Detection Of Amblyopia Research Articles

High specificity of the pediatric vision scanner in a private pediatric primary care setting

The Pediatric Vision Scanner (PVS) directly detects strabismus and amblyopia by analyzing binocular scans for birefringence that, due to the organization of the radially arranged Henle fibers, is characteristic of steady, bifoveal fixation. In a pediatric ophthalmology office setting,1 we found that the PVS had 97% sensitivity and 87% specificity for detection of strabismus and amblyopia. However, this study did not directly assess performance of the PVS in a primary care screening setting, where it is designed to be used. Here we report PVS specificity and positive likelihood ratio for a cohort of children screened in a pediatric primary care setting.

Performance of the Plusoptix A09 photoscreener in detecting amblyopia risk factors in Chinese children attending an eye clinic.

PurposeTo assess the accuracy of the Plusoptix A09 photoscreener in detecting amblyopia risk factors in children and determine referral criteria when using Plusoptix A09 for a large-scale vision screening.MethodsPediatric patients attending our eye clinic underwent a comprehensive ophthalmic examination that included photorefraction, orthoptic examination, anterior segment assessment, fundus examination and cycloplegic retinoscopy. The measurements were collected for statistical analyses.ResultsOne hundred and seventy-eight children (mean age ± SD: 6.2±2.4 years, range: 2.2 to 14.1 years) were included in the study. The mean spherical equivalent (SE) obtained using Plusoptix A09 (PSE) was 0.57 D lower than that obtained from cycloplegic retinoscopy (CRSE) (P = 0.00). However, there was no statistically significant difference of Jackson cross cylinder J0 and J45 between Plusoptix A09 (PJ) and cycloplegic retinoscopy (CRJ) (P = 0.14, P = 0.26). The relationship of SE obtained from Plusoptix A09 and SE obtained from cycloplegic retinoscopy was presented as the equation: CRSE = 0.358 + 0.776 PSE + 0.064 PSE 2 + 0.011 PSE 3. Based on the Receiver Operating Characteristic (ROC) curve, the Plusoptix A09 had an overall sensitivity of 94.9% and specificity of 67.5% for detecting refractive amblyopia risk factors. The sensitivity and specificity of the Plusoptix A09 for detection of strabismus were 40.7% and 98.3%, respectively; detection of amblyopia and/or strabismus was 84.7% and 63.2%, respectively.ConclusionsThe Plusoptix A09 photoscreener underestimated hyperopia and overestimated myopia according to SE when compared with cycloplegic retinoscopy. The accuracy of the Plusoptix A09 in detecting amblyopia risk factors in children could be improved by the regression equation and optimized criteria for refractive amblyopia risk factors developed in the present study. Moreover, the Plusoptix A09 photoscreener is not suitable for a large-scale strabismus screening when it is applied solely.

Prevalence of amblyopia in primary school children in Qassim province, Kingdom of Saudi Arabia.

Purpose:To determine the prevalence and causes of amblyopia in primary school children in Qassim province, Kingdom of Saudi Arabia (KSA).Materials and Methods:In this cross sectional study, 5176 children, aged 6 to 13 years (mean - 9.53 ± 1.88 years) were evaluated. There were 2573 (49.71%) males and 2603 (50.29%) females. Distance visual acuity (V/A) was tested monocularly using a logMAR chart with and without correction. Cycloplegic refraction was performed in children with reduced vision. To determine the etiology of amblyopia, children were enrolled if there was a difference in V/A of two or more lines between eyes or an absolute reduction in acuity <20/30 in either eye, that could not be corrected by refraction. P ≤ 0.05 was considered statistically significant.Results:There 202 out of 5176 (3.90%) with ambylopia. There are 98 (1.88%) amblyopic females. There was no statistical difference in gender for amblyopes (P > 0.05). The prevalence of amblyopia was statistically significant higher in the older age group (10-13 year) compared to younger age group (6 to 9 years) (P < 0.05). Unilateral amblyopia (3.24%) was more frequent than bilateral amblyopia (0.66%). The most frequent causes of amblyopia were refractive error (94.56%), of which anisometropic amblyopia was present in 77.72%, isoametropic amblyopia in 16.84% and strabismus in 5.44%.Conclusion:The prevalence of amblyopia in Qassim province, KSA, is 3.9% which is similar or higher than other published studies on amblyopia. Anisometropic refractive errors are the most common underlying cause for this population. We recommend implementation of visual screening programs for children with appropriate clinical and social settings for early detection and proper management of amblyopia.

Efficiency of electronically monitored amblyopia treatment between 5 and 16 years of age: new insight into declining susceptibility of the visual system.

The notion of a limited, early period of plasticity of the visual system has been challenged by more recent research demonstrating functional enhancement even into adulthood. In amblyopia ("lazy eye") it is still unclear to what extent the reduced effect of treatment after early childhood is due to declining plasticity or lower compliance with prescribed patching. The aim of this study was to determine the dose-response relationship and treatment efficiency from acuity gain and electronically recorded patching dose rates, and to infer from these parameters on a facet of age dependence of functional plasticity related to occlusion for amblyopia. The Occlusion Dose Monitor was used to record occlusion in 27 participants with previously untreated strabismic and/or anisometropic amblyopia aged between 5.4 and 15.8 (mean 9.2) years during 4months of conventional treatment. Group data showed improvement of acuity throughout the age span, but significantly more in patients younger than 7years despite comparable patching dosages. Treatment efficiency declined with age, with the most pronounced effects before the age of 7years. Thus, electronic recording allowed this first quantitative insight into occlusion treatment spanning the age range from within to beyond the conventional age for patching. Though demonstrating improvement in over 7year old patients, it confirmed the importance of early detection and treatment of amblyopia. Treatment efficiency is presented as a tool extending insight into age-dependent functional plasticity of the visual system, and providing a basis for comparisons of effects of patching vs. emerging alternative treatment approaches for amblyopia.

Calibration of a new remote autorefractor, the 2WIN compared to PlusoptixS12 and SPOT with amblyopic patients

Pediatricians are interested in the amblyopia detection ability of photoscreeners while ophthalmologists ponder their value as autorefractors. The 2WIN is capable of estimating refractive error and ocular alignment by infrared photoscreening.

Assessing binocular interaction in amblyopia and its clinical feasibility.

PurposeTo measure binocular interaction in amblyopes using a rapid and patient-friendly computer-based method, and to test the feasibility of the assessment in the clinic.MethodsBinocular interaction was assessed in subjects with strabismic amblyopia (n = 7), anisometropic amblyopia (n = 6), strabismus without amblyopia (n = 15) and normal vision (n = 40). Binocular interaction was measured with a dichoptic phase matching task in which subjects matched the position of a binocular probe to the cyclopean perceived phase of a dichoptic pair of gratings whose contrast ratios were systematically varied. The resulting effective contrast ratio of the weak eye was taken as an indicator of interocular imbalance. Testing was performed in an ophthalmology clinic under 8 mins. We examined the relationships between our binocular interaction measure and standard clinical measures indicating abnormal binocularity such as interocular acuity difference and stereoacuity. The test-retest reliability of the testing method was also evaluated.ResultsCompared to normally-sighted controls, amblyopes exhibited significantly reduced effective contrast (∼20%) of the weak eye, suggesting a higher contrast requirement for the amblyopic eye compared to the fellow eye. We found that the effective contrast ratio of the weak eye covaried with standard clincal measures of binocular vision. Our results showed that there was a high correlation between the 1st and 2nd measurements (r = 0.94, p<0.001) but without any significant bias between the two.ConclusionsOur findings demonstrate that abnormal binocular interaction can be reliably captured by measuring the effective contrast ratio of the weak eye and quantitative assessment of binocular interaction is a quick and simple test that can be performed in the clinic. We believe that reliable and timely assessment of deficits in a binocular interaction may improve detection and treatment of amblyopia.

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

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

The Effects of Blur and Eccentric Viewing on Adult Acuity for Pediatric Tests: Implications for Amblyopia Detection

The detection of amblyopia in children relies on an accurate assessment of visual acuity. Visual deficits in anisometropic and strabismic amblyopia are different, but the influence of chart design, in particular position, and type of crowding features on visual acuity in the two types of amblyopia, is not clear. Certain aspects of amblyopic spatial vision are mimicked in healthy individuals by imposing increasing levels of blur and retinal eccentricity. We measured the effects of these conditions on visual acuity in healthy adults, with crowded and uncrowded vision tests. Visual acuity was measured under conditions of blur (0-4 D) and eccentric viewing (0-5 degrees) using high-contrast optotypes derived from common children's acuity charts. Optotypes were presented in isolation, in commercially available crowded configurations, and in configurations with closer target-flanker separations than those currently available. Dioptric blur had similar degradative effects on crowded and isolated visual acuity (P > 0.05), whereas eccentric viewing resulted in a larger deterioration of visual acuity for crowded tests (E2 of 0.86-1.06) than for isolated optotypes (E2 of 1.57-1.72) (P < 0.05). Maximum crowding effects occurred for closer target-flanker separations than those currently used commercially. In so far as blur and eccentric viewing mimic spatial acuity deficits in amblyopia, the results suggest that crowded tests might be of limited value in the detection of anisometropic amblyopia, but should be valuable in the detection of strabismic amblyopia. Crowding effects would be greater if flanking features were placed closer to the target than they currently are in commercially available charts.

Study of Changes in the B-Wave of Electroretinogram in Early Detection of Organic Amblyopia in Children

Background: Amblyopia or Lazy eye is a common problem among children and indicating the existence of underlying diseases such as strabismus or refractive error, and therefore its diagnosis and treatment is needed, to prevent complications in the visual system and therefore, identifying and treating these children is an important task. One of the methods proposed is the use of electrophysiological tests mainly Electroretinography (ERG), ERG deals with retina of visual system. The aim of present research is an attempt to survey the retina of these patients and look for possible changes in b wave of ERG pattern.Methods: 50 children with organic amblyopia were enrolled in this study, the demographic information of the patients was recorded in a list prepared for this purpose. The ERG, mainly the b wave was measured in the patient population. The results obtained were analyzed by software SPSS19.Results: The mean voltage of b wave in case and control group was. 34.88 and 90.96 μv respectively. The difference between the two groups is statistically significant (P<0.05),however, the latency in patients and healthy population was 86.56 and 43.6 msec respectively, which is statistically significant (P<0.05)too.Conclusion: In general we can conclude that ERG test; provide useful information about retina of the children suffering from amblyopia which will be discussed in the manuscript in detail.Keywords: Amblyopia, children, ERG b-wave

Sensitivity and specificity of grating and vernier stimuli for detection of amblyopia by sVEP

Sensitivity and specificity of grating and vernier stimuli for detection of amblyopia by sVEP

Visually evoked potential detection of amblyopia in the clinic

Preverbal children with amblyopia risk factors can be challenging to manage, as they may have a fixation preference but may or may not have amblyopia. We developed a user and patient friendly test using visually evoked potentials (VEPs) to aide in management of such children.

Validity of a layperson-administered Web-based vision screening test for the detection of amblyopia in the home environment

To determine the sensitivity and specificity of a Web-based vision screening test (WBT), LazyeyeTest.org, administered by an untrained layperson in their home environment.

Objective detection of amblyopia and strabismus . . . not just screening for risk factors

To date, preschool vision screening for strabismus and/or amblyopia involves assessment of risk factors, including refractive error and stereoacuity. Most children who are positive for risk factors never develop strabismus or amblyopia. The Pediatric Vision Scanner (PVS) is the first objective, automated screening device that directly assesses bifoveal fixation. This study was undertaken to assess the ability of the PVS to identify patients with strabismus and/or amblyopia in a pediatric ophthalmology office setting.

Amblyopia Prevalence and Risk Factors in Australian Preschool Children

To determine the prevalence of and factors associated with amblyopia in a sample of Australian preschool children. Population-based, cross-sectional study. The Sydney Paediatric Eye Disease Study examined 2461 (73.8% participation) children aged between 6 and 72 months from 2007 to 2009. Visual acuity (VA) was assessed in children aged ≥ 30 months using the Electronic Visual Acuity system, and a subset using the logarithm of the minimum angle of resolution chart. Amblyopia was categorized into unilateral and bilateral subtypes: Unilateral amblyopia was defined as a 2-line difference in reduced VA between the 2 eyes, in addition to strabismus, anisometropia, and/or visual axis obstruction; bilateral amblyopia was defined as bilateral reduced VA with either bilateral visual axis obstruction or significant bilateral ametropia. Information on ethnicity, birth parameters, and measures of socioeconomic status were collected in questionnaires completed by parents. Amblyopia. We included 1422 children aged 30 to 72 months, of whom 27 (1.9%) were found to have amblyopia or suspected amblyopia. Mean spherical equivalent for the amblyopic eyes was +3.57 diopters, with a mean VA of 20/50. Only 3 of the 27 amblyopic children had previous diagnoses or treatments for amblyopia. In regression analysis controlling for age, gender, and ethnicity, amblyopia was significantly associated with hyperopia (odds ratio [OR], 15.3; 95% confidence interval [CI], 6.5-36.4), astigmatism (OR, 5.7; 95% CI, 2.5-12.7), anisometropia (OR, 27.8; 95% CI, 11.2-69.3), and strabismus (OR, 13.1; 95% CI, 4.3-40.4). There were no significant associations of amblyopia with low birthweight (<2500 g), preterm birth (<37 weeks), maternal smoking, age, gender, ethnicity, or measures of socioeconomic status (all P>0.05). Amblyopia was found in 1.9% of this Australian preschool sample, which is comparable with prevalence rates reported by other recent studies in preschool children. Refractive errors, particularly significant hyperopia and astigmatism, in addition to anisometropia and strabismus, were the major amblyogenic factors. There was a low amblyopia detection rate in this preschool population, which suggests that different strategies are required to improve current vision screening strategies in preschoolers. The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Rapid, High-Accuracy Detection of Strabismus and Amblyopia Using the Pediatric Vision Scanner

Purpose. The Pediatric Vision Scanner (PVS) detects strabismus by identifying ocular fixation in both eyes simultaneously. This study was undertaken to assess the ability of the PVS to identify patients with amblyopia or strabismus, particularly anisometropic amblyopia with no measurable strabismus. Methods. The PVS test, administered from 40 cm and requiring 2.5 seconds of attention, generated a binocularity score (BIN, 0%-100%). We tested 154 patients and 48 controls between the ages of 2 and 18 years. BIN scores of amblyopic children and controls were measured, and 21 children received sequential PVS measurements to detect any changes in BIN resulting from amblyopia treatment. Results. With the pass/refer threshold set at BIN 60%, sensitivity and specificity were 96% for the detection of amblyopia or strabismus. Assuming a 5% prevalence of amblyopia or strabismus, the inferred positive and negative predictive values of the PVS were 56% and 100%, respectively. Fixation accuracy was significantly reduced in amblyopic eyes. In anisometropic amblyopia patients treated successfully, the BIN improved to 100%. Conclusions. The PVS identified children with amblyopia or strabismus with high sensitivity and specificity, while successful treatment restored normal BIN scores in amblyopic patients without strabismus. The results support the hypothesis that the PVS detects strabismus and amblyopia directly. Future strategies for screening by nonspecialists may thus be based on diagnostic detection of amblyopia and strabismus rather than the estimation of risk factors, allowing for rapid, accurate identification of children with amblyopia early in life when it is most amenable to treatment.

The Use of COVD-QOL Questionnaire in School Vision Screening

Purpose:To evaluate the application of College of Optometrist in Vision Development (COVD) Quality of Life (QOL) questionnaire in vision screening for normal school children and children with learning disabilities (LD) and to determine appropriate referral-score for different target population.Methods:A total of 90 children (Normal: 45, LD: 45) who attended government primary schools aged between 6 to 12 years old were recruited. An interview session with normal children and parents or teachers in children with LD was made to determine visual symptoms using shorter version of COVD-QOL questionnaire. A comprehensive eye examination was performed after completion of the questionnaire. The evaluation was made base on the sensitivity and specificity for detection of refractive error, amblyopia, strabismus, vergence and accommodative disorders.Results:The mean score for normal children and children with LD were 22.47±10.75 and 12.24±8.72 respectively. Rapidity of the test in normal children and children with LD were 177.27±9.52 seconds and 162.16±16.58 seconds respectively. In normal children referral score of =20 showed highest sensitivity (66.7%) and specificity (95.8%) for detection of amblyopia. Sensitivity and specificity for referral-score of =20, =10 and =4 for detection of overall vision problems in children with LD were (20.4%, 100.0%), (54.5%, 100.0%) and (81.8%, 100.0%) respectively.Conclusion:COVD-QOL questionnaire was recommended as an easy, rapid and cost-effective tool for school vision screening. Different referral-score was suggested for different target population.

Detection and treatment of amblyopia in children

Refractive errors are a common cause of decreased visual acuity. They can be found in 2-4% of preschool children. If not discovered on time and not properly treated, they can lead to amblyopia and strabismus. The active participation of parents and paediatricians is of great importance in timely discovering and treatment of amblyopia. The most common causes of amblyopia are strabismus (50.1%) and refractive error (44.7%). The best treatment results are achieved in amblyopic children with strabismus. The cooperation of physicians of all specialties, above all paediatricians and ophthalmologists, as well as a good collaboration of parents based on their being well-informed, must exist in the process of timely diagnosing and treating of amblyopia.

The base-to-base induced-tropia prism test for detection of amblyopia: A pilot study

To investigate the accuracy of the base-to-base prism test (BBPT), which entails inducing an esotropia with the use of base-in prisms before each eye, in the diagnosis of amblyopia. Participants were consecutive patients recruited from a pediatric ophthalmology practice who were able to perform logMAR acuity testing. All participants underwent an orthoptic examination, including logMAR visual acuity testing, and a sensorimotor evaluation. Patients with an interocular difference of 2 or more lines were considered to have amblyopia. Fixation preference was assessed by use of both the vertical fixation test and the BBPT. The agreement between the BBPT and visual acuity was analyzed and compared with the agreement between the vertical fixation test and visual acuity. Fifty-one consecutive patients aged 4 to 17 (mean, 9.8 years; SD ± 3.4) were included, of whom 11 were diagnosed with amblyopia. Kappa analysis showed moderate but significant agreement between the BBPT and logMAR (κ = 0.453, p = 0.001), whereas the vertical fixation test demonstrated only a fair agreement (κ = 0.254, p = 0.061). The overall sensitivity for the BBPT was 72.7% (95% confidence interval [95% CI], 43.4%-90.3%) but only 40% for the vertical fixation test (95% CI, 16.8%-69.7%). For the BBPT, specificity was 80% (95% CI, 65.2%-89.5%); for the vertical fixation test, 78% (95% CI, 63.3%-88.0%). The BBPT appears to be more sensitive than the vertical fixation test for detecting amblyopia in our patient population. The 2 tests had similar specificity.

Design of a randomized clinical trial to improve rates of amblyopia detection in preschool aged children in primary care settings

Purpose To present the design of a cluster randomized controlled trial (cRCT) to evaluate the effectiveness of a web-based intervention for improving provider knowledge about strabismus and amblyopia (S/A) and preschool vision screening (PVS), increase PVS rates, and improve rates of S/A diagnoses made by eye specialists. This is the first cRCT targeting amblyopia prevention. Methods Participants were Medicaid providers in AL, SC, or IL who had Internet access and had filed at least 8 claims for well child visits (WCV) for children ages 3 or 4 years old during a 12-month period before enrollment. Randomization to the Intervention (vision) or Control (blood pressure) arm occurred at the cluster level, defined as the provider (or group of providers) and his/her patients seen for WCVs. Results 65 Intervention providers (IPs) with 3547 children aged 3 or 4 years, and 71 Control providers (CPs) with 5053 children enrolled. The study will report measures of knowledge and self-reported vision screening behaviors from web-based data. The primary outcomes will be rates of PVS among PCPs, and rates of diagnosis of S/A by eye specialists among the children belonging to Control and Intervention practices. Conclusions We had the same difficulty recruiting PCPs as reported by others. Baseline rates of PVS were low (14.1%), as were rates that S/A were diagnosed by eye providers (1.4%). Our data show a need to improve both primary outcome measures.

Detecção de ambliopia, ametropias e fatores ambliogênicos em comunidade assistida por Programa da Saúde da Família no Rio de Janeiro, Brasil

OBJETIVOS: Determinar a prevalencia dos fatores ambliogenicos e ambliopia na area adscrita do Programa Saude da Familia (PSF) da Lapa (RJ) e, estimar na mesma area a sensibilidade e especificidade entre metodos de medida de acuidade visual (tabelas ETDRS e LEA) em criancas pre-escolares. METODOS: Estudo transversal de 93 criancas entre tres a seis anos da area adscrita do PSF Lapa, RJ. Todas as criancas foram submetidas a avaliacao oftalmologica completa que incluiu: anamnese dirigida, ectoscopia, medida da acuidade visual com tabela de ETDRS e LEA de forma duplo cega, reflexo vermelho, teste de Titmus, refracao objetiva sob cicloplegia, refracao subjetiva, avaliacao da motilidade ocular, biomicroscopia do segmento anterior, fundoscopia sob midriase. Os dados foram coletados na Policlinica Ronaldo Gazolla, da Universidade Estacio de Sa. RESULTADOS: A prevalencia dos fatores ambliogenicos foi encontrada e distribuida em: 8,4 % de estrabismo; 11,86% de anisometropia e 15,2% de ametropia. O teste de acuidade visual ETDRS apresentou sensibilidade de 100% e especificidade de 18% para deteccao de ambliopia. O teste de acuidade visual LEA apresentou sensibilidade de 100% e especificidade de 30,9% para deteccao de ambliopia. CONCLUSAO: Ambas tabelas ETDRS e LEA podem ser usadas para a triagem de ambliopia porque tiveram 100% de sensibilidade. A especificidade foi maior para a tabela LEA. Porem ainda em nivel baixo. Portanto, ha necessidade da complementacao com o exame oftalmologico completo para confirmar e ratificar a presenca de fatores ambliogenicos em pacientes triados positivamente. A triagem visual feita pelos Agentes Comunitarios de Saude pode identificar criancas com disturbios visuais, referenciando para exame oftalmologico completo; em um grupo etario onde a resolucao dos problemas visuais se apresenta como prioridade. O Programa de Saude da Familia pode ser utilizado para avaliar o estado de visao das criancas brasileiras e seria util que essa avaliacao fosse um marcador estatistico do SUS.