Acuity In Adults Research Articles

Foveal thickness and its association with visual acuity in adults born preterm with very low birth weight: A two-country birth cohort study.

To explore foveal and parafoveal thickness in adults born preterm with very low birth weight (VLBW) and its association with best-corrected visual acuity (BCVA) and gestational age (GA) compared to adults born at term. In a joint study of the Helsinki Study of Very Low Birth Weight Adults (Finland) and the NTNU Low Birth Weight Life study (Norway), 106 VLBW and 143 term-born controls were examined with spectral-domain optical coherence tomography and BCVA at age 31-43 years. Thickness of retinal layers was segmented in the foveal and parafoveal areas of the macula. The total retinal thickness in the foveal area was thicker in VLBW adults compared with controls; mean (SD): 292.5 μm (28.2) and 272.4 μm (20.2); p < 0.001, and thinner in the parafoveal areas of the macula. These findings could be explained by a thicker inner retinal layer in the foveal area found in VLBW adults compared with controls (mean difference 20.4 μm; CI: 15.0 to 25.9), where a thicker fovea was associated with lower GA, but not BCVA. Adults born preterm with VLBW had a thicker retina in the foveal area than controls and this was associated with GA, but not with BCVA. These changes seem to be related to a thicker inner retinal layer in VLBW adults. The findings imply that signs of macular underdevelopment are still present in adulthood, but not necessarily related to reduced visual function.

OCTA biomarkers in adults aged 50 and above: a prospective and cross-sectional community-based study

Background/AimsTo assess the normative values and parameters of optical coherence tomography angiography (OCTA) influencing the best corrected visual acuity (BCVA) in adults aged 50 and above.MethodsThis was a prospective cross-sectional study from an eye screening programme in Hong Kong for 4188 citizens aged 50 and above. Images were analysed using a validated quantification software calculating vessel density and capillary perfusion density (CPD), along with other OCTA parameters, such as the foveal avascular zone area (FAZ) and circularity. OCTA data was collected from May 2019 to December 2020, including a total of 4188 healthy eyes from 4188 subjects.ResultsMean superficial vessel density (MSVD) was 14.48 ± 3.60 mm− 1, while the mean capillary perfusion density (MCPD) was 0.41 ± 0.06. Multivariate analysis revealed ageing (β = 0.321, p < 0.001), being male (β=-0.089, p < 0.001), having a high body mass index (BMI) (β = 0.039, p = 0.006), high FAZ area and low FAZ circularity (β = 0.039 and − 0.034, p = 0.01 and 0.024 respectively), low MSVD in the outer ring (β=-0.513, p < 0.001), specifically in the nasal and temporal outer quadrants (β = -0.226 and − 0.259, p < 0.001 for both), and low MCPD in the outer superior quadrant (β= -0.123, p = 0.016) being independently associated with BCVA.ConclusionHigh FAZ area and low FAZ circularity, low MSVD in the outer ring, specifically the nasal and temporal outer quadrants, and low MCPD in the outer superior quadrant can be used as biomarkers in predicting a low visual acuity in adults aged 50 and above.

A randomized phase 2 clinical trial of phentolamine mesylate eye drops in patients with severe night vision disturbances

PurposeDim light vision disturbances (DLD) comprise a wide range of symptoms affecting the quality of vision at low illumination including glare, halos, and starbursts. This exploratory study investigated 1.0% phentolamine mesylate ophthalmic solution (PMOS) as a treatment to improve vision and image quality for patients with DLD.MethodsIn this placebo-controlled, randomized, double-masked clinical trial, 24 adult patients with severe DLD were randomized in a 2:1 ratio to receive either one dose of PMOS or placebo. Subjects were eligible if they reported experiencing severe night vision difficulty that was not eliminated by distance spectacle correction and scored ≥0.3 log units below the normal range of contrast sensitivity assessed under mesopic conditions with glare at ≥2 spatial frequencies. Key efficacy outcomes were change from baseline in pupil diameter, contrast sensitivity, and visual acuity. Safety measures including intraocular pressure, conjunctival hyperemia, and systemic effects were also assessed.ResultsEight subjects were randomized to placebo (63% female; mean age 47 years) and 16 were randomized to PMOS (75% female; mean age 42 years). Mean (SD) pupil diameter of PMOS-treated subjects decreased significantly − 1.3 mm (0 to − 2.8 mm) with p < 0.0001. Mean contrast sensitivity with glare in PMOS-treated subjects improved significantly post-treatment at spatial frequencies 3, 6, 12, and 18 cycles per degree (p ≤ 0.03). PMOS also demonstrated improvements in the numbers of letters read for mesopic and photopic, high- and low-contrast visual acuity (LCVA). Importantly, a statistically greater proportion of PMOS-treated eyes registered mesopic LCVA 5 letter (69% vs. 31%, p = 0.029) and 10 letter (34% vs. 6%, p = 0.04) improvement, with a trend at 15 letters (19% vs. 0%, p = 0.16). PMOS was well tolerated with the only reported side effect being a mild increase in conjunctival hyperemia.ConclusionPMOS was well tolerated and effectively reduced pupil size with improvements in contrast sensitivity and visual acuity in adults with severe DLD. Future Phase 3 studies should be conducted to further evaluate its potential to treat DLD.Trial registrationThe trial registration number is NCT04004507 (02/07/2019). Retrospectively registered.

Repetitive visual cortex transcranial random noise stimulation in adults with amblyopia

We tested the hypothesis that five daily sessions of visual cortex transcranial random noise stimulation would improve contrast sensitivity, crowded and uncrowded visual acuity in adults with amblyopia. Nineteen adults with amblyopia (44.2 ± 14.9 years, 10 female) were randomly allocated to active or sham tRNS of the visual cortex (active, n = 9; sham, n = 10). Sixteen participants completed the study (n = 8 per group). tRNS was delivered for 25 min across five consecutive days. Monocular contrast sensitivity, uncrowded and crowded visual acuity were measured before, during, 5 min and 30 min post stimulation on each day. Active tRNS significantly improved contrast sensitivity and uncrowded visual acuity for both amblyopic and fellow eyes whereas sham stimulation had no effect. An analysis of the day by day effects revealed large within session improvements on day 1 for the active group that waned across subsequent days. No long-lasting (multi-day) improvements were observed for contrast sensitivity, however a long-lasting improvement in amblyopic eye uncrowded visual acuity was observed for the active group. This improvement remained at 28 day follow up. However, between-group differences in baseline uncrowded visual acuity complicate the interpretation of this effect. No effect of tRNS was observed for amblyopic eye crowded visual acuity. In agreement with previous non-invasive brain stimulation studies using different techniques, tRNS induced short-term contrast sensitivity improvements in adult amblyopic eyes, however, repeated sessions of tRNS did not lead to enhanced or long-lasting effects for the majority of outcome measures.

Evaluation of quality of life and visual acuity after posterior capsulotomy with neodymium: YAG laser in adults

Abstract Purpose: To determine the impact of neodymium:YAG (Nd:YAG) laser posterior capsulotomy on quality of life and visual acuity in adults. Methods: A prospective study that included patients over 65 years old with clinical indications for Nd: YAG laser capsulotomy. On the day of the procedure, corrected distance visual acuity tests, slit-lamp examination and posterior capsule opacification (PCO) photo documentation were performed, followed by application of the National Eye Institute Visual Function Questionnaire (NEI-VFQ-25). The PCO rate was evaluated with Evaluation of Posterior Capsule opacification (EPCO 2000) software. Four weeks after the posterior capsulotomy, corrected distance visual acuity was measured, and the NEI-VFQ-25 was applied again. Complications were also reported. Results : Sixty eyes from 45 patients were enrolled in the study. The mean age was 71.51 ± 6.38 years (65 to 93). Comparing the results before and after the Nd:YAG laser capsulotomy, there was a statistically significant improvement in quality of life according to the NEI-VFQ-25 (p<0.001) and in visual acuity (p=0.0). The mean score in NEI-VFQ-25 Questionnaire before capsulotomy was 62.07 ± 20.90 (16.81-95.90) and after was 83.95±19.49 (20.68 - 100.0). The mean CDVA before the procedure was 0.75 ± 0.35 LogMAR (0.1-1.3) and after was 0.21 ± 0.20 LogMAR (0.0-1.3). The mean PCO rate measured by the EPCO software was 0.688 ± 0.449. There was a positive correlation between the EPCO score and the total score of quality of life after Nd: YAG laser capsulotomy (r=0.845, p=0.00). Damage to intraocular lens was the only complication observed in six eyes (10%). Conclusion: Nd: YAG laser capsulotomy, in addition to improving visual acuity, is able to improve quality of life.

The Effect of Combined Patching and Citalopram on Visual Acuity in Adults with Amblyopia: A Randomized, Crossover, Placebo-Controlled Trial.

Nonhuman animal models have demonstrated that selective serotonin reuptake inhibitors (SSRIs) can enhance plasticity within the mature visual cortex and enable recovery from amblyopia. The aim of this study was to test the hypothesis that the SSRI citalopram combined with part-time patching of the fellow fixing eye would improve amblyopic eye visual acuity in adult humans. Following a crossover, randomized, double-blind, placebo-controlled design, participants completed two 2-week blocks of fellow fixing eye patching. One block combined patching with citalopram (20 mg/day) and the other with a placebo tablet. The blocks were separated by a 2-week washout period. The primary outcome was change in amblyopic eye visual acuity. Secondary outcomes included stereoacuity and electrophysiological measures of retinal and cortical function. Seven participants were randomized, fewer than our prespecified sample size of 20. There were no statistically significant differences in amblyopic eye visual acuity change between the active (mean ± SD change = 0.08 ± 0.16 logMAR) and the placebo (mean change = −0.01 ± 0.03 logMAR) blocks. No treatment effects were observed for any secondary outcomes. However, 3 of 7 participants experienced a 0.1 logMAR or greater improvement in amblyopic eye visual acuity in the active but not the placebo blocks. These results from a small sample suggest that larger-scale trials of SSRI treatment for adult amblyopia may be warranted. Considerations for future trials include drug dose, treatment duration, and recruitment challenges. This study was preregistered as a clinical trial (ACTRN12611000669998).

Levodopa as Treatment for Adults with Amblyopia

Levodopa is a medication used in treatment for Parkinson�s disease, which is associated with low levels of a chemical called dopamine in the brain. Levodopa is turned into dopamine in the body and therefore increases levels of this chemical. Levodopa was used as a treatment of amblyopia alone or in combination with classical treatment of occlusion. Visual acuity is improved after treatment with oral Levodopa. When is used as an adjunct to the occlusion therapy, Levodopa can be associated with long-term improvement in the vision, and may have also better compliance for patching. Levodopa stimulates the brain plasticity in adult age and can be used in treatment for amblyopia. Patients have also an increase of the visual acuity after orthoptic treatment for amblyopia and when Levodopa is administered, the vision increases much more. Contrary to the classical conception, according to which amblyopia cannot be treated after 10-12 years of age and it is untreatable in adults, studies about treatment with Levodopa in amblyopic eyes, may allow the improvement of the visual acuity in adults, as well.

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

ObjectivesVisual 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...

Assessment of Visual Acuity in Patients with Dementia using Teller Acuity Cards

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

Evaluation of Vestibular and Dynamic Visual Acuity in Adults with Congenital Deafness

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.

Visual Acuity in Adults with Asperger’s Syndrome: No Evidence for “Eagle-Eyed” Vision

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

Perceptual learning improves contrast sensitivity and visual acuity in adults with anisometropic amblyopia

To evaluate the effects of perceptual learning on contrast-sensitivity function and visual acuity in adult observers with amblyopia, 23 anisometropic amblyopes with a mean age of 19.3 years were recruited and divided into three groups. Subjects in Group I were trained in grating detection in the amblyopic eye near pre-training cut-off spatial frequency. Group II received a training regimen of repeated contrast-sensitivity function measurements in the amblyopic eye. Group III received no training. We found that training substantially improved visual acuity and contrast-sensitivity functions in the amblyopic eyes of all the observers in Groups I and II, although no significant performance improvement was observed in Group III. For observers in Group I, performance improvements in the amblyopic eyes were broadly tuned in spatial frequency and generalized to the fellow eyes. The latter result was not found in Group II. In a few cases tested, improvements in visual acuity following training showed about 90% retention for at least 1 year. We concluded that the visual system of adult amblyopes might still retain substantial plasticity. Perceptual learning shows potential as a clinical tool for treating child and adult amblyopia.

Prevalence of Uncorrected Binocular Distance Visual Acuity in Hispanic and Non-Hispanic Adults: Results from the HHANES and the NHANES I

Objective This study aimed to provide a comparative analysis of American population-based prevalence of uncorrected binocular distance visual acuity in Hispanics and non-Hispanics. Design The study design was a population-based survey. Participants Data from the Hispanic Health and Nutrition Examination Survey between 1982 and 1984 and the National Health and Nutrition Examination Survey I from 1974 through 1975 were analyzed to investigate the epidemiology of uncorrected binocular distance visual acuity in adults 25 to 74 years of age in Cuban Americans (N = 391), Mexican Americans (N = 1350), Puerto Ricans (N = 504), African Americans (N = 245), and nonHispanic white Americans (N = 2571). Main outcome measure Uncorrected binocular distance visual acuity in both eyes was assessed using Sloan letters or Landolt rings. Results Prevalence rates of 20/50 or worse uncorrected binocular distance visual acuity were 22%, 24%, 19%, 18%, and 32% for African Americans, Cuban Americans, Mexican Americans, Puerto Ricans, and non-Hispanic whites, respectively. After adjustment for gender and age, the rates were significantly higher ( P < 0.05) for nonHispanic whites compared to each of the other ethnic groups. Significant increases in the prevalence of 20/50 or worse distance visual acuity were observed for increasing age groups (25–39, 40–59, and 60–74 years) within each gender-ethnic subgroup. Analysis of differences in prevalence by gender (controlling for age) indicated a slightly higher prevalence of 20/50 or worse distance visual acuity in women than in men (range of odds ratios, 1.1–2.1). Based on 1993 census population estimates in the United States, more than 42 million adults 25 to 74 years of age have an uncorrected binocular distance visual acuity of 20/50 or worse. Approximately 1.7 million of these adults are of Hispanic origin. Conclusion The prevalence of impaired uncorrected binocular distance visual acuity generally is lower in Hispanics than in non-Hispanic whites.

Glasgow Acuity Cards: a new test for the measurement of letter acuity in children.

Problems with design and format of the traditional Snellen chart have led to the development of alternative charts for the measurement of visual acuity in adults. However, advances in chart design for the measurement of visual acuity in pre-school children have not paralleled those used in adult test charts. Visual acuity can be measured in infants and very young children using behavioural and electrophysiological techniques but clinical measurement of letter acuity tends to commence when the child is old enough to interact and co-operate with the examiner. Charts which are commercially available in the UK for measuring letter acuity in pre-school children (3-5 years old) either use single optotypes or are derivatives of the Snellen format. There is a need for a test of letter acuity for use with this young age group which is accurate, reliable and based upon sound and established design principles. Glasgow Acuity Cards have been designed to include features that should allow change in letter acuity to be detected in pre-school children, especially those undergoing vision therapy training. The test is performed at 3 m and incorporates several design features which have been used previously in adult charts but are new to childrens' test charts. These include: linear progression of letter sizes using a log scale; letters of approximately equal legibility; equal number of letters per line; control of contour interaction; screening cards to determine initial level of acuity. The test is quick and easy to perform and should provide a means of detecting change in letter acuity, with increased confidence.