suprasellar extension height of the tumors > 18.5 mm,the risk of causing permanent visual acuity and visual field impairments increased.There were significant differences in postoperative visual acuity improvement,visual acuity and visual field impairment score (VIS) grades between the suprasellar extension height of tumors ≤20 mm group and the and > 20 mm group (P < 0.01).There was no significant difference in the improvement of visual field (P > 0.05);(3) the patients with the duration of preoperative visual acuity and visual field impairments >13.5 months,the postoperative visual acuity and visual field impairments were more difficult to improve.There was significant difference between the recovery of visual acuity in patients with the duration of the disease

  20. Avaliação da acuidade visual Snellen Snellen visual acuity evaluation

    Directory of Open Access Journals (Sweden)

    Marcio Zapparoli

    2009-12-01

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

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

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    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.

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

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    Hoshina K

    2013-03-01

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

  3. A double dissociation of the acuity and crowding limits to letter identification, and the promise of improved visual screening.

    Science.gov (United States)

    Song, Shuang; Levi, Dennis M; Pelli, Denis G

    2014-05-05

    Here, we systematically explore the size and spacing requirements for identifying a letter among other letters. We measure acuity for flanked and unflanked letters, centrally and peripherally, in normals and amblyopes. We find that acuity, overlap masking, and crowding each demand a minimum size or spacing for readable text. Just measuring flanked and unflanked acuity is enough for our proposed model to predict the observer's threshold size and spacing for letters at any eccentricity. We also find that amblyopia in adults retains the character of the childhood condition that caused it. Amblyopia is a developmental neural deficit that can occur as a result of either strabismus or anisometropia in childhood. Peripheral viewing during childhood due to strabismus results in amblyopia that is crowding limited, like peripheral vision. Optical blur of one eye during childhood due to anisometropia without strabismus results in amblyopia that is acuity limited, like blurred vision. Furthermore, we find that the spacing:acuity ratio of flanked and unflanked acuity can distinguish strabismic amblyopia from purely anisometropic amblyopia in nearly perfect agreement with lack of stereopsis. A scatter diagram of threshold spacing versus acuity, one point per patient, for several diagnostic groups, reveals the diagnostic power of flanked acuity testing. These results and two demonstrations indicate that the sensitivity of visual screening tests can be improved by using flankers that are more tightly spaced and letter like. Finally, in concert with Strappini, Pelli, Di Pace, and Martelli (submitted), we jointly report a double dissociation between acuity and crowding. Two clinical conditions-anisometropic amblyopia and apperceptive agnosia-each selectively impair either acuity A or the spacing:acuity ratio S/A, not both. Furthermore, when we specifically estimate crowding, we find a double dissociation between acuity and crowding. Models of human object recognition will need to

  4. 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

    2013-06-20

    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. Blinded, diagnostic test study. Single centre (University) in Auckland, New Zealand. 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. Visual acuity measured under a number of conditions. 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). 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.

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

    Science.gov (United States)

    Irman Grčar, Irena; Grčar, Rok; Pfeifer, Vladimir

    2017-01-01

    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. PMID:28243608

  6. 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.

  7. Reliability of Snellen charts for testing visual acuity for driving: prospective study and postal questionnaire.

    Science.gov (United States)

    Currie, Z; Bhan, A; Pepper, I

    2000-10-21

    To assess the ability of patients with binocular 6/9 or 6/12 vision on the Snellen chart (Snellen acuity) to read a number plate at 20.5 m (the required standard for driving) and to determine how health professionals advise such patients about driving. Prospective study of patients and postal questionnaire to healthcare professionals. 50 patients with 6/9 vision and 50 with 6/12 vision and 100 general practitioners, 100 optometrists or opticians, and 100 ophthalmologists. Ophthalmology outpatient clinics in Sheffield. Ability to read a number plate at 20.5 m and health professionals' advice about driving on the basis of visual acuity. 26% of patients with 6/9 vision failed the number plate test, and 34% with 6/12 vision passed it. Of the general practitioners advising patients with 6/9 vision, 76% said the patients could drive, 13% said they should not drive, and 11% were unsure. Of the general practitioners advising patients with 6/12 vision, 21% said the patients could drive, 54% said they should not drive, and 25% were unsure. The level of acuity at which optometrists, opticians, and ophthalmologists would advise drivers against driving ranged from 6/9(-2) (ability to read all except two letters on the 6/9 line of the Snellen chart) to less than 6/18. Snellen acuity is a poor predictor of an individual's ability to meet the required visual standard for driving. Patients with 6/9 vision or less should be warned that they may fail to meet this standard, but those with 6/12 vision should not be assumed to be below the standard.

  8. Crowding is proportional to visual acuity in young and aging eyes.

    Science.gov (United States)

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

    2015-01-01

    Spatial crowding decreases object recognition and conscious visual perception in clutter. In a previous study we used brief presentation times to reveal the effects of a crowded presentation in the fovea. Here we aimed to test the relationships between varying visual acuity (VA) and crowding in the fovea, under the assumption that in uncorrected presbyopia, the processing is relatively normal, whereas the retinal input is blurred. We tested whether normal participants whose near VA is gradually reduced due to age-related deterioration (presbyopia, or "aging eye") will show an acuity-dependent increase in foveal crowding. We used brief presentations and acuity-threshold letter targets in order to magnify the crowding-effect amplitude in the fovea. A total of 195 participants with an age range of 20-68 years and an average of 44.3 ± 11.7 years (M ± SD) were divided into four age groups, all without any optical correction for the near distance. Our findings show that crowding is proportional to VA. This proportionality is affected by VA-age dependency, with a nonlinear S-shaped pattern: A steep VA reduction begins to develop, which is compatible with the normal onset age of presbyopia symptoms and a saturation in the VA-age dependency in the oldest age group, for which we propose a VA-eccentricity account. Finally, there is a high variance in the crowding amplitude in the young, even before the onset age of presbyopia symptoms, suggesting crowding conditions with limited presentation times as a highly sensitive measure of VA, which predicts visual performance in complex tasks, such as reading.

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

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    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.

  10. The Exact Estimation of Visual Acuity by VEP Technology:A Report of 726 Cases of Eye Injury

    Institute of Scientific and Technical Information of China (English)

    饶广勋; 吴炳为; 张玲莉

    2010-01-01

    This study explored the accuracy of using visual evoked potentials(VEP)technology for visual acuity estimation.The enrolled 726 patients with post-traumatic unilateral decrease in visual acuity included the injured eyes served as the experimental group,and the healthy eyes as the control group.The least signal visual angle(LSVA),and amplitude and latency of P100 were chosen as test indexes.The results under different experimental conditions were recorded by PRVEP technology.All data collected were processed...

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

    OpenAIRE

    N. N. Temirov; N. E. Temirov

    2015-01-01

    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...

  12. Effect of macular photocoagulation on visual acuity of Omani patients with clinically significant macular edema

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    Zafar A Zaidi

    2009-01-01

    Full Text Available Background: The aim of this study was to determine the effect of macular laser treatment on the visual acuity (VA of Omani diabetic patients with clinically significant macular edema (CSME. Visual outcome was also correlated with duration and control of diabetes and presence or absence of hypertension and hyperlipidemia. Materials and Methods: This is a retrospective noncomparative cohort study involving 101 eyes of 72 Omani diabetic patients. Change in VA was determined using Snellen′s VA chart. The mean duration of follow-up was approximately 21 months (range, 16-24 months. Results: 29.7% of the patients maintained their vision, 35.6% showed improvement, whereas 34.7% showed a decrease in their vision. Positive visual outcome showed a statistically significant direct relationship with tight control of diabetes and absence of hypertension and an inverse relationship with the duration of diabetes. Presence of hyperlipedemia did not show a statistically significant relationship with positive visual outcome. However, it showed a trend to better visual outcome in the absence of hyperlipedemia. Peak incidence of macular edema was seen at the age of 52.3 years. Conclusion: Macular photocoagulation was found to be an effective method of treatment for CSME among Omani diabetic patients, which has resulted in a positive visual outcome in 65.3% of the patients (stable and improved vision. Effective control of diabetes, duration of diabetes, and hypertension are the factors which influence the postlaser visual outcome.

  13. 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.

  14. 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.

  15. Investigating photoreceptor densities, potential visual acuity, and cone mosaics of shallow water, temperate fish species.

    Science.gov (United States)

    Hunt, D E; Rawlinson, N J F; Thomas, G A; Cobcroft, J M

    2015-06-01

    The eye is an important sense organ for teleost species but can vary greatly depending on the adaption to the habitat, environment during ontogeny and developmental stage of the fish. The eye and retinal morphology of eight commonly caught trawl bycatch species were described: Lepidotrigla mulhalli; Lophonectes gallus; Platycephalus bassensis; Sillago flindersi; Neoplatycephalus richardsoni; Thamnaconus degeni; Parequula melbournensis; and Trachurus declivis. The cone densities ranged from 38 cones per 0.01 mm(2) for S. flindersi to 235 cones per 0.01 mm(2) for P. melbournensis. The rod densities ranged from 22800 cells per 0.01 mm(2) for L. mulhalli to 76634 cells per 0.01 mm(2) for T. declivis and potential visual acuity (based on anatomical measures) ranged from 0.08 in L. gallus to 0.31 in P. melbournensis. Higher rod densities were correlated with maximum habitat depths. Six species had the regular pattern of four double cones arranged around a single cone in the photoreceptor mosaic, while T. declivis had only rows of double cones. P. melbournensis had the greatest potential ability for detecting fine detail based on eye anatomy. The potential visual acuity estimates and rod densities can be applied to suggest the relative detection ability of different species in a commercial fishing context, since vision is a critical sense in an illuminated environment for perceiving an oncoming trawl.

  16. 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.

  17. Night vision goggle (NVG) visual acuity under ideal conditions with various adjustment procedures.

    Science.gov (United States)

    DeVilbiss, C A; Antonio, J C; Fiedler, G M

    1994-08-01

    Night operations involve diverse mission areas and require an increased reliance on the use of night vision devices, such as night vision goggles (NVG's). Any reduction in goggle or visual performance which goes undetected can have a serious effect on flight safety and operational capability. Under controlled lighting conditions, a crewmember should be able to obtain the best possible goggle performance, and to determine if the goggle is functioning properly. These data represent a sample of 218 current USAF aircrew members representing all crew positions in both rotary and fixed-wing aircraft. Three measurements of goggle performance, expressed as NVG visual acuity, were obtained. The first measure, obtained after crewmembers adjusted the goggles with their usual adjustment methods, showed that they routinely obtain less than optimal acuity levels; i.e., averaging between 20/50 and 20/55. The second measure, taken when the NVG Resolution Chart was provided to augment their "usual" method of adjustment, showed improved performance; i.e., averaging 20/45. The third measure, taken following participation in an NVG Adjustment Procedures class, showed the greatest improvement, averaging between 20/35 and 20/40. In summary, it is reasonable to conclude that aircrew members who are able to obtain the best possible performance for their NVG's under controlled preflight conditions will obtain the best possible goggle performance under the widely varying flight conditions.

  18. 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

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    Nurul Farhana Abu Bakar

    2014-01-01

    Full Text Available Context: Children with learning disabilities might have difficulties to communicate effectively and give reliable responses as required in various visual function testing procedures. Aims: 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. Materials and Methods: 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. Results: 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 < 0.001 but not in Cambridge Crowding Cards, Lang Stereo test II and CVTME. Conclusion: Non verbal or "matching" approaches were found to be more superior in testing visual functions in children with learning disabilities. Modifications of vision testing procedures are essential for children with learning disabilities.

  19. Effect of myopic defocus on static visual acuity and dynamic visual acuity%近视性离焦对静态视力和动态视力的影响

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    邓军; 保金华; 陈浩

    2011-01-01

    Background Researches have suggested that the defocus can induce the change of static visual acuity,but whether it produce influence on dynamic visual acuity is not clear.Objective This study was to investigate the impact of myopic defocus on static visual acuity and dynamic visual acuity and explore the essential difierence between static visual acuity and dynamic visual acuity. Methods Forty volunteers were enrolled in this trial.including 20 adults with the age of 27.4±1.64 years and 20 children with the age of 11.70+1.49 years.All the eyes of subjects received regular examined to excluded the eye disease with the best corrected vision of ≥1.0 D,astigmatism of ≤0.75 D and anisometropia <1.50 D.+1.00 D,+1.50 D,+2.00 D,+2.50 D slasses were ware respectively for the defocus on the foundation of full correction.Dynamic visual acuity was inspected by using selfmade DVA-I training software.and static visual acuity wag tested by static visual acuity chart (Precision Vision,CAT.NO.2125).This clinical trial complied with the Helsinki Declaration and obtained the approval of Ethic Committee of Wenzhou Medical College.Written informed consent was received from each individual prior to the protocol. Results The dynamic and static visual acuities were gradually decreased with the elevation of defocus (F=506.907,P=0.000).No significant differences were found between static visual acuity and dynamic visual acuity in adult or children at various defocus(P>0.05).The regression linear analysis showed that a positive correlation between static visual acuity with defoeus(R2=0.819,t=26.72,P=0.000) or dynamic visual acuity with defoeus(R2=0.826,t=27.42,P=0.000).The slope and intercept between defocus with static visual acuity were steeper than that between defocus and dynamic visual acuity (slope:F=34.18,P=0.000;intercept:F=1005.56,P=0.001). Conclusion The effect of defocus on static visual acuity is different from that of dynamic visual acuity.It could be speculated that

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

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    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.

  1. Optimización de la agudeza visual en las FAS Optimization of visual acuity in Spanish Armed Forces

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    J. Medin Catoira

    2011-06-01

    Full Text Available Introducción: La existencia de una agudeza visual óptima es requerida para la mayor parte de las actividades del personal de las FAS, pero se hace estrictamente necesaria en el despliegue dentro del teatro de operaciones internacional. Material y Método: Hemos realizado un estudio sobre el registro de la agudeza visual en un grupo aleatorio (n = 54 durante los reconocimientos periódicos de permanencia realizados en nuestro centro. Resultados: Sólo 3 casos (5,56% reconocen ver mal; 20 (37,04% han utilizado corrección en algún momento de su vida; 12 (22,22% utilizan corrección; en 32 (60,38% sería altamente recomendable el uso de corrección. Ningún caso (0% de los usuarios de corrección posee corrección de repuesto (en gafas. Conclusión: Se hace incidencia en el control y registro de los parámetros visuales en el personal de las FAS, especialmente en actividades de riesgo y despliegue internacional.Introduction: The existence of an optimal visual acuity is required for most of the activities of the membrers of the Armed Forces, but it is strictly necessary in the deployment within the international theater. Materials and Methods: We conducted a study of visual acuity in a random group of periodical surveys in our center. Results: Only 3 cases (5.56% recognize look bad; 20 (37.04% have used correction at some point in their lives; 12 (22.22% used correction; in 32 cases (60.38% was highly recommended the use of correction. No cases (0% of users of correction has a duplicate of it (in glasses. Conclusions: The study suggests the need for better surveillance and control of visual parameters of the Armed Forces members, especially in risky activities and international deployment.

  2. A Standardized Procedure and Normative Values for Measuring Binocular Dynamic Visual Acuity

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    Amanda Miskewicz-Zastrow, OD

    2015-04-01

    Full Text Available Background: Binocular dynamic visual acuity (BDVA is the ability to differentiate fine details in a moving object such as seams on a pitched baseball or the rotation of a tennis ball, both of which can travel up to speeds exceeding 100 miles per hour. BDVA is one of many binocular visual measurements to examine binocular function. This study was designed to provide a standardized procedure for measuring BDVA and normal values for a sample population. Previous studies have used different techniques for measurement, and thus have no normative data for comparison. Methods: The BCVA attachment to the Bernell Rotation Trainer was used to measure BDVA in 22 subjects (10 females and 12 males between the ages of 23 and 30. Only subjects with a refractive error between +1.00 D and -7.00 D (spherical equivalent and with best corrected visual acuity of 20/20 or better were able to participate in the study. BDVA was recorded at three different rotation speeds (29 RPM, 24 RPM, and 16 RPM. At each RPM, accuracy and the time to completion of all nine lines were measured. The subjects were also asked to complete a questionnaire designed to evaluate factors that may influence the BDVA results. Results: A decrease in RPM resulted in a corresponding decrease in the subject’s completion time and an increase in accuracy. The same trend was seen when comparing males and females; however, the females’ accuracy was lower and the time was greater when compared to the males, but these were not statistically significant. Conclusions: This was the first study designed to use the Bernell Rotation Trainer to quantitatively measure BDVA in a standardized way. Our results showed similar trends in both males and females. In addition, this study provides a strong foundation for future research, such as comparing BDVA of athletes and non-athletes, or comparing athletes with different skill levels, or comparing athletes who participate in different sports.

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

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

    2015-06-01

    A recent threefold increase in laser treatment for advanced retinopathy of prematurity (ROP) triggered a nationwide preschool ophthalmic and developmental status among extremely preterm survivors. Here, we discuss refraction and visual acuity. Survivors (n = 178) from a national birth cohort (February 2004 to March 2006) of gestational age refraction and keratometry were achieved by Retinomax autokeratorefractor and visual acuities by symbol recognition (HOTV, logMAR). 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 was 0.1 in FT and 0.2 in PT, in Snellen equivalents 0.8 and 0.63. Snellen acuity ≤0.5 occurred across the ROP subgroups, but mainly in those with at least ROP stage 3. Two children had low vision. The overall fair outcome for refraction and function is in accordance with other recent northern Europe experience. The results differ in particular from the poorer ophthalmic outcomes reported in the pioneer US treatment studies (cryotherapy for ROP and ETROP). The diode laser ablations (n = 32) appeared effective in our series; except one child, all treated subjects had good or fair social vision at the age of 4 years. © 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  4. Comparison of distance and near visual acuity in patients with vision loss due to cataract.

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    Mercado, Carmel L; Doroslovački, Pavle; Wang, Jiangxia; Siddiqui, Aazim A; Kolker, Andrew F; Kolker, Richard J

    2017-02-01

    The purpose of this study was to assess whether there is a disparity in distance and near best-corrected visual acuity (BCVA) in cataract eyes. 102 patients with cataract (N = 121 eyes) were seen in clinic between January and November 2013 at the Wilmer Eye Institute Comprehensive Eye Service. An age-related macular degeneration (ARMD) group (N = 27 eyes) was also identified for comparison. Distance and near BCVA were measured as part of the standard ophthalmic evaluation. Snellen measurements were converted to their LogMAR equivalents for statistical analysis. Near was better than distance BCVA with mean difference of 1.38 lines (P distance BCVA disparity is a statistically significant finding seen with cataracts. This may have further implications in patients with both cataract and ARMD as the presence of disparity may suggest a cataract etiology playing a greater role in vision loss. This comparison may be useful for surgical prognostication and as a quick triage tool in conjunction with, or in place of, a potential acuity meter and dilated near-pinhole test.

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

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    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.

  6. Comparison of visual acuity results in preschool children with lea symbols and bailey-lovie e chart

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    Nijil Sanker

    2013-01-01

    Full Text Available Purpose: To compare visual acuity with two visual acuity charts in preschool children. Materials and Methods: Visual acuity measurement with Lea symbols and Bailey-Lovie tumbling E chart was performed on children between 3 and 6 years of age. Visual acuity data from the two charts were analyzed with Bland-Altman plot to determine the limits of agreement. The Wilcoxon signed test was performed in children aged 3-4 years and in children aged 5-6 years separately to evaluate the influence of age. The inter-eye difference between the two charts were further analyzed with the paired t-test. A p value < 0.05 was considered statistically significant. Results: A total of 47 children were enrolled for the study. The average logarithm of the Minimum Angle of Resolution (LogMAR monocular visual acuity with Lea symbols (0.17 ± 0.13 was better than the Bailey-Lovie tumbling E chart (0.22 ± 0.14. The mean difference between Bailey-Lovie tumbling E chart and Lea symbol chart was 0.05 ± 0.12 in logMAR units. A second analysis eliminating outliers showed the same result but lower differences (n = 43, 0.05 ± 0.05 logMAR units. Visual acuity results between the two charts in children aged 3-4 years showed a significant difference (p = 0.000, but not for children aged 5-6 years (p = 0.059. Inter-eye differences between the two charts was not statistically significant (p = 0.77. Conclusion: Bailey-Lovie tumbling E chart is comparable to the Lea symbols chart in pre-school children. But preference should be given to Lea symbols for children aged 3-4 years as the symbols are more familiar than a directional test for this age group.

  7. [Laser pointers are not toys; eye injury with permanent loss of visual acuity].

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    Keunen, Jan E E; Delbecq, Ann-Laure M H; Cruysberg, J R M Hans; van Meurs, Jan C; Gan, Ivan M; Berendschot, Tos T J M

    2014-01-01

    In the nineteen-nineties, there was much hype in the European media about presumed laser pointer maculopathy. However, the recent introduction of more powerful and therefore more dangerous laser pointers and their easy availability on the internet necessitates vigilance on the issue. This is an urgent matter, as here we report three cases of proven maculopathy due to an unsafe laser pointer. Three boys aged 13, 9 and 12 years used an unsafe laser pointer as a toy and looked repeatedly into the pointer, resulting in a permanent reduction in visual acuity due to macular damage. Laser pointers are not designed to be children's toys or instruments to annoy people in a crowd. Health authorities and the ophthalmic community should be aware of the potential danger of improper use of high-output laser pointers and warn the general public before the widespread availability of unsafe laser pointers and consequently laser pointer-induced macular damage becomes a true social problem.

  8. 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.

  9. 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.

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

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    Miyata, Kimie; Yoshikawa, Tadanobu; Mine, Masashi; Nishi, Tomo; Okamoto, Nozomi; Ueda, Tetsuo; Kawasaki, Ryo; Kurumatani, Norio; Ogata, Nahoko

    2017-01-01

    Abstract 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. PMID:28451472

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

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    Anusha Y. Sukha

    2017-01-01

    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 < 0.0001. Mean-contrast VA at each contrast level between the age groups indicated that mean-contrast VA were not significantly different between the young and middle-age groups (p > 0.05 but were statistically different between the young and elderly groups (p < 0.01. Only mean-contrast VA 10% was significantly different

  12. Bifocals in children with Down syndrome (BiDS) - visual acuity, accommodation and early literacy skills.

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    Nandakumar, Krithika; Leat, Susan J

    2010-09-01

    Reduced accommodation is seen in children and young adults with Down syndrome (DS), yet providing bifocals has not become a routine clinical management. This study investigates the impact of bifocals on visual function, visual perceptual and early literacy skills in a group of school children with DS.   In this longitudinal study, each child was followed for 5months with single-vision (SV) lenses after which bifocals were prescribed if required, based on their accommodative response. Visual acuity (VA), accommodation, perceptual and literacy skills were measured after adaptation to bifocals and 5months later. Educational progress and compliance with spectacle wear were assessed through school and parental reports.   Fourteen children and young adults with DS participated in the study. Eighty-five percent required bifocals with additions ranging from +1.00D to +3.50D. The mean near logMAR VA improved with bifocals (p=0.007) compared to SV lenses. Repeated measures anova showed that there was more accurate focus (less accommodative lag) through the bifocals (p=0.002), but no change in the accommodation exerted through the distance portion compared to SV lenses (p=0.423). There was a main effect of time on sight words (p=0.013), Word Identification (p=0.047), Visual Closure (p=0.006) and Visual Form Constancy (p=0.001). Bifocals provide clearer near vision in DS children with reduced accommodation. This is shown by improved VA and decreased lag of accommodation. The results indicate that the improvement in VA results in improved scores in early literacy skills. Better compliance with bifocals over SV lenses was seen. © 2010 The Authors. Journal compilation © 2010 Acta Ophthalmol.

  13. Comparison of visual acuity levels in pediatric patients with amblyopia using Wright figures, Allen optotypes, and Snellen letters.

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    Mocan, Mehmet Cem; Najera-Covarrubias, Mario; Wright, Kenneth W

    2005-02-01

    To compare and correlate the clinical performance of Wright figures in visual acuity assessments of pediatric patients with amblyopia to those obtained through Allen cards and Snellen letters. Best-corrected visual acuity of 26 amblyopic children were measured with the Wright figures(c), Snellen letters, and isolated Allen optotypes, respectively. Amblyopia was defined as two lines of visual acuity difference or a visual acuity level of 20/30 or lower as determined by Snellen chart. The results were evaluated for statistical intergroup differences using the Wilks' Lambda multivariate analysis of variance and for correlation using the Pearson correlation coefficient test. The mean age of the subjects was 8.27 +/- 2.46 years (range: 5 to 15 years). The mean logMAR values for the Wright figures(c), Snellen letters, and Allen optotypes were 0.40 +/- 0.20, 0.47 +/- 0.23, and 0.29 +/- 0.28, respectively. When compared with Snellen letters, the Wright figures correlated to a higher degree ( r = 0.46, P Snellen letter testing, the sensitivity of Wright figures(c) and Allen cards in diagnosing amblyopic eyes was 87.0 and 56.5%, respectively ( P = 0.016). Wright figures, designed primarily to evaluate the vision in the preliterate pediatric population, correlate more closely to Snellen letters and have a higher rate of correctly identifying amblyopia than isolated Allen optotypes in pediatric patients.

  14. Prospective evaluation of visual acuity assessment: a comparison of snellen versus ETDRS charts in clinical practice (An AOS Thesis).

    Science.gov (United States)

    Kaiser, Peter K

    2009-12-01

    first, to prospectively compare visual acuity (VA) scores obtained with Snellen charts versus Early Treatment Diabetic Retinopathy Study (ETDRS) charts in a "real world" retinal practice, and second, to see if there was a difference in visual acuity measurements obtained with ETDRS charts starting at 4 or 2 meters. Prospective, consecutive evaluation of patients who underwent best-corrected visual acuity testing of their right eye performed at a single seating by the same experienced, certified vision examiner in the same room with standardized low light conditions using a projected Snellen chart at 20 feet, and two different back-illuminated ETDRS charts placed 4 and 2 meters from the patient. One hundred sixty-three eyes were included in the study. The mean Snellen VA was 0.67 logMAR (20/94), ETDRS VA at 4 meters was 0.54 logMAR (~20/69), and ETDRS VA at 2 meters was 0.51 logMAR (~20/65). The mean difference was 6.5 letters better on the ETDRS chart (P=.000000001). As the VA worsened, there was increased variability between the charts and the mean discrepancy between charts also increased. Subgroup analysis revealed the greatest difference between charts was in the poor vision subgroup (Snellen charts. The difference was greatest with poor visual acuity (<20/200) and in patients with exudative AMD. Thus, caution should be exercised when comparing data using the different charts.

  15. Comparative study of visual acuity and aberrations after intralase femtosecond LASIK: small corneal flap versus big corneal flap

    Institute of Scientific and Technical Information of China (English)

    Ya-Li; Zhang; Lei; Liu; Chang-Xia; Cui; Ming; Hu; Zhao-Na; Li; Li-Jun; Cao; Xiu-Hua; Jing; Guo-Ying; Mu

    2014-01-01

    AIM:To study the effects of different flap sizes on visual acuity, refractive outcomes, and aberrations after femtosecond laser for laser keratomileusis (LASIK). ·METHODS: In each of the forty patients enrolled, 1 eye was randomly assigned to receive treatment with a 8.1mm diameter corneal flap, defined as the small flap, while the other eye was treated with a 8.6mm diameter corneal flap, defined as the big flap. Refractive errors, visual acuity, and higher -order aberrations were compared between the two groups at week 1, month 1 and 3 postoperatively. · RESULTS: The postoperative refractive errors and visual acuity all conformed to the intended goal. Postoperative higher -order aberrations were increased, especially in spherical aberration (Z12) and vertical coma (Z7). There were no statistically significant differences between the two groups in terms of postoperative refractive errors, visual acuity, root mean square of total HOAs (HO -RMS), trefoil 30° (Z6), vertical coma (Z7), horizontal coma (Z8), trefoil 0° (Z9), and spherical aberration (Z12) at any point during the postoperative follow-up. ·CONCLUSION: Both the small and big flaps are safe and effective procedures to correct myopia, provided the exposure stroma meets the excimer laser ablations. The personalized size corneal flap is feasible, as we can design the size of corneal flap based on the principle that the corneal flap diameter should be equal to or greater than the sum of the maximum ablation diameter and apparatus error.

  16. Clinical effect of Conbercept to improve visual acuity of patients with wet age-related macular degeneration

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    Zhen-Liu Zhu

    2015-11-01

    Full Text Available AIM:To observe the clinical effect of conbercept to improve visual acuity of patients with wet age-related macular degeneration(wAMD. METHODS:Seventy patients(70 eyeswith wAMD were selected and divided into study group and control group according to different therapies. The control group received intravitreal injection of triamcinolone acetonide. The study group adopted the intravitreal injection with conbercept. Uncorrected visual acuity, the score of reading ability, the central macular thickness(CMTand the macular pigment optical density of two groups before and after treatment was observed. RESULTS: the visual acuity of study group was 0.47±0.11 and 0.60±0.14 respectively at 6mo and 1a after treatments, those of control group were 0.27±0.09 and 0.30±0.15. The differences between the two groups at the two points were statistically significant(PPPCONCLUSION:The intravitreal injection with conbercept has a favorable clinical effect on the treatment of wAMD, Which can greatly improve the uncorrected visual acuity and is worthy promotion.

  17. 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.

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

    Science.gov (United States)

    Shibru, Getahun; Mulugeta, Abiy

    2017-01-01

    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 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. PMID:28706737

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

    Science.gov (United States)

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

    2017-01-01

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

  20. A neural computation for visual acuity in the presence of eye movements.

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    Xaq Pitkow

    2007-12-01

    Full Text Available Humans can distinguish visual stimuli that differ by features the size of only a few photoreceptors. This is possible despite the incessant image motion due to fixational eye movements, which can be many times larger than the features to be distinguished. To perform well, the brain must identify the retinal firing patterns induced by the stimulus while discounting similar patterns caused by spontaneous retinal activity. This is a challenge since the trajectory of the eye movements, and consequently, the stimulus position, are unknown. We derive a decision rule for using retinal spike trains to discriminate between two stimuli, given that their retinal image moves with an unknown random walk trajectory. This algorithm dynamically estimates the probability of the stimulus at different retinal locations, and uses this to modulate the influence of retinal spikes acquired later. Applied to a simple orientation-discrimination task, the algorithm performance is consistent with human acuity, whereas naive strategies that neglect eye movements perform much worse. We then show how a simple, biologically plausible neural network could implement this algorithm using a local, activity-dependent gain and lateral interactions approximately matched to the statistics of eye movements. Finally, we discuss evidence that such a network could be operating in the primary visual cortex.

  1. Retrospective, controlled observational case study of patients with central retinal vein occlusion and initially low visual acuity treated with an intravitreal dexamethasone implant.

    Science.gov (United States)

    Winterhalter, Sibylle; Vom Brocke, Gerrit Alexander; Pilger, Daniel; Eckert, Annabelle; Schlomberg, Juliane; Rübsam, Anne; Klamann, Matthias Karl; Gundlach, Enken; Dietrich-Ntoukas, Tina; Joussen, Antonia Maria

    2016-10-27

    Patients with initially low visual acuity were excluded from the therapy approval studies for retinal vein occlusion. But up to 28 % of patients presenting with central retinal vein occlusion have a baseline BCVA of less than 34 ETDRS letters (0.1). The purpose of our study was to assess visual acuity and central retinal thickness in patients suffering from central retinal vein occlusion and low visual acuity (central retinal vein occlusion, which were treated with a dexamethasone implantation. Visual acuity, central retinal thickness and intraocular pressure were measured monthly. Analyses were performed separately for eyes with visual acuity central retinal thickness, however, was reduced in both groups, falling from 694 to 344 μm (1 month; p = 0.003,) to 361 μm (2 months; p = 0,002) and to 415 μm (3 months; p = 0,004) in the low visual acuity group and from 634 to 315 μm (1 month; p central retinal vein occlusion and initially low visual acuity, a dexamethasone implantation can lead to an important reduction of central retinal thickness but may be of limited use to increase visual acuity.

  2. Prospective Evaluation of Visual Acuity Assessment: A Comparison of Snellen Versus ETDRS Charts in Clinical Practice (An AOS Thesis)

    Science.gov (United States)

    Kaiser, Peter K.

    2009-01-01

    Purpose: The purpose of this study was twofold: first, to prospectively compare visual acuity (VA) scores obtained with Snellen charts versus Early Treatment Diabetic Retinopathy Study (ETDRS) charts in a “real world” retinal practice, and second, to see if there was a difference in visual acuity measurements obtained with ETDRS charts starting at 4 or 2 meters. Methods: Prospective, consecutive evaluation of patients who underwent best-corrected visual acuity testing of their right eye performed at a single seating by the same experienced, certified vision examiner in the same room with standardized low light conditions using a projected Snellen chart at 20 feet, and two different back-illuminated ETDRS charts placed 4 and 2 meters from the patient. Results: One hundred sixty-three eyes were included in the study. The mean Snellen VA was 0.67 logMAR (20/94), ETDRS VA at 4 meters was 0.54 logMAR (~20/69), and ETDRS VA at 2 meters was 0.51 logMAR (~20/65). The mean difference was 6.5 letters better on the ETDRS chart (P=.000000001). As the VA worsened, there was increased variability between the charts and the mean discrepancy between charts also increased. Subgroup analysis revealed the greatest difference between charts was in the poor vision subgroup (<20/200) with a difference of 0.2 logMAR (10 letters; P=.0000002). Patients with exudative age-related macular degeneration (AMD) had the greatest disparity on vision testing, but patients with dry AMD and diabetic retinopathy also exhibited significant differences. Conclusions: Visual acuity scores were significantly better on ETDRS charts compared to Snellen charts. The difference was greatest with poor visual acuity (<20/200) and in patients with exudative AMD. Thus, caution should be exercised when comparing data using the different charts. PMID:20126505

  3. Ethanol consumption impairs vestibulo-ocular reflex function measured by the video head impulse test and dynamic visual acuity.

    Science.gov (United States)

    Roth, Thomas N; Weber, Konrad P; Wettstein, Vincent G; Marks, Guy B; Rosengren, Sally M; Hegemann, Stefan C A

    2014-01-01

    Ethanol affects many parts of the nervous system, from the periphery to higher cognitive functions. Due to the established effects of ethanol on vestibular and oculomotor function, we wished to examine its effect on two new tests of the vestibulo-ocular reflex (VOR): the video head impulse test (vHIT) and dynamic visual acuity (DVA). We tested eight healthy subjects with no history of vestibular disease after consumption of standardized drinks of 40% ethanol. We used a repeated measures design to track vestibular function over multiple rounds of ethanol consumption up to a maximum breath alcohol concentration (BrAC) of 1.38 per mil. All tests were normal at baseline. VOR gain measured by vHIT decreased by 25% at the highest BrAC level tested in each subject. Catch-up saccades were negligible at baseline and increased in number and size with increasing ethanol consumption (from 0.13° to 1.43° cumulative amplitude per trial). DVA scores increased by 86% indicating a deterioration of acuity, while static visual acuity (SVA) remained unchanged. Ethanol consumption systematically impaired the VOR evoked by high-acceleration head impulses and led to a functional loss of visual acuity during head movement.

  4. 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.

  5. Nerve growth factor eye drops improve visual acuity and electrofunctional activity in age-related macular degeneration: a case report

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    Alessandro Lambiase

    2009-12-01

    Full Text Available Age-related macular degeneration (ARMD is a severe disease affecting visual function in the elderly. Currently available surgical and medical options do not guarantee a significant impact on the outcome of the disease. We describe the effects of nerve growth factor eye drop treatment in a 94 years old female with ARMD, whose visual acuity was progressively worsening in spite of previous surgical and medical treatments. NGF eye drops improved visual acuity and electrofunctional parameters as early as 3 months after initiation of treatment. These results are in line with previous reports on a neuroprotective effect of NGF on retinal cells and on NGF eye drops bioavailability in the retina and optic nerve. No side effects were observed after five years of follow-up, suggesting that topical NGF treatment may be a safe and effective therapy for ARMD.

  6. 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.

  7. 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.

  8. Aircrew visual acuity viewing with different night vision goggle eyepiece diopter settings

    Science.gov (United States)

    Angel, Share-Dawn P.; Baldwin, J. Bruce

    2004-09-01

    The AN/AVS-9 night vision goggle (NVG) has an eyepiece lens that can be adjusted from +2 to -6 diopters (D). We have shown previously1,2,3 that on average NVG users tend to select about -1D, with a range of +0.5D to -4D3. This study was designed to evaluate NVG visual acuity (NVG VA) and subjective ratings for a range of diopter settings including user-selected and three fixed settings of -0.25D, -1D and -2D. Twenty-one experienced USAF Special Operations aircrew members, including 15 pilots, served as subjects. The median user-selected setting was -1.25D and ranged from +0.5D to -3.5D. Only 2 of the 21 subjects had user-selected NVG VA significantly better than a fixed setting of -1D. Of those two, one was not wearing prescribed glasses and the other was 49 years old, presbyopic, and could not focus through the -1D lenses. Subjective ratings and NVG VA indicated that most people could fly with a fixed setting of -1D for each eye, although two individuals needed different diopter settings for the right and left eyes. The new Panoramic NVG (PNVG) has a fixed eyepiece focus of -1D. Results suggest the PNVG should have a limited set of accessory lenses available.

  9. MEASUREMENTS OF VISUAL ACUITY, CARDIOVASCULAR AND ANTHROPOMETRIC PARAMETERS AMONG NKWU' CONSUMERS IN MID-WESTERN NIGERIA

    Institute of Scientific and Technical Information of China (English)

    ONYESOM I; NAIHO A

    2006-01-01

    'Nkwu' is the generic name for all kinds of alcoholic liquors locally brewed from palm sap. It is the beverage commonly consumed in the mid-western and eastern Nigeria. No information is yet available on the parameters, body mass index and visual acuity. Seven hundred and thirty-eight apparently healthy-looking, and most suitable men, who gave their consent were selected after interview. The results showed that long induced significant increase in mean blood pressure parameters (systolic blood pressure, diastolic blood pressure, mean arterial blood pressure and pulse rate) in older men (41-50 and 51-60 age brackets) when compared with their respective age-matched control (non-drinkers) mean value. Such drinking pattern also significantly (P<0.05) reduced their body mass index when compared with similar control values. By extension, it can be cardiovascular dysfunction and nutritional complications. However, further epidemiological, biochemical and post-mortem investigations are required in order to generate data and information needed to alert the communities, and possibly advise the lay public.

  10. Baseline predictors of visual acuity and retinal thickness in patients with retinal vein occlusion.

    Science.gov (United States)

    Kim, Sang Jin; Yoon, Young Hee; Kim, Ha Kyoung; Yoon, Hee Seong; Kang, Se Woong; Kim, June-Gone; Park, Kyu Hyung; Jo, Young Joon; Lee, Dong-Hoon

    2015-04-01

    This study investigated the baseline predictors of best corrected visual acuity (BCVA) and central retinal thickness (CRT) at 6 months in patients with treatment-naïve branch retinal vein occlusion (BRVO) and central retinal vein occlusion (CRVO). This multicenter, interventional case series included 208 BRVO and 123 CRVO patients with follow-up period of 6 months or more. Outcome measures of BCVA (logMAR) included absolute change from baseline and a gain or loss of ≥ 0.3 from baseline. Outcome measures of CRT included absolute change from baseline and a measurement of ≤ 250 µm or ≥ 400 µm at 6 months. Univariate and multiple regression analyses were done to find baseline predictors. For BRVO, younger age, worse baseline BCVA, and shorter duration of symptom were associated with more gain in BCVA. For CRVO, worse baseline BCVA was associated with more gain in BCVA. For CRT outcomes, higher baseline CRT predicted greater decrease at 6 months in both BRVO and CRVO. Younger age and better baseline BCVA were associated with an increased likelihood of measurement of a ≤ 250 µm outcome for BRVO and CRVO, respectively. For CRVO, smoking was associated with greater decrease from baseline and decreased likelihood of measurement of a CRT ≥ 400 µm at 6 months. In conclusion, several baseline factors including age, symptom duration, and baseline BCVA and CRT are associated with BCVA and CRT outcomes at 6 months, which may help to predict disease course for RVO patients.

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

    Science.gov (United States)

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

    2017-01-01

    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. PMID:28203479

  12. Distance stereo acuity improvement in intermittent exotropic patients following strabismus surgery.

    Science.gov (United States)

    O'Neal, T D; Rosenbaum, A L; Stathacopoulos, R A

    1995-01-01

    To determine whether distance stereo acuity improved following strabismus surgery in patients with intermittent exotropia, we tested 20 patients (5 to 87 years old) preoperatively and postoperatively using the Mentor BVAT II Video acuity tester (Santa Barbara, Calif) and binocular visual system. Acuity improved in 75% as assessed by contour circles and in 45% as assessed by random dot E tests at distance. Our results suggest that surgical realignment of intermittent exotropia restores distance stereo acuity. We conclude that measuring distance stereo acuity offers valuable information in the evaluation of the intermittent exotropic patient.

  13. 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

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

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    Alastair eHaigh

    2013-06-01

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

  15. Comment on amniotic membrane covering promotes healing of cornea epithelium and improves visual acuity after debridement for fungal keratitis

    Institute of Scientific and Technical Information of China (English)

    Ahmet; Tas; Abdullah; Ilhan; Umit; Yolcu; Uzeyir; Erdem

    2015-01-01

    <正>Dear Editor,We congratulate Zeng et al[1]for their study entitled"Amniotic membrane covering promotes healing of cornea epithelium and improves visual acuity after debridement for fungal keratitis".The authors endeavored to present an alternative method for ophthalmologists in the treatment of a challenging case.We would like to express our reservations and ask for the attitudes of the authors about

  16. Macular edema in central retinal vein occlusion: correlation between optical coherence tomography, angiography and visual acuity.

    Science.gov (United States)

    Martinet, Virginie; Guigui, Benjamin; Glacet-Bernard, Agnès; Zourdani, Alain; Coscas, Gabriel; Soubrane, Gisèle; Souied, Eric H

    2012-08-01

    To analyze the characteristics and the course of macular edema secondary to central retinal vein occlusion (CRVO) using optical coherence tomography (OCT) and to determine correlations between clinical, tomographic and angiographic data, in particular including retinal ischemia. In this retrospective study, 53 consecutive patients with CRVO were included. At each follow-up visit, patients underwent complete ophthalmological examination, including best-corrected visual acuity (BCVA) and OCT. Fluorescein angiography was performed at baseline and on demand during follow-up. 243 OCTs were analyzed. Mean age was 61 years and mean follow-up 13 months. The first structural change, observed very early after the onset of the occlusion, was a diffuse increase at the level of the outer nuclear layer without change at the level of the inner retina. This early change seemed characteristic of retinal vein occlusion. Cystoid spaces were subsequently observed in all retinal layers and were combined with serous retinal detachment in 51 %. During the first 6 months, central retinal thickness was higher in ischemic CRVO (mean, 691 μm) than in non-ischemic CRVO (mean, 440 μm, p central retinal thickness without subretinal fluid) of 700 μm or greater, peripheral ischemia was present in 69 % of eyes, final BCVA was 20/200 or less in 75 % and never reached 20/40 during follow-up. The integrity of the junction of the photoreceptors' inner and outer segments was correlated with a better prognosis (p < 0.05). Foveal thickness was inversely correlated to BCVA at each visit and could have a prognostic value. OCT examination in CRVO revealed useful data for the diagnosis of CRVO and its prognosis. The largest macular edemas seemed to be the hallmark of ischemic CRVO.

  17. Stroboscopic Goggles as a Countermeasure for Dynamic Visual Acuity and Landing Sickness in Crewmembers Returning from Long-Duration Spaceflight

    Science.gov (United States)

    Rosenberg, M. J. F.; Kreutzberg, G. A.; Peters, B. T.; Reschke, M. F.

    2017-01-01

    Long-term exposure to microgravity causes sensorimotor adaptations that result in functional deficits upon returning to a gravitational environment. At landing, the vestibular system and the central nervous system, responsible for coordinating head and eye movements via the vestibulo-occular reflex (VOR), are adapted to microgravity and must re-adapt to the Earth's gravitational environment. This re-adaptation causes decrements in gaze control and dynamic visual acuity, with astronauts reporting oscillopsia and blurred vision. These effects are caused by retinal slip, or the inability to keep an image focused on their retina, which is thought to drive motion sickness symptoms experienced upon landing. Retinal slip can be estimated by dynamic visual acuity (DVA); visual acuity while in motion. Peters et al. (2011) find that DVA is worsened in astronauts by an average of 0.75 eye-chart lines one day after landing. Previously, the use of stroboscopic goggles has shown to be effective in minimizing motion sickness symptoms due to retinal slip (Reschke et al. 2007). In this study, we simulated the decrement in DVA caused by sensorimotor re-adaptation by using minifying lenses and then testing the efficacy of stroboscopic goggles in preventing retinal slip and improving DVA. Dynamic visual acuity is assessed using an oscillating chair developed in the Neuroscience Laboratory at JSC. This chair is motor-driven and oscillates vertically at 2 Hz with a vertical displacement of +/- 2 cm to simulate the vertical translations that occur while walking. As the subject is being oscillated, they are asked to discern the direction of Landolt-C optotypes of varying sizes and record their direction using a gamepad. The visual acuity thresholds are determined using an algorithm that alters the size of the optotype based on the previous responses of the subject using a forced-choice best parameter estimation that is able to rapidly converge on the threshold value. Visual acuity

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

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    Mariette Nel

    2014-08-01

    Full Text Available Introduction: Learning problems influencing the social and psychological development of children may result from poor visual acuity (VA, insufficient amplitude of accommodation and receded near point of convergence (NPC. This study assessed Grade 4 and 5 academic achievement (< 50%, 51-69% and ≥ 70% in relation to visual acuity, amplitude of accommodation and NPC. The study attempts to determine the association between these visual functions and academic performance. Methods: A cross-sectional study included a randomised sample of learners (n = 199 selected from five public schools in Bloemfontein. Information was obtained on each participant regarding history, visual acuity (distance and near, amplitude of accommodation and NPC (subjective and objective. Participant aggregates for the most recent school term and the grade average were compared to measures of these visual functions.Results: The children’s median age was 10.3 years (with range 8.7 to 12.7 years and 53.8% were female. More than 50% of children were Sesotho-speaking. Complaints revealed by his-tory-taking were mostly headaches (57.8% and eyestrain (58.3%. Regarding academic achievement, 18.6% of the learners were below average, 53.8% on average and 27.6% above average. Of the learners tested, 42.2% achieved a VA of 6/6 or better on both distance and near visual acuity. Amplitude of accommodation was less than the minimum requirements in 17.6% of participants. Approximately 30% of those below grade average did not meet the minimum requirements for amplitude of accommodation, compared to 13% of learners above grade average, which was statistically significant. More than 70% had a receded break point (> 5 cm for NPC and 85.7% had a receded recovery point (> 7 cm.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

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

    Science.gov (United States)

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

    2016-12-01

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

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

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    Regina Halfeld Furtado de Mendonça

    2012-10-01

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

  1. A novel visual facial anxiety scale for assessing preoperative anxiety

    Science.gov (United States)

    Cao, Xuezhao; Yumul, Roya; Elvir Lazo, Ofelia Loani; Friedman, Jeremy; Durra, Omar; Zhang, Xiao; White, Paul F.

    2017-01-01

    Background There is currently no widely accepted instrument for measuring preoperative anxiety. The objective of this study was to develop a simple visual facial anxiety scale (VFAS) for assessing acute preoperative anxiety. Methods The initial VFAS was comprised of 11 similarly styled stick-figure reflecting different types of facial expressions (Fig 1). After obtaining IRB approval, a total of 265 participant-healthcare providers (e.g., anesthesiologists, anesthesiology residents, and perioperative nurses) were recruited to participate in this study. The participants were asked to: (1) rank the 11 faces from 0–10 (0 = no anxiety, while 10 = highest anxiety) and then to (2) match one of the 11 facial expression with a numeric verbal rating scale (NVRS) (0 = no anxiety and 10 = highest level of anxiety) and a specific categorical level of anxiety, namely no anxiety, mild, mild-moderate, moderate, moderate-high or highest anxiety. Based on these data, the Spearman correlation and frequencies of the 11 faces in relation to the 11-point numerical anxiety scale and 6 categorical anxiety levels were calculated. The highest frequency of a face assigned to a level of the numerical anxiety scale resulted in a finalized order of faces corresponding to the 11-point numeric rating scale. Results The highest frequency for each of the NVRS anxiety scores were as follow: A0, A1, A2, A3, A4, A5, A7, A6, A8, A9 and A10 (Fig 2). For the six categorical anxiety levels, a total of 260 (98.1%) participants chose the face A0 as representing ‘no’ anxiety, 250 (94.3%) participants chose the face A10 as representing ‘highest’ anxiety and 147 (55.5%) participants chose the face A8 as representing ‘moderate-high’ anxiety. Spearman analysis showed a significant correlation between the faces A3 and A5 assigned to the mild-moderate anxiety category (r = 0.58), but A5 was ultimately chosen due to its higher frequency compared to the frequency of A3 (30.6% vs 24.9%)(Fig 3

  2. Correlation between optical coherence tomography and multifocal electroretinogram findings with visual acuity in retinitis pigmentosa

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    Moschos MM

    2013-10-01

    Full Text Available Marilita M Moschos, Irini P Chatziralli, George Verriopoulos, Aristeides Triglianos, Dimitrios S Ladas, Dimitrios BrouzasLaboratory of Electrophysiology, First Department of Ophthalmology, University of Athens, Athens, GreeceIntroduction: Our purpose was to study the correlation between the macular morphology and function in eyes with retinitis pigmentosa (RP.Methods: Sixty-six eyes from 33 patients with RP and with different visual acuity (VA were studied using optical coherence tomography (OCT and multifocal electroretinogram (mfERG. Correlation analysis was performed between VA, macular thickness, mfERG amplitude, and latency.Results: Retinal thickness, retinal response density, and latency of the mfERG in the foveal area were independently and positively associated with VA (P = 0.002; P < 0.0001; P = 0.029; and P = 0.002, respectively, whereas there was no evidence for a correlation between VA and the amplitude of mfERG in the parafoveal area. Evidence of a correlation between the OCT and the mfERG evaluation was of borderline significance (P = 0.047. Also, there was evidence for an inverse association of VA with latency in ring 1 and ring 2 (b = -0.138; 95% confidence interval: -0.261, -0.015; P = 0.029. In accordance with the univariate findings, when foveal retinal thickness, mfERG amplitude, and latency in ring 1 were inserted simultaneously in the same model, all the three variables remained significantly associated with VA (P = 0.016; P < 0.0001; and P = 0.031, respectively. Nevertheless, some individual values deviated from the expected range. More specifically, 15 eyes showed a normal retinal thickness, whereas the respective VA was relatively low and the mfERG values were abnormal. Conversely, in seven eyes, despite the low retinal thickness, the respective VA was high.Conclusion: The combined use of OCT with mfERG appears to be more appropriate for the estimation of macular function.Keywords: retinitis pigmentosa, OCT, mfERG, VA

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

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    O. A. Oduntan

    2009-12-01

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

  4. The effect of tinted soft contact lens wear on functional visual acuity and higher-order aberrations.

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    Watanabe, Kazuhiro; Kaido, Minako; Ishida, Reiko; Dogru, Murat; Negishi, Kazuno; Tsubota, Kazuo

    2014-06-01

    To investigate the differences of functional visual acuity (FVA) and high order aberrations (HOAs) in relation to tinted and clear hydrogel soft contact lens (SCL) wear. A prospective comparative study was performed in 16 eyes of 16 healthy volunteers. Dynamic visual acuity (using a FVA measurement system) and higher-order aberrations (using a wavefront sensor) were compared in subjects wearing two types of soft contact lenses: 1-day Acuvue(®) (Vistakon, Jacksonville, FL) clear and the 1-day Acuvue(®) Define(TM) (Vistakon, Jacksonville, FL) tinted lens. The blink rates were recorded during FVA testing. The correlation between the difference of HOAs and differences in FVA values was analyzed. The mean LogMAR FVA scores with clear and tinted SCLs were 0.07 ± 0.13 and 0.14 ± 0.17 (P<0.05). The mean blink frequencies with clear and tinted SCL wear were 18.4 ± 8.3 and 25.3 ± 4.7 blinks/min (P<0.05). Both 3rd-order aberrations and total HOAs showed statistically significant differences between the two types of soft contact lenses for 6mm pupil measurements (P<0.05). A significant positive linear correlation was observed between ΔHOAs and ΔLogMAR FVA for 6mm pupil measurements (R=0.53, P=0.04). Tinted contact lens wear appears to induce a reduction in optical quality. Functional visual acuity measurement is a useful procedure to study the changes of visual performance and quality in tinted contact lens wear. Copyright © 2013 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  5. 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.

  6. Amniotic membrane covering promotes healing of cornea epithelium and improves visual acuity after debridement for fungal keratitis

    Institute of Scientific and Technical Information of China (English)

    Bo; Zeng; Ping; Wang; Ling-Juan; Xu; Xin-Yu; Li; Hong; Zhang; Gui-Gang; Li

    2014-01-01

    AIM:To investigate the effect of amniotic membrane covering(AMC) on the healing of cornea epithelium and visual acuity for fungal keratitis after debridement.METHODS:Twenty fungal keratitis patients were divided into two groups randomly, the AMC group and the control group, ten patients each group. Both debridement of the infected cornea tissue and standard anti-fungus drugs treatments were given to every patients, monolayer amniotic membrane were sutured to the surface of the entire cornea and bulbar conjunctiva with 10-0 nylon suture for patients in the AMC group.The diameter of the ulcer was determined with slit lamp microscope and the depth of the infiltration was determined with anterior segment optical coherence tomography. Uncorrected visual acuity(UCVA) was tested before surgery and three month after healing of the epithelial layer. The healing time of the cornea epithelium, visual acuity(VA) was compared between the two groups using t- test.RESULTS:There was no statistical difference of the diameter of the ulcer, depth of the infiltration, height of the hypopyon and VA between the two groups beforesurgery(P >0.05). The average healing time of the AMC group was 6.89 ±2.98 d, which was statistically shorter than that of the control group(10.23±2.78d)(P <0.05).The average UCVA of the AMC group was 0.138 ±0.083,which was statistically better than that of the control group(0.053±0.068)(P <0.05).CONCLUSION:AMC surgery could promote healing of cornea epithelium after debridement for fungal keratitis and lead to better VA outcome.

  7. Observers' Judgments of the Effects of Glare on Their Visual Acuity for High and Low Contrast Stimuli.

    Science.gov (United States)

    Sewall, Ashley A Stafford; Borzendowski, Stephanie A Whetsel; Tyrrell, Richard A; Stephens, Benjamin R; Rosopa, Patrick J

    2016-07-01

    Disability glare refers to a reduction in the ability to discern a stimulus that is positioned near another stimulus that has a much higher luminance. While it is common for drivers to report that they have been "blinded" by oncoming headlights, it is unclear whether observers can accurately judge when they are visually disabled by glare. This experiment sought to quantify the accuracy with which observers can judge when a glare source reduces their visual acuity. Seventeen observers estimated their disability glare threshold (DGT)-the luminance of a glare source that would be just sufficient to impair their ability to discern the orientation of a Landolt C that was surrounded by the glare source. These estimated DGTs were compared to the participant's actual DGTs. Participants consistently underestimated the intensity of glare that was required to impair their acuity. On average, estimates of glare threshold were 88% lower than actual glare threshold intensities. Participants' judgments were affected by stimulus size but not stimulus contrast. These results suggest that observers can exaggerate the debilitating effects of glare and that they can fail to appreciate that high contrast stimuli are more robust to glare. A driver who believes that even the lowest intensities of headlight glare can visually impair an oncoming driver may be reluctant to use high beam headlamps, despite their significant visibility advantages.

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

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    Venkataratnam

    2015-10-01

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

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

    OpenAIRE

    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

    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 re-test, the child was ...

  10. Effect of hemodialysis on visual acuity, intraocular pressure, and macular thickness in patients with chronic kidney disease

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    Chelala E

    2015-01-01

    Full Text Available Elias Chelala,1,2,* Ali Dirani,1,2,* Ali Fadlallah,1,2 Elise Slim,1,2 Youssef Abdelmassih,1,2 Henry Fakhoury,3 Patrick Baz,1,2 Riad Bejjani1,2 1Faculty of Medicine, Saint-Joseph University, 2Hôtel-Dieu de France Hospital, Saint-Joseph University, 3Eye and Ear Hospital, Beirut, Lebanon *These two authors contributed equally to this work Background: The aim of this study was to evaluate the effects of hemodialysis (HD on visual acuity, intraocular pressure (IOP, and central foveal thickness (CFT in patients with chronic kidney disease.Materials and methods: Forty-nine eyes from 49 chronic kidney-disease patients were analyzed. Causes of chronic kidney disease included diabetes mellitus (n=9 patients, hypertensive nephrosclerosis (n=15 patients, and other causes (n=25 patients. All patients underwent HD in the Dialysis Unit of Hôtel-Dieu de France Hospital. Best-corrected visual acuity, CFT, and IOP were evaluated before and after HD. CFT was measured with spectral domain optical coherence tomography, and IOP was measured with Goldmann applanation tonometry.Results: Neither decimal best-corrected visual acuity (pre-HD 0.71±0.32, post-HD 0.72±0.31; P=0.877 nor CFT (pre-HD 251.39±39.29, post-HD 253.09±39.26; P=0.272 significantly changed after HD. However, mean IOP significantly decreased from 13.99±2.48 before HD to 12.65±2.41 mmHg after HD (P=0.001. IOP change was significantly correlated with serum albumin levels (P=0.008 and weight changes (P=0.047.Conclusion: HD can affect various ocular parameters. This is particularly true of IOP, which decreases significantly following HD. Keywords: chronic kidney disease, hemodialysis, visual acuity, central macular thickness, intraocular pressure

  11. Sighting dominance, handedness, and visual acuity preference: three mutually exclusive modalities?

    Science.gov (United States)

    Pointer, J S

    2001-03-01

    It is tempting, even perhaps for the clinician, to assume prima facie that an individual's handedness is indicative of other lateral asymmetries, including ocular (sighting) dominance and preferred monocular acuity. An analysis of new data relating to these three modalities, as collated from counter-balanced groups of normally sighted male and female children and adults examined in optometric practice, confirms the general fallacy of this assumption and considers why it is such a persistent misconception. The degree of association between the three modalities in right-preferent individuals is revealed as statistically no greater than chance. On the basis of this study, estimates of right-sided hand, eye and/or acuity congruency are derived for the information of the clinician in the prescribing environment of the consulting room.

  12. Reproducibility of Nigh Vision Goggle Visual Acuity Measurements Using Landolt C’s

    Science.gov (United States)

    1999-12-08

    Task, 1979), Snellen Acuity (Bailey & Lovie, 1979; Wiley, 1989; Miller, Provines, Block & Tredici, 1984), square-wave targets (Task & Genco , 1986...the observer focused the corresponding objective lens by viewing the 3 x 3A, NVG high- contrast square-wave resolution chart (Task & Genco , 1986...for television displays. Technical Report No. AMRL-TR-79-7. NTIS: Alexandria VA. Task, H. L. and Genco , L. V. (1986). Contrast sensitivity function

  13. Higher Cognitive Function in Elderly Individuals with Previous Cataract Surgery: Cross-Sectional Association Independent of Visual Acuity in the HEIJO-KYO Cohort.

    Science.gov (United States)

    Miyata, Kimie; Obayashi, Kenji; Saeki, Keigo; Tone, Nobuhiro; Tanaka, Kunihiko; Nishi, Tomo; Morikawa, Masayuki; Kurumatani, Norio; Ogata, Nahoko

    2016-06-01

    Cataract surgery improves visual acuity and drastically increases the capacity for light reception to the retina. Although previous studies suggested that both light exposure and visual acuity were associated with cognitive function, the relationships between cataract surgery, visual acuity, and cognitive function have not been evaluated in large populations. In this cross-sectional study, we measured cognitive function using the Mini-Mental State Examination and best-corrected visual acuity in pseudophakic (previous cataract surgery) and phakic (no previous cataract surgery) elderly individuals. Of 945 participants (mean age 71.7 years), 166 (17.6%) had pseudophakia and 317 (33.5%) had impaired cognitive function (score ≤26). The pseudophakic group showed significantly better visual acuity than the phakic group (p = 0.003) and lower age-adjusted odds ratio (ORs) for cognitive impairment (OR 0.66; p = 0.038). Consistently, in multivariate logistic regression models, after adjusting for confounding factors, including visual acuity and socioeconomic status, ORs for cognitive impairment were significantly lower in the pseudophakic group than in the phakic group (OR 0.64; 95% confidence interval 0.43-0.96; p = 0.031). This association remained significant in sensitivity analysis, excluding participants with low cognitive score ≤23 (n = 36). In conclusion, in a general elderly population, prevalence of cognitive impairment was significantly lower in pseudophakic individuals independently of visual acuity. The association was also independent of several major causes of cognitive impairment such as aging, gender, obesity, socioeconomic status, hypertension, diabetes, sleep disturbances, depressive symptoms, and physical inactivity.

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

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    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.

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

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    Denes eSzucs

    2013-07-01

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

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

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    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.

  17. Modeling peripheral visual acuity enables discovery of gaze strategies at multiple time scales during natural scene search

    Science.gov (United States)

    Ramkumar, Pavan; Fernandes, Hugo; Kording, Konrad; Segraves, Mark

    2015-01-01

    Like humans, monkeys make saccades nearly three times a second. To understand the factors guiding this frequent decision, computational models of vision attempt to predict fixation locations using bottom-up visual features and top-down goals. How do the relative influences of these factors evolve over multiple time scales? Here we analyzed visual features at fixations using a retinal transform that provides realistic visual acuity by suitably degrading visual information in the periphery. In a task in which monkeys searched for a Gabor target in natural scenes, we characterized the relative importance of bottom-up and task-relevant influences by decoding fixated from nonfixated image patches based on visual features. At fast time scales, we found that search strategies can vary over the course of a single trial, with locations of higher saliency, target-similarity, edge–energy, and orientedness looked at later on in the trial. At slow time scales, we found that search strategies can be refined over several weeks of practice, and the influence of target orientation was significant only in the latter of two search tasks. Critically, these results were not observed without applying the retinal transform. Our results suggest that saccade-guidance strategies become apparent only when models take into account degraded visual representation in the periphery. PMID:25814545

  18. Comparison of visual acuity in macular degeneration patients measured with snellen and early treatment diabetic retinopathy study charts.

    Science.gov (United States)

    Falkenstein, Iryna A; Cochran, Denine E; Azen, Stanley P; Dustin, Laurie; Tammewar, Ajay M; Kozak, Igor; Freeman, William R

    2008-02-01

    To compare the measurements of visual acuity (VA) results measured with Snellen and Early Treatment Diabetic Retinopathy Study (ETDRS) charts in eyes with and without age-related macular degeneration (AMD). Cross-sectional study. One hundred four participants (190 eyes) selected from a university retina practice; 80 participants (142 eyes) had some degree of AMD. Visual acuity was measured in each patient using standard procedure with both Snellen and ETDRS charts in random order. Statistical analysis of the results was performed. Difference in VA measured by both charts in logarithm of minimal angle of resolution (logMAR) notations. Overall, the mean Snellen VA was 0.78 logMAR (= 20/120), and the mean ETDRS VA in the same eye was 0.54 logMAR (= 20/70; P20/30). On average, 20/200 on Snellen was 20/95 on ETDRS (>3 lines difference), and 20/30 on Snellen was 20/25 on ETDRS (Snellen and ETDRS charts, and it was more pronounced in the group with poor vision. The ETDRS measurements yielded better VA, particularly in participants with vision Snellen charts) with outcomes from clinical trials (which typically measure VA using ETDRS charts).

  19. Impact of positive coupling of the eye's trefoil and coma in retinal image quality and visual acuity.

    Science.gov (United States)

    Villegas, Eloy A; Alcón, Encarna; Artal, Pablo

    2012-08-01

    When the eye's higher-order aberrations are measured and reported, as important as the magnitude of each individual term are the possible combinations between them, which may change the overall retinal image quality and therefore visual performance. We have evaluated the relationships among different aberration terms in the human eye-coma, trefoil, and spherical aberration-and their effects on both retinal image quality and visual acuity (VA). In a group of normal young subjects with normal to excellent vision, we measured the eye's aberrations and high contrast VA under natural conditions after carefully correcting defocus and astigmatism. Among the different combinations of aberration terms, we only found a significant negative correlation (r2=0.30) between the vertical coefficients of trefoil C(3,-3) and coma C(3,-1). This is a positive coupling that produces a better retinal image quality than any of the other possible combinations of these terms. However, this improvement in image quality is limited by the presence of other aberrations. Only in a few eyes that presented the larger values of coupled vertical trefoil and coma appeared a significant improvement of image quality. Although we did not find a clear correction between the coma-trefoil vertical coupling and VA, most eyes with large amounts of aberrations (RMS>0.4 μm) have these terms coupled, keeping decimal acuity around 1.2 or higher.

  20. 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).

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

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    Romy Frömer

    Full Text Available 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.

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

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    José David Paulo Trujillo

    2007-08-01

    Full Text Available Purpose: To determine the variation of near visual acuity, in patients exposed during short periods to intense magnetic fields in studies of magnetic resonance imaging. Methods: Descriptive study of a case series that included 40 healthy and literate individuals older than 40 years, nine of them men, submitted to a procedure of head and neck magnetic resonance imaging; all of them had near visual acuity better than 20/200 without glasses, and were not under the effects of ansiolytic medications. Near vision was measured with the Jaeger chart before and immediately after the RM imaging procedure. Measurements were carried out by two different observers; every one of them did not know the results obtained by the other. Results: Means for near vision acuity before and after the magnetic resonance imaging procedure were, respectively, 1.4324 ± 0.4766 m and 1.4375 ± 0.5024 m (p = 0.505. Conclusions: In the evaluated group, no statistically significant change was observed in near vision acuity after head and neck magnetic resonance imaging procedures. Objetivos: determinar la variación de la agudeza visual cercana en pacientes expuestos a campos magnéticos intensos por períodos cortos en estudios de resonancia magnética. Métodos: estudio descriptivo de una serie de casos, que incluyó 9 hombres y 31 mujeres alfabetas mayores de 40 años; debían tener una agudeza visual mejor de 20/200 y no estar bajo los efectos de medicamentos ansiolíticos. Estas personas fueron sometidas a procedimientos diagnósticos de resonancia magnética de cabeza y cuello; antes del procedimiento e inmediatamente después de terminarlo se les midió la agudeza visual (AV con la carta de visión cercana de Jaeger. Las mediciones fueron llevadas a cabo por dos observadores diferentes, cada uno de los cuales desconocía los resultados obtenidos por el otro. Resultados: las medias de la agudeza visual cercana antes y después de la resonancia magnética fueron

  3. 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.

  4. Visual Acuity Testing Using Autorefraction or Pinhole Occluder as Compared with a Manual Protocol Refraction in Individuals with Diabetes

    Science.gov (United States)

    Sun, Jennifer K.; Aiello, Lloyd Paul; Cavallerano, Jerry D.; Stockman, Margaret; Miller, Kellee M.; Qin, Haijing; Beck, Roy W.; Glassman, Adam R.

    2010-01-01

    Purpose To compare visual acuity (VA) scores obtained after autorefraction or using a pinhole occluder to scores obtained after refraction according to a standard clinical research protocol. Design Prospective, comparative case series Participants One hundred and ten study participants (209 eyes) with diabetes mellitus and a broad range of diabetic retinopathy severity and visual acuity (VA). Methods VA was measured after autorefraction by a Topcon KR-8000 autorefractor as well as after a Diabetic Retinopathy Clinical Research Network (DRCR.net) protocol manual refraction. The order of testing was randomized and examiners were masked to the source of each refraction. A second VA measurement, utilizing an identical DRCR.net manual refraction, was made in a subset of eyes (N = 144, 69%) in order to establish test-retest variability for comparison purposes. All eyes underwent VA testing using a pinhole occluder. Main Outcome Measures Best corrected VA as measured by the Electronic Early Treatment Diabetic Retinopathy Study Visual Acuity Test© (E-ETDRS). Results In all eyes, the median E-ETDRS VA letter score (EVA) obtained after manual refraction (MR-EVA) was 69 (Snellen equivalent 20/40), ranging from 4 to 93 (20/800 to 20/16). The median MR-EVA was slightly better than the median EVA obtained after autorefraction (AR-EVA), with a median difference (AR-EVA – MR-EVA) of −1 letter (25th, 75th percentiles: −4, 2 letters). The absolute difference between AR-EVA and MR-EVA was similar to the test-retest variability of MR-EVA alone. In contrast, MR-EVA was better than EVA obtained using a pinhole occluder (PH-EVA), (median PH-EVA – MR-EVA: −4 letters [−9, 0]), and had significantly less test-retest variability (Prefraction (median difference: +0.25 Diopters [0, +0.63 Diopters]). Conclusions Given the substantial time and effort required for training and certification of study protocol refractionists, and the similarity between AR-EVA and MR-EVA, further

  5. Influence of adaptive-optics ocular aberration correction on visual acuity at different luminances and contrast polarities.

    Science.gov (United States)

    Marcos, Susana; Sawides, Lucie; Gambra, Enrique; Dorronsoro, Carlos

    2008-10-06

    We evaluated the visual benefit of correcting astigmatism and high-order aberrations with adaptive optics (AO) on visual acuity (VA) measured at 7 different luminances (ranging from 0.8 to 50 cd/m(2)) and two contrast polarities (black letters on white background, BoW, and white letters on black background, WoB) on 7 subjects. For the BoW condition, VA increased with background luminance in both natural and AO-corrected conditions, and there was a benefit of AO correction at all luminances (by a factor of 1.29 on average across luminances). For WoB VA increased with foreground luminance but decreased for the highest luminances. In this reversed polarity condition AO correction increased VA by a factor of 1.13 on average and did not produce a visual benefit at high luminances. The improvement of VA (averaged across conditions) was significantly correlated (p = 0.04) with the amount of corrected aberrations (in terms of Strehl ratio). The improved performance with WoB targets with respect to BoW targets is decreased when correcting aberrations, suggesting a role of ocular aberrations in the differences in visual performance between contrast polarities.

  6. Idiopathic macular hole: post-operative morpho-functional assessment and prognostic factors for recovery of visual acuity

    Directory of Open Access Journals (Sweden)

    Flavio Tirelli

    2013-09-01

    Full Text Available INTRODUCTION: Idiopathic macular hole (MH is a full-thickness retinal damage typical of the advanced age with a high social impact because, as it affects the macula, it produces severe loss of vision. AIM: This study aims to evaluate the therapeutic efficacy of surgery and to determine prognostic factors, considering how hypovision weighs on individual quality of life and on public health. METHODS: All patients affected by MH were evaluated with an ophthalmic visit, measurement of visual acuity and Optical Coherence Tomography (OCT documentation before surgical intervention. Surgical treatment followed and, subsequently, all the patients were examined with the same documentation at 7 days, 1 month, 3 months, 6 months and 12 months. RESULTS: Surgical therapy, with the modern techniques available, demonstrated the efficacy of anatomical recovery and retinal function. Furthermore, the quantitative characteristics of the MH in the OCT scanning revealed an important prognostic function.

  7. Global motion perception is independent from contrast sensitivity for coherent motion direction discrimination and visual acuity in 4.5-year-old children.

    Science.gov (United States)

    Chakraborty, Arijit; Anstice, Nicola S; Jacobs, Robert J; Paudel, Nabin; LaGasse, Linda L; Lester, Barry M; Wouldes, Trecia A; Harding, Jane E; Thompson, Benjamin

    2015-10-01

    Global motion processing depends on a network of brain regions that includes extrastriate area V5 in the dorsal visual stream. For this reason, psychophysical measures of global motion perception have been used to provide a behavioral measure of dorsal stream function. This approach assumes that global motion is relatively independent of visual functions that arise earlier in the visual processing hierarchy such as contrast sensitivity and visual acuity. We tested this assumption by assessing the relationships between global motion perception, contrast sensitivity for coherent motion direction discrimination (henceforth referred to as contrast sensitivity) and habitual visual acuity in a large group of 4.5-year-old children (n=117). The children were born at risk of abnormal neurodevelopment because of prenatal drug exposure or risk factors for neonatal hypoglycemia. Motion coherence thresholds, a measure of global motion perception, were assessed using random dot kinematograms. The contrast of the stimuli was fixed at 100% and coherence was varied. Contrast sensitivity was measured using the same stimuli by fixing motion coherence at 100% and varying dot contrast. Stereoacuity was also measured. Motion coherence thresholds were not correlated with contrast sensitivity or visual acuity. However, lower (better) motion coherence thresholds were correlated with finer stereoacuity (ρ=0.38, p=0.004). Contrast sensitivity and visual acuity were also correlated (ρ=-0.26, p=0.004) with each other. These results indicate that global motion perception for high contrast stimuli is independent of contrast sensitivity and visual acuity and can be used to assess motion integration mechanisms in children.

  8. Relations of low contrast visual acuity, quality of life and multiple sclerosis functional composite: a cross-sectional analysis.

    Science.gov (United States)

    Schinzel, Johann; Zimmermann, Hanna; Paul, Friedemann; Ruprecht, Klemens; Hahn, Katrin; Brandt, Alexander U; Dörr, Jan

    2014-02-20

    Although common and often disabling in multiple sclerosis (MS), visual dysfunction is currently not adequately accounted for in both clinical routine and MS trials. Sloan low contrast letter acuity (SLCLA) is a standardised chart-based measure of visual function particular at low contrast and has been suggested as additional visual component to the Multiple Sclerosis Functional Composite (MSFC). Here, we evaluate the relations between SLCLA, retinal integrity, MSFC, and quality of life (QoL) in MS patients. Cross-sectional analysis of retinal nerve fibre layer (RNFL) thickness, MSFC, SLCLA (2.5% and 1.25% contrast levels), visual evoked potentials, and QoL (Short Form (SF) 36, National Eye Institute Visual Functioning Questionnaire (NEIVFQ)) using baseline data of 92 MS patients from an ongoing prospective longitudinal trial. Relations between RNFL thickness or P100 latency and SLCLA were analysed using generalised estimating equations (GEE) accounting for intra-individual inter-eye dependencies and corrected for age, gender, and history of optic neuritis. Pearson's correlations were used to assess relations between SLCLA, MSFC, and QoL. SLCLA reflected RNFL thickness (p = 0.021) and P100 latency (p = 0.004) and predicted vision-related QoL, reflected by the NEIVFQ39 subscores "general vision" and "near activities" (p QoL reflected by SF36. Implementing SLCLA into MSFC, thus creating a four-dimensional MSFC4, captured aspects of disability reflected by the NEIVFQ39 subscores "general vision" (r = 0.42, p QoL in MS. More importantly, using a prospective cross-sectional approach we provide evidence that extending the MSFC by SLCLA as an additional visual component increases the performance of MSFC to capture MS-related disability. Longitudinal data on the relation between SLCLA, MSFC, and QoL will be available in the near future.

  9. Evaluation of visual acuity measurements after autorefraction vs manual refraction in eyes with and without diabetic macular edema.

    Science.gov (United States)

    Sun, Jennifer K; Qin, Haijing; Aiello, Lloyd Paul; Melia, Michele; Beck, Roy W; Andreoli, Christopher M; Edwards, Paul A; Glassman, Adam R; Pavlica, Michael R

    2012-04-01

    To compare visual acuity (VA) scores after autorefraction vs manual refraction in eyes of patients with diabetes mellitus and a wide range of VAs. The letter score from the Electronic Visual Acuity (EVA) test from the electronic Early Treatment Diabetic Retinopathy Study was measured after autorefraction (AR-EVA score) and after manual refraction (MR-EVA score), which is the research protocol of the Diabetic Retinopathy Clinical Research Network. Testing order was randomized, study participants and VA examiners were masked to refraction source, and a second EVA test using an identical supplemental manual refraction (MR-EVAsuppl score) was performed to determine test-retest variability. In 878 eyes of 456 study participants, the median MR-EVA score was 74 (Snellen equivalent, approximately 20/32). The spherical equivalent was often similar for manual refraction and autorefraction (median difference, 0.00; 5th-95th percentile range, -1.75 to 1.13 diopters). However, on average, the MR-EVA scores were slightly better than the AR-EVA scores, across the entire VA range. Furthermore, the variability between the AR-EVA scores and the MR-EVA scores was substantially greater than the test-retest variability of the MR-EVA scores (P refraction. Differences between individual autorefractor models were identified. However, even among autorefractor models that compare most favorably with manual refraction, VA variability between autorefraction and manual refraction is higher than the test-retest variability of manual refraction. The results suggest that, with current instruments, autorefraction is not an acceptable substitute for manual refraction for most clinical trials with primary outcomes dependent on best-corrected VA.

  10. 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 retinal vascular diseases and following treatment is warranted. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  11. Impact of surgery on visual acuity and life quality of senile patients

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    Mariela Julia Curbelo Gómez

    2009-09-01

    Full Text Available Background: Cataract surgery is widely accepted nowadays since it helps improving vision and life quality. Objective: To assess the visual outcome, life quality and advantages of microsurgery in one of the most common visual diseases. Methods: A prospective, descriptive, study including variables as age, gender, general and visual personal pathological history of all the patients who attended to the provisional consultation of the General Hospital “Dr. Gustavo Aldereguía Lima” in Cienfuegos between January, 1st 2008 and March 31st, 2008. 285 patients of 60 years and more were studied using questionnaires and a complete ophthalmological study. Results: Two months after the surgery it was proved that visual sharpness improved significantly reaching 0,5 and more in almost all the patients (97,2 %; 96,8% changes their life quality after the surgery. Satisfaction degree was 96.9 % and 96.8 %. Conclusions: We recommend this surgery since the operated patients present evidences of improvement in visual functioning and sharpness and life quality compared with their conditions before the surgery.

  12. Long-term preservation of cone photoreceptors and visual acuity in rd10 mutant mice exposed to continuous environmental enrichment.

    Science.gov (United States)

    Barone, Ilaria; Novelli, Elena; Strettoi, Enrica

    2014-01-01

    In human patients and animal models of retinitis pigmentosa (RP), a gradual loss of rod photoreceptors and decline in scotopic vision are the primary manifestations of the disease. Secondary death of cones and gradual, regressive remodeling of the inner retina follow and progress at different speeds according to the underlying genetic defect. In any case, the final outcome is near-blindness without a conclusive cure yet. We recently reported that environmental enrichment (EE), an experimental manipulation based on exposure to enhanced motor, sensory, and social stimulation, when started at birth, exerts clear beneficial effects on a mouse model of RP, by slowing vision loss. The purpose of this study was to investigate in the same mouse the long-term effects of chronic exposure to an EE and assess the outcome of this manipulation on cone survival, inner retinal preservation, and visual behavior. Two groups of rd10 mutant mice were maintained in an EE or standard (ST) laboratory conditions up to 1 year of age. Then, retinal preservation was assessed with immunocytochemistry, confocal microscopy examination, cone counts, and electron microscopy of the photoreceptor layer, while visual acuity was tested behaviorally with a Prusky water maze. rd10 mice are a model of autosomal recessive RP with a typical rod-cone, center to the periphery pattern of photoreceptor degeneration. They carry a mutation of the rod-specific phosphodiesterase gene and undergo rod death that peaks at around P24, while cone electroretinogram (ERG) is extinct by P60. We previously showed that early exposure to an EE efficiently delays photoreceptor degeneration in these mutants, extending the time window of cone viability and cone-mediated vision well beyond the phase of maximum rod death. Here we find that a maintained EE can delay the degeneration of cones even in the long term. Confocal and electron microscopy examination of the retinas of the rd10 EE and ST mice at 1 year of age showed major

  13. Visual Analogue Scale for Anxiety and Amsterdam Preoperative Anxiety Scale Provide a Simple and Reliable Measurement of Preoperative Anxiety in Patients Undergoing Cardiac Surgery

    OpenAIRE

    Joaquín Hernández-Palazón; Diego Fuentes-García; Luis Falcón-Araña; Antonio Rodríguez-Ribó; Carlos García-Palenciano; María José Roca-Calvo

    2015-01-01

    Background: Anxiety is an emotional state characterized by apprehension and fear resulting from anticipation of a threatening event. Objectives: The present study aimed to analyze the incidence and level of preoperative anxiety in the patients scheduled for cardiac surgery by using a Visual Analogue Scale for Anxiety (VAS-A) and Amsterdam Preoperative Anxiety and Information Scale (APAIS) and to identify the influencing clinical factors. Patients and Methods: This prospective, longitu...

  14. Near visual acuity in an inner city Hispanic community: understanding the barriers and benefits of correction

    Directory of Open Access Journals (Sweden)

    Thomas Wubben

    2014-07-01

    Full Text Available Presbyopia is age-related loss of accommodation that gradually impairs near vision. Few studies have examined the burden of presbyopia in the United States of America (USA and none have examined it in economically disadvantaged or minority populations, in which there are increased rates of visual impairment and decreased use of eye care services.

  15. 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 wit...

  16. 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...

  17. The Potential Importance of Detection of Neovascular Age-Related Macular Degeneration When Visual Acuity Is Relatively Good.

    Science.gov (United States)

    Ho, Allen C; Albini, Thomas A; Brown, David M; Boyer, David S; Regillo, Carl D; Heier, Jeffrey S

    2017-03-01

    The advent of anti-vascular endothelial growth factor treatment has changed the prognosis for patients with neovascular age-related macular degeneration (nvAMD). The ability to stabilize or improve vision with these treatments is a major step in enabling patients to continue to function at the highest possible level. Many studies have demonstrated that the better the visual acuity (VA) is at the time of treatment initiation, the higher the likelihood that VA will be better during at least the following 2 years; as such, detection of nvAMD when VA is relatively good is important. Data on the VA of patients with intermediate AMD and VA at the time of nvAMD diagnosis suggest that patients are typically losing an average of 3 to 5 lines of vision and possibly more between the time that intermediate AMD progresses to nvAMD and the diagnosis of nvAMD is made. The average patient may have nvAMD for 6 to 12 months before diagnosis and treatment initiation. Current efforts in management of nvAMD are primarily aimed at optimizing anti-vascular endothelial growth factor treatments that have the potential to improve VA outcomes by a magnitude of letters. Additional tools or other efforts to identify patients with nvAMD before substantial vision loss has occurred may reduce the amount of visual loss sustained with anti-vascular endothelial growth factor therapy, and have the potential to improve VA outcomes substantially.

  18. Effect of letter separation on computerised visual acuity measurements: comparison with the gold standard Early Treatment Diabetic Retinopathy Study (ETDRS) chart.

    Science.gov (United States)

    Shah, Nilpa; Laidlaw, D Alistair H; Brown, Graham; Robson, Chloe

    2010-03-01

    Contour interaction plays an important role in letter recognition and has long been known to influence clinical visual acuity measurements. LogMAR charts originally employed between-letter and line spacing of one letter width/height; however, in more recent designs, half letter width spacing has become accepted without validation. COMPlog is a computerised visual acuity measurement device being developed and validated for routine and research clinical use and is available commercially. This study was performed to investigate the effect of letter separation on computerised visual acuity measurements. An iterative series of experiments was performed in which test and retest fully interpolated five letters-per-line logMAR visual acuity measurements were taken in three groups of a total 100 adult subjects. Each group had visual acuity measured using ETDRS charts 1 and 2 and on COMPlog using various combinations of letter and line spacing. The first group consisted of 31 subjects tested using 3.75 and 2.50 stroke width spacing, the second 45 subjects using 2.50 and 1.25 stroke width spacing and the last group, 24 subjects tested using 1.90 stroke width spacing. The methods of Bland and Altman were used to analyse the data. No significant bias was noted between the gold standard ETDRS measurements and those taken using COMPlog with 3.75 stroke width spacing. Significant bias of half a logMAR line was found with crowding of 1.90 and 1.25 stroke widths. A small systematic bias with a reduction of 1 ETDRS letter was found with spacing of 2.50 stroke widths which has not been demonstrated in previous validation studies. Crowding of 2.50 stroke widths is the smallest spacing which can be used in the design of COMPlog.

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

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    Anand Vinekar

    2015-01-01

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

  20. Determinants of visual acuity outcomes in eyes with neovascular AMD treated with anti-VEGF agents: an instrumental variable analysis of the AURA study.

    Science.gov (United States)

    Holz, F G; Tadayoni, R; Beatty, S; Berger, A R; Cereda, M G; Hykin, P; Staurenghi, G; Wittrup-Jensen, K; Nilsson, J; Kim, K; Sivaprasad, S

    2016-08-01

    PurposeTo identify the strongest variable(s) linked with the number of ranibizumab injections and outcomes in AURA, and to identify ways to improve outcomes using this association.MethodsAURA was a large observational study that monitored visual acuity over a 2-year period in patients with neovascular age-related macular degeneration (AMD) who received ranibizumab injections. Baseline characteristics, resource use, and outcomes were analyzed using an instrumental variable approach and regression analysis.ResultsData were analyzed from 2227 patients enrolled in AURA. Optical coherence tomography (OCT) and ophthalmoscopy were the most common diagnostic tests used, and this combination was the strongest instrumental variable. Use of OCT and ophthalmoscopy affected the number of injections given and resulted in an increase in visual acuity gains from baseline of 17.6 letters in year 1 and 2.5 letters in year 2. Regression models using the instrumental variable (OCT and ophthalmoscopy combined) showed that ≥5.1 (95% CI: 3.3-11.4) ranibizumab injections were needed to maintain visual acuity from baseline to year 1 and ≥8.3 (95% CI: 5.3-18.8) injections were needed to maintain visual acuity from year 1 to year 2. To gain ≥15 letters, ≥7.9 (95% CI: 5.1-17.5) ranibizumab injections would be needed in year 1 and ≥16.1 (95% CI: 10.3-36.4) injections would be needed over 2 years.ConclusionsThese findings highlight the role that regular monitoring plays in guiding neovascular AMD therapy and they showed that the number of ranibizumab injections needed to maintain visual acuity is higher than that administered in AURA.

  1. Visual acuity testing using autorefraction or pinhole occluder compared with a manual protocol refraction in individuals with diabetes.

    Science.gov (United States)

    Sun, Jennifer K; Aiello, Lloyd Paul; Cavallerano, Jerry D; Stockman, Margaret; Miller, Kellee M; Qin, Haijing; Beck, Roy W; Glassman, Adam R

    2011-03-01

    To compare visual acuity (VA) scores obtained after autorefraction or using a pinhole occluder to scores obtained after refraction according to a standard clinical research protocol. Prospective, comparative case series. One hundred ten study participants (209 eyes) with diabetes mellitus and a broad range of diabetic retinopathy severity and VA. We measured VA after autorefraction by a Topcon KR-8000 autorefractor as well as after a Diabetic Retinopathy Clinical Research Network (DRCR.net) protocol manual refraction. The order of testing was randomized and examiners were masked to the source of each refraction. A second VA measurement, utilizing an identical DRCR.net manual refraction, was made in a subset of eyes (n = 144; 69%) to establish test-retest variability for comparison purposes. All eyes underwent VA testing using a pinhole occluder. Best corrected VA as measured by the Electronic Early Treatment Diabetic Retinopathy Study Visual Acuity Test (E-ETDRS). In all eyes, the median E-ETDRS VA letter score (EVA) obtained after manual refraction (MR-EVA) was 69 (Snellen equivalent 20/40), ranging from 4 to 93 (20/800 to 20/16). The median MR-EVA was slightly better than the median EVA obtained after autorefraction (AR-EVA), with a median difference (AR-EVA - MR-EVA) of -1 letter (25th, 75th percentiles, -4, 2 letters). The absolute difference between AR-EVA and MR-EVA was similar to the test-retest variability of MR-EVA alone. In contrast, MR-EVA was better than EVA obtained using a pinhole occluder (PH-EVA; median PH-EVA - MR-EVA, -4 letters [-9, 0]), and had significantly less test-retest variability (Prefraction (median difference, +0.25 diopters [0, +0.63]). Given the substantial time and effort required for training and certification of study protocol refractionists, and the similarity between AR-EVA and MR-EVA, further evaluation of autorefraction, but not pinhole occluder testing, as an alternative to the current clinical research gold standard of ETDRS

  2. The effects of ranibizumab injections on fluorescein angiographic findings and visual acuity recovery in age-related macular degeneration

    Directory of Open Access Journals (Sweden)

    Gungel H

    2014-05-01

    Full Text Available Hulya Gungel,1 Ozen Ayranci Osmanbasoglu,1 Cigdem Altan,2 Deniz Oygar Baylancicek,3 Isil Basgil Pasaoglu2 1Istanbul Education and Research Hospital, Eye Clinic, 2Beyoglu Eye Education and Research Hospital, 3Kudret Eye Hospital, Istanbul, Turkey Aim: The objective of the study reported here was to evaluate the effect of ranibizumab on retinal circulation times and vessel caliber and to analyze the correlation of these factors with visual acuity (VA prognosis in patients with age-related macular degeneration (AMD.Subjects and methods: This prospective cohort study included 52 eyes of 46 patients (mean age 73.5 years [standard deviation 7.7]; 28 males, 18 females. The study parameters were best-corrected visual acuity (BCVA, central macular thickness (CMT (pre- and posttreatment: for 3 months after the last injection, retinal circulation times, diameter of retinal arteriole (DRA, and diameter of retinal vein (DRV (pre- and posttreatment: after a loading dose of three consecutive injections of ranibizumab with a 4-week interval in the initial phase. The pretreatment, posttreatment measurements, and their differences were recorded for analyses. The injections were repeated when needed. Eyes were grouped into one of two groups according to VA recovery: Group 1, cases showing significant recovery of VA (n=21, 37%, and Group 2, cases showing preservation of VA (n=22, 42% and deterioration of VA (n=11, 21%. Differences were compared statistically in and between groups. Logistic regression analysis was undertaken to determine the correlation of these parameters with VA recovery.Results: There was a significant reduction in DRA (P=0.007 and CMT levels (P=0.001 in both study groups after treatment. When the two groups were compared, the differences in pretreatment values of DRA (P=0.001, DRV (P=0.017, CMT (P=0.039, and mean BCVA (P=0.00 were found to be statistically significant. Posttreatment changes in DRA (P=0.013 and mean CMT (P=0

  3. 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.

  4. 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).

  5. Are blind people more likely to accept free cataract surgery? A study of vision-related quality of life and visual acuity in Kenya.

    Science.gov (United States)

    Briesen, Sebastian; Roberts, Helen; Ilako, Dunera; Karimurio, Jefitha; Courtright, Paul

    2010-01-01

    To determine possible differences in visual acuity, socio-demographic factors and vision-related Quality of Life (QoL) between people accepting and people refusing sponsored cataract surgery. Three hundred and fifty seven local residents with visually impairing cataract, presenting at screening sites in Kwale District, Kenya were clinically assessed and interviewed. The World Health Organization (WHO) QoL-questionnaire WHO/Prevention of Blindness and Deafness Visual Functioning Questionnaire 20 (PBD-VFQ20) was used to determine the vision-related QoL. A standardized questionnaire asked for socio-demographic data and prior cataract surgery in one eye. After interview, patients were offered free surgery. Primary outcome was the mean QoL-score between acceptors and non-acceptors. Secondary outcomes were visual acuity and socio-demographic factors and their contribution to QoL-scores and the decision on acceptance or refusal. Fifty nine people (16.5%) refused and 298 accepted cataract surgery. Vision-related QoL was poorer in people accepting than in those refusing (mean score 51.54 and 43.12 respectively). People with poor visual acuity were only slightly more likely to accept surgery than people with better vision; the strongest predictors of acceptance were the QoL-score and gender. Men were twice as likely to accept compared to women. Of people who accepted surgery, 73.8% had best eye vision of 20/200 or better. In this population, visual acuity was of limited use to predict a person's decision to accept or refuse cataract surgery. QoL-scores provide further insight into which individuals will agree to surgery and it might be useful to adapt the QoL-questions for field use. Gender inequities remain a matter of concern with men being more likely to get sight-restoring surgery.

  6. 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.

  7. 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.

  8. RELATIONSHIP BETWEEN RETINAL THICKNESS AND VISUAL ACUITY IN EYES WITH RETINAL VEIN OCCLUSION TREATED WITH DEXAMETHASONE IMPLANT.

    Science.gov (United States)

    Danis, Ronald P; Sadda, Srinivas; Jiao, Jenny; Li, Xiao-Yan; Whitcup, Scott M

    2016-06-01

    To evaluate the relationship between changes in best-corrected visual acuity (BCVA) and central retinal thickness (CRT) in eyes from two clinical trials of dexamethasone intravitreal implant 0.7 mg for macular edema after branch or central retinal vein occlusion. Patients with vision loss as a result of macular edema (≥6-week duration) after branch retinal vein occlusion or central retinal vein occlusion were treated with a single dexamethasone intravitreal implant or sham. Prospectively defined outcomes included BCVA and CRT (as assessed by optical coherence tomography). There was a modest but statistically significant negative linear correlation between changes in CRT and changes in BCVA in both treatment groups at Days 90 and 180 (correlation coefficient: -0.23 to -0.34; P < 0.001). Improvements in BCVA at Day 180 were significantly greater (P < 0.001) in eyes that achieved and maintained CRT ≤250 μm from Day 90 to 180 (mean BCVA improvement: 14 letters; 49% of eyes with ≥15-letter gain) than in eyes that never achieved CRT ≤250 μm (mean BCVA improvement: 2 letters; 13% of eyes with ≥15-letter gain). The greatest improvements in BCVA were seen in eyes that achieved and maintained the greatest improvements in CRT.

  9. Visual Analogue Scale for Anxiety and Amsterdam Preoperative Anxiety Scale Provide a Simple and Reliable Measurement of Preoperative Anxiety in Patients Undergoing Cardiac Surgery

    Directory of Open Access Journals (Sweden)

    Joaquín Hernández-Palazón

    2015-03-01

    Full Text Available Background: Anxiety is an emotional state characterized by apprehension and fear resulting from anticipation of a threatening event. Objectives: The present study aimed to analyze the incidence and level of preoperative anxiety in the patients scheduled for cardiac surgery by using a Visual Analogue Scale for Anxiety (VAS-A and Amsterdam Preoperative Anxiety and Information Scale (APAIS and to identify the influencing clinical factors. Patients and Methods: This prospective, longitudinal study was performed on 300 cardiac surgery patients in a single university hospital. The patients were assessed regarding their preoperative anxiety level using VAS-A, APAIS, and a set of specific anxiety-related questions. Their demographic features as well as their anesthetic and surgical characteristics (ASA physical status, EuroSCORE, preoperative Length of Stay (LoS, and surgical history were recorded, as well. Then, one-way ANOVA and t-test were applied along with odds ratio for risk assessment. Results: According to the results, 94% of the patients presented preoperative anxiety, with 37% developing high anxiety (VAS-A ≥ 7. Preoperative LoS > 2 days was the only significant risk factor for preoperative anxiety (odds ratio = 2.5, CI 95%, 1.3 - 5.1, P = 0.009. Besides, a positive correlation was found between anxiety level (APAISa and requirement of knowledge (APAISk. APAISa and APAISk scores were greater for surgery than for anesthesia. Moreover, the results showed that the most common anxieties resulted from the operation, waiting for surgery, not knowing what is happening, postoperative pain, awareness during anesthesia, and not awakening from anesthesia. Conclusions: APAIS and VAS-A provided a quantitative assessment of anxiety and a specific qualitative questionnaire for preoperative anxiety in cardiac surgery. According to the results, preoperative LoS > 2 days and lack of information related to surgery were the risk factors for high anxiety levels.

  10. Preoperative automatic visual behavioural analysis as a tool for intraocular lens choice in cataract surgery

    Directory of Open Access Journals (Sweden)

    Heloisa Neumann Nogueira

    2015-04-01

    Full Text Available Purpose: Cataract is the main cause of blindness, affecting 18 million people worldwide, with the highest incidence in the population above 50 years of age. Low visual acuity caused by cataract may have a negative impact on patient quality of life. The current treatment is surgery in order to replace the natural lens with an artificial intraocular lens (IOL, which can be mono- or multifocal. However, due to potential side effects, IOLs must be carefully chosen to ensure higher patient satisfaction. Thus, studies on the visual behavior of these patients may be an important tool to determine the best type of IOL implantation. This study proposed an anamnestic add-on for optimizing the choice of IOL. Methods: We used a camera that automatically takes pictures, documenting the patient’s visual routine in order to obtain additional information about the frequency of distant, intermediate, and near sights. Results: The results indicated an estimated frequency percentage, suggesting that visual analysis of routine photographic records of a patient with cataract may be useful for understanding behavioural gaze and for choosing visual management strategy after cataract surgery, simultaneously stimulating interest for customized IOL manufacturing according to individual needs.

  11. RETINAL MICROVASCULATURE AND VISUAL ACUITY AFTER INTRAVITREAL AFLIBERCEPT IN EYES WITH CENTRAL RETINAL VEIN OCCLUSION: An Optical Coherence Tomography Angiography Study.

    Science.gov (United States)

    Winegarner, Andrew; Wakabayashi, Taku; Hara-Ueno, Chikako; Sato, Tatsuhiko; Busch, Caleb; Fukushima, Yoko; Sayanagi, Kaori; Nishida, Kentaro; Sakaguchi, Hirokazu; Nishida, Kohji

    2017-09-07

    To investigate vascular perfusion and foveal avascular zone area in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) after intravitreal aflibercept therapy in central retinal vein occlusion eyes and their association with best-corrected visual acuity. Thirty-five subjects with central retinal vein occlusion and macular edema were evaluated. After macular edema resolution following intravitreal aflibercept, subjects underwent optical coherence tomography angiography to measure SCP and DCP perfusion and the foveal avascular zone within a 3 × 3-mm area. Correlations between best-corrected visual acuity and optical coherence tomography angiography measurements were examined. After intravitreal aflibercept therapy, mean retinal vascular area was 3.41 ± 0.74 mm in the SCP and 3.25 ± 0.91 mm in the DCP. Foveal avascular zone area was 1.03 ± 1.04 mm in the SCP and 1.78 ± 1.73 mm in the DCP. Improved best-corrected visual acuity was significantly associated with better SCP and DCP perfusion (both P retinal perfusion and less retinal ischemia are associated with better visual outcomes after aflibercept in eyes with central retinal vein occlusion.

  12. 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

  13. Intravitreal ranibizumab therapy versus photodynamic therapy for idiopathic choroidal neovascularization: a comparative study on visual acuity, retinal and choroidal thickness

    Institute of Scientific and Technical Information of China (English)

    Shi Xuehui; Wei Wenbin; Zhang Cong

    2014-01-01

    Background Photodynamic therapy (PDT) has been recommended as a main treatment for idiopathic choroidal neovascularization (I-CNV).But the visual results of PDT were inconsistent and variable,and PDT may bring severe damage to the retinal pigment epithelium and choriocapillaries.In recent years,intravitreal ranibizumab therapy,showing favorable visual outcomes,has developed as an advanced treatment for choroidal neovascularization (CNV).Although both methods have been reported to be effective in treating I-CNV,there is no detailed comparative report between the two methods.This study aimed to compare visual outcomes,retinal and choroidal thickness between intravitreal ranibizumab therapy and PDT in the treatment of I-CNV,and investigate the correlation of visual outcomes with retinal and choroidal thickness in each of the two groups.Methods Thirty-seven eyes of 37 patients with I-CNV were involved in this study; 19 eyes were treated with intravitreal ranibizumab therapy and 18 eyes were treated with PDT.The best corrected visual acuity (BCVA) was recorded before and at each follow-up visit after treatments (IogMAR).Enhanced-depth imaging optical coherence tomography (EDI-OCT) was used to evaluate the retinal structural changes,and to measure central retinal thickness (CRT) and central choroidal thickness (CCT).Results Mean BCVA was 0.64±0.27 in PDT group and 0.69±0.22 in ranibizumab group at baseline (P=0.55).When compared with the baseline,mean BCVA in PDT group was improved significantly at 3-month after PDT (0.41±0.16,P=0.002),then changed little (0.42±0.25 at 12-month,P=0.88).Whereas mean BCVA in Ranibizumab group was improved significantly at each follow-up visit.It improved much more obviously in the first month and then remained stable.The mean BCVA in the ranibizumab group was significantly better at each follow-up visit than that in PDT (P <0.05).When compared with the baseline,mean CRT in PDT group decreased significantly since 3-month visit

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

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    Bruce, A.; Fairley, L; Chambers, B; Wright, J.; Sheldon, TA

    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 participat...

  15. Collateral vessel presence in branch and central retinal vein occlusions and their impact on visual acuity and anatomical gains: a retrospective analysis.

    Science.gov (United States)

    Singh, Rishi P; Lee, Tamara J; Yau, Linda; Rubio, Roman G

    2014-11-01

    To evaluate the incidence of collateral vessel formation and to determine their impact on best-corrected visual acuity and central foveal thickness in patients with branch or central retinal vein occlusion (BRVO, CRVO) receiving 0.3 mg or 0.5 mg of ranibizumab, or sham. This retrospective analysis was performed in patients with macular edema secondary to retinal vein occlusion who received 6 monthly intravitreal injections of ranibizumab (0.3 mg or 0.5 mg), or sham, followed by 6 months of as-needed treatment. Collateral vessel presence, change from baseline best-corrected visual acuity, and change from baseline central foveal thickness were assessed at baseline and months 3, 6, 9, and 12. At month 12, 19.6% of BRVO patients receiving sham/0.5 mg and 16.7% receiving ranibizumab (0.3 mg and 0.5 mg pooled) manifested collaterals at the disk, whereas 48.2% and 47.2% displayed collaterals within the retina, respectively. In CRVO patients, 57.9% and 59.2% of all groups manifested collaterals on the disk, respectively, whereas 12.1% and 15.1% displayed collaterals within the retina. Mean best-corrected visual acuity gain in ranibizumab-treated BRVO and CRVO patients was similar, irrespective of collaterals within the retina ( P > 0.05; CRVO: P > 0.05). The location of collaterals differed between retinal vein occlusion subtypes and ranibizumab treatment did not affect collateral vessel incidence. The presence of collaterals did not seem to impact best-corrected visual acuity gains at month 12 in both BRVO and CRVO patients receiving ranibizumab, whereas generally greater central foveal thickness reductions were observed with presence of collaterals in BRVO patients.

  16. Evaluation of Visual Acuity Measurements after Autorefraction versus Manual Refraction in Eyes with and without Diabetic Macular Edema

    Science.gov (United States)

    Sun, Jennifer K.; Qin, Haijing; Aiello, Lloyd Paul; Melia, Michele; Beck, Roy W.; Andreoli, Christopher M.; Edwards, Paul A.; Glassman, Adam R.; Pavlica, Michael R.

    2012-01-01

    Objective To compare visual acuity (VA) scores after autorefraction versus research protocol manual refraction in eyes of patients with diabetes and a wide range of VA. Methods Electronic Early Treatment Diabetic Retinopathy Study (E-ETDRS) VA Test© letter score (EVA) was measured after autorefraction (AR-EVA) and after Diabetic Retinopathy Clinical Research Network (DRCR.net) protocol manual refraction (MR-EVA). Testing order was randomized, study participants and VA examiners were masked to refraction source, and a second EVA utilizing an identical manual refraction (MR-EVAsupl) was performed to determine test-retest variability. Results In 878 eyes of 456 study participants, median MR-EVA was 74 (Snellen equivalent approximately 20/32). Spherical equivalent was often similar for manual and autorefraction (median difference: 0.00, 5th and 95th percentiles −1.75 to +1.13 Diopters). However, on average, MR-EVA results were slightly better than AR-EVA results across the entire VA range. Furthermore, variability between AR-EVA and MR-EVA was substantially greater than the test-retest variability of MR-EVA (Prefraction. Differences between individual autorefractor models were identified. However, even among autorefractor models comparing most favorably to manual refraction, VA variability between autorefraction and manual refraction is higher than the test-retest variability of manual refraction. The results suggest that with current instruments, autorefraction is not an acceptable substitute for manual refraction for most clinical trials with primary outcomes dependent on best-corrected VA. PMID:22159173

  17. Visual acuity measured with a smartphone app is more accurate than Snellen testing by emergency department providers.

    Science.gov (United States)

    Pathipati, Akhilesh S; Wood, Edward H; Lam, Carson K; Sáles, Christopher S; Moshfeghi, Darius M

    2016-06-01

    To assess the accuracy of best-corrected visual acuity (BCVA) measured by non-ophthalmic emergency department (ED) staff with a standard Snellen chart versus an automated application (app) on a handheld smartphone (Paxos Checkup, San Francisco, CA, USA). The study included 128 subjects who presented to the Stanford Hospital ED for whom the ED requested an ophthalmology consultation. We conducted the study in two phases. During phase 1 of the study, ED staff tested patient BCVA using a standard Snellen test at 20 feet. During phase 2 of the study, ED staff tested patient near BCVA using the app. During both phases, ophthalmologists measured BCVA with a Rosenbaum near chart, which was treated as the gold standard. ED BCVA measurements were benchmarked prospectively against ophthalmologists' measurements and converted to logMAR. ED logMAR BCVA was 0.21 ± 0.35 (approximately 2 Snellen lines difference ± 3 Snellen lines) higher than that of ophthalmologists when ED staff used a Snellen chart (p = .0.00003). ED BCVA was 0.06 ± 0.40 (less than 1 Snellen line ± 4 Snellen lines) higher when ED staff used the app (p = 0.246). Inter-observer difference was therefore smaller by more than 1 line (0.15 logMAR) with the app (p = 0.046). BCVA measured by non-ophthalmic ED staff with an app was more accurate than with a Snellen chart. Automated apps may provide a means to standardize and improve the efficiency of ED ophthalmologic care.

  18. 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.

  19. Comparison of visual acuity measurements via three different methods in preschool children: Lea symbols, crowded Lea symbols, Snellen E chart.

    Science.gov (United States)

    Inal, Asli; Ocak, Osman Bulut; Aygit, Ebru Demet; Yilmaz, Ihsan; Inal, Berkay; Taskapili, Muhittin; Gokyigit, Birsen

    2017-06-20

    The aim of this study was to compare three different methods to measure visual acuity (VA) in healthy and amblyopic preschool children: a Snellen E chart (SE), a single Lea symbols (SLS), and a crowded Lea symbols (CLS). Seventy-eight eyes of 54 patients (28 females, 26 males) were included in this cross-sectional, comparative study. The control group consisted of 30 healthy cases, and the amblyopic group consisted of 24 patients with amblyopia. Best-corrected VA (BCVA) measurements with SLS, CLS, and SE were compared in control eyes (CE), amblyopic eyes (AE), and fellow eyes (FE) separately. The mean age of the cohort was 5.7 ± 0.7 years (range 5-7 years). The mean refractive error was +1.02 ± 0.36 D (diopter, spherical equivalent) in CE, +5.59 ± 2.45 D in AE, and +3.96 ± 2.38 D in FE. The median BCVA (logMAR) was (in order of SLS, CLS, and SE) 0.00 [interquartile range (IQR) 0.10], 0.10 (IQR 0.10), 0.00 (IQR 0.10) in CE, 0.25 (IQR 0.33), 0.35 (IQR 0.30), 0.25 (IQR 0.38) in AE, and 0.10 (IQR 0.08), 0.10 (IQR 0.00), 0.10 (IQR 0.10) in FE. There was no statistically significant difference between the three methods in terms of the CE or FE (p > 0.05). In contrast, there was a statistically significant difference in AE (p < 0.05). The mean VA measurement with SLS was higher compared with CLS in AE. A positive and strong correlation between the three charts was found in all of the groups (p < 0.001). We found SLS, CLS, and SE to be consistent: all three methods can be used to obtain measurements of VA in healthy and amblyopic preschool children.

  20. The Best Corrected Presenting Distance Visual Acuity in Forensic Medicine%"最好矫正日常生活视力"在司法鉴定中的意义

    Institute of Scientific and Technical Information of China (English)

    刘瑞珏

    2011-01-01

    目前我国法医学鉴定实践中有关视力障碍的评价主要是以WHO防盲研究小组于1973年制定的疾病分级标准为依据,所考察的是"最好矫正视力".有时最好矫正视力与日常生活中实际使用的视力可能不一致.WHO于2003年新制定的盲及视力损害分类标准,提出用"日常生活视力"取代"最好矫正视力".在司法鉴定实践中由于伤者的夸大或伪装,"日常生活视力"往往不能反映伤者的真实视力.笔者提出,由鉴定人在"日常生活视力"的基础上评估其"最好矫正日常生活视力",可有助于更公正地进行视功能评定.%At present the sight impairment evaluation in forensic medicine of China is based on the inter national classification of disease by WHO in 1973. The main measured indicator is "best corrected visual acuity". It is different from "presenting distance visual acuity" in some situations. In the new blindness and vision loss classification made by WHO in 2003, "presenting distance visual acuity" took the place of the "best corrected visual acuity". In the practice of forensic medicine, "presenting distance visual acuity" can not reflect the real visual acuity duo to the exaggeration or disguise of the wounded. We suggest to use "the best corrected presenting distance visual acuity" instead of "presenting distance visual acuity" in order to avoid the influences of the exaggeration or disguise of the wounded.

  1. Three-year follow-up of ranibizumab treatment of wet age-related macular degeneration: influence of baseline visual acuity and injection frequency on visual outcomes

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    Razi F

    2016-02-01

    Full Text Available Faraz Razi,1 Adnaan Haq,2 Prabhu Tonne,3 Maharatnam Logendran3 1Department of Paediatrics, Basingstoke and North Hampshire Hospital, Basingstoke, UK; 2Department of Ophthalmology, Leicester General Hospital, Leicester, UK; 3Department of Ophthalmology, Northampton General Hospital, Northampton, UK Purpose: To determine the effect of ranibizumab on visual acuity (VA following a 3-year treatment period for patients diagnosed with wet age-related macular degeneration. To establish whether baseline VA and injection frequency influence visual outcomes. Patients and methods: Retrospective review of 70 patients (76 eyes treated with 0.5 mg intravitreal ranibizumab for 3 consecutive months, and pro re nata thereafter (three + pro re nata protocol, over a 3-year period. VA was measured using Early Treatment Diabetic Retinopathy Study (ETDRS charts at baseline, 12, 24, and 36 months. The number of injections administered at the end of years 1, 2, and 3 were also recorded. Eyes were stratified according to baseline VA, as well as the number of injections administered at the end of year 1. Linear regression analysis determined the relationship between VA and both baseline VA and injection frequency. P<0.05 was considered statistically significant. Results: At 36 months, VA improved by a mean of 5.3 ETDRS letters (P=0.002, with 29% of eyes (n=22 demonstrating a clinically significant improvement in VA (gain of ≥15 ETDRS letters. Improvements in VA from baseline to 36 months were inversely proportional to the baseline VA (R=0.414, P=<0.001. A positive correlation was observed between injection frequency and change in VA from baseline to 36 months (R=0.244, P=0.036. Conclusion: Mean improvement in VA is inversely proportional to baseline VA, and directly proportional to injection frequency. Keywords: long-term results, Lucentis, neovascular AMD

  2. Retinal Oxygen Saturation Correlates With Visual Acuity but Does Not Predict Outcome After Anti-VEGF Treatment in Central Retinal Vein Occlusion.

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    Jeppesen, Signe Krejberg; Bek, Toke

    2017-05-01

    Occlusion of the central retinal vein (CRVO) is a frequent cause of visual loss. The occlusion induces hypoxia in the retina and the larger retinal veins, but the significance of retinal oxygen saturation for visual acuity at diagnosis and after anti-VEGF treatment for CRVO has not been studied in detail. Retinal oximetry was performed in 91 patients consecutively referred for specialist evaluation of CRVO. The correlation between oxygen saturation in larger retinal vessels and visual acuity at the primary examination and the predictive value of oxygen saturation for visual prognosis after three monthly intravitreal injections with anti-VEGF medication were studied. At referral, the oxygen saturation in larger retinal vessels of the affected eye was significantly higher in arterioles (100.7 ± 1.4% vs. 96.3 ± 0.6%) and significantly lower in venules (37.8 ± 2.6% vs. 58.2 ± 1.3%) than in the unaffected eye (P retinal arterioles (P = 0.002) and a significant positive correlation with the saturation in retinal venules (P = 0.013). Multiple linear regression showed that BCVA, but not oxygen saturations, contributed significantly to predicting visual outcome after three monthly intravitreal injections with VEGF inhibitor. The correlation between retinal oxygen saturation and BCVA at the time of diagnosis of CRVO may help understanding hemodynamic and visual changes in the acute stages of the disease. However, retinal oximetry cannot replace measures of retinal function as a predictive parameter for the visual outcome in CRVO after three monthly intravitreal anti-VEGF injections.

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

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

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    Jian Feng Wu

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

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

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    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.

  6. Evaluation and analysis of children's graphic visual acuity chart and Teller visual acuity cards on infants%儿童图形视力表与Teller视敏锐度卡在婴幼儿视力检测中应用分析

    Institute of Scientific and Technical Information of China (English)

    吴丽波; 姚晶磊; 成娟娟; 焦永红

    2014-01-01

    Objective To evaluate the feasibility and reliability of visual assessment system of Children's Graphic Visual Acuity Chart and Teller Visual Acuity Cards on infants.Methods A total of 185 patients were included in this study from Strabismus and Amblyopia Out-patient Department,Beijing Tongren Hospital in 2012.Among those,118 eyes were checked in 59 infants from 2 to 3 years old with Children's Graphic Visual Acuity Chart,252 eyes were checked in 126 infants from 5 months to 2 years old with Teller Visual Acuity Cards.They were divided into 10 groups according to their age sequence,and every 2 months for one group.The visual acuity was recorded and results were analyzed statistically.Results Visual acuity was obtained with Children's Graphic Visual Acuity Chart,and the results were as follows:0.1-0.2 accounted for 14.41% (17 in 118),0.3-0.5,64.40% (76 in 118),0.6 21.19% (25 in 118); Similarly,visual acuity with Teller Visual Acuity Cards were obtained,the results were as follows:13cy/cm accounted for 21.43% (54 in 252),4.8-9.8cy/cm 20.63% (52 in 252),1.3-3.2cy/cm 42.86% (108 in 252),0.86cy/cm 10.71% (27 in 252),0.43cy/cm 4.37% (11 in 252).Conclusions Children's graphic visual acuity chart and Teller visual acuity cards are feasible and reliable visual assessment system on 5 months to 3 years old children.Compared with conventional test,the two visual assessment systems can find abnormal low vision earlier.At the same time,these visual assessment systems can be developed for early intervention and treatment programs on congenital eye disorders in infants with low vision.%目的 探讨儿童图形视力表、Teller视敏锐度卡在婴幼儿视力检测中的可行性和可靠性.方法 对2010年1~12月在北京同仁医院眼科斜弱视门诊就诊的185例患儿,分别使用儿童图形视力表检测2~3岁患儿59例118只眼,用Teller视敏锐度卡检测5个月至2岁患儿126例252只眼.每2个月龄为一组,共分为10组进行视力

  7. Correlation Between the Findings of Optical Coherent Retinal Tomography (OCT), Stereo Biomicroscopic Images from Fundus of an Eye and Values from Visual Acuity of Diabetic Macular Edema

    Science.gov (United States)

    Nisic, Faruk; Turkovic, Samir; Mavija, Milka; Jovanovic, Nina; Alimanovic, Emina Halilovic-

    2014-01-01

    Introduction: Diabetic maculopathy is the major cause of reduced visual acuity in patients with non-proliferative diabetic retinopathy and occurs on average in 29% of patients who have diabetes for 20 or more years. Aim: The aim of this study is to re examine the correlation between the findings of optical coherence retinal tomography, stereo bio-microscopic images from fundus of an eye and values from visual acuity of diabetic macular edema. In addition, the aim is to show the importance of various ophthalmic tests for establishing diagnosis in time. Material and methods: The research sample consisted of 90 subjects-patients from Cabinet for photographic documentation, fluorescein angiography and laser photocoagulation in Department of Ophthalmology at the University Clinical Centre in Sarajevo. The study was a one-year long, prospective, clinical study. Results: Research has shown a positive correlation between the various tests that are applied for the diagnosis of diabetic macular edema. Accurate and early diagnosis is of great importance for the treatment in time of this disease by applying laser photocoagulation, intravitreal injections of Anti-VEGF drugs or surgical treatment by Pars Plana Vitrectomy. PMID:25395723

  8. 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.

  9. Visual Acuity Before and After Treatment in Patients with Chemical Injuries at the National Eye Center, Cicendo Eye Hospital, Bandung from 2010 to 2011

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    Endi Pramudya Laksana

    2015-09-01

    Full Text Available Background: Chemical trauma is one of the emergency cases in ophthalmology since it can lead to severe, permanent blindness if not immediately treated. This study aimed to reveal pre- and post-therapy visual acuity on patients with chemical trauma at theNational Eye Center, Cicendo Eye Hospital, Bandung. Methods: This study was performed on 40 patients’ medical records from the National Eye Center, Cicendo Eye Hospital Bandung from January 2010 to January 2011 as secondary data, using the descriptive retrospective method. The data were divided into two groups: acid and alkali trauma. The collected data were analyzed and presented in tables. Results: Chemical trauma cases were mostly caused by caustic soda (17/40 whereas the least were caused by vinegar (3/40 and commonly occurred on adult patients in the right eye on alkali trauma. Patients with chemical trauma generally had normal eyesight before therapy.The number of patients with acid and alkali trauma who experienced improved eyesight after therapy alkali were similar (3 patients while worsening symptoms occurred in one patient with alkali chemical trauma from mild to medium low vision. Conclusions: There are some improvements of visual acuity after treatment in patients with chemical injuries.

  10. 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.

  11. Subthreshold Micropulse Photocoagulation for Persistent Macular Edema Secondary to Branch Retinal Vein Occlusion including Best-Corrected Visual Acuity Greater Than 20/40

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    Keiji Inagaki

    2014-01-01

    Full Text Available To assess the efficacy of subthreshold micropulse diode laser photocoagulation (SMDLP for persistent macular edema secondary to branch retinal vein occlusion (BRVO, including best-corrected visual acuity (BCVA > 20/40, thirty-two patients (32 eyes with macular edema secondary to BRVO were treated by SMDLP. After disease onset, all patients had been followed for at least 6 months prior to treatment. Baseline Snellen visual acuity was used to categorize the eyes as BCVA ≤ 20/40 (Group I or BCVA > 20/40 (Group II. Main outcome measures were reduction in central macular thickness (CMT in optical coherence tomography (OCT and BCVA at 6 months. In the total subject-pool at 6 months, BCVA had not changed significantly but CMT was significantly reduced. Group I exhibited no significant change in CMT at 3 months but exhibited significant reductions at 6 and 12 months. Group II exhibited a marginally significant reduction in CMT at 3 months and a significant reduction at 6 months. In patients with persistent macular edema secondary to BRVO, SMDLP appears to control macular edema with minimal retinal damage. Our findings suggest that SMDLP is an effective treatment method for macular edema in BRVO patients with BCVA > 20/40.

  12. Effects of Mild Hypercapnia During Head-Down Bed Rest on Ocular Structures, Cerebral Blood Flow, aud Visual Acuity in Healthy Human Subjects

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    Laurie, S. S.; Taibbi, G.; Lee, S. M. C.; Martin, D. S.; Zanello, S.; Ploutz-Snyder, R.; Hu, X.; Stenger, M. B.; Vizzeri, G.

    2014-01-01

    The cephalad fluid shift induced by microgravity has been hypothesized to cause an elevation in intracranial pressure (ICP) and contribute to the development of the Visual Impairment/Intracranial Pressure (VIIP) syndrome, as experienced by some astronauts during long-duration space flight. Elevated ambient partial pressure of carbon dioxide (PCO2) on ISS may also raise ICP and contribute to VIIP development. We seek to determine if the combination of mild CO2 exposure, similar to that occurring on the International Space Station, with the cephalad fluid shift induced by head-down tilt, will induce ophthalmic and cerebral blood flow changes similar to those described in the VIIP syndrome. We hypothesize that mild hypercapnia in the head-down tilt position will increase choroidal blood volume and cerebral blood flow, raise intraocular pressure (IOP), and transiently reduce visual acuity as compared to the seated or the head-down tilt position without elevated CO2, respectively.

  13. Correcting Finger Counting to Snellen Acuity.

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    Karanjia, Rustum; Hwang, Tiffany Jean; Chen, Alexander Francis; Pouw, Andrew; Tian, Jack J; Chu, Edward R; Wang, Michelle Y; Tran, Jeffrey Show; Sadun, Alfredo A

    2016-10-01

    In this paper, the authors describe an online tool with which to convert and thus quantify count finger measurements of visual acuity into Snellen equivalents. It is hoped that this tool allows for the re-interpretation of retrospectively collected data that provide visual acuity in terms of qualitative count finger measurements.

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

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    Thom L

    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

  15. Investigation and analysis on visual acuity situation among students in a college%某校大学生视力状况调查分析

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    胡贵贤; 张喆

    2016-01-01

    Objective To investigate the visual acuity in different grades of students in our college ,and to analyzes the reasons for the visual acuity decrease in college students to provide a reference for health care of college students. Methods A total of 5 351 students(4 804 female students,547 male students) of grade 2013,2012,2011 were performed the routine binocu-lar visual acuity detection by adopting the national standard logarithmic eye chart. Results The overall detection rate of poor eyesight among students in our college was 52.79%,in which,mild,moderate,and severe poor vision detection rates were 26.62%, 25.45%and 47.93%respectively. The poor vision rates in 3 grades of students were 32.81%,60.67%and 68.19%respectively. Conclusion The poor vision rate is gradually increased with the grade increase ,namely the vision presents a decreasing trend during college period.%目的通过对本校不同年级学生进行视力状况调查,分析大学生视力下降的原因,为在校大学生的健康保健提供参考。方法对本校2013级、2012级、2011级5351名学生(其中女生4804名,男生547名)采用国家标准对数视力表,常规对两眼分别进行检查。结果本校学生总的视力不良检出率为52.79%,其中轻、中、重度视力不良检出率分别为26.62%,25.45%,47.93%。3个年级学生的视力不良率分别为32.81%、60.67%、68.19%。结论视力不良率随年级的增加而逐渐增加,即学生在大学期间视力呈下降趋势。

  16. Factors Contributing to Discrepancy Between Visual Acuity Fractions Derived From a Snellen Chart and Letter Scores on the Early Treatment Diabetic Retinopathy Study Chart.

    Science.gov (United States)

    Chen, Fred K; Agelis, Lillian Evangelia; Peh, Khaik K; Teong, Joanne; Wong, Evan Norman Xi Ming

    2014-01-01

    To report factors influencing the relationship between visual acuity (VA) fractions measured on Snellen chart and letter scores on the Early Treatment Diabetic Retinopathy Study (ETDRS) chart. This was a retrospective review from a single ophthalmology outpatient clinic. All patients had routine consecutive VA testing in the right eye using a Snellen chart (1-6 m) and the ETDRS chart (4 m and/or 1 m), by the same optometrist, using a standardized testing protocol for each chart. Both acuity fractions and letter scores were converted to their equivalent logarithm of minimum angle of resolution (logMAR) for comparison. Multiple regression analysis was performed. A total of 237 patients with a wide range of ocular disease and VAs were enrolled. Mean age was 63 years (range, 18-95 years). Recorded VA (logMAR) was better on Snellen chart by a mean (95% limits of agreement) of -0.07 (-0.33 to +0.18, P Snellen and ETDRS charts was nonuniform across VA range. This has implications on interpretation of published studies converting Snellen fractions to logMAR for analysis and reporting of VA outcomes.

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

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    Roberta Lílian Fernandes de Sousa

    2012-12-01

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

  18. 新型对数视力表与“C”形对数视力表的一致性与稳定性分析%Concordance and reliability of new logMAR visual acuity chart and Landolt C logarithmical visual acuity chart

    Institute of Scientific and Technical Information of China (English)

    李刚

    2013-01-01

    Objective To evaluate new logMAR visual acuity chart's test-retest reliability and concordance with "C" logarithm visual acuity chart.Methods This was a cross-sectional study.Measurements using two versions of each chart design were obtained on the right eye of 48 high school students.The test-retest reliability was analyzed by intraclass correlation coefficient (ICC) and Cronbach's Alpha coefficients,and Bland-Altman plots were used to compare the agreement between the two charts.Results The Cronbach's Alpha coefficients of "C" logarithm visual acuity chart was more than 0.8,and the ICC was near 0.9.For the new logMAR visual acuity chart,the Cronbach's Alpha coefficients was near 0.8,and the ICC was more than 0.75.The Bland-Altman plots displayed relatively good agreement between the two charts.The 95% limits of agreement were 0.173 to -0.133 logMAR and 0.198 to-0.116 logMAR for the test and retest measurements respectively.Conclusion In healthy eyes,the new logMAR visual acuity chart has high test-retest reliability and good concordance with Landolt C logarithmical visual acuity chart.%目的 评价新型对数视力表与具有8个方向视标选项的“C”形对数视力表之间的一致性与稳定性.方法 横断面研究.对48例应届高中毕业生分别进行新型对数视力表与“C”形对数视力表的视力检查,采用组内相关系数(ICC)和Cronbach's Alpha系数分析视力测量结果的重复性,采用Bland-Altman分析一致性.结果 “C”形对数视力表Cronbach's Alpha系数在0.8以上,ICC接近0.9,新型对数视力表Cronbach's Alpha系数接近0.8,ICC>0.75,均显示较好的重测稳定性.2种视力表第1次和第2次视力测量均具有较好的一致性,95%一致性界限分别为(0.173,-0.133)logMAR和(0.198,-0.116)logMAR.结论 新型对数视力表检查结果稳定,和“C”形对数视力表一致性较好.

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

    Directory of Open Access Journals (Sweden)

    Negar Horri

    2011-01-01

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

  20. 孔源性视网膜脱离成功复位后中心凹形态与视力的关系%Foveal microstructure and visual acuity after rhegmatogenous retinal detachment scleral buckling repair

    Institute of Scientific and Technical Information of China (English)

    杨嘉嵩; 宋宗明

    2012-01-01

    Objective To evaluate the correlation between macular microstructure and best-corrected visual acuity (BCVA) after successful repair of rhegmatogenous retinal detachment (RRD) underwent scleral buckling procedure. Methods Retrospective,consecutive,observational case series.Seventy-three eyes of 73 patients with RRD underwent successful sclera buckling procedure.The average age of the 39 male patients and 34 female patients was 46.6±11.2 year-old.Among them,48 eyes had a macula-off retinal detachment and the other eyes had a macula-on retinal detachment.A microstructure of the fundus was obtained by spectral domain-optical coherence tomography (SD-OCT) to assess the postoperative macular anatomy and the thickness of the retina.The correlation between the postoperative best-corrected visual acuity (BCVA) and lesions of the macula was evaluated..Results Foveal abnormalities were found in 59 eyes (80.8%) using the SD-OCT,of which subretinal fluid in 47 eyes,16 eyes had a epiretinal membrane,macular edema in 11 eyes,and 33 eyes had disruption or loss of IS/OS junction.Thirty-one eyes had complete reabsorption of subretinal fluid with a mean 5.8±2.6 months.Disruption of the photoreceptor IS/OS junction was observed only in macula-off eyes,whereas other microstuctureal abnormalities were observed in both macula-on and macula-off eyes.In preoperative macula-off eyes,the postoperative BCVA was significantly correlated with the integrity of the photoreceptor IS/OS junction detected by SD-OCT postoperatively (r =0.835; P <0.001). Conclusions After successful anatomically repair of rhegrnatogenous retinal detachment using sclera buckling procedure,the mean time of absorption of subretinal fluid is about 6 months.The status of photoreceptor IS/OS junction correlates significantly with the final visual acuity and may be the determining factor that influences of the visual acuity after surgery.%目的 评价孔源性视网膜脱离(rhegmatogenous retinal detachment,RRD)巩

  1. Current smoking is associated with a poor visual acuity improvement after intravitreal ranibizumab therapy in patients with exudative age-related macular degeneration.

    Science.gov (United States)

    Lee, Sangmoon; Song, Su Jeong; Yu, Hyeong Gon

    2013-05-01

    In this study, the risk factors that may influence visual improvement after intravitreal ranibizumab (IVR) treatment for exudative age-related macular degeneration (AMD) were examined. From 2008 to 2012, 420 patients (448 eyes) with exudative AMD were prospectively registered at Seoul National University Hospital. From this group of patients, 125 eyes were included in this study. All patients were treated with 3 consecutive IVR injections. The visual acuity (VA) was evaluated at baseline and 1 month after the third ranibizumab injection. To evaluate the risk factors associated with VA improvement after IVR, patient demographic data and systemic risk factors were analyzed. Patients were divided into a poor VA improvement group and a good VA improvement group, with reference to the median visual improvement in all eyes. Among 125 eyes, 66 eyes (52.8%) were included in the responder group and 59 eyes (47.2%) in the non-responder group. The median VA improvement after 3 monthly ranibizumab injections was -0.05 logMAR. Multivariate analyses revealed that current smoking (adjusted OR, 7.540; 95% CI, 1.732-32.823) was independently associated with poor VA improvement after IVR treatment for exudative AMD. In conclusion, cigarette smoking is an independent risk factor for lower VA gains with IVR treatment for exudative AMD.

  2. 手术切口大小对白内障术后视力和角膜的影响%The influence of operation incision size on postoperative visual acuity and cornea in cataract patients

    Institute of Scientific and Technical Information of China (English)

    江晓琴; 蔡方荣

    2012-01-01

    group’s, and the SAI value was no difference between the two groups. 7 days after operation, SAI and SRI values were higher than the preoperative level, but 90 days later, returned to the preoperative level. CONCLUSION:The implementation of 3.5 mm clear corneal incision phacoemulsification effect is better, postoperative visual acuity and astigmatism were fast recovered,and corneal shape changes smaler.

  3. 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.

  4. Avaliação da acuidade visual em escolares da 1ª série do ensino fundamental Assessment of visual acuity in pupils of elementary schools

    Directory of Open Access Journals (Sweden)

    José Aparecido Granzoto

    2003-01-01

    Full Text Available RESUMO OBJETIVOS: Estudar a importância dos programas de promoção de saúde ocular na avaliação da acuidade visual para detecção precoce de distúrbios oftalmológicos, em programas de promoção da saúde ocular. MÉTODOS: Estudo descritivo de delineamento transversal. Foram avaliados escolares primários, pertencentes a 21 escolas municipais de Pelotas, RS, por meio de questionário com as variáveis: sexo e idade, percepção da própria visão, uso de óculos ou lentes de contato e medida da acuidade visual (AV pela escala de Snellen. Os alunos com AV PURPOSE: To study the meaning of visual acuity evaluation in ocular health programs for the early detection of ophthalmic disorders. METHODS: In this cross-sectional descriptive survey, schoolchildren of 21 elementary schools of Pelotas, RS were evaluated. Age, sex, awareness about own vision, wearing glasses or contact lenses were recorded by application of a questionnaire. Visual acuity (VA was assessed with Snellen E optotypes. Children with VA< 0.7 or symptoms of eye problems were referred to the specialist for a detailed ophthalmologic examination. RESULTS: Of the 1502 schoolchildren included in the research, 774 (51.5% were male. The majority, 1328 (88.41%, was aged from 6 to 8 years. Approximately 90% of the children believed to have a good vision. VA of 227 children (15.1% was below standard. Of them, 124 (54.6% were female. Of those who thought they had no visual problem, 193 (14.23% were referred to an ophthalmologist. CONCLUSION: Results of this study stress the importance of VA screening. The main purpose of ocular health campaigns consists of helping children to develop their full potentialities.

  5. 日常生活视力在儿童近视防治实践中的应用%Application of presenting visual acuity in the prevention and control of myopia in children

    Institute of Scientific and Technical Information of China (English)

    何鲜桂; 赵蓉; 陆丽娜; 朱剑锋

    2012-01-01

    Objective To evaluate the role of presenting visual acuity in the prevention and control of childhood myopia. Methods With stratified random cluster sampling, 41 243 children of grade 1 to 9 from 55 schools situated in 8 districts in Shanghai were selected to conduct the uncorrected visual acuity. In children who were wearing glasses, visual acuity was measured both with and without spectacles. The analyses of presenting visual acuity were based on worse and better eye vision, respectively. Re-sults Of the 41 243 children, the moderately visually impaired and the mildly impaired of presenting were 11.6% and 2. 3% , respectively. As the grades increased, the rate of visually impaired in children increased,to grade 4 it maintained at about 17%. Uncorrected visual acuity and presenting visual acuity worse than 4. 9 were 21 595 (52.4% ) and 15 717(38. 1% ) children, respectively. In comparison with the uncorrected visual acuity, presenting visual acuity as an indicator for screening could help 5 878 (27. 2% ) children avoid having received appropriate refraction correction and being referred to the clinic again. Conclusion The use of presenting visual acuity as an indicator could help us to know the daily visual quality among children, and improve the efficiency of myopia screening. It may be a valuable indicator for the prevention and control of myopia in children.%目的 探讨日常生活视力指标在儿童近视防治实践中的应用,为在学校卫生领域正确评价儿童视力状况提供依据.方法 整群抽取上海市8个区55所中小学校一~九年级41 243名学生,行裸眼远视力检查,戴镜者同时检查戴镜视力,分别以较好眼和较差眼分析日常生活视力实践应用情况.结果 受检人群较好眼日常生活视力良好有24461名(59.3%),视力轻度受损4779名(11.6%),视力中度损害934名(2.3%);视力受损率(≤4.7)随年级增长而上升,上升趋势至四年级以上趋于平缓,保持在17

  6. Effect of Bevacizumab vs Aflibercept on Visual Acuity Among Patients With Macular Edema Due to Central Retinal Vein Occlusion: The SCORE2 Randomized Clinical Trial.

    Science.gov (United States)

    Scott, Ingrid U; VanVeldhuisen, Paul C; Ip, Michael S; Blodi, Barbara A; Oden, Neal L; Awh, Carl C; Kunimoto, Derek Y; Marcus, Dennis M; Wroblewski, John J; King, Jacqueline

    2017-05-23

    Studies have established the efficacy and safety of aflibercept for the treatment of macular edema due to central retinal vein occlusion. Bevacizumab is used off-label to treat this condition despite the absence of supporting data. To investigate whether bevacizumab is noninferior to aflibercept for the treatment of macular edema secondary to central retinal or hemiretinal vein occlusion. The SCORE2 randomized noninferiority clinical trial was conducted at 66 private practice or academic centers in the United States, and included 362 patients with macular edema due to central retinal or hemiretinal vein occlusion who were randomized 1:1 to receive aflibercept or bevacizumab. The first participant was randomized on September 17, 2014, and the last month 6 visit occurred on May 6, 2016. Analyses included data available as of December 30, 2016. Eyes were randomized to receive intravitreal injection of bevacizumab (1.25 mg; n = 182) or aflibercept (2.0 mg; n = 180) every 4 weeks through month 6. The primary outcome was mean change in visual acuity (VA) letter score (VALS) from the randomization visit to the 6-month follow-up visit, based on the best-corrected electronic Early Treatment Diabetic Retinopathy Study VALS (scores range from 0-100; higher scores indicate better VA). The noninferiority margin was 5 letters, and statistical testing for noninferiority was based on a 1-sided 97.5% confidence interval. Among 362 randomized participants (mean [SD] age, 69 [12] years; 157 [43.4%] women; mean [SD] VALS at baseline, 50.3 [15.2] [approximate Snellen VA 20/100]), 348 (96.1%) completed the month 6 follow-up visit. At month 6, the mean VALS was 69.3 (a mean increase from baseline of 18.6) in the bevacizumab group and 69.3 (a mean increase from baseline of 18.9) in the aflibercept group (model-based estimate of between-group difference, -0.14; 97.5% CI, -3.07 to ∞; P = .001 for noninferiority), meeting criteria for noninferiority. Ocular adverse events in

  7. Vitrectomy for optic disc pit-associated maculopathy with or without preoperative posterior vitreous detachment

    Directory of Open Access Journals (Sweden)

    Haruta M

    2012-08-01

    Full Text Available Masatoshi Haruta, Rika Kamada, Yumi Umeno, Ryoji YamakawaDepartment of Ophthalmology, Kurume University School of Medicine, Kurume, Fukuoka, JapanBackground: The purpose of this study was to evaluate the efficacy of pars plana vitrectomy for the treatment of optic disc pit-associated maculopathy with or without preoperative posterior vitreous detachment.Methods: We reviewed the clinical records of four consecutive patients who underwent pars plana vitrectomy in one eye for the treatment of optic disc pit-associated maculopathy, with an emphasis on the preoperative condition of the posterior hyaloid membrane.Results: Two of four eyes were confirmed to have an attached posterior hyaloid membrane, which was subsequently removed during surgery. Following vitrectomy, these two eyes experienced an improvement in visual acuity with complete retinal attachment of the macula. However, the other two eyes, which already had a posterior vitreous detachment at the time of surgery, showed a decrease in visual acuity with persistent maculopathy postoperatively.Conclusion: Pars plana vitrectomy for optic disc pit-associated maculopathy was beneficial for improving visual acuity in two eyes without preoperative posterior vitreous detachment but not in two eyes with preoperative posterior vitreous detachment. Our study suggests that preoperative assessment of a posterior hyaloid membrane is clinically important in predicting the surgical outcome of optic disc pit-associated maculopathy.Keywords: gas tamponade, internal limiting membrane, macular hole, optical coherence tomography, posterior hyaloid membrane, retinal detachment

  8. Validation of a Manually Oscillating Chair for In-The-Field Assessment of Dynamic Visual Acuity on Crewmembers Within Hours of Returning From Long-Duration Spaceflight

    Science.gov (United States)

    Kreutzberg, G. A.; Rosenberg, M. J. F.; Peters, B. T.; Reschke,M. F.

    2017-01-01

    Long-duration spaceflight results in sensorimotor adaptations, which cause functional deficits during gravitational transitions, such as landing on a planetary surface after long-duration microgravity exposure. Both the vestibular system and the central nervous system are affected by gravitational transitions. These systems are responsible for coordinating head and eye movements via the vestibulo-ocular reflex (VOR) and go through an adaptation period upon exposure to microgravity. Consequently, they must also re-adapt to Earth's gravitational environment upon landing. This re-adaptation causes decrements in gaze control and dynamic visual acuity, with crewmembers reporting oscillopsia and blurred vision caused by retinal slip, or the inability to keep an image focused on their retina. This is thought to drive motion sickness symptoms experienced by most crewmembers following landing. Retinal slip can be estimated by dynamic visual acuity (DVA); visual acuity while in motion. Previously, DVA has been assessed in the laboratory where subjects walked at 6.4 km/hr on a motorized treadmill. Using this method, Peters et al. (2011) found that DVA is worsened in astronauts by an average of 0.75 eye-chart lines one day after landing. However, it is believed that re-adaptation occurs quickly and that DVA might be worse immediately upon re-exposure to a gravitational environment. Since many crewmembers are unable to walk safely upon landing, it was necessary to develop a method for replicating the vertical head movements associated with walking. In addition, the use of a chair to imitate the head displacement caused by walking isolates eye-head interactions without allowing for trunk and lower-body compensation, as seen with treadmill walking (Mulavara & Bloomberg 2003). Therefore, a modality for assessing DVA in the field within a few hours of landing was developed. In this study, we validated the ability of a manually operated oscillating chair to reproduce the oscillatory

  9. [Comparison of the threshold interpolation and whole-line method on logMAR chart and Snellen chart for visual acuity testing].

    Science.gov (United States)

    Veselý, P; Ventruba, J

    2009-10-01

    The main goal of our study was to prove the statistical significant difference between the threshold interpolation logMAR method on ETDRS chart and the whole-line method on Snellen chart with Sloan letters. We had 108 measurements with the threshold interpolation method and the whole-line method on ETDRS chart and the whole-line method on Snellen chart. The average value measured with the threshold method in ETDRS was 1,132 (min. 0,660, max. 1,580), with the whole-line method on ETDRS it was 1,134 (min. 0,630, max. 1,580) and with the whole-line method on Snellen chart it was 1,183 (min. 0,630, max. 1,600). We have proved statistical significant difference between the threshold interpolation method made on ETDRS chart and the whole-line method made on Snellen chart (p Snellen chart were overvalued. The exact and reliable measuring of visual acuity is an important component of further examinations (e.g. contrast sensitivity, perimetry, tonometry), which enable us to make a correct diagnosis of pathological changes on human eye structures.

  10. Risk factors for decreased visual acuity in preschool children: the multi-ethnic pediatric eye disease and Baltimore pediatric eye disease studies.

    Science.gov (United States)

    Tarczy-Hornoch, Kristina; Varma, Rohit; Cotter, Susan A; McKean-Cowdin, Roberta; Lin, Jesse H; Borchert, Mark S; Torres, Mina; Wen, Ge; Azen, Stanley P; Tielsch, James M; Friedman, David S; Repka, Michael X; Katz, Joanne; Ibironke, Josephine; Giordano, Lydia

    2011-11-01

    To investigate risk factors associated with unilateral or bilateral decreased visual acuity (VA) in preschool children. Population-based, cross-sectional prevalence study. Population-based samples of 6504 children ages 30 to 72 months from California and Maryland. Participants were preschool African-American, Hispanic, and non-Hispanic white children from Los Angeles, California, and Baltimore, Maryland. Data were obtained by a parental interview and a detailed ocular examination. Logistic regression models were used to evaluate the independent associations between demographic, behavioral, and clinical risk factors with unilateral and bilateral decreased VA. Odds ratios (ORs) for various risk factors associated with interocular difference (IOD) in VA of ≥2 lines with ≤20/32 in the worse eye, or bilateral decreased VA preschool children should be considered in light of these risk associations. The authors have no proprietary or commercial interest in any of the materials discussed in this article. Copyright © 2011 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  11. Onset and duration of visual acuity improvement after dexamethasone intravitreal implant in eyes with macular edema due to retinal vein occlusion.

    Science.gov (United States)

    Kuppermann, Baruch D; Haller, Julia A; Bandello, Francesco; Loewenstein, Anat; Jiao, Jenny; Li, Xiao-Yan; Whitcup, Scott M

    2014-09-01

    To evaluate the onset and duration of improvement in best-corrected visual acuity (BCVA) in eyes treated with dexamethasone intravitreal implant 0.7 mg (DEX implant) for macular edema after branch or central retinal vein occlusion. Post hoc analysis of data from 2 previously reported multicenter, 6-month, randomized sham-controlled clinical trials. Patients received a single DEX implant (n = 427) or sham procedure (n = 426) in the study eye. The primary endpoint was the percentage of eyes with ≥ 15-letter improvement in BCVA from baseline at postimplant Day 7. The baseline mean BCVA was 20/80. At Day 7, 10.3% of DEX implant-treated eyes versus 4.0% of sham-treated eyes (P retinal vein occlusion, 5.1; and central retinal vein occlusion, 5.8) with DEX implant and 1.6 letters (branch retinal vein occlusion, 2.3; and central retinal vein occlusion, 0.1) with sham (P < 0.001). The mean time from initial observation of ≥ 15-letter BCVA gain to the last observation of ≥ 15-letter BCVA gain was 70 days. Dexamethasone intravitreal implant treatment led to improvement in BCVA compared with sham procedure as early as postimplant Day 7. The duration of ≥ 3-line improvement was typically 2 to 3 months.

  12. 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

    of Ophthalmology, Odense University Hospital, Denmark. Purpose: ReLEx is a relative new corneal refractive procedure, where a stromal lenticule is cut by a femtosecond laser and manually extracted. The purpose of this study was to compare uncorrected and corrected distance visual acuity (UDVA and CDVA), refractive......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...... and ReLEx treatments were made with a VisuMax® femto-second laser (Carl Zeiss-Meditec, Jena, Germany). In FS-LASIK, the photoablation was performed with a MEL-80 flying spot excimer laser (Carl Zeiss-Meditec, Jena, Germany). In ReLEx, lenticule diameter was 6.50 mm, whereas the FS-LASIK ablation zone...

  13. EARLY CRT MONITORING USING TIME-DOMAIN OPTICAL COHERENCE TOMOGRAPHY DOES NOT ADD TO VISUAL ACUITY FOR PREDICTING VISUAL LOSS IN PATIENTS WITH CENTRAL RETINAL VEIN OCCLUSION TREATED WITH INTRAVITREAL RANIBIZUMAB: A Secondary Analysis of Trial Data.

    Science.gov (United States)

    Bell, Katy J L; Hayen, Andrew; Glasziou, Paul; Mitchell, Andrew S; Farris, Maria; Wright, Jonathan; Duerr, Hans-Peter; Mitchell, Paul; Irwig, Les

    2017-03-01

    Our primary purpose was to assess the clinical (predictive) validity of central retinal thickness (CRT) and best corrected visual acuity (BCVA) at 1 week and 1 month after starting treatment with ranibizumab for central retinal vein occlusion. The authors also assessed detectability of response to treatment. The authors used data from 325 participants in the CRUISE study, which included measurement of time-domain CRT and BCVA at baseline, 1 week, 1 month, and 6 months postrandomization. Analysis of covariance models were fitted to assess clinical validity, and distributions of change were constructed to assess detectability of response. There was no evidence that 1-week CRT, and very strong evidence that 1-week BCVA were associated with baseline-adjusted BCVA at 6 months (P = 0.17 and P central retinal vein occlusion patients seemed more informative than time-domain optical coherence tomography monitoring.

  14. Preoperational Graphic Representation: From Intellectual Realism to Visual Realism in Draw a House-Tree Task.

    Science.gov (United States)

    Kalyan-Masih, Violet

    In a pilot study of children's drawings of "a house with a tree behind it," Piagetian sequence (scribbling, fortuitous realism, failed realism, intellectual realism, and visual realism) was tentatively supported. Children's strategies in decentering from intellectual to visual realism were noted. The study reported in this paper was…

  15. The UK Neovascular AMD Database Report 3: inter-centre variation in visual acuity outcomes and establishing real-world measures of care.

    Science.gov (United States)

    Liew, G; Lee, A Y; Zarranz-Ventura, J; Stratton, I; Bunce, C; Chakravarthy, U; Lee, C S; Keane, P A; Sim, D A; Akerele, T; McKibbin, M; Downey, L; Natha, S; Bailey, C; Khan, R; Antcliff, R; Armstrong, S; Varma, A; Kumar, V; Tsaloumas, M; Mandal, K; Egan, C; Johnston, R L; Tufail, A

    2016-11-01

    PurposeInternational variations in visual acuity (VA) outcomes of eyes treated for neovascular age-related macular degeneration (nAMD) are well-documented, but intra-country inter-centre regional variations are not known. These data are important for national quality outcome indicators. We aimed to determine intra-country and inter-centre regional variations in outcomes for treatment of nAMD.Patients and methodsProspective multicentre national database study of 13 UK centres that treated patients according to a set protocol (three loading doses, followed by Pro-Re-Nata retreatment). A total of 5811 treatment naive eyes of 5205 patients received a total of 36 206 ranibizumab injections over 12 months.ResultsMean starting VA between centres varied from 48.9 to 59.9 ETDRS letters. Mean inter-centre VA change from baseline to 12 months varied from +6.9 letters to -0.6 letters (mean of +2.5 letters). The proportion of eyes achieving VA of 70 letters or more varied between 21.9 and 48.7% at 12 months. Median number of injections (visits) at each centre varied from 5 to 8 (9 to 12), with an overall median of 6 (11). Age, starting VA, number of injections, and visits, but not gender were significantly associated with variation in these VA outcomes (Peven after adjusting for these factors.ConclusionThere are modest differences in VA outcomes between centres in the UK. These differences are influenced, but not completely explained, by factors such as patient age, starting VA, number of injections, and visits. These data provide an indication of the VA outcomes that are achievable in real-world settings.

  16. Second-year visual acuity outcomes of nAMD patients treated with aflibercept: data analysis from the UK Aflibercept Users Group.

    Science.gov (United States)

    Almuhtaseb, H; Johnston, R L; Talks, J S; Lotery, A J

    2017-06-16

    PurposeTo audit the visual acuity (VA) outcomes achieved at the end of year two in 17 UK centres, which followed the year 1 VIEW protocol in year 1, but a variable approach in year 2 for aflibercept for neovascular macular degeneration (nAMD).Patients and methodsRetrospective data analysis, from an electronic medical record, of a consecutive series of treatment-naive nAMD patients who received aflibercept for 2 consecutive years, having followed the VIEW protocol in year one, defined as eyes having received 7 or 8 injections from baseline.ResultsThe mean number of intravitreal injections (IVI)s during year 2 was 3.7 in 1180 eyes (1083 patients). The mean baseline VA of the whole cohort was 56.3 ETDRS letters, improving to 61.3 at 1 year (+5) and 59.1 (+2.8) at the end of year 2. The mean VA letter score at the end of year 2, stratified by number of IVIs into three groups was as follows: group A, 57.3 (gain of +1.7) (44% of eyes (/=6 IVIs)). Even though there were VA gains in the three groups over the 2-years, there was a drop in VA in year one to two. Eyes that received >/=6 IVIs (group C) had a smaller reduction of VA during year 2 than those which received year 1 results in higher VA gains in year 2 of treatment.Eye advance online publication, 16 June 2017; doi:10.1038/eye.2017.108.

  17. Five-year visual acuity outcomes and injection patterns in patients with pro-re-nata treatments for AMD, DME, RVO and myopic CNV.

    Science.gov (United States)

    Wecker, Thomas; Ehlken, Christoph; Bühler, Anima; Lange, Clemens; Agostini, Hansjürgen; Böhringer, Daniel; Stahl, Andreas

    2017-03-01

    Anti vascular endothelial growth factor (VEGF) therapy is an established treatment for various retinal diseases. Long-term data on injection frequencies and visual acuity (VA), however, are still rare. Five-year analysis of real-life VA developments and injection patterns from 2072 patients (2577 eyes; 33 187 injections) with chronically active disease undergoing pro-re-nata treatment for age-related macular degeneration (AMD), diabetic macular oedema (DME), retinal vein occlusion (RVO) and myopic choroidal neovascularisation (CNV). Maximum mean VA gain in year 1 was+5.2 letters in AMD, +6.2 in DME, +10 in RVO and+7.2 in myopic CNV. Over 5 years, however, VA in patients with AMD declined. By year 5, 34% of patients with AMD had experienced VA loss of >15 letters, 56% had remained stable and 10% had gained >15 letters. Long-term VA developments in DME and RVO were more favourable with 81% of DME and 79% of patients with RVO gaining or maintaining vision at 5 years. In AMD, median injection frequency was six in year 1 and between four and five in consecutive years. In DME and RVO, median injection frequency was six in year 1 but lower compared with AMD in consecutive years. Injection frequency in DME was weakly associated with patient age (rs=0.1; p=0.03). In AMD, the initial VA gain was not maintained long term despite higher injection numbers compared with DME, RVO and myopic CNV. The presented real-world data provide a peer-group-based estimate of VA developments and injection frequencies for counselling patients undergoing long-term anti-VEGF therapy. 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/.

  18. Importance of Central Retinal Sensitivity for Prediction of Visual Acuity after Intravitreal Bevacizumb in Eyes with Macular Edema Associated with Branch Retinal Vein Occlusion.

    Science.gov (United States)

    Sugimoto, Masahiko; Ichio, Atsushi; Kondo, Mineo

    2016-01-01

    To determine whether the baseline retinal sensitivity can predict the best-corrected visual acuity (BCVA) at 1 month after intravitreal bevacizumab (IVB) in eyes with macular edema (ME) associated with a branch retinal vein occlusion (BRVO). We evaluated 16 eyes of 16 patients who had ME associated with a BRVO. The mean ± standard deviation age was 69.1 ± 8.9 years, and all had a single IVB injection. The BCVA, central macular thickness (CMT), integrity of the ellipsoid zone (EZ) of the photoreceptors, and retinal sensitivity were determined before (baseline) and at 1 day, 1 week, and 1 month following the IVB. The average threshold retinal sensitivity (AT) within the central 10° was determined by Macular Integrity Assessment. The correlations between the BCVA at 1 month and the CMT, integrity of the EZ, and AT at each visit were determined. One month after IVB, the BCVA improved significantly from 0.56 ± 0.27 logMAR units to 0.32 ± 0.28 logMAR units, and the CMT from 611.4 ± 209.3 μm to 258.7 ± 64.0 μm (P retinal sensitivity (r = 0.76) were moderately correlated with the BCVA at 1 month. These results indicate that both the integrity of the EZ and the AT at 1 day after the IVB can predict the BCVA after treatment for ME associated with BRVO. There is a possibility that these parameters will predict the effectiveness of IVB for each case.

  19. Acuity, crowding, reading and fixation stability.

    Science.gov (United States)

    Falkenberg, Helle K; Rubin, Gary S; Bex, Peter J

    2007-01-01

    People with age-related macular disease frequently experience reading difficulty that could be attributed to poor acuity, elevated crowding or unstable fixation associated with peripheral visual field dependence. We examine how the size, location, spacing and instability of retinal images affect the visibility of letters and words at different eccentricities. Fixation instability was simulated in normally sighted observers by randomly jittering single or crowded letters or words along a circular arc of fixed eccentricity. Visual performance was assessed at different levels of instability with forced choice measurements of acuity, crowding and reading speed in a rapid serial visual presentation paradigm. In the periphery: (1) acuity declined; (2) crowding increased for acuity- and eccentricity-corrected targets; and (3), the rate of reading fell with acuity-, crowding- and eccentricity-corrected targets. Acuity and crowding were unaffected by even high levels of image instability. However, reading speed decreased with image instability, even though the visibility of the component letters was unaffected. The results show that reading performance cannot be standardised across the visual field by correcting the size, spacing and eccentricity of letters or words. The results suggest that unstable fixation may contribute to reading difficulties in people with low vision and therefore that rehabilitation may benefit from fixation training.

  20. 西藏地区影响老年性白内障术后视力改善因素分析%Study of impact factors on visual acuity improvement for senile cataract surgery in Tibet

    Institute of Scientific and Technical Information of China (English)

    才瑜; 潘英姿; 聂红平; 杨松霖

    2010-01-01

    Objective To analyze impact factors for visual acuity improvement of senile cataract surgery in Tibet prospectively. Methods Of 278 cases were included. To study relations of visual acuity improvement between pre- and post-cataract surgery with patient age, nucleus classification, small incision cataract surgery (SICS) or Phacoemulsification (PHACO) and corneal edema. LogMAR chart was used in visual acuity analysis. Results 1. Univariate analysis: There was no significant difference between PHACO group and SICS group on visual acuity improvement (PHACO 0.92± 0.48, SICS 0.83± 0.46, P >0.05). Age group for 70- and 80- years-old had less improvement on visual acuity (P <0.05). Diffuse corneal edema had much more influence than central corneal edema on visual acuity improvement (0.52± 0.42, 0.70± 0.44, diffuse vs central, respectively). 2. Multivariate analysis: There were significant differences in age and location of corneal edema on visual acuity improvement (P <0.05). Conclusions There is no significant difference on visual acuity improvement between PHACO and SICS. Ophthalmologist can choose either PHACO or SICS for better rehabilitation of visual acuity, depending on area economics, his own experience and so on in Tibet. Visual acuity improvement in cataract surgery is significantly affected by the age of the patients. Since medication is deficient in Tebit, screening of cataract in Tibet is very important for detecting and treating cataract as early as possible. Diffuse corneal edema has much more influence than central edema on visual acuity improvement when corneal edema degrees are not different. It's important to avoid corneal endothelium damage in cataract surgery.%目的 分析影响西藏地区老年性白内障术后视力改善的因素.方法 对西藏地区接受白内障手术的老年性白内障278例,分析年龄、核分级、术式(超声乳化术和小切口白内障囊外摘除术)、人工晶状体度数、角膜水肿部位等对

  1. [Landolt C and snellen e acuity: differences in strabismus amblyopia?].

    Science.gov (United States)

    Becker, R; Gräf, M

    2006-01-01

    Assessment of visual acuity depends on the optotypes used for measurement. The ability to recognize different optotypes differs even if their critical details appear under the same visual angle. Since optotypes are evaluated on individuals with good visual acuity and without eye disorders, differences in the lower visual acuity range cannot be excluded. In this study, visual acuity measured with the Snellen E was compared to the Landolt C acuity. 100 patients (age 8 - 90 years, median 60.5 years) with various eye disorders, among them 39 with amblyopia due to strabismus, and 13 healthy volunteers were tested. Charts with the Snellen E and the Landolt C (Precision Vision) which mimic the ETDRS charts were used to assess visual acuity. Three out of 5 optotypes per line had to be correctly identified, while wrong answers were monitored. In the group of patients, the eyes with the lower visual acuity, and the right eyes of the healthy subjects, were evaluated. Differences between Landolt C acuity (LR) and Snellen E acuity (SE) were small. The mean decimal values for LR and SE were 0.25 and 0.29 in the entire group and 0.14 and 0.16 for the eyes with strabismus amblyopia. The mean difference between LR and SE was 0.55 lines in the entire group and 0.55 lines for the eyes with strabismus amblyopia, with higher values of SE in both groups. The results of the other groups were similar with only small differences between LR and SE. Using the charts described, there was only a slight overestimation of visual acuity by the Snellen E compared to the Landolt C, even in strabismus amblyopia. Small differences in the lower visual acuity range have to be considered.

  2. 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

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

    Directory of Open Access Journals (Sweden)

    Mariana Rabello Laignier

    2010-03-01

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

  4. Preoperative visualization of the trajectory for CT-guided stereotactic surgery; A technical note

    Energy Technology Data Exchange (ETDEWEB)

    Ohira, Takayuki; Toya, Shigeo; Momoshima, Hirotaka; Shiga, Hayao (Keio Univ., Tokyo (Japan). School of Medicine)

    1989-04-01

    A method is reported for confirming the entire trajectory on CT images using Komai's CT stereotactic apparatus and a GE 8800 CT scanner. For this purpose, we used the 'oblique reformation software with a parameter mode' contained in the GE 8800 CT scanner and made a 'Y-angle ring' for Komai's stereotactic apparatus. The value of the angle between the axial plane and the arc (Y angle) was put on the scale of the ring during operation. Pseudo-coronal and pseudo-sagittal images containing the entire trajectory were re-formed by this software using 6 values of the X, Y, and Z coordinates for the target and trephination points. This method allows the quick visualization of various potential routes, thus aiding the optimal selection of the best actual surgical paths. (author).

  5. 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.

  6. Investigation and analysis of visual acuity of students in one health school%某卫生学校学生视力状况调查分析

    Institute of Scientific and Technical Information of China (English)

    董兆

    2015-01-01

    Objective To investigate and analysis students' vision in one health school and the influence factors of low vision, which will provide a scientific basis for further improve students' visual acuity level.Methods: In a random sample of one health school four professional in grade 2010-2014, a total of 2238 students as investigation object, and using E type international standard logarithmic chart and related questionnaire, detection, investigation and statistical analysis.Results: The total poor vision rate of the respondents was 83.87%. give priority to with moderate, The rate in female respondents(85.54%) was higher than that of male(76.67%). The rate(87.29%) in senior students (grade 4 and 5) was higher than that of junior (grade 1~3) students(79.34%). The rate in nursing students(86.46%) was higher than that of other students(P<0.05). The students with normal vision pay more attention to maintain the correct reading distance, the using time of mobile phones everyday is shorter, more like sports, more like animal liver and vegetables. Objective: The main cause of the health school students vision loss is myopic, vision care is a dififcult task. Bad behaviors of using eyes, lack of exercise, poor dietary habits are all risk factors of poor vision.%目的 了解某卫生学校学生的视力状况以及视力低下的影响因素,为进一步改善学生视力水平提供科学依据.方法 以随机抽取的某卫生学校2010级至2014级四个专业共2238名学生为调查对象,采用E字型国际标准对数视力表和相关调查问卷,进行检测、调查和统计分析.结果 被调查者的视力低下率为83.87%,以中度为主,女生(85.54%)视力低下率高于男生(76.67%),高年级(四、五年级)学生视力低下率(87.29%)高于低年级(一、二、三年级)学生(79.34%),护理专业学生的视力低下率(86.46%)高于其他专业学生(P<0.05).视力正常的学生更注意保持正确的阅读距离、每天使用手机的时间较

  7. 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 < 0.05 determined as statistically significant. There were 49 and 50 participants in the Tablet and Keyboard group respectively. The 95% CI of the difference between the scores from the test and retest in each group

  8. 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

    Directory of Open Access Journals (Sweden)

    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

  9. Preoperative Quantitative MR Tractography Compared with Visual Tract Evaluation in Patients with Neuropathologically Confirmed Gliomas Grades II and III: A Prospective Cohort Study

    Science.gov (United States)

    Delgado, Anna F.; Nilsson, Markus; Latini, Francesco; Mårtensson, Johanna; Zetterling, Maria; Berntsson, Shala G.; Alafuzoff, Irina; Lätt, Jimmy; Larsson, Elna-Marie

    2016-01-01

    Background and Purpose. Low-grade gliomas show infiltrative growth in white matter tracts. Diffusion tensor tractography can noninvasively assess white matter tracts. The aim was to preoperatively assess tumor growth in white matter tracts using quantitative MR tractography (3T). The hypothesis was that suspected infiltrated tracts would have altered diffusional properties in infiltrated tract segments compared to noninfiltrated tracts. Materials and Methods. Forty-eight patients with suspected low-grade glioma were included after written informed consent and underwent preoperative diffusion tensor imaging in this prospective review-board approved study. Major white matter tracts in both hemispheres were tracked, segmented, and visually assessed for tumor involvement in thirty-four patients with gliomas grade II or III (astrocytomas or oligodendrogliomas) on postoperative neuropathological evaluation. Relative fractional anisotropy (rFA) and mean diffusivity (rMD) in tract segments were calculated and compared with visual evaluation and neuropathological diagnosis. Results. Tract segment infiltration on visual evaluation was associated with a lower rFA and high rMD in a majority of evaluated tract segments (89% and 78%, resp.). Grade II and grade III gliomas had similar infiltrating behavior. Conclusion. Quantitative MR tractography corresponds to visual evaluation of suspected tract infiltration. It may be useful for an objective preoperative evaluation of tract segment involvement. PMID:27190647

  10. Preoperative Quantitative MR Tractography Compared with Visual Tract Evaluation in Patients with Neuropathologically Confirmed Gliomas Grades II and III: A Prospective Cohort Study

    Directory of Open Access Journals (Sweden)

    Anna F. Delgado

    2016-01-01

    Full Text Available Background and Purpose. Low-grade gliomas show infiltrative growth in white matter tracts. Diffusion tensor tractography can noninvasively assess white matter tracts. The aim was to preoperatively assess tumor growth in white matter tracts using quantitative MR tractography (3T. The hypothesis was that suspected infiltrated tracts would have altered diffusional properties in infiltrated tract segments compared to noninfiltrated tracts. Materials and Methods. Forty-eight patients with suspected low-grade glioma were included after written informed consent and underwent preoperative diffusion tensor imaging in this prospective review-board approved study. Major white matter tracts in both hemispheres were tracked, segmented, and visually assessed for tumor involvement in thirty-four patients with gliomas grade II or III (astrocytomas or oligodendrogliomas on postoperative neuropathological evaluation. Relative fractional anisotropy (rFA and mean diffusivity (rMD in tract segments were calculated and compared with visual evaluation and neuropathological diagnosis. Results. Tract segment infiltration on visual evaluation was associated with a lower rFA and high rMD in a majority of evaluated tract segments (89% and 78%, resp.. Grade II and grade III gliomas had similar infiltrating behavior. Conclusion. Quantitative MR tractography corresponds to visual evaluation of suspected tract infiltration. It may be useful for an objective preoperative evaluation of tract segment involvement.

  11. Comparison of the INNOVA Visual Acuity System Stereotest with the Frisby-Davis 2 Stereotest for the Evaluation of Distance Stereoacuity.

    Science.gov (United States)

    Singman, Eric L; Matta, Noelle S; Silbert, David I; Tian, Jin

    2013-01-01

    Distance stereo acuity has been shown to be useful in monitoring conditions such as control of intermittent strabismus. The Frisby Davis distance (FD2) stereotest has been shown to be reliable and is felt to be the gold standard in England. The device however is not widely available in the United States or Canada and is not automated. This study compares the Innova distance stereoacuity test with the Frisby Davis distance (FD2) stereotest. Twenty-seven patients with normal acuity and a normal ophthalmology exam were evaluated. Prior to dilation all patients had an Innova distance stereoacuity test and FD2 test. Both the Innova distance stereoacuity test and the FD2 test were performed at ten feet. The results of the tests were compared using Bland-Altman plot analysis. The INNOVA system tended to underestimate distance stereoacuity by approximately 30 arc seconds compared to the FD2 test. If the INNOVA results were corrected by this amount, then there was a good correlation between the INNOVA results and the FD2. The Innova distance stereoacuity test underestimates stereopsis by approximately 30 arc seconds but does so with sufficient consistency that it may serve as an acceptable method of measuring distance stereoacuity. This study is the first that has correlated the Innova stereoacuity test with the FD2.

  12. Visual loss after spine surgery

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    Kapil Mohan

    2012-01-01

    Full Text Available Incidence of perioperative visual loss ranges from 0.06% to 0.2% with the most common cause as ischemic optic neuropathy. We report one-year follow up of a 50-years-old hypertensive housewife who underwent lumbar decompression and fusion for degenerative scoliosis, but woke up with painless unilateral visual loss. Fundus examination was normal. Her visual acuity improved from initial finger counting close to face to finger counting at 3 m at 1 year. Identification of high risk patients may help in appropriate preoperative counselling, prevention and early recognition of this devastating complication.

  13. Relação entre acuidade visual e atividades instrumentais de vida diária em idosos em seguimento ambulatorial Relationship between visual acuity and instrumental activities of daily living of the elderly in clinical segment

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    Sheila de Melo Borges

    2010-06-01

    Full Text Available OBJETIVO: Avaliar a influêrcia da acuidade visual nas atividades instrumentais de vida diária em idosos em seguimento ambulatorial. MÉTODOS: Foram entrevistados, por meio de instrumento próprio, 64 idosos em seguimento ambulatorial num hospital universitário de Campinas/SP. Os sujeitos foram divididos em dois grupos, conforme os valores obtidos na medida da AV: o grupo I, composto pelos idosos com visão normal ou próxima do normal; e o grupo II, formado por aqueles com baixa visão. Foram realizadas correlações bivariadas entre as variáveis, a fim de identificar as seguintes relações entre os grupos de acuidade visual e as atividades instrumentais de vida diária. RESULTADOS: Foram observadas diferenças significativas entre os idosos com visão normal ou próxima do normal (grupo I e aqueles com baixa visão (grupo II, com respeito às variáveis. O grupo II apresentou maior dificuldade do que o grupo I no escore total do instrumento, bem como nas seguintes tarefas: uso do telefone, preparo de refeições, trabalhos manuais, lavar e passar roupa e tomar corretamente os remédios. CONCLUSÃO: Neste estudo, idosos com baixa visão de ambos os sexos apresentam maior dificuldade para realizar as AIVDs do que idosos com visão normal ou próxima do normal.OBJECTIVE: To evaluate the influence of visual acuity in instrumental activities of daily living in elderly patients in follow-up period. METHODS: through own instruments, sixty-four elderly men and women were interviewed in clinical segment at an academic hospital of Campinas/SP. They were then divided into two groups in accordance to the values that were obtained through the measure of the VA: the first group consisted of elderly people with normal vision or close to the normal, and the second group was formed of those with low vision. Bivariate correlations were made between the variables in order to identify the following relations: between groups of visual and instrumental

  14. Comparison of Snellen acuity, VER acuity, and Arden grating scores in macular and optic nerve diseases.

    Science.gov (United States)

    Skalka, H W

    1980-01-01

    Patients with various macular and optic nerve abnormalities underwent Snellen acuity, transient VER acuity, and Arden grating testing. Snellen acuity was the coarsest of the 3 evaluations, generally falling after Arden scores and VER acuity had already undergone significant degradation. The Arden gratings appeared to be the most sensitive of the 3 tests, equalling VER performance in optic nerve diseases and surpassing it in macular diseases. Variations in results between the different tests are generally understandable if one considers the functions tested by each and the anatomical derangements caused by the diseases in question. The Arden grating test appears to be an excellent and sensitive screening test for central visual disturbances. Images PMID:7356929

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

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    Jorge Antonio Meireles-Teixeira

    2000-10-01

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

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

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    Solange Rios Salomão

    2008-08-01

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

  17. [Status of center point thickness and correlation between anatomic and best corrected visual acuity changes after photocoagulation, in diabetic macular edema].

    Science.gov (United States)

    Lima-Gómez, Virgilio; Razo Blanco-Hernández, Dulce Milagros

    2013-01-01

    Antecedentes: el grosor del punto central en pacientes con edema macular diabético cambia después del tratamiento, dependiendo del estado basal; se desconoce si esta variación reduce la correlación entre los cambios anatómicos y de capacidad visual. Objetivo: identificar la contribución del grosor del punto central basal a la correlación entre los cambios anatómicos y de capacidad visual, después de tratar el edema macular diabético. Material y métodos: estudio observacional, prospectivo, longitudinal y analítico, en diabéticos con edema macular tratados con fotocoagulación, estratificado por grupos: capacidad visual < 0.5 con (1) o sin engrosamiento central (2), y capacidad visual = 0.5 con (3) o sin engrosamiento central (4). Se identificó la correlación entre los cambios de grosor del punto central, volumen macular y capacidad visual (Spearman). Resultados: 79 ojos, 17 del grupo 1 (21.5%), 21 del 2 (26.6%), 14 del 3 (17.7%), 27 del 4 (34.2%). El grosor del punto central aumentó en los grupos 2 y 4, la capacidad visual disminuyó en el 3 y el volumen en todos. Las correlaciones entre el grosor del punto central y la capacidad visual en el grupo 3, y entre el volumen y la capacidad visual en el grupo 1 fueron negativas. La correlación de la muestra entre los cambios anatómicos y de capacidad visual fue baja (r= 0.14). Conclusiones: el aumento del grosor del punto central en ojos sin engrosamiento previo generó correlaciones opuestas entre grupos, y redujo la de la muestra. Estratificar conforme al grosor del punto central basal facilitaría identificar variables que afectan la respuesta terapéutica funcional.

  18. Development of a clinically feasible logMAR alternative to the Snellen chart: performance of the "compact reduced logMAR" visual acuity chart in amblyopic children.

    Science.gov (United States)

    Laidlaw, D A H; Abbott, A; Rosser, D A

    2003-10-01

    The "compact reduced logMAR" (cRLM) chart is being developed as a logMAR alternative to the Snellen chart. It is closer spaced and has fewer letters per line than conventional logMAR charts. Information regarding the performance of such a chart in amblyopes and children is therefore required. This study aimed to investigate the performance of the cRLM chart in amblyopic children. Timed test and retest measurements using two versions of each chart design were obtained on the amblyopic eye of 43 children. Using the methods of Bland and Altman the agreement, test-retest variability (95% confidence limits for agreement, TRV) and test time of the cRLM and the current clinical standard Snellen chart were compared to the gold standard ETDRS logMAR chart. No systematic bias between chart designs was found. For line assignment scoring the respective TRVs were 0.20 logMAR, 0.20 logMAR, and 0.30 logMAR. Single letter scoring TRVs were cRLM (95% CL 0.17) logMAR, ETDRS (95% CL 0.14) logMAR, and Snellen (95% CL 0.29) logMAR. Median testing times were ETDRS 60 seconds, cRLM 40 seconds, Snellen 30 seconds. The sensitivity to change of the cRLM equalled or approached that of the gold standard ETDRS and was at least 50% better than that of Snellen. This enhanced sensitivity to change was at the cost of only a 10 second time penalty compared to Snellen. The cRLM chart was approximately half the width of the ETDRS chart. The cRLM chart may represent a clinically acceptable compromise between the desire to obtain logMAR acuities of reasonable and known sensitivity to change, chart size, and testing time.

  19. CLINICAL OBSERVATION OF CORNEAL CURVATURE AND CONTRAST VISUAL ACUITY BY RIGID GAS PERMEABLE CONTACT LENS%硬性角膜接触镜对圆锥角膜曲率和对比度视力的观察

    Institute of Scientific and Technical Information of China (English)

    韩联仪; 黄燕; 郑德海

    2011-01-01

    [目的]观察普通屈光不正和圆锥角膜患者配戴硬性角膜接触镜(RGPCL) 1~2年的视力矫正,对比敏感度,及角膜塑形效果.[方法]对66例(126只眼)6~32岁的患者进行验光,计算机辅助角膜地形图,角膜屈率计检查,对比敏感度观察戴框架眼镜和RGPCL矫正视力和视觉质量变化.[结果]总体平均近视球镜度(4.47±3.13)DS,平均柱镜度(3.91±2.39) DC.裸眼视力(0.18±0.18),戴框架镜较正视力(0.895±0.33),RGP矫正视力(1.06±0.24).戴RGPCL视力明显优于戴框架镜较正视力,两者差异具有统计学意义(P<0.05).角膜地形图各项值戴RGP-CL前后统计显示,戴RGP后角膜前表面陡峭K值(Ks),平均K值(AveK),角膜散光cyl,锥顶K值,均较戴RGPCL前降低,各项指标差异均具有统计学意义(P<0.05).对比敏感度全频段RGPCL均比框架镜明显升高.[结论]合理的配戴RGPCL,不仅可以获得较好的矫正视力,提高对比敏感度曲线,改善视觉质量.还可以获得显著的角膜塑形效果,有效控制圆锥角膜的进展.%[Objective] To investigate the effects on optical correction, contrast sensitivity and orthokeratology with rigid gas permeable contact lens (RGPCL) fitting 1-2 years in patients with ametropia and keratoconus. [Methods] Corrected visual acuity, comeal topography, cornea] curvature and contrast sensitivity were compared in 66 patients (126 eyes) of 6-32 years old with spectacles and RGPCL. [Results] The average spherical dioptre were (4.47±3.13) DS, cylindrical spherical were (3.91±2.39) DC. Uncorrected visual acuity were 0.18±0.18e, the mean corrected vision with spectacles and with RGPCL fitting were 0.895±0.33 and 1.06±0.24, respectively. The patients with RGPCL fitting got better corrected vision than those with spectacles, the differences between the two groups were statistically significant (P < 0.05). The comeal topography showed that the Ks, AveK, cyl and apex K value after RGPCL fitting

  20. 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

  1. The effects of diffusion blur on Snellen and grating acuity and foveal function in amblyopia.

    Science.gov (United States)

    Han, S H; Kim, S K; Lee, J B; Lee, M S

    1998-08-01

    In order to verify that the effects of diffusion blur on Snellen and grating acuity in amblyopic eyes resemble those obtained from the peripheral or central retina in normal controls, we conducted the following experiment using a liquid crystal window (Edmund Scientific Co.) to produce diffusion blur on Snellen and grating acuity. Spatial frequencies used for a Snellen chart and Teller acuity card were 3.2, 6.5, 13.0, 26.0 cyc/cm at a working distance of 55 cm. The values of diffusive blur on central and peripheral visual acuity obtained from 20 normal healthy control eyes were compared with those values of central visual acuity in 26 amblyopic eyes. The diffusion blur had a strong negative effect on both Snellen and grating acuity in amblyopic eyes, but it had more potent effects on grating acuity (p 0.05). Snellen acuity obtained from diffusion blur overestimated grating acuity in the normal central acuity group and amblyopic central acuity group. The result of this investigation demonstrated that the liquid crystal diffusion blur had a strong negative effect on both Snellen and grating acuity and suggested that the visual function of an amblyopic retina resembled that of a normal central retina.

  2. 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.; Vizzeri, G.

    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.

  3. 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.

  4. Color improves ‘visual’ acuity via sound

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    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. Combined intravitreal bevacizumab with phacoemulsification in visually significant cataract and visually significant exudative maculopathy

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    Ahmad Mansour

    2011-01-01

    Full Text Available Purpose : We investigated the visual outcome of combined phacoemulsification with intravitreal bevacizumab, in eyes with dense cataract and visually significant exudative maculopathy. Materials and Methods : Prospective longitudinal pilot study of consecutive patients treated by two surgeons in 2006, using intravitreal bevacizumab at the end of phacoemulsification. The historical control group consisted of consecutive subjects with exudative maculopathy and dense cataract treated by the same surgeons with the help of phacoemulsification without intravitreal bevacizumab prior to 2006. Results : Thirty-one treated patients had the mean (SD logMar best corrected visual acuity improving from - 1.48 (0.50 preoperatively to - 0.67 (0.38 in the first postoperative week ( p < 0.001, to - 0.64 (0.40 in the first postoperative month ( p < 0.001, and to - 0.62 (0.42 ( p < 0.001 on the last follow-up (mean 4.2 months, range 1 - 9 months. Fourteen control patients had the mean (SD logMar best corrected visual acuity improving from - 1.78 (0.79 preoperatively, to - 0.91 (0.53 in the first postoperative week ( p < 0.001, to - 0.86 (0.45 in the first postoperative month ( p < 0.001, and to - 0.90 (0.47 ( p < 0.001 on the last follow- up (mean 19.6 months, range 1 - 49 months. Initial visual acuities, final visual acuities, and percentage of visual improvement at one month were all not significantly better in the intervention compared to the control group at one month. In the study group, the fovea was flattened at the one-month follow-up, by 90-diopter slit lamp examination and / or Optical coherence tomography. Conclusion : The combination of intravitreal bevacizumab and phacoemulsification is beneficial for maximal visual rehabilitation in the first postoperative month.

  6. Color improves “visual” acuity via sound

    OpenAIRE

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

    2014-01-01

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

  7. 77 FR 7549 - Revised Medical Criteria for Evaluating Visual Disorders

    Science.gov (United States)

    2012-02-13

    ... proposed 2.00A5a(ii) that explains how we use visual acuity measurements not recorded in Snellen notation... provide the equivalent visual acuity efficiency percentages corresponding to Snellen best- corrected... visual acuity efficiency values that correspond to Snellen best-corrected central visual acuities for...

  8. Acuity systems and control charting.

    Science.gov (United States)

    Shaha, S H

    1995-01-01

    The strengths of control charting and other statistical process control (SPC) tools have not previously been applied to acuity systems. Intermountain Health Care, Salt Lake City, Utah, developed a new acuity system that relies heavily upon control charting for an array of purposes, including immediate feedback to caregivers regarding decisions, ongoing feedback to managers regarding decision patterns, and longer-term feedback regarding trends and budget-relevant information. The use of control charts has eliminated the need for auditing acuity-based staffing and has maintained the reliability of classifications at levels above 95 percent. Implications for other novel applications are offered.

  9. 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

  10. Use of intravitreal bevacizumab or triamcinolone acetonide as a preoperative adjunct to vitrectomy for vitreous haemorrhage in diabetics

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    Daniel Araújo Ferraz

    2013-02-01

    Full Text Available PURPOSE: To evaluate the effect of preoperative intravitreal bevacizumab (IVB or triamcinolone (IVT on the rate of early postvitrectomy hemorrhage in proliferative diabetic retinopathy (PDR. METHODS: Eligible eyes were assigned randomly to 1 of 3 groups: the IVB group received 1.25 mg bevacizumab, the IVT group received 4,0mg triamcinolone and the control group underwent a sham procedure. The primary outcome measure was the incidence of early postvitrectomy hemorrhage. Secondary outcome measures included changes in visual acuity (BCVA and adverse events. RESULTS: Twenty and seven eyes, 9 in each group were randomized. The incidence of vitreous hemorrhage was lower in the IVB group (p=0.18. Postoperative vitreous hemorrhage at 1 month also was less in the IVB group compared with the control group (p > 0.05. The rate of bleeding immediately after surgery was higher in IVT group with 4 (44.4% cases. The overall mean visual acuity was 1.72 ± 0.37 logMAR preoperatively and 1.32 ± 0.73 logMAR in 6 months after surgery. Accessing visual acuity by group evidenced that the IVB group had initial mean logMAR VA of 1.87 and 1.57 logMAR VA at the six months (p = 0.84. In IVT group, initial mean VA was 1.75 logMAR and 0.96 logMAR VA at six months (p < 0.001. And in control group, the initial mean VA was 1.85 logMAR and 1.57 logMAR VA at six months (p= 0.34. CONCLUSION: Intravitreal injection of bevacizumab 1 week before vitrectomy seems to reduce the incidence of early postvitrectomy hemorrhage in diabetic patients. There was a better visual acuity outcome in the triamcinolone group.

  11. Comparison of Visual, Refractive and Topographic Keratometry Outcomes of Intacs and Intacs SK in Mild to Moderate Keratoconus Eyes

    OpenAIRE

    Abdulrahman Al Muammar

    2015-01-01

    Purpose: The purpose was to evaluate and compare the visual and refractive outcomes, topographic keratometry (K) and complications of Intacs and Intacs SK for mild to moderate keratoconus. Methods: In this retrospective study, all mild to moderate keratoconus eyes that underwent implantation of Intacs (Intacs group) or Intacs SK (Intacs SK group) with minimum follow-up of 12 months were included. Preoperative and postoperative uncorrected distance visual acuity (UDVA), corrected distance ...

  12. Value of visual evoked potential monitoring during trans-sphenoidal pituitary surgery.

    Science.gov (United States)

    Chacko, A G; Babu, K S; Chandy, M J

    1996-06-01

    The visual outcome of 22 patients undergoing trans-sphenoidal excision of pituitary macroadenomas with intraoperative flash visual evoked potential (VEP) monitoring (Group A), was compared with a non-randomized group of 14 patients who had undergone similar operations without VEP monitoring (Group B). Tumour size, preoperative visual acuity, peripheral fields, and latencies and amplitudes of P1 and P2 were analysed to ascertain the best predictor of postoperative visual function. It was found that patients in Group A had a significantly greater improvement in field defects than those in Group B. There was no difference in postoperative improvement in visual acuity between the two groups. None of the variables analysed were good predictors of visual outcome.

  13. ANALYSIS OF COLLEGE FRESHMEN'S VISUAL ACUITY IN ANHUI UNIVERSITY OF TECH-NOLOGY%安徽工业大学入学新生视力20年调查结果分析

    Institute of Scientific and Technical Information of China (English)

    姚锦

    2012-01-01

    [Objective] This study aims at investigating the current college freshmen's eyesight conditions and the major factors concerned, thus to offer good grounds for further measures taken for students' eyesight protection. [Methods] Measured college freshmen's eyesight through the E-type international visual acuity testing chart, then analyzed naked eyesight with the chi-square lest. The statistical analysis was applied to the final data. [Results] (1) The poor eyesight rates of male and female were respectively 80.67% and 85.46% and the female poor eyesight rate was higher than the male. The differential degree had a statistical significance (x2=21.85, P<0.05). (2) Among those college freshmen, male or female, with, poor eyesight, the rale of middle level of low eyesight was higher dian the light level of low eyesight, while the weight level of low eyesight was higher than middle level of low eyesight. The differential degree had a statistical significance. (3) The contrast between the 1980s-90s and the 21st century showed: The last two decades of the 20lh century witnessed the ever-increasing trend of the college freshmen's poor eyesight rale white the rate went to stability from the 1990s to the early years of the new century. [Conclusion] To best prevent college freshmen's visual acuity conditions from going worsening, more active and scientific measures may be taken for preventing and curing college students' nearsightedness on campus.%[目的]了解大学新生视力状况及其影响因素,为高校视力保健提供依据.[方法]采用E字型国际标准对数视力表对入学体检的大学新生进行裸眼视力检测,采用卡方检验方法,对数据进行统计学处理.[结果](1)男女视力不良率分别是80.67%和85.46%,女生视力不良率高于男生,差别有统计学意义(x2=21.85,P<0.05).(2)在视力不良率大学新生中,不论男女,中度视力低下率高于轻度视力低下率,重度视力低下率又大大高于中度视力

  14. 黄斑部脉络膜新生血管的OCT图像特征及与视力的相关性%Correlation between optical coherence tomography image characteristics of macular choroidal neovascularization and visual acuity

    Institute of Scientific and Technical Information of China (English)

    张敏芳; 孟晓红; 陈军; 冉黎

    2011-01-01

    目的 观察黄斑部脉络膜新生血管(choroidal neovascularization,CNV)的光学相干断层扫描(optical coherence tomography,OCT)图像特征,评估其与最佳矫正视力的相关性. 方法 收集在我院经眼底荧光血管造影(fundus fluorescein angiography,FFA)及吲哚氰绿血管造影(indocyanine green angiography,ICGA)检查确诊为黄斑部典型性CNV高度近视(high myopia,HM)、年龄相关性黄斑变性(age-related macular degeneration,AMD)及中心性渗出性脉络膜视网膜病变(central exudative chorioretinopathy,CEC)患者共34例36眼,经验光检查得到最佳矫正视力(best corrected visual acuity,BCVA);采用OCT仪检查并分析CNV的图像特征,并测量CNV突破RPE/脉络膜毛细血管复合层的基底部宽度、高度、离中心凹的距离及中心处视网膜神经上皮层组织厚度,分别评估其与视力改变的相关性. 结果 CNV的OCT图像特征:RPE/脉络膜毛细血管层下见大小不等局限性增强隆起反射带;合并病灶周围视网膜神经上皮层组织下局限性无反射暗区或组织内反射增厚.AMD所引起的CNV基底部宽度、高度及中心处神经上皮层组织厚度值均最大.经直线相关分析统计显示:AMD和CEC所引起CNV的基底部宽度及中心处视网膜神经上皮层组织厚度均与BCVA具有负相关性(均为P<0.05),而HM所引起的CNV仅中心处视网膜神经上皮层组织厚度与BCVA具有负相关性(P<0.05). 结论 OCT能有效测量CNV的长度及黄斑水肿程度,在有效评估其与BCVA的相关性中具有重要作用.%Objective To investigate the optical coherence tomography (OCT) image characteristics of macular choroidal neovascularization (CNV) and evaluate their correlation with visual acuity. Methods Thirty-six eyes of 34 cases with high myopia, age-related macular degeneration ( AMD) and center exudation chorioretinopathy, which were diagnosed as typical macular CNV using fundus fluorescein angiography and indocyanine

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

    Directory of Open Access Journals (Sweden)

    Maria-Andreea Gamulescu

    2012-01-01

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

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

    Science.gov (United States)

    Gamulescu, Maria-Andreea; Panagakis, Georgios; Theek, Carmen; Helbig, Horst

    2012-01-01

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

  17. Visual quality after epipolis laser in situ keratomileusis surgery in mild and moderate myopia

    Directory of Open Access Journals (Sweden)

    Yin-Liang Huang

    2015-07-01

    Full Text Available AIM: To comprehensively evaluate of visual quality after epipolis laser in situ keratomileusis(EPI-LASIKin mild to moderate myopia.METHODS: Sixty cases(120 eyesundergone EPI-LASIK with equivalent diopter(SEwere divided into two groups: mild myopia group(60 eyesand moderate myopia group(60 eyes. Objective visual acuity, aberration, contrast sensitivity and glare sensitivity were measured before and 1wk; 1, 6mo after operation, and made comparative analysis. RESULTS: Postoperative uncorrected visual acuity(UCVAof two groups were better than that of preoperative(PPPPPPPCONCLUSION: Visual quality is poorer in mild myopia patients than that in moderate myopia at early stage after EPI-LASIK. Better visual quality is observed at mid-late stage.

  18. On Using Vernier Acuity to Assess Magnocellular Sensitivity

    Science.gov (United States)

    Skottun, Bernt C.; Skoyles, John R.

    2010-01-01

    A recent study [Keri, S., & Benedek, G. (2009). Visual pathway deficit in female fragile x premutation carriers: A potential endophenotype. "Brain and Cognition", 69, 291-295] has found Vernier acuity deficiencies together with contrast sensitivity defects consistent with a magnocellular deficit in female fragile x premutation carriers. This may…

  19. Preoperative Anxiety before Spinal Anesthesia: Does Internet-based Visual Information/Multimedia Research Decrease Anxiety and Information Desire? A Prospective Multicentered Study

    OpenAIRE

    Tulgar, Serkan; Boga, Ibrahim; Piroglu, Mustafa Devrim; Ates, Nagihan Gozde; Bombaci, Elif; Can, Tuba; Selvi, Onur; Tas, Zafer; Kose, Halil Cihan

    2017-01-01

    Background: Preoperative anxiety may lead to peroperative or postoperative problems when not overcome. Aims: The aim of this study was to examine the effect of seeking information and other factors on the anxiety of patients preoperatively. Settings and Design: This study was a prospective, multicentered survey. Materials and Methods: Patients scheduled to undergo surgical procedures under spinal anesthesia, preoperatively evaluated as the American Society of Anesthesia 1?3 and where spinal a...

  20. Visual Outcomes after Vitrectomy for Terson Syndrome Secondary to Traumatic Brain Injury.

    Science.gov (United States)

    Narayanan, Raja; Taylor, Stanford C; Nayaka, Ashraya; Deshpande, Riddhima; St Aubin, Daniel; Hrisomalos, Frank N; Hu, Jonathan; Rajagopal, Rithwick; Tewari, Asheesh; Apte, Rajendra S

    2017-01-01

    To evaluate visual outcomes after vitrectomy for intraocular hemorrhages secondary to traumatic brain injury. Retrospective, observational case series. A total of 28 eyes in 20 patients undergoing vitrectomy for Terson syndrome secondary to traumatic brain injury between 1997 and 2015. We reviewed the records of patients undergoing a standard 20-gauge or 23-gauge pars plana vitrectomy for intraocular hemorrhages secondary to traumatic brain injury, and the timing of vitrectomy in relation to the inciting intracranial event was recorded. The primary outcome measure was the change in the preoperative visual acuity score at postoperative month 1 and at the last noted clinic appointment. A total of 28 eyes in 20 patients (all male) underwent pars plana vitrectomy for intraocular hemorrhages secondary to traumatic brain injury. The mean preoperative baseline logarithm of the minimum angle of resolution (logMAR) (Snellen) best-corrected visual acuity (BCVA) was 1.81±0.56 (20/1290). At 1-month postoperative follow-up, the mean BCVA was 0.30±0.33 (20/40). At the date of the last follow-up, the mean BCVA was 0.15±0.24 (20/30) and the median BCVA was 0.00 (20/20). Although the difference between preoperative and postoperative BVCA was significantly different at 1 month and the final postoperative clinic visits (P visual acuity as a predictor of final postoperative visual acuity outcome (r=-0.32; P = 0.09; 95% confidence interval [CI] -0.62 - 0.06). At the date of the last follow-up, the differences in visual outcomes between the individuals undergoing vitrectomy within 3 months of the inciting event, 0.08±0.15 (20/25), were not significantly different than those undergoing surgical intervention after 3 months, 0.18±0.27 (20/30) (P = 0.28). Three cases among those undergoing vitrectomy after 3 months were complicated by retinal detachment, none of which resulted in a BCVA worse than when the patient originally presented preoperatively. In this retrospective series of

  1. Visual performance in cataract patients with low levels of postoperative astigmatism: full correction versus spherical equivalent correction

    Directory of Open Access Journals (Sweden)

    Lehmann RP

    2012-03-01

    correction of low levels of preoperative corneal astigmatism.Keywords: aspheric intraocular lens, astigmatism, cataract surgery, contrast sensitivity, reading acuity, visual acuity

  2. Relationship between central visual acuity and retinal volume of macular fovea accessed by spectral domain optical coherence tomography in Stargardt disease%Stargardt病的频域相干光断层扫描图像分析

    Institute of Scientific and Technical Information of China (English)

    张枝桥; 张承芬; 董方田; 陈有信; 于伟泓; 戴荣平; 郑霖

    2011-01-01

    Objective To assess the relationship between central visual acuity and retinal volume of macular fovea in patients with Stargardt disease by spectral-domain optical coherence tomography ( SD OCT). Methods It was a retrospective case series study. Twenty eyes of 10 patients with Stargardt disease were investigated by three-dimensional spectral-domain optical coherence tomography. SD OCT images were obtained and retrospectively analyzed. The retinal volumes of macular fovea were measured by SD OCT,whose diameters were set as 3 mm and 1 mm separately ( volume 3 and volume 1). The retinal thickness of macular fovea (macular thickness) and the width of IS/OS conjunction loss of macular fovea (IS/OS loss)were also measured by SD OCT. We correlated the logMAR BCVA with IS/OS loss, macular thickness,volume 3 and volume 1 by linear regression analysis. Results LogMAR BCVA was from 0. 3 to 1. 22.IS/OS loss was from 847 μm to 5306 μm. Macular thickness was from 20 μm to 126μm. Volume 3 and volume 1 was from 1. 06 to 1. 76 mm3 and 0. 06 to 0. 13 mm3. LogMAR BCVA correlated with the IS/OS loss (r = 0.695,P<0. 05) , macular thickness (r= - 0. 601 ,P < 0. 05), and volume 3 ( r = -0.725,P<0. 05 ). LogMAR BCVA did not correlate with volume 1 ( r = - 0. 364, P > 0. 05). Conclusions SD OCT could demonstrate the retinal structure of Stargardt disease clearly. The retinal volume of macular fovea accessed by SD OCT correlated with the visual acuity of Stargardt disease.%目的 应用频域相干光断层扫描(OCT)技术评价Stargardt病患者黄斑区视网膜容积与中心视力之间的关系.方法 回顾性病例系列研究.收集10例(20只眼)Stargardt病的临床资料进行回顾性分析.所有患者均使用频域OCT分别测量黄斑中心凹区视网膜厚度、黄斑中心凹区光感受器细胞内外节缺失宽度、黄斑中心凹区直径3 mm和1 mm范围内的视网膜容积.运用线性回归分析法,比较最小分辨角对数(logMAR)视力与黄

  3. Imitating the effect of amblyopia on VEP-based acuity estimates.

    Science.gov (United States)

    Heinrich, Sven P; Bock, Celia M; Bach, Michael

    2016-12-01

    Acuity testing based on visual evoked potentials (VEPs) overestimates acuity in patients with amblyopia. We hypothesized that distortion and fragmentation of the stimulus in amblyopia impede recognition of optotypes, while it leaves the pattern onset response in the VEP mostly unaffected, resulting in overestimation of acuity. Acuity VEPs were recorded in visually normal participants with the stimulus degraded by patterned polymethyl methacrylate panes, which induce distortion and fragmentation. For comparison, frosted panes were used to induce blur through wide-angle scattering. Standard psychophysical optotype acuity was recorded under the same conditions. With the distorted and fragmented stimuli, the VEP consistently overestimated acuity relative to psychophysical optotype acuity. With blurred stimuli, both measures were in good agreement. The data support the assumption that stimulus distortion and fragmentation leave VEP-based measures of acuity relatively unaffected, resulting in a discrepancy between measures of acuity that are based on checkerboard VEPs on one hand and psychophysical optotype recognition on the other hand. The technique of stimulus degradation described here provides a simple and efficient way of imitating effects that are known from amblyopia and may thus serve as a tool in the evaluation of vision tests.

  4. Comparison of Snellen acuity and objective assessment using the spatial frequency sweep PVER.

    Science.gov (United States)

    Arai, M; Katsumi, O; Paranhos, F R; Lopes De Faria, J M; Hirose, T

    1997-07-01

    We compared the vision objectively assessed by spatial frequency sweep pattern-reversal visual-evoked response (SPVER) with the Snellen acuity in patients. SPVER acuity and Snellen acuity were measured in 100 patients with various ocular pathologies, including macular diseases, diffuse retinal degeneration, optic nerve diseases, glaucoma, and high myopia. For SPVER, 10 sinusoidally modulated vertical gratings were presented as stimuli. The responses were averaged and displayed through the discrete Fourier transform on the monitor display. The PVER acuity was determined by extrapolating the SPVER amplitude-spatial frequency function to baseline. Vision ranged from 20/15 to 20/400 with Snellen acuity, and from 20/25 to 20/190 with SPVER. The overall correlation between the two acuities was r = 0.666. The correlation varied from r = 0.895 in eyes with glaucoma to r = 0.436 in eyes with optic nerve disease. Seventy-seven eyes (77%) had a visual acuity agreement of within 1.0 octave between the two measurements. The SPVER acuity and the Snellen acuity correlated to a certain degree. Discrepancies were found in certain diseases, with the highest disparity in patients with optic nerve disease. We conclude that the SPVER is effective in estimating vision objectively, particularly in patients in whom the standard Snellen test is impossible to perform or yields unreliable results.

  5. VEP-based acuity assessment in low vision.

    Science.gov (United States)

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

    2017-10-04

    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.

  6. Baseline Factors Associated With 6-Month Visual Acuity and Retinal Thickness Outcomes in Patients With Macular Edema Secondary to Central Retinal Vein Occlusion or Hemiretinal Vein Occlusion: SCORE2 Study Report 4.

    Science.gov (United States)

    Scott, Ingrid U; VanVeldhuisen, Paul C; Ip, Michael S; Blodi, Barbara A; Oden, Neal L; King, Jacqueline; Antoszyk, Andrew N; Peters, Mark A; Tolentino, Michael

    2017-06-01

    Macular edema (ME) is the leading cause of decreased visual acuity (VA) associated with retinal vein occlusion (RVO). Identifying factors associated with better outcomes in RVO eyes treated with anti-vascular endothelial growth factor (VEGF) therapy may provide information useful in counseling patients. To investigate baseline characteristics associated with 6-month VA and central subfield thickness (CST) outcomes in participants in the Study of Comparative Treatments for Retinal Vein Occlusion 2 (SCORE2). A total of 362 patients with central RVO or hemi-RVO were enrolled between September 17, 2014, and November 18, 2015, and randomized 1:1 in a masked fashion to receive bevacizumab or aflibercept. At month 6, 348 participants (96%) had VA outcomes measured and 335 participants (93%) had spectral domain optical coherence tomography outcomes measured. The current data analysis was conducted from February 27, 2017, to April 7, 2017. Eyes were randomly assigned to receive an intravitreal injection of bevacizumab, 1.25 mg, or aflibercept, 2.0 mg, at baseline and every 4 weeks, with the primary outcome measured at 6 months. Change from baseline in VA letter score (VALS), VALS gain of 15 or more, change from baseline in CST, CST less than 300 µm, and resolution of ME. Baseline factors associated with 6-month outcome at the 0.05 level in univariate regressions were included in multivariate regressions, with those significant after multiplicity control by the Hochberg method reported. The mean (SD) age of patients was 69 (12) years, and 43% were women. Younger patient age (odds ratio [OR], 0.95 per year of age; 95% CI, 0.93-0.98; P = .007) and lower baseline VALS (OR, 0.96 per letter; 95% CI, 0.94-0.98; P < .001) were associated with a 6-month VALS gain of 15 or greater. Compared with bevacizumab, aflibercept treatment was associated with a higher odds of ME resolution (OR, 3.59; 95% CI, 2.22-5.80; P < .001) and CST less than 300 µm (OR,  5.30; 95% CI, 2

  7. Long-term visual outcomes after Crystalens® HD intraocular lens implantation

    Directory of Open Access Journals (Sweden)

    Karavitaki AE

    2014-05-01

    Full Text Available Alexandra E Karavitaki, Ioannis G Pallikaris, Sophia I Panagopoulou, George A Kounis, George Kontadakis, George D KymionisInstitute of Vision and Optics, University of Crete, Crete, GreecePurpose: Our purpose was to evaluate the long-term visual outcomes after bilateral implantation of Crystalens® HD (Bausch and Lomb, Inc. accommodative intraocular lenses.Methods: In this study, 25 patients (50 eyes who underwent cataract surgery and bilateral Crystalens HD accommodative intraocular lens implantation were included. The Crystalens HD lens was implanted in the bag in both eyes, without any intra- or postoperative complications. The visual parameters measured before and after surgery were: uncorrected distance visual acuity, corrected distance visual acuity (CDVA (using the Early Diabetic Retinopathy Study [EDTRS] logMAR charts, uncorrected intermediate visual acuity, and uncorrected near visual acuity using a Birkhäuser reading chart, at a distance of 66 cm and 33 cm for intermediate and near vision, respectively, directly illuminated by a lamp of 60 watts. After surgery, the patients were evaluated at 1, 3, 6, 12, 24, and 36 months.Results: The mean age was 68.70±7.1 (range: 54 to 83 years. The mean follow-up was 42.72±0.49 (range: 42.33 to 43.27 months. The uncorrected distance visual acuity improved from 0.56±0.41 (range: 0 to 2 preoperatively to 0.19±0.13 (range: 0 to 0.38 (logMAR scale at the last follow-up visit, and the CDVA improved from 0.17±0.18 (range: 0 to 0.7 preoperatively to 0.05±0.05 (range: −0.02 to 0.22 at the last follow-up visit. No eyes lost lines of CDVA during the follow-up period, while 54% of patients gained one or more lines of CDVA. The uncorrected intermediate and near visual acuity was J2 or better in 71% and 69% of our patients, respectively.Conclusion: Crystalens HD implantation seems to provide an improvement in visual acuity for far, intermediate, and near distances.Keywords: presbyopia, accommodation

  8. Retropupillary fixation of iris-claw lens in visual rehabilitation of aphakic eyes

    Directory of Open Access Journals (Sweden)

    G Jayamadhury

    2016-01-01

    Full Text Available Context: Surgical outcome of retropupillary fixation of iris claw lens. Aims: To evaluate the various indications, intra and post-operative complications, and visual outcome of retropupillary fixation of iris claw lens in aphakic eyes. Settings and Design: The study design is a retrospective study at a tertiary eye care center. Methods: Review of medical records of 61 aphakic eyes of 61 patients, who were rehabilitated with retropupillary fixation of an iris claw lens, with a follow-up duration of at least 1 year. Statistical Analysis Used: Data analysis was performed using paired t-test and Chi-square test. Results: Mean preoperative uncorrected visual acuity was 1.66 ± 0.3 LogMAR and postoperative acuity at 1 year was 0.53 ± 0.5 LogMAR (P = 0.00001. Preoperative distant best-corrected visual acuity was 0.30 ± 0.48 LogMAR and postoperative acuity at 1 year was 0.27 ± 0.46 LogMAR (P = 0.07. Mean preoperative astigmatism was 1.43 ± 1.94 D and postoperatively was 1.85 ± 2.16 D (P = 0.0127. Mean endothelial cell count was 2353.52 ± 614 cells/mm2 preoperatively which decreased to 2200 ± 728 cells/mm2 at 1 year follow-up (P = 0.006. There was no significant difference in central macular thickness and intraocular pressure pre and post-surgery. Complications included ovalization of pupil in 9.83%, hypotony in 1.63%, toxic anterior segment syndrome in 1.63%, cystoid macular edema in 11.47%, epiretinal membrane in 3.27%, and iris atrophy in 6.55%. Conclusion: Iris claw is a safe and an effective method of rehabilitating aphakic eyes.

  9. Visual outcomes and optical quality after implantation of a diffractive multifocal toric intraocular lens

    Science.gov (United States)

    Chen, Xiangfei; Zhao, Ming; Shi, Yuhua; Yang, Liping; Lu, Yan; Huang, Zhenping

    2016-01-01

    Background: This study evaluated the visual function after implantation of a multifocal toric intraocular lenses (IOLs). Materials and Methods: This study involved 10 eyes from eight cataract patients with corneal astigmatism of 1.0 diopter (D) or higher who had received phacoemulsification with implantation of an AcrySof IQ ReSTOR Toric IOL. Six-month evaluations included visual acuity, spherical equivalent (SE), defocus curve, residual astigmatism, IOL rotation, contrast sensitivity (CS), wavefront aberrations, modulation transfer function (MTF), and patient satisfaction assessments. Results: At 6 months postoperatively, uncorrected distance visual acuity (logarithm of the minimum angle of resolution) was 0.09 ± 0.04, corrected distance visual acuity was 0.02 ± 0.11, and uncorrected near visual acuity was 0.12 ± 0.07. The mean SE was −0.095 ± 0.394 D (±0.50 D in 90%). Refractive astigmatism at the 6-month follow-up visit was significantly reduced to 0.35 ± 0.32 D from 1.50 ± 0.41 D presurgery (P 0.05). There was an increase in MTF results between preoperative and postoperative evaluations at all spatial frequencies. Conclusions: The diffractive multifocal toric IOL is able to provide a predictable astigmatic correction with apparently outstanding levels of optical quality after implantation. PMID:27221680

  10. Factors influencing improvement of visual field after trans-sphenoidal resection of pituitary macroadenomas: a retrospective cohort study

    Directory of Open Access Journals (Sweden)

    Fen-Fen Yu

    2015-12-01

    Full Text Available To investigate the influencing factors of visual field improvement after trans-sphenoidal resection of pituitary macroadenomas. This retrospective cohort study included 201 patients (366 eyes with visual field defect induced by pituitary macroadenomas. All of them were treated with trans-sphenoidal surgery. Ophthalmologic evaluation, best-corrected visual acuity (BCVA, and visual field examination were performed before and 3mo after surgery. BCVA, visual field defect index mean deviation (MD, duration of symptoms, age, sex, and volume of tumors were compared. Expression of vascular endothelial growth factor (VEGF and Ki-67 of tumor tissue were detected by immunohistochemical technique. The mean age of patients was 44.23±1.29y. Ninety-three patients were female and 108 were male. The mean tumor volume was 14.36±6.23 cm3. The mean duration of preoperative symptoms was 11.50±0.88mo. Mean preoperative MD was -17.50±0.82 dB. Mean Preoperative visual acuity was 0.64±0.04. Postoperative visual field improved in 270 (73.77% eyes, unchanged in 96 (26.23% eyes. Multivariate logistic regression displayed that the factors independently influencing visual field improvement were young age (OR=1.71, 95%CI: 1.325-2.387, P=0.013, low preoperative MD absolute value (OR=1.277, 95%CI: 1.205-1.355, P After pituitary macroadenomas trans-sphenoidal resection, the independent influencing factors of the visual fields recovery were low preoperative MD absolute value, young age, small volume of tumor, and expression levels of VEGF/ Ki-67.

  11. 玻璃体腔注射贝伐单抗治疗PDR黄斑水肿后患者的满意度和视力%Patient satisfaction and visual acuity after intravitreal bevacizumab as a treatment for macular edema in proliferative diabetic retinopathy

    Institute of Scientific and Technical Information of China (English)

    Lala Ceklic; Slobodanka Latinovic; Aljoscha S Neubauer; Marijana Malesevic

    2009-01-01

    AIM: To investigate patient assessed visual function and visual acuity after treatment with the unselective anti-VEGF inhibitor bevacizumab in diabetic macular edema after scatter laser photocoagulation due to proliferative diabetic retinopathy(PDR).METHODS: The case series of consecutive 30 eyes of 30 patients with PDR and persistent diabetic macular edema were treated with a single intravitreal dose of 1.25mg bevacizumab in 0.05mL (Avastin) in combination with scatter argon laser photocoagulation. The control group consisted of 30 eyes of 30 patients with PDR who received scatter laser photocoagulation alone. Main outcome measures were Snellen visual acuity,fundus clinical findings and patients self estimated quality of vision evaluated in scale of 0-100 percentages.RESULTS: Baseline visual acuity was mean 0.48±0.58 logMAR in the bevacizumab group and 0.61±0.78 (n.s.) in the control group. After 6 months,visual acuity hat not changed significantly to 0.33±0.41 and 0.52±0.68 in the bevacizumab and control group,respectively. Clinical examination showed only a trend to some improvement in macular edema. Subjective patient assessment of visual function on the visual analogue scale (VAS) showed an improvement from 60.2±17.5 to 76.0±15.6 (P<0.01) 6 months after the injection of bevacizumab. In the control group self-assessed visual function was mean 59.6±19.8,which did not differ from the baseline bevacizumab group (n.s.) but was high significantly (P<0.01) lower than after bevacizumab. CONCLUSION: Self-assessed visual acuity and patient satisfaction were significantly improved after intravitreal bevacizumab (Avastin) as additional therapy to scatter laser photocoagulation therapy for macular edema in PDR than after laser therapy alone. Visual acuity did not change significantly in this comparative case series over 6 months.KEYWORDS: proliferative diabetic retinopathy; visual acuity; self assessment; bevacizumab; scatter laser photocoagulation%目的:增生性

  12. Functional assessment of reattached macula in nine cases with excellent Snellen acuities.

    Science.gov (United States)

    Ozgür, S; Esgin, H

    2007-04-01

    To compare the macular functions of patients with excellent visual acuity after retinal detachment (RD) surgery, with the healthy fellow eye. Of 214 patients, nine patients, who were successfully operated because of unilateral RD involving the macula and achieved excellent visual acuity, were analysed. The fellow eyes of the patients were taken as the control group. The macular functions were evaluated with visual acuity, contrast sensitivity, colour vision, visual field, and pattern VEP in operated and nonoperated eyes. There was no significant difference in visual acuity, contrast sensitivity, colour vision, and VEP outcomes between operated and nonoperated eyes. However, it was seen that the mean deviation in the visual field was significantly higher in the operated eyes (5.8+/-1.8 dB) when compared with the undetached fellow eyes (3.1+/-1.8 dB), (t=12.5; P=0.013). Even though the visual acuity, colour vision, contrast sensitivity, and VEP results returned to normal after a successful RD surgery, we found that the mean deviation measured by the visual field, which reflects the retinal sensitivity, was still significantly low after nearly 5 years follow-up.

  13. Preoperative Anxiety before Spinal Anesthesia: Does Internet-based Visual Information/Multimedia Research Decrease Anxiety and Information Desire? A Prospective Multicentered Study.

    Science.gov (United States)

    Tulgar, Serkan; Boga, Ibrahim; Piroglu, Mustafa Devrim; Ates, Nagihan Gozde; Bombaci, Elif; Can, Tuba; Selvi, Onur; Tas, Zafer; Kose, Halil Cihan

    2017-01-01

    Preoperative anxiety may lead to peroperative or postoperative problems when not overcome. The aim of this study was to examine the effect of seeking information and other factors on the anxiety of patients preoperatively. This study was a prospective, multicentered survey. Patients scheduled to undergo surgical procedures under spinal anesthesia, preoperatively evaluated as the American Society of Anesthesia 1-3 and where spinal anesthesia was agreed on beforehand, were included. Patients completed State-Trait Anxiety Inventory Scale-State (STAI-S) survey preoperatively. Patients who sought information were also asked to complete the Amsterdam Preoperative Anxiety and Information Scale survey. Quantitative data were compared with one-way ANOVA with post hoc analysis or Kruskal-Wallis test. Comparison of two groups of parameters showing normal distribution was compared using Student's t-test. Comparison of groups versus anxiety was performed using Chi-square and Fisher's exact tests. A total of 330 patients were included. Average STAI-S scores were similar when evaluated for patients' demographic data, gender, marital status, place of residence, type of operation, preoperative fasting time, and comorbidities. University graduates were found to have lower anxiety when compared to other educational statuses. Seeking information from the internet caused a significant decrease in surgical anxiety (P anxiety. Interestingly, those seeking information had higher information desire levels compared to patients who had not sought other sources of information (P information regarding surgical procedure and/or spinal anesthesia have lower preoperative anxiety levels, their information desire remains high. Apart from detailed information given by the anesthesiologist or surgeon, having access to correct and validated information in multimedia form may decrease anxiety and information desire.

  14. EFFECTS OF PREOPERATIVE SOFT CONTACT LENS WEAR ON HIGHER-ORDER ABERRATIONS AFTER LASER IN SITU KERATOMILEUSIS

    Institute of Scientific and Technical Information of China (English)

    YU Jing; CHEN Hui; CHENG Xin-liang; WANG Fang

    2008-01-01

    Objective To evaluate the effects of preoperative soft contact lens (SCL) wear on higher-order aberrations(HOAs)correction after wavefront-guided and conventional laser in situ keratomileusis (LASIK).Methods A prospective randomized double-masked comparative study was conducted in 180 eyes of 90 patients scheduled for LASIK, including 92 eyes of 46 patients with previous SCL wear. The patients were divided into four groups: no SCL-conventional group, SCL-conventional group, no SCL-wavefront group and SCL-wavefront group. Preoperative and postoperative examinations included uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), contrast sensitivity and HOAs.Results The UCVA and BSCVA were 20/20 in all patients at 6 months postoperatively. And 36.3%, 22.7%, 18.1% and 35.4% gained one line or more of BSCVA in no SCL-wavefront group, SCL-wavefront group, no SCL-conventional group and SCL-conventional group, respectively. Both the safety index and efficacy index surpassed one in 4 groups and were highest in no SCL-wavefront group. The increase in root-mean-square (RMS) values of HOAs was significantly lower in no SCL-wavefront group and higher in SCL-wavefront group. At 6 months postoperatively, the increase in RMS of HOAs (RMSh) were 0.67, 1.58, 1.17 and 1.28 in no SCL-wavefront group, SCL-wavefront group, no SCL-conventional group and SCL-conventional group, respectively.Conclusion Preoperative contact lens wear has significant influence on the efficacy of HOAs correction in wavefront-guided LASIK. Patients with contact lens wear preoperatively should be cautious when scheduled for wavefront-guided LASIK.

  15. Simulating Visibility Under Reduced Acuity and Contrast Sensitivity

    Science.gov (United States)

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

    2017-01-01

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

  16. Comparative evaluation of teller and cardiff acuity tests in normals and unilateral amblyopes in under-two-year-olds

    OpenAIRE

    Sharma Pradeep; Bairagi Debasis; Sachdeva Murli; Kaur Kulwant; Khokhar Sudarshan; Saxena Rohit

    2003-01-01

    Purpose: To compare and evaluate Teller Acuity Cards (TAC) and Cardiff Acuity Cards (CAC) to assess vision in children below the age of two. Methods: The study evaluated TAC and CAC to assess visual acuity in 90 normal children divided into three age groups, 0 - 6 months (group I), 6 - 12 months (group II) and 12 - 24 months (group III). 30 cases of unilateral amblyopiogenic conditions, 10 cases each of unilateral refractive error, unilateral esotropia, and unilateral cataract, were also ...

  17. Non-rigid alignment of pre-operative MRI, fMRI, and DT-MRI with intra-operative MRI for enhanced visualization and navigation in image-guided neurosurgery.

    Science.gov (United States)

    Archip, Neculai; Clatz, Olivier; Whalen, Stephen; Kacher, Dan; Fedorov, Andriy; Kot, Andriy; Chrisochoides, Nikos; Jolesz, Ferenc; Golby, Alexandra; Black, Peter M; Warfield, Simon K

    2007-04-01

    The usefulness of neurosurgical navigation with current visualizations is seriously compromised by brain shift, which inevitably occurs during the course of the operation, significantly degrading the precise alignment between the pre-operative MR data and the intra-operative shape of the brain. Our objectives were (i) to evaluate the feasibility of non-rigid registration that compensates for the brain deformations within the time constraints imposed by neurosurgery, and (ii) to create augmented reality visualizations of critical structural and functional brain regions during neurosurgery using pre-operatively acquired fMRI and DT-MRI. Eleven consecutive patients with supratentorial gliomas were included in our study. All underwent surgery at our intra-operative MR imaging-guided therapy facility and have tumors in eloquent brain areas (e.g. precentral gyrus and cortico-spinal tract). Functional MRI and DT-MRI, together with MPRAGE and T2w structural MRI were acquired at 3 T prior to surgery. SPGR and T2w images were acquired with a 0.5 T magnet during each procedure. Quantitative assessment of the alignment accuracy was carried out and compared with current state-of-the-art systems based only on rigid registration. Alignment between pre-operative and intra-operative datasets was successfully carried out during surgery for all patients. Overall, the mean residual displacement remaining after non-rigid registration was 1.82 mm. There is a statistically significant improvement in alignment accuracy utilizing our non-rigid registration in comparison to the currently used technology (paugmented reality visualization to aid the surgeon.

  18. Non-rigid alignment of preoperative MRI, fMRI, and DT-MRI with intra-operative MRI for enhanced visualization and navigation in image-guided neurosurgery

    Science.gov (United States)

    Archip, Neculai; Clatz, Olivier; Whalen, Stephen; Kacher, Dan; Fedorov, Andriy; Kot, Andriy; Chrisochoides, Nikos; Jolesz, Ferenc; Golby, Alexandra; Black, Peter M.; Warfield, Simon K.

    2012-01-01

    Objective The usefulness of neurosurgical navigation with current visualizations is seriously compromised by brain shift, which inevitably occurs during the course of the operation, significantly degrading the precise alignment between the preoperative MR data and the intra-operative shape of the brain. Our objectives were (i) to evaluate the feasibility of non-rigid registration that compensates for the brain deformations within the time constraints imposed by neurosurgery, and (ii) create augmented reality visualizations of critical structural and functional brain regions during neurosurgery using pre-operatively acquired fMRI and DT-MRI. Materials and Methods Eleven consecutive patients with supratentorial gliomas were included in our study. All underwent surgery at our intra-operative MR imaging–guided therapy facility and have tumors in eloquent brain areas (e.g. precentral gyrus and cortico-spinal tract). Functional MRI and DT-MRI, together with MPRAGE and T2w structural MRI were acquired at 3T prior to surgery. SPGR and T2w images were acquired with a 0.5T magnet during each procedure. Quantitative assessment of the alignment accuracy was carried out and compared with current state-of the-art systems based only on rigid-registration. Results Alignment between preoperative and intra-operative datasets was successfully carried out during surgery for all patients. Overall, the mean residual displacement remaining after non-rigid registration was 1.82 mm. There is a statistically significant improvement in alignment accuracy utilizing our non-rigid registration in comparison to the currently used technology (paugmented reality visualization to aid the surgeon. PMID:17289403

  19. Analysis of correlation between corneal topographical data and visual performance

    Science.gov (United States)

    Zhou, Chuanqing; Yu, Lei; Ren, Qiushi

    2007-02-01

    Purpose: To study correlation among corneal asphericity, higher-order aberrations and visual performance for eyes of virgin myopia and postoperative laser in situ keratomileusis (LASIK). Methods: There were 320 candidates 590 eyes for LASIK treatment included in this study. The mean preoperative spherical equivalence was -4.35+/-1.51D (-1.25 to -9.75), with astigmatism less than 2.5 D. Corneal topography maps and contrast sensitivity were measured and analyzed for every eye before and one year after LASIK for the analysis of corneal asphericity and wavefront aberrations. Results: Preoperatively, only 4th and 6th order aberration had significant correlation with corneal asphericity and apical radius of curvature (pcorneal asphericity (pcorneal aberrations had no significant correlation with visual acuity and area under the log contrast sensitivity (AULCSF) (P>0.05). Postoperatively, corneal aberrations still didn't have significant correlation with visual acuity (P>0.05), but had significantly negative correlation with AULCSF (PCorneal asphericity had no significant correlation with AULCSF before and after the treatment (P>0.05). Conclusions: Corneal aberrations had different correlation with corneal profile and visual performance for eyes of virgin myopia and postoperative LASIK, which may be due to changed corneal profile and limitation of metrics of corneal aberrations.

  20. Automated measurement of resolution acuity in infants using remote eye-tracking.

    Science.gov (United States)

    Jones, Pete R; Kalwarowsky, Sarah; Atkinson, Janette; Braddick, Oliver J; Nardini, Marko

    2014-10-28

    To validate a novel, automated test of infant resolution acuity based on remote eye-tracking. Infants aged 2 to 12 months were tested binocularly using a new adaptive computerized test of infant vision using eye tracking (ACTIVE), and Keeler infant acuity cards (KIAC). The ACTIVE test ran automatically, using remote eye-tracking to assess whether the infant fixated a black-and-white grating of variable spatial frequency. Test-retest reliability was assessed by performing each test twice. Accuracy was assessed by comparing acuity measures across tests and with established age-norms, and by comparing low-contrast acuity estimates in adults with data reported previously. All infants completed the ACTIVE test at least once. Median test duration was 101 seconds. Measured visual acuity increased with age (P 0.183). An adaptive computerized test of infant vision using eye-tracking provides a rapid, automated measure of resolution acuity in preverbal infants. The ACTIVE performed comparably to the current clinical gold standard (acuity cards) in terms of testability, reliability, and accuracy, and its principles can be extended to measure other visual functions. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

  1. Visual agnosia.

    Science.gov (United States)

    Álvarez, R; Masjuan, J

    2016-03-01

    Visual agnosia is defined as an impairment of object recognition, in the absence of visual acuity or cognitive dysfunction that would explain this impairment. This condition is caused by lesions in the visual association cortex, sparing primary visual cortex. There are 2 main pathways that process visual information: the ventral stream, tasked with object recognition, and the dorsal stream, in charge of locating objects in space. Visual agnosia can therefore be divided into 2 major groups depending on which of the two streams is damaged. The aim of this article is to conduct a narrative review of the various visual agnosia syndromes, including recent developments in a number of these syndromes.

  2. 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

  3. Visualization

    OpenAIRE

    Balon, Andreja

    1990-01-01

    The present thesis entails the field of visualization which is divided into visualization along traditional lines and visualization in computer science. As the psychological aspect of image is of vital importance for visualization, it is shortly described in the beginning. Visualization in computer science is divided into three main fields: scientific visualization, program visualization and visual programming. An explanation and examples of approach to applications are given for each field....

  4. Pituitary Macroadenoma and Visual Impairment: Postoperative Outcome Prediction with Contrast-Enhanced FIESTA.

    Science.gov (United States)

    Hisanaga, S; Kakeda, S; Yamamoto, J; Watanabe, K; Moriya, J; Nagata, T; Fujino, Y; Kondo, H; Nishizawa, S; Korogi, Y

    2017-09-14

    Contrast-enhanced FIESTA can depict anterior optic pathways in patients with large suprasellar tumors. We assessed whether the degree of kink in the optic nerve at the optic canal orifice on contrast-enhanced FIESTA correlates with the postoperative improvement of visual impairment in patients with pituitary macroadenoma. Thirty-one patients with pituitary macroadenoma who underwent preoperative MR imaging and an operation were evaluated. We measured the optic nerve kinking angle on sagittal oblique contrast-enhanced FIESTA parallel to the optic nerve; the optic nerve kinking angle was defined as the angle between a line parallel to the planum sphenoidale and a line parallel to the intracranial optic nerve at the optic canal orifice. We used logistic regression analyses to determine whether the clinical (sex, age, and duration of symptoms) and imaging (tumor height, chiasmal compression severity, hyperintense optic nerve on T2WI, and optic nerve kinking angle) characteristics were associated with the postoperative improvement (good-versus-little improvement) of visual acuity disturbance and visual field defect. There were 53 impaired sides before the operation: 2 sides with visual acuity disturbance alone, 25 with visual field defect alone, and 26 with both. After the operation, good improvement was found in 17 of the 28 sides with visual acuity disturbance and in 32 of the 51 sides with visual field defects. Only the optic nerve kinking angle was significantly associated with good improvement of the visual acuity disturbance (P = .011) and visual field defect (P = .002). The degree of the optic nerve kinking angle was an independent predictor of postoperative improvement, indicating that irreversible damage to the optic nerve may be associated with its kinking at the optic canal orifice. © 2017 American Society of Neuroradiology.

  5. Congenital cataract surgery with intraocular lens implantation in microphthalmic eyes: visual outcomes and complications

    Directory of Open Access Journals (Sweden)

    Marcelo Carvalho Ventura

    2013-08-01

    Full Text Available PURPOSE: To report the visual outcomes and complications of congenital cataract surgery with primary intraocular lens implantation in microphthalmic eyes of children younger than 4 years of age. METHODS:This retrospective interventional case series included 14 microphthalmic eyes from 10 children who underwent congenital cataract surgery with primary intraocular lens implantation younger than 4 years of age. Seven patients had bilateral cataracts (11 eyes met the study's inclusion criteria and 3 patients had unilateral cataract. Patients' medical charts were reviewed to obtain information regarding the preoperative and postoperative ophthalmological examination. Main outcome measures were intraocular pressure (IOP, best-corrected visual acuity, and intraoperative and postoperative complications. RESULTS: Mean age at the time of surgery was 21.7 ± 2.9 months. Mean ocular axial length was 19.2 ± 0.9 mm. Mean preoperative IOP was 9.7 ± 1.7 mmHg and 10.3 ± 3.1 mmHg on final follow-up (P=0.18. There were no intraoperative complications. Two (15.4% eyes developed secondary visual axis opacification, of which only one needed to be reoperated due to significantly decreased vision (0.5 logMAR. Preoperative and postoperative best-corrected visual acuity was 2.09 ± 0.97 logMAR and 0.38 ± 0.08 logMAR in bilateral cases and 1.83 ± 1.04 logMAR and 0.42 ± 0.13 logMAR in unilateral cases, respectively. CONCLUSION: Primary intraocular lens implantation in congenital cataract surgery in microphthalmic eyes resulted in a significant best-corrected visual acuity improvement with no intraoperative complications and minimal postoperative complications.

  6. Factors affecting tactile spatial acuity.

    Science.gov (United States)

    Craig, J C; Kisner, J M

    1998-01-01

    Tactile spatial acuity on the fingerpad was measured using a grating orientation task. In this task, subjects are required to identify the orientation of square-wave gratings placed on the skin. Previous studies have shown that performance varies as a function of the width of the grooves in the gratings. In the present study, both groove width and the overall size and configuration of the contactors were varied. Sensitivity improved with wider grooves and with larger contactors. Additional measurements showed that the improved sensitivity is not the result of the increase in total area contacted, but rather is due to two other factors associated with larger contactors. One is the greater linear extent of the larger contactors. The other appears to be due to the reduction in the interference produced by the outer edge of the contactor. Specifically, as the contactor increases in size, the distance between the outer edge and the center portion of the grooves also increases. It was also shown that subjects are more sensitive to a single, continuous groove as compared with two grooves of the same total length but spatially discontinuous. Similarly, subjects are more sensitive to a contactor with a continuous groove than to a contactor in which just the end points of the groove are presented. The results are generally consistent with the results of peripheral, neurophysiological recordings. The results are discussed in terms of the way in which both spatial and intensive factors may affect sensitivity to grating orientation.

  7. Development of a clinically feasible logMAR alternative to the Snellen chart: performance of the “compact reduced logMAR” visual acuity chart in amblyopic children

    Science.gov (United States)

    Laidlaw, D A H; Abbott, A; Rosser, D A

    2003-01-01

    Background/aim: The “compact reduced logMAR” (cRLM) chart is being developed as a logMAR alternative to the Snellen chart. It is closer spaced and has fewer letters per line than conventional logMAR charts. Information regarding the performance of such a chart in amblyopes and children is therefore required. This study aimed to investigate the performance of the cRLM chart in amblyopic children. Methods: Timed test and retest measurements using two versions of each chart design were obtained on the amblyopic eye of 43 children. Using the methods of Bland and Altman the agreement, test-retest variability (95% confidence limits for agreement, TRV) and test time of the cRLM and the current clinical standard Snellen chart were compared to the gold standard ETDRS logMAR chart. Results: No systematic bias between chart designs was found. For line assignment scoring the respective TRVs were 0.20 logMAR, 0.20 logMAR, and 0.30 logMAR. Single letter scoring TRVs were cRLM (95% CL 0.17) logMAR, ETDRS (95% CL 0.14) logMAR, and Snellen (95% CL 0.29) logMAR. Median testing times were ETDRS 60 seconds, cRLM 40 seconds, Snellen 30 seconds. Conclusion: The sensitivity to change of the cRLM equalled or approached that of the gold standard ETDRS and was at least 50% better than that of Snellen. This enhanced sensitivity to change was at the cost of only a 10 second time penalty compared to Snellen. The cRLM chart was approximately half the width of the ETDRS chart. The cRLM chart may represent a clinically acceptable compromise between the desire to obtain logMAR acuities of reasonable and known sensitivity to change, chart size, and testing time. PMID:14507755

  8. The Predictability of Preoperative Pilocarpine-Induced Lens Shift on the Outcomes of Accommodating Intraocular Lenses Implanted in Senile Cataract Patients

    Science.gov (United States)

    Li, Jin; Chen, Qi; Lin, Zhibo; Leng, Lin; Huang, Fang

    2016-01-01

    Purpose. To evaluate the predictability of lens shift induced by pilocarpine (LSPilo) on the outcomes of accommodating intraocular lens (Acc-IOL) implantation. Methods. Twenty-four eyes of 24 senile cataract patients who underwent phacoemulsification and Acc-IOL implantation were enrolled. LSPilo was evaluated with anterior segment optical coherence tomography (AS-OCT). At 3 months postoperatively, the best corrected distance visual acuities (BCDVA), distance-corrected near visual acuities (DCNVA), and subjective and objective accommodations were measured. IOL shifts under accommodation stimulus (IOLSAcc) were evaluated with AS-OCT. Results. The mean LSPilo was 112.29 ± 30.72 µm. LSPilo was not associated with any preoperative parameters. The mean IOLSAcc was 130.46 ± 42.71 µm. The mean subjective and objective accommodation were 1.54 ± 0.39 D and 1.27 ± 0.41 D, respectively. The mean postoperative BCDVA and DCNVA (log MAR value) were 0.22 ± 0.11 and 0.24 ± 0.12, respectively. LSPilo positively correlated with IOLSAcc (r = 0.541; P = 0.006), subjective accommodation (r = 0.412; P = 0.022), and objective accommodation (r = 0.466; P = 0.045), respectively. Conclusion. LSPilo is an independent preoperative parameter associated with the postoperative Acc-IOL mobility and pseudophakic accommodation. It may offer valuable information for ophthalmologists in determining the suitable candidates for Acc-IOL implantation. PMID:27516899

  9. 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

  10. [A significant increase in intraoperative flash visual evoked potential amplitude during craniopharyngioma surgery-case report].

    Science.gov (United States)

    Kawaguchi, Tomohiro; Ogawa, Yoshikazu; Fujiwara, Satoru; Tominaga, Teiji

    2015-04-01

    The flash visual evoked potential (VEP) is a useful diagnostic modality for visual preservation during surgery. Decreased VEP amplitude is recognized to indicate visual deterioration;however, whether intraoperative VEP can detect visual improvement remains unclear. We describe a craniopharyngioma case with a significant increase in VEP amplitude during surgery. A 67-year-old woman presented with progressive gait disturbance and impaired consciousness. Head magnetic resonance imaging demonstrated a sellar-suprasellar tumor compressing the optic chiasm upward with significant ventricular dilation. Her Glasgow Coma Scale was E3V3M5. Visual fields and acuity could not be examined because of impaired consciousness, and she could not see/recognize objects on a table. Preoperative VEP showed reproducible waveforms. Tumor removal by the extended transsphenoidal approach was performed with VEP monitoring. Increased VEP amplitude was observed after dural incision and persisted until the surgery ended. Postoperative VEP waveforms were also reproducible, but visual fields/acuity could not be examined because of cognitive dysfunction. Useful visual function was restored, and she became independent in daily life. The histological diagnosis was craniopharyngioma. The patient underwent ventriculo-peritoneal shunting for hydrocephalus 16 days after tumor removal. The postoperative course was uneventful and she was transferred to another hospital for rehabilitation. Intraoperative VEP may indicate visual improvement during surgery, which is a useful objective assessment for visual function in patients with impaired consciousness and cognitive dysfunction.

  11. 广州地区3~6岁学龄前儿童视力发育及屈光状态流行病学调查%Epidemiological study of the development of refraction and visual acuity in preschoolers aged 3 to 6 in the Guangzhou area

    Institute of Scientific and Technical Information of China (English)

    赵峰; 郑德慧; 李振; 杨智宽; 蓝卫忠; 曾骏文; 刘雯; 陈林兴; 刘文彦; 卢金华

    2010-01-01

    Objective To investigate the refractive error and best corrective visual acuity of preschoolers aged 3 to 6 years. Methods Ten kindergartens were randomly selected from different districts in the Guangzhou area. Refractive error and best corrected visual acuity of the preschoolers were measured. Refractive error was determined by an autorefractor, which was rechecked by cycloplegic retinoscopy with cyclopentolate. Best corrected visual acuity was measured with an EDTRS vision chart. Data was analyzed with one-way ANOVA using Bonferroni correction. Results Two thousand four hundred and eighty children were examined in the study. There were 201 boys and 172 girls in the 3-year-old group and 434/384, 437/410, 238/204 in the 4-, 5- and 6-year-old groups, respectively. The mean ages in months were 43.3±2.8, 53.8±3.3, 65.5±3.4 and 75.1 ±2.6, respectively. The spherical equivalent refractions of the corresponding age groups were (1.66±0.70)D, (1.67±0.80)D, (1.59±0.81)D and (1.48±0.72)D, respectively. And the differences among the groups were statistically significant (P=0.000). The Bonferroni multiple comparisons showed that the difference between any pair of groups was statistically significant, except for that between the 3-year-old and 4-year-old groups, and between the 3-year-old and 5-year-old groups. The best corrected visual acuities on the LogMAR scale for the corresponding age groups were 0.26±0.14, 0.18±0.10, 0.13± 0.08 and 0.10±0.08, respectively. The difference among groups was statistically significant (P=0.000). The Bonferroni multiple comparisons between any pair of groups were also statistically significant (P=0.000). Conclusion Hyperopic refractive error gradually decreases with an increase of age during the 3rd to 6th years. The norms of the best corrected visual acuity shows a slow rise during this period, which indicates that age is an indispensable factor in making a diagnosis of amblyopia in children.%目的 了解广州地Ⅸ3~6岁学

  12. A comparative study on visual acuity and stereopsis outcomes between perceptual learning based on cloud services and conventional therapy for amblyopia%基于云服务技术的视知觉训练与传统综合训练对改善弱视患儿视力和立体视功能的疗效比较

    Institute of Scientific and Technical Information of China (English)

    汤玮玮; 王潇潇; 陶黎明

    2016-01-01

    Background Amblyopia is a developmental disorder of spatial vision that results in both monocular and binocular deficits.Conventional therapy for amblyopia which focuses on monocular training can improve visual acuity.However,how to improve the binocular function,especially stereopsis is rarely studied.Objective This study was to evaluate the outcome of perceptual learning based on cloud services of improving stcreopsis and visual acuity for amblyopia.Methods A randomized-controlled clinical study was performed.One hundred and seven amblyopic patients (178 eyes) with the age of 5-18 years old were recruited in The Second Affiliated Hospital of Anhui Medical University from July 2013 to March 2014.The patients were randomized into the perceptual learning group and the conventional therapy group.A perceptual learning based on cloud services with computer under the best corrected visual acuity was carried out in the perceptual learning group with 30-day duration as a course for 5-6 cycles,and training feedback data was obtained after each cycle for the regulation of following treatment.The dominant eye was covered during the training process.In the conventional therapy group,a training regimen of health eye covering that combined with eyesight training of amblyopic eye was performed.The stereopsis and visual acuity of the patients were estimated after training.Written informed consent was obtained from the parents or custodians of the children before entering the cohort.Results The total effective rate of visual acuity improvement is significantly higher in the perceptual learning group than that in the conventional therapy group after training (Z =6.368,P=0.012).The mean stereopsis value of the amblyopic eyes in the perceptual learning group and the conventional therapy group was (127±53)" and (174±67)" after training,which was significantly higher than (273 ±95)" and (311 ±103)" before training,respectively,and the increasing range of the mean stereopsis was

  13. Are flash-evoked visual potentials useful for intraoperative monitoring of visual pathway function?

    Science.gov (United States)

    Cedzich, C; Schramm, J; Fahlbusch, R

    1987-11-01

    Flash-evoked visual potentials (VEPs) recorded from the scalp were used in a series of 35 patients with tumors along the visual pathway: 3 orbital tumors, 25 perisellar tumors, 4 intraventricular tumors, and 3 occipital lesions. Preoperatively, various combinations of impaired visual fields and visual acuity were observed in over 90% of the patients. A postoperative decrease in visual function was observed in 3 cases. Of the 25 perisellar lesions, 13 were operated through a standard frontotemporal craniotomy and 12 were operated through a transnasal-transsphenoidal approach. VEPs were highly susceptible to volatile anesthetics, and there was a significant incidence of spontaneous latency increases and amplitude decreases in a large number of patients. There was an unacceptably high number of cases with significant VEP alteration occurring without concomitant visual function change. During trepanation or the transnasal approach, a reversible potential loss was observed in 11 patients, a profoundly altered wave form was seen in 8 cases, and a loss of single peaks was observed in 15 patients. During dissection of the tumor, a reversible potential loss or a potential with unidentifiable peaks was found in 25 cases; however, the VEPs recovered during closure or in the recovery room. There was no correlation between intraoperative VEP changes and the postoperative changes in visual function. In only 1 patient with an insignificant postoperative decrease in visual acuity from 0.4 to 0.3 was there a concomitant intraoperative potential loss. The major conclusion of our findings is that light-emitting diode flash-evoked VEPs demonstrate intraoperative changes that appear too early and too prominently to be caused solely by manipulation of the optic pathways.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. 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/.

  15. Pre-operative variables affecting final vision outcome with a critical review of ocular trauma classification for posterior open globe (zone III) injury

    Science.gov (United States)

    Agrawal, Rupesh; Ho, Sue Wei; Teoh, Stephen

    2013-01-01

    Purpose: To identify pre-operative variables affecting the outcome of posterior open globe (zone III) injuries. Secondary objective was to re-look at the definition or landmarks for zone III injury and its clinical significance for predicting visual prognosis following open globe injury. Materials and Methods: Retrospective review of medical records of all hospitalized patients with surgical repair of open globe injury over last 10 years at a tertiary referral eye care center in Singapore. Out of 172 eyes with open globe injury, 28 eyes (16.3%) with zone III injury was identified and reviewed further. Pre-operative visual acuity (VA) and other variables, extent of scleral wound in reference to rectus insertion, relative afferent pupillary defect (RAPD) and final vision outcome were recorded. Results: Median age was 37 years with male predilection (92.9%). Mean follow-up was 12.9 months. Pre-operative VA was no light perception (NLP) in 16 (57.1%) eyes. Final VA remained NLP in 14 eyes (50.0%). The factors contributing to poor post-operative vision based on univariate regression analysis were the presence of RAPD, poor pre-operative VA, blunt trauma, extent of trauma, associated traumatic cataract, hyphema, vitreous loss and associated vitreo-retinal trauma. Further on, zone III injuries with scleral wound limited anterior to rectus insertion (6 eyes) had better vision outcome than those with injuries extending beyond rectus insertion (22 eyes). Conclusion: Initial VA, blunt ocular trauma, visual axis involvement, loss of light perception, presence of RAPD, traumatic cataract, hyphema, vitreous loss were the important determinants for final visual outcome in patients with zone III injury. Wound extending posterior to rectus insertion has poorer outcome as those limited anterior to rectus insertion. We suggest that there may be a need to relook at zone III injuries with reference to rectus insertion for prognostic significance, and further studies are warranted. PMID

  16. Optical Filter Effects on Night Vision Goggle Acuity and Preservation of Dark Adaptation

    Science.gov (United States)

    2010-09-01

    2010 NVG FILTER STUDY — THOMAS ET AL. uncorrected or best corrected Snellen visual acuities of 20/20 (6/6) or better and were evaluated with their ha... Snellen equivalent of the mean in parenthesis. * Indicates a signifi cant difference ( P , 0.05). TABLE II. TIME REQUIRED TO ACHIEVE BASELINE

  17. Relation between Approximate Number System Acuity and Mathematical Achievement: The Influence of Fluency

    Science.gov (United States)

    Wang, Li; Sun, Yuhua; Zhou, Xinlin

    2016-01-01

    Previous studies have observed inconsistent relations between the acuity of the Approximate Number System (ANS) and mathematical achievement. In this paper, we hypothesize that the relation between ANS acuity and mathematical achievement is influenced by fluency; that is, the mathematical achievement test covering a greater expanse of mathematical fluency may better reflect the relation between ANS acuity and mathematics skills. We explored three types of mathematical achievement tests utilized in this study: Subtraction, graded, and semester-final examination. The subtraction test was designed to measure the mathematical fluency. The graded test was more fluency-based than the semester-final examination, but both involved the same mathematical knowledge from the class curriculum. A total of 219 fifth graders from primary schools were asked to perform all three tests, then given a numerosity comparison task, a visual form perception task (figure matching), and a series of other tasks to assess general cognitive processes (mental rotation, non-verbal matrix reasoning, and choice reaction time). The findings were consistent with our expectations. The relation between ANS acuity and mathematical achievement was particularly clearly reflected in the participants’ performance on the visual form perception task, which supports the domain-general explanations for the underlying mechanisms of the relation between ANS acuity and math achievement. PMID:28066291

  18. A comparison of the effects of ageing upon vernier and bisection acuity.

    Science.gov (United States)

    Garcia-Suarez, Luis; Barrett, Brendan T; Pacey, Ian

    2004-05-01

    While most positional acuity tasks exhibit an age-related decline in performance, the effect of ageing upon vernier acuity continues to be the subject of some debate. In the present study we employed a stimulus design that enabled the simultaneous determination of bisection and vernier acuities in 36 subjects, aged between 22 and 84 years. This approach provided a means for directly testing the hypothesis that ageing affects bisection acuity but not vernier acuity by ensuring that differences in stimulus configuration and in the subject's task were kept to an absolute minimum. Optimum thresholds increased as a function of age for both bisection and vernier tasks. Inter-subject threshold variability also increased with age. Issues surrounding the comparison of absolute vernier thresholds across different studies are discussed and two important methodological factors are identified: the precise statistical method used to estimate thresholds, and the magnitude, in angular terms, of the smallest spatial offset of the elements of the vernier stimulus which can be displayed. Comparison with previously published data indicates that the discrepancy between this study and most previous investigations with respect to the effect of age upon vernier performance can be at least partly accounted for by differences in the minimum displayable vernier offset. Vernier thresholds do increase with age. The increased variability of vernier thresholds in older subjects would appear to limit the diagnostic value of the test as a means of enabling normal ageing to be distinguished from visual loss due to pathology of the eye or visual system.

  19. Reduced sampling efficiency causes degraded Vernier hyperacuity with normal aging: Vernier acuity in position noise

    OpenAIRE

    2012-01-01

    Vernier acuity, a form of visual hyperacuity, is amongst the most precise forms of spatial vision. Under optimal conditions Vernier thresholds are much finer than the inter-photoreceptor distance. Achievement of such high precision is based substantially on cortical computations, most likely in the primary visual cortex. Using stimuli with added positional noise, we show that Vernier processing is reduced with advancing age across a wide range of noise levels. Using an ideal observer model, w...

  20. Effect of rigid gas permeable contact lens on wavefront aberration and contrast visual acuity in low to moderate myopia%硬性透氧性角膜接触镜矫正中低度近视对人眼单色光波前像差和对比度视力的影响

    Institute of Scientific and Technical Information of China (English)

    常枫; 沈政伟; 陈云辉; 李梅; 周和政

    2013-01-01

    Background Rigid gas permeable (RGP) contact lens,as a kind of new correction of refraction error,has been wildly used,but whether it will cause eye optical system of the change and influence on the visual acuity is unclear.Objective Present study was to evaluate and compare the visual quality of low to moderate myopia following wearing of RGP contact lens and spectacles.Methods Sixty-eight eyes of 35 subjects with low or mediate myopia were included in this study.Wave-front aberrations and visual acuities under the different contrasts (10%,30%,40%,52%,76%,92%) in the light or dark environment were examined before and 3 months after wearing of RGP corneal contact lens.These parameters were compared with those after wearing of spectacles with paired t test.Results The best corrected visual acuity (BCVA) was improved significantly from 0.94±0.10 to 1.26±0.03 3 months after wearing of RGP corneal contact lens (t=-9.266,P=0.000).After fitting of RGP corneal contact lens,the total higher order wave-front aberrations,the 3rd and 4th order aberrations were significantly declined in comparison with those of before fitting (total:t=4.683,P=0.000;RMS3:t=4.656,P=0.000;RMS4:t=3.929,P=0.000).However,no significant differences were detected in the 5th and 6th order aberrations between RGP corneal contact lens fitting and spectacles wearing (RMS5:t=1.766,P=0.083 ;RMS6:t=1.150,P=0.256).In both bright and dark environments,BCVA values were much better in the eyes with RGP corneal contact lens wearing than that in the eyes with spectacles wearing (all P<0.05).The BCVA was always reduced with the decline of contrast level whether bright or dark backgrounds both in RGP corneal contact lens wearing eyes and spectacles wearing eyes.Conclusions Wearing of RGP corneal contact lens provides better visual quality for low to moderate myopia than the spectacles wearing.%背景 硬性透氧性(RGP)角膜接触镜作为一种新兴的矫正屈光不正的方法已广泛使用,

  1. Morphometric analysis of fovea with spectral-domain optical coherence tomography and visual outcome postsurgery for retinal detachment

    Directory of Open Access Journals (Sweden)

    Manish Nagpal

    2014-01-01

    Full Text Available Purpose: The purpose of this study was to correlate the postoperative best-corrected visual acuity (BCVA with spectral-domain optical coherence tomography (SD-OCT findings in fovea involving rhegmatogenous retinal detachment (RRD surgery. Materials and Methods: Thirty eyes with preoperative fovea-involving RRD, who underwent scleral buckling (SB (6 eyes and pars plana vitrectomy (PPV (19 eyes and combined SB and PPV (5 eyes were recruited. Patients underwent clinical examination and SD-OCT scan of fovea preoperatively and at 30 days and 90 days postoperatively. The correlations between SD-OCT findings and BCVA were analyzed. Results: Inner segment/outer segment (IS/OS junction integrity was the indicator of better BCVA at 30 days and 90 days (P = 0.0002 and P = 0.0003, respectively whereas outer retinal corrugation (ORC was related to worse BCVA at 30 days and 90 days (P = 0.001. External limiting membrane did not have a co-relation with visual outcome, but cystoid macular edema showed co-relation at 90 days (P = 0.047. All eyes of SB and 3 eyes of PPV had a minimal subfoveal fluid at 30 days follow-up that had no effect on visual acuity. All retinas were attached at final follow-up. Conclusion: IS/OS junction integrity and ORC may be important predictors of postoperative visual outcome after anatomically successful RRD surgery.

  2. Relationship of visual quality and postoperative dominant eye changes with age-related cataract

    Directory of Open Access Journals (Sweden)

    Xiao-Ling Li

    2015-05-01

    Full Text Available AIM: To investigate age-related cataract and its postoperative dominant eye changes and visual quality of patients. METHODS: Totally 102 patients(204 eyeswith age-related cataract in our hospital from January 2013 to November 2014 were selected, and according to preoperative best corrected visual acuity(BCVAwere divided into two groups, in which the both eyes BCVA difference ≥2 lines(78 cases, 156 eyeswas group A, and both eyes BCVA difference ≤1 line(24 cases, 48 eyeswas group B. Dominant eyes were detected preoperatively and at postoperative 1 and 3mo. Contrast sensitivity and investigated visual satisfaction were tested.RESULTS: Preoperative dominant eye corrected visual acuity was 0.34 ± 0.11, significantly higher than that of the non-dominant eye(0.15 ± 0.09, and there was statistically significant difference(PP>0.05; At postoperative 3mo, 17 cases in the group A had dominant eye changes, and change rate was 21.79%(17/78. At postoperative 3mo, the dominant eye change rate in the group B was 20.83%(5/24, and there was no statistical significant difference between the two groups(P>0.05. The dominant eye change group and non-change groups patients with different spatial frequency contrast sensitivity test showed no statistical significance(P>0.05, Postoperative 3mo after operationvisual satisfaction questionnaire display, score of group A was(91.35±10.26points, score of group B was(90.15±9.75points(P>0.05, the dominant eye change group score was(90.08±9.77points, score non-change group was(91.43±10.22points(P>0.05.CONCLUSION: The dominant eye changes exist in postoperative eyes with age-related cataract, but there is no effect on visual quality.

  3. Visual function of the idiopathic macular hole

    Directory of Open Access Journals (Sweden)

    Jian-Tao Ren

    2015-02-01

    Full Text Available The idiopathic macular hole(IMHis research priority associated with the regenerate quickly of vitrectomy. The unaided visual acuity and the best corrected visual acuity is partial for the visual acuity of the patient with IMH.The mechanism and clinical significance of modern visual function measurements associated with IMH, including contrast sensitivity, visual field, multifocal electroretinogram, and stereoscopic vision, have been introduced. These measurements could be of great value in early diagnosis of IMH, assessment of surgical indication and evaluation of visual performance after vitrectomy. They would also be helpful to the analysis of postoperative impaired visual function and its management. Having an adequate understanding of the contents and significance of visual function is helpful to the improvement of IMH surgery techniques and postoperative visual acuity.

  4. The effects of time, luminance, and high contrast targets: revisiting grating acuity in the domestic cat.

    Science.gov (United States)

    Clark, Daria L; Clark, Robert A

    2013-11-01

    Based on optical clarity and retinal cone density, the cat has a potential acuity of 20-30 cycles per degree (cpd), yet most behavioral studies estimate feline acuity between 3 and 9 cpd. Those studies, however, were limited by restrictive experimental conditions that may have inadvertently lowered the estimated grating acuity. Two domestic cats previously trained on a two-choice visual discrimination task were retrained on a grating detection/discrimination task with unlimited time, high luminance, high contrast targets, and adequate space to prevent poor accommodation from affecting the results. Initially, vertical gratings of increasing cpd were tested until failure. Then, horizontal gratings of increasing cpd were tested until failure. Finally, the finest horizontal grating resolved was confirmed with a third test requiring 24 correct out of 36 consecutive trials, yielding a binomial probability less than 0.02 of non-random occurrence. M1, a 7-year-old male gray tabby with +2.00 OU refraction, tested for a grating detection acuity of 15 cpd for both vertical and horizontal gratings (binomial probability = 0.009). F1, a 2-year-old female gray tabby with +0.25 OU refraction, tested for a grating orientation discrimination acuity of 20 cpd for both vertical and horizontal gratings (binomial probability = 0.004). These results demonstrate that a young cat with good focus is capable of discriminating 20 cpd, in close agreement with the physiologic maximum. Uncorrected focusing errors appear to degrade visual performance. Optimum experimental conditions resulted in better grating acuity measurements than previously reported, emphasizing the importance of environmental factors in feline behavioral testing.

  5. Reduced sampling efficiency causes degraded Vernier hyperacuity with normal aging: Vernier acuity in position noise.

    Science.gov (United States)

    Li, Roger W; Brown, Brian; Edwards, Marion H; Ngo, Charlie V; Chat, Sandy W; Levi, Dennis M

    2012-01-01

    Vernier acuity, a form of visual hyperacuity, is amongst the most precise forms of spatial vision. Under optimal conditions Vernier thresholds are much finer than the inter-photoreceptor distance. Achievement of such high precision is based substantially on cortical computations, most likely in the primary visual cortex. Using stimuli with added positional noise, we show that Vernier processing is reduced with advancing age across a wide range of noise levels. Using an ideal observer model, we are able to characterize the mechanisms underlying age-related loss, and show that the reduction in Vernier acuity can be mainly attributed to the reduction in efficiency of sampling, with no significant change in the level of internal position noise, or spatial distortion, in the visual system.

  6. Visual acuity and refractive outcomes of different corneal incisions in phacoemulsification%角膜地形图引导下不同部位角膜切口白内障超声乳化术后角膜散光分析

    Institute of Scientific and Technical Information of China (English)

    石春和; 姜焕荣; 倪鸿昌

    2014-01-01

    目的:比较角膜地形图引导下不同部位透明角膜切口白内障超声乳化术后散光情况。方法选择行透明角膜切口超声乳化白内障吸除联合人工晶状体植入术的年龄相关性白内障患者198例(231例)为研究对象,分成A、B、C 3组,A组选择在上方11点位透明角膜切口,B组选择在颞侧透明角膜切口,C组选择在角膜最大曲率子午线上透明角膜切口,分别于术前,术后1周、1个月及3个月随访,行视力及角膜地形图检查,记录并比较3组术后视力及角膜散光的变化情况。结果术后3个月时C组裸眼视力≥1.0者多于A组和B组( P <0.05);C组患者术后3个月与术前相比,散光度明显减小( P <0.05);C组分别与A组、B组相比,术后1周、1个月及3个月时的散光度均明显减小( P <0.05);术后3个月平均手术源性角膜散光度(SIA),C组最小。结论角膜地形图引导下位于角膜最大曲率子午线上透明角膜切口有助于减小术前及术后散光,术后获得较好的裸眼视力。%Objective To compare the effects of different corneal topography guided incisions on corneal refraction after phacoemulsification.Methods Totally 198 cataract patients (231 eyes) enrolled in the study.Patients were random-ly assigned into 3 groups and clear corneal incisions were made at either superior , or temporal, or along the steepest meridi-an.Routine ophthalmic examinations and corneal topography were performed for each patient before surgery and at 1 week, 1 month, and 3 months after the surgery.Results At 3 months after the surgery,uncorrected visual acuity (≥1.0) was-significantly better in patients whose corneal incisions were made at the deepest meridian than in patients whose corneal in -cisions were made elsewhere ( P <0.05 ) .Astigmatism was also significantly reduced in this group of patients ( P <0.05) starting from 1 week after the surgery and

  7. The Eyes Have It: Visual Help for Auditory Acuity.

    Science.gov (United States)

    Prince, Albert

    A non-aversive modification of Bekesy Audiometric Procedures (BAP) used in assessing hearing ability has been found to produce interpretable audiograms from children whose responses to the unmodified BAP were erratic and uninterpretable. In an experiment with six 8-year-old children, three subjects were assigned to a condition in which a light cue…

  8. Computed estimation of visual acuity after laser refractive keratectomy

    Science.gov (United States)

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

    1991-06-01

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

  9. Variable acuity remote viewing system flight demonstration

    Science.gov (United States)

    Fisher, R. W.

    1983-01-01

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

  10. Perfluorocarbon in vitreoretinal surgery and preoperative bevacizumab in diabetic tractional retinal detachment

    Institute of Scientific and Technical Information of China (English)

    J; Fernando; Arevalo; Martin; A; Serrano; Juan; D; Arias

    2014-01-01

    AIM: To describe the en bloc perfluorodissection(EBPD) technique and to demonstrate the applicabilityof using preoperative intravitreal bevacizumab duringsmall-gauge vitreoretinal surgery(23-gauge transconjunctival sutureless vitrectomy) in eyes with advancedproliferative diabetic retinopathy(PDR) with tractionalretinal detachment(TRD).METHODS: This is a prospective, interventional caseseries. Participants included 114(eyes) with advancedproliferative diabetic retinopathy and TRD. EBPD wasperformed in 114 eyes(consecutive patients) during23-gauge vitrectomy with the utilization of preoperativebevacizumab(1.25 mg/-0.05 mL). Patients mean age was 45 years(range, 21-85 years). Surgical time had a mean of 55 min(Range, 25-85 min). Mean follow up of this group of patients was 24 mo(range, 12-32 mo). Main outcome measures included best-corrected visual acuity(BCVA), retinal reattachment, and complications.RESULTS: Anatomic success occurred in 100%(114/-114) of eyes. Significant visual improvement [≥ 2 Early Treatment Diabetic Retinopathy Study(ETDRS) lines] was obtained in 69.2%(79/-114), in 26 eyes(22.8%) BCVA remained stable, and in 8 eyes(7%) BCVA decreased(≥ 2 ETDRS lines). Final BCVA was 20/-50 or better in 24% of eyes, between 20/-60 and 20/-400 in 46% of eyes, and worse than 20/-400 in 30% of eyes. Complications included cataract in 32(28%) eyes, iatrogenic retinal breaks in 9(7.8%) eyes, vitreous hemorrhage requiring another procedure in 7(6.1%) eyes, and phthisis bulbi in 1(0.9%) eye.CONCLUSION: This study demonstrates the usefulne-ss of using preoperative intravitreal bevacizumab and EBPD during smallgauge vitreoretinal surgery in eyes with TRD in PDR.

  11. Comparison of visual, refractive and topographic keratometry outcomes of intacs and intacs SK in mild to moderate keratoconus eyes

    Directory of Open Access Journals (Sweden)

    Abdulrahman Al Muammar

    2015-01-01

    Full Text Available Purpose: The purpose was to evaluate and compare the visual and refractive outcomes, topographic keratometry (K and complications of Intacs and Intacs SK for mild to moderate keratoconus. Methods: In this retrospective study, all mild to moderate keratoconus eyes that underwent implantation of Intacs (Intacs group or Intacs SK (Intacs SK group with minimum follow-up of 12 months were included. Preoperative and postoperative uncorrected distance visual acuity (UDVA, corrected distance visual acuity (CDVA, manifest refraction, manifest cylinder, spherical equivalent (SE, minimum topographic keratometry, maximum topographic keratometry, and average topographic keratometry were compared in both groups. Results: There were 16 eyes in the Intacs group and 18 eyes in the Intacs SK group. Preoperatively, both groups were comparable for most parameters except gender and minimum K and average K. At 6 months postoperatively there were statistically significant improvements in UDVA, CDVA, manifest sphere, SE, minimum K, maximum K, and average K (P 0.05. The outcomes remained stable with no statistically significant differences between the 6 and 12 months visits. There were no complications in both groups. Conclusion: Both models of Intacs significantly improved vision and refractive outcomes, and topographic keratometry in cases of mild to moderate keratoconus. Intacs SK provided better (not statistically significant results.

  12. Dynamic response to initial stage blindness in visual system development.

    Science.gov (United States)

    Long, Erping; Zhang, Xiayin; Liu, Zhenzhen; Wu, Xiaohang; Tan, Xuhua; Lin, Duoru; Cao, Qianzhong; Chen, Jingjing; Lin, Zhuoling; Wang, Dongni; Li, Xiaoyan; Li, Jing; Wang, Jinghui; Li, Wangting; Lin, Haotian; Chen, Weirong; Liu, Yizhi

    2017-07-01

    Sensitive periods and experience-dependent plasticity have become core issues in visual system development. Converging evidence indicates that visual experience is an indispensable factor in establishing mature visual system circuitry during sensitive periods and the visual system exhibits substantial plasticity while facing deprivation. The mechanisms that underlie the environmental regulation of visual system development and plasticity are of great interest but need further exploration. Here, we investigated a unique sample of human infants who experienced initial stage blindness (beginning at birth and lasting for 2-8 months) before the removal of bilateral cataracts. Retinal thickness (RT), axial length (AL), refractive status, visual grating acuity and genetic integrity were recorded during the preoperative period or at surgery and then during follow-up. The results showed that the development of the retina is malleable and associated with external environmental influences. Our work supported that the retina might play critical roles in the development of the experience-dependent visual system and its malleability might partly contribute to the sensitive period plasticity. © 2017 The Author(s).

  13. Feasibility assessment of visual quality analyzer KR-1W guiding personalized aspheric IOL implantation

    Directory of Open Access Journals (Sweden)

    Xiao-Li Wang

    2015-01-01

    Full Text Available AIM: To discuss the feasibility of using the visual quality analyzer KR-1W to guide the relatively personalized aspheric intraocular lens(IOLimplants to make the whole eye spherical aberration close to 0.1μm.METHODS: In this prospective case series study, the corneal spherical aberration with 6mm aperture of 73 patients(100 eyeswas measured with KR-1W Visual Function Analyzer 1d before surgery. For the sake of the whole postoperative spherical aberration were close to 0.1μm, 9 cases(16 eyeswith corneal spherical aberration 0.35μm were implanted Tecnis ZA9003 IOL, named Tecnis group. Aspherical IOL was implanted after phacoemulsification through a cornea 2.75mm incision without suture.Uncorrected visual acuity, beat corrected visual acuity, spherical aberration of the whole eye and jnternal optics(mainly IOLat 6mm pupil diameter were examined at 3mo postoperatively. The relevant data were analyzed using t-test and variance analysis.RESULTS: The whole ocular spherical aberration at 6mm pupil diameter in all postoperative were 0.084±0.032μm; in Tecnis group, the data were 0.091 ± 0.021μm; in AO group, the data were 0.0814-0.013μm; IQ group were 0.093±0.042μm. There was no significantly different between the predicted value and actual value of ocular spherical aberration at 6 mm pupil diameter in all postoperative(t=1.932, P=0.061and in the three groups. The difference value in the predicted values of the preoperative spherical aberrations of the whole eye and the actual values after surgery was 0.013±0.041μm; there was no statistically significant difference(F=2.537, P=0.091. Respectively compared the uncorrected visual acuity and besta corrected visual acuity among three groups of postoperative, no significant difference were found(F=0.897, P=0.421; F=1.423, P=0.097.CONCLUSION: Personality selection of aspheric IOL based on preoperative corneal spherical aberration of patients is feasible and produces satisfactory target postoperative

  14. Functional MRI of the visual cortex and visual testing in patients with previous optic neuritis

    DEFF Research Database (Denmark)

    Langkilde, Annika Reynberg; Frederiksen, J.L.; Rostrup, Egill

    2002-01-01

    to both the results of the contrast sensitivity test and to the Snellen visual acuity. Our results indicate that fMRI is a useful method for the study of ON, even in cases where the visual acuity is severely impaired. The reduction in activated volume could be explained as a reduced neuronal input...

  15. Response Classification Images in Vernier Acuity

    Science.gov (United States)

    Ahumada, Albert J., Jr.; Beard, B. L.; Ellis, Stephen R. (Technical Monitor)

    1997-01-01

    Orientation selective and local sign mechanisms have been proposed as the basis for vernier acuity judgments. Linear image features contributing to discrimination can be determined for a two choice task by adding external noise to the images and then averaging the noises separately for the four types of stimulus/response trials. This method is applied to a vernier acuity task with different spatial separations to compare the predictions of the two theories. Three well-practiced observers were presented around 5000 trials of a vernier stimulus consisting of two dark horizontal lines (5 min by 0.3 min) within additive low-contrast white noise. Two spatial separations were tested, abutting and a 10 min horizontal separation. The task was to determine whether the target lines were aligned or vertically offset. The noises were averaged separately for the four stimulus/response trial types (e.g., stimulus = offset, response = aligned). The sum of the two 'not aligned' images was then subtracted from the sum of the 'aligned' images to obtain an overall image. Spatially smoothed images were quantized according to expected variability in the smoothed images to allow estimation of the statistical significance of image features. The response images from the 10 min separation condition are consistent with the local sign theory, having the appearance of two linear operators measuring vertical position with opposite sign. The images from the abutting stimulus have the same appearance with the two operators closer together. The image predicted by an oriented filter model is similar, but has its greatest weight in the abutting region, while the response images fall to nonsignificance there. The response correlation image method, previously demonstrated for letter discrimination, clarifies the features used in vernier acuity.

  16. PREOPERATIVE ENDOSCOPIC MARKING OF UNPALPABLE COLONIC TUMORS

    Directory of Open Access Journals (Sweden)

    A. L. Goncharov

    2013-01-01

    Full Text Available The identification of small colon lesions is one of the major problems in laparoscopic colonic resection.Research objective: to develop a technique of visualization of small tumors of a colon by preoperative endoscopic marking of a tumor.Materials and methods. In one day prior to operation to the patient after bowel preparation the colonoscopy is carried out. In the planned point near tumor on antimesentery edge the submucous infiltration of marking solution (Micky Sharpz blue tattoo pigment, UK is made. The volume of entered solution of 1–3 ml. In only 5 months of use of a technique preoperative marking to 14 patients with small (the size of 1–3 cm malignant tumors of the left colon is performed.Results. The tattoo mark was well visualized by during operation at 13 of 14 patients. In all cases we recorded no complications. Time of operation with preoperative marking averaged 108 min, that is significantly less in comparison with average time of operation with an intra-operative colonoscopy – 155 min (р < 0.001.Conclusions. The first experience of preoperative endoscopic marking of non palpable small tumors of a colon is encouraging. Performance of a technique wasn't accompanied by complications and allowed to reduce significantly time of operation and to simplify conditions of performance of operation.

  17. Evaluation of visual acuity under different contrasts and luminances in eyes implanted with aspheric multifocal intraocular lenses%非球面多焦点人工晶状体植入眼不同背景亮度及不同对比度视功能观察

    Institute of Scientific and Technical Information of China (English)

    赵银莹; 李军花; 常平骏; 赵云娥

    2010-01-01

    目的 分析非球面多焦点人工晶状体(MIOL)[ReSTOR MIOL(SN6AD3)]植入眼在不同背景亮度不同对比度下的视功能.方法 采用前瞻性研究.2009年2月至2009年7月行白内障超声乳化吸除并植入SN6AD3且随访资料完整的病例26例(42眼),术后6个月在最佳远矫正状态下,采用多功能电子视力测量仪(MFVA-100)测试不同背景亮度(250、85、25 cd/m2)下不同对比度(100%、25%、10%、5%)视标的LogMAR视力.采用Dunnett's T3多重比较法对所得视力进行统计分析.结果 在250 cd/m2背景亮度下,不同对比度(100%、25%、10%、5%)视力平均值分别为0.01、0.23、0.40、0.62;85 cd/m2背景亮度下为0.02、0.26、0.46、0.74;25 cd/m2背景亮度下为0.08、0.32、0.49、0.63;在这3种背景亮度下,视力随着对比度下降而下降,差异有统计学意义(P均<0.05).同一对比度视标,不同背景亮度(250、85、25 cd/m2)下的视力采用Dunnett's T3多重比较法分析,结果示差异无统计学意义(P均>0.05).结论 植入非球面ReSTOR MIOL(SN6AD3)患者无论在高亮(250 cd/m2)、标准(85 cd/m2)、中间(25 cd/m2)背景亮度下均可获得满意的视力.视标的对比度对视力的影响较背景亮度更大.%Objective To evaluate the differences in contrast visual acuity (VA) under different background illuminations in patients who had been implanted with the ReSTOR aspheric multifocal intraocular lens (MIOL)(SN6AD3). Methods This was a prospective study. Forty-two eyes of 26 patients who had received ReSTOR MIOL (SN6AD3) implantation after cataract extraction were enrolled. Six months postoperatively, best corrected distance VA was measured at 4 contrast levels (100%, 25%, 10%, 5%) under 3 background illumination levels (250 cd/m2, 85 cd/m2, 25 cd/m2)using a multi-functional visual acuity tester (MFVA-100). Dunnett's T3 multiple comparison was used for statistical anaylysis. Results The mean VA at the 4 contrast levels (100%, 25%, 10%, 5%)under 250 cd

  18. Preoperative preparation of children

    Directory of Open Access Journals (Sweden)

    Priya Reshma Aranha

    2017-01-01

    Full Text Available Surgery is a stressful and anxiety provoking experience for children. Millions of children undergo surgery every year. The majority of children experience significant preoperative anxiety which intern can affect their recovery. Preoperative anxiety may bring about physical and physiological changes in children, which can be particularly evident in terms of increased heart rate and blood pressure. To identify various strategies used to minimize the preoperative anxiety of children and update their clinical effectiveness among children undergoing surgery, the authors searched PubMed, MEDLINE, CINAHL, ScienceDirect, Google Scholar, Scopus, and Cochrane Library for identifying the relevant studies and retrieved available literature. It is concluded that utilization of the strategies available to reduce the preoperative anxiety of children will be a promising intervention to reduce anxiety, to promote relaxation, satisfaction, and speedy recovery. Many of these techniques are simple, cost-effective and can be easily carried out by nurses. It is essential to use the age appropriate and individualized methods in preparing children for surgery. Further research is required to strengthen the evidence.

  19. Manual aiming in healthy aging: does proprioceptive acuity make the difference?

    Science.gov (United States)

    Helsen, Werner F; Van Halewyck, Florian; Levin, Oron; Boisgontier, Matthieu P; Lavrysen, Ann; Elliott, Digby

    2016-04-01

    The present study examines whether non-active older adults are more dependent on visual information when executing aiming movements and whether age-related declines in proprioception play a mediating role herein. Young (N = 40) and older adults (N = 38) were divided into physically active and non-active subgroups based on self-reported sports participation levels. In experiment 1, participants executed wrist-aiming movements with and without visual feedback. In experiment 2, passive proprioceptive acuity was assessed using wrist motion detection and position matching tests. Results showed similar aiming accuracy across age groups both with and without visual feedback, but older adults exhibited longer movement times, prolonged homing-in phase, and made more corrective submovements. Passive proprioceptive acuity was significantly affected by physical activity level and age, with participants in the active group scoring better than their non-active peers. However, these declines did not predict performance changes on the aiming task. Taken together, our observations suggest that decline in proprioceptive acuity did not predict performance changes on the aiming task and older adults were able to compensate for their decreased motion and position sense when allowed sufficient time. In line with these observations, we proposed that older adults are able to compensate for their decline in proprioception by increasin