Evaluation of the Spot Vision Screener in School-Aged Children

PURPOSE

To determine the accuracy of the Spot Vision Screener (Welch Allyn, Skaneateles Falls, NY) in children 6 years and older and recommend device thresholds to improve its accuracy for the detection of refractive error.

METHODS

The Spot Vision Screener results were compared with three gold standard conditions of increasingly narrow refractive error criterion. The sensitivity, specificity, positive predictive value, and negative predictive value of the Spot Vision Screener in detecting each gold standard criterion were calculated. The most accurate threshold setting for each parameter was identified by calculating the area under the curve receiver operating characteristic.

RESULTS

The Spot Vision Screener was able to successfully evaluate 313 of 330 children (95%). The sensitivity of the Spot Vision Screener to detect American Association for Pediatric Ophthalmology and Strabismus guidelines for amblyopia risk factors was 89.5% and the specificity was 76.7%. The sensitivity decreased to 80% and the specificity increased to 75.3% with narrower refractive criteria. The sensitivity in detecting refractive criteria improved with the proposed optimized device thresholds. Estimates for the general population indicate that the positive predictive value is reasonable at 52.3% to 61.8%, depending on the stringency of the criteria, with excellent negative predictive values.

CONCLUSIONS

In school-aged children, the primary screening focus shifts from preventing amblyopia to detecting visual disturbances, including refractive error, that may interfere with academic performance. In this age group, the Spot Vision Screener was an acceptable method of detecting significant refractive error with improved sensitivity with threshold optimization. [J Pediatr Ophthalmol Strabismus. 2020;57(3):146-153.].

National and sub national prevalence of Amblyopia and its trends from 1990 to 2018 in Iran

PURPOSE

To determine the national and subnational prevalence of amblyopia and the respective provincial distribution and trend during 1990-2018 in Iran.

METHODS

Amblyopia data retrieved from 26 original studies, systematic reviews, Data has been cleaned by STATA and a linear mixed effect spatio-temporal model was used to calculate Gaussian process regression mean functions. Using a Bayesian approach, by pooling empirical data based on the assumed prior, a posterior distribution obtained for age and sex specific prevalence prediction nationally during the study time and provincially.

RESULTS

The overall age-adjusted prevalence of Amblyopia was 0.03 (95% CI, 0.022-0.035). The prevalence was comparable in boys and girls (p = 0.85), highest prevalence was in >30 years old (p = 0.038). Our extrapolation revealed a stable trend of prevalence of Amblyopia in Iran during 1990-2018 (national screening program has been active from 1990 onwards). While Amblyopia prevalence suggested a declining trend in three provinces of Hormozgan, Qom and Tehran and it went up in 13 other provinces.

CONCLUSION

Amblyopia prevalence seems unchanged despite the concurrent screening program. It is noteworthy that the coverage of the program has been improved and has reached more than 85% in 2018. Our finding mandates a formal evaluation on the program.

Evaluation of All Causes of Visual Function Loss in Children With Congenital Blepharoptosis

PURPOSE

To evaluate the overall frequency of visual function loss in pediatric patients with congenital blepharoptosis.

METHODS

This retrospective study was conducted in a tertiary center. The clinical records of patients younger than 18 years who were diagnosed as having congenital blephroptosis, underwent surgery, and had at least 1 year of postoperative follow-up were evaluated. Visual acuity results, presence of structural eye abnormalities, presence and type of amblyopia and strabismus, and refractive errors were recorded. The Mann-Whitney U test, chi-square test, and stepwise regression analysis were used for statistical analyses.

RESULTS

The mean final visual acuity was 0.11 ± 0.23 logarithm of the minimum angle of resolution (logMAR) (range: 0.0 to 1.0 logMAR) at the final follow-up visit for 143 eyes of 123 patients (65 male and 58 female). In this cohort, 30 patients (24.4%) had amblyopia and 5 patients (4.1%) had visual loss related to structural eye pathology, amounting to a total of 35 patients (28.5%) with visual function loss. The mean final visual acuities of patients without amblyopia, patients with amblyopia, and patients with organic eye disorders were 0.01 ± 0.03, 0.29 ± 0.28, and 0.55 ± 0.42 logMAR, respectively. Severe blepharoptosis (≥ 4 mm) was present in 25 patients (83.3%) with amblyopia. Deprivational amblyopia was detected in 25 of 36 eyes (69.4%) with amblyopia. Independent risk factors associated with final visual acuity were presence of amblyopia at presentation (correlation coefficient [ß] ± standard error [SE] = -0.29 ± 0.04; P < .001), anisometropia (ß ± SE = -0.27 ± 0.06; P < .001), and ptosis severity (ß ± SE = -0.09 ± 0.04; P = .012). Visual impairment (visual acuity < 20/40) persisted in 11.9% of eyes at the final follow-up.

CONCLUSIONS

Visual function loss was present in one-third of pediatric patients with congenital blepharoptosis. Both amblyopia and structural eye disorders contribute to visual impairment in this patient population. Structural eye pathology contributes independently to 4.1% of visual loss in this clinical setting. [J Pediatr Ophthalmol Strabismus. 2020;57(2):97-102.].

Development of a system based on artificial intelligence to identify visual problems in children: study protocol of the TrackAI project

INTRODUCTION

Around 70% to 80% of the 19 million visually disabled children in the world are due to a preventable or curable disease, if detected early enough. Vision screening in childhood is an evidence-based and cost-effective way to detect visual disorders. However, current screening programmes face several limitations: training required to perform them efficiently, lack of accurate screening tools and poor collaboration from young children.Some of these limitations can be overcome by new digital tools. Implementing a system based on artificial intelligence systems avoid the challenge of interpreting visual outcomes.The objective of the TrackAI Project is to develop a system to identify children with visual disorders. The system will have two main components: a novel visual test implemented in a digital device, DIVE (Device for an Integral Visual Examination); and artificial intelligence algorithms that will run on a smartphone to analyse automatically the visual data gathered by DIVE.

METHODS AND ANALYSIS

This is a multicentre study, with at least five centres located in five geographically diverse study sites participating in the recruitment, covering Europe, USA and Asia.The study will include children aged between 6 months and 14 years, both with normal or abnormal visual development.The project will be divided in two consecutive phases: design and training of an artificial intelligence (AI) algorithm to identify visual problems, and system development and validation. The study protocol will consist of a comprehensive ophthalmological examination, performed by an experienced paediatric ophthalmologist, and an exam of the visual function using a DIVE.For the first part of the study, diagnostic labels will be given to each DIVE exam to train the neural network. For the validation, diagnosis provided by ophthalmologists will be compared with AI system outcomes.

ETHICS AND DISSEMINATION

The study will be conducted in accordance with the principles of Good Clinical Practice. This protocol was approved by the Clinical Research Ethics Committee of Aragón, CEICA, on January 2019 (Code PI18/346).Results will be published in peer-reviewed journals and disseminated in scientific meetings.

TRIAL REGISTRATION NUMBER

ISRCTN17316993.

Correlation between higher-order aberrations and visual acuity recovery (CoHORT) after spectacles treatment for pediatric refractive amblyopia: A pilot study using iDesign measurement

Purpose

To determine the correlation between higher-order aberrations (HOAs) and best-corrected visual acuity (BCVA) recovery speed after spectacles treatment using iDesign measurements in refractive amblyopic children.

Methods

This is a prospective case series. Children aged from 3 to 7 years with refractive amblyopia (Landolt C equivalent < 0.8) were recruited. All participants were followed for at least 6 months after full correction of the refraction error by spectacles. The HOAs were measured using iDesign before and after cycloplegia at first visit and at 3-month intervals. Then correlation between BCVA recovery after treatment for 6 months and HOAs was determined.

Results

We analyzed 24 eyes of 12 children (mean age, 4.5 years). Baseline mean BCVA was logarithm of minimal angle of resolution (logMAR) 0.335 (Landolt C equivalent 0.46), which improved to logMAR 0.193 (Landolt C equivalent 0.64) after treatment with full-correction spectacles for 6 months. The amblyopic eye BCVA recovery was negatively correlated with tetrafoil with/without cycloplegia (P = 0.006 and 0.022, respectively) and trefoil with cycloplegia (P = 0.049).

Conclusions

trefoil and tetrafoil measured with iDesign negatively correlates with the BCVA recovery speed of refractive amblyopic eyes after spectacles treatment in this pilot study. The current study results may aid in further investigation for diagnosis and treatment of refractory refractive and idiopathic amblyopia.

Amblyopia: Detection and Treatment

Amblyopia is the leading cause of monocular vision loss in children. Early recognition and treatment are important to prevent vision loss. The U.S. Preventive Services Task Force recommends vision screening for all children at least once between three and five years of age to detect the presence of amblyopia or its risk factors. The American Association for Pediatric Ophthalmology and Strabismus and the American Academy of Pediatrics recommend routine, age-appropriate red reflex testing, examination for signs of strabismus, and vision chart testing. Photoscreening may be a useful adjunct to traditional vision screening, but there is limited evidence that it improves visual outcomes. Treatments for amblyopia include patching, atropine eye drops, and optical penalization of the nonamblyopic eye. In children with moderate amblyopia, patching for two hours per day is as effective as six hours, and daily atropine is as effective as daily patching. Children younger than seven years receive the most benefit from treatment, but older children may still benefit. Amblyopia recurs in 25% of children, so continued surveillance is important.

Intact Visuospatial Cognition in Amblyopia: Results From the Gutenberg Health Study

PURPOSE

To determine whether amblyopia interferes with cognitive functions requiring visuospatial processing, measured by the Tower of London (ToL) test.

METHODS

The current study was based on a sub-cohort from the population-based Gutenberg Health Study and included 1,569 participants aged 35 to 44 years. Amblyopia was defined as a visual acuity of 0.63 or worse (worse eye) in the presence of an amblyogenic factor; prevalence was 5%. There were three groups: participants with amblyopia (n = 78), participants with a visual acuity of 0.63 or worse (worse eye) without amblyopia (n = 65), and participants with a visual acuity of better than 0.63 (worse eye) (n = 1,426). Visuospatial planning ability was measured by the ToL test (touch-screen version), and the performance score ranged from 0 to 24, depending on the number of correctly solved problems. The authors used linear regression models to investigate the association between amblyopia and ToL test scores, adjusting for age, sex, and socioeconomic status.

RESULTS

The mean ± standard deviation of ToL test performance was 15.31 ± 3.29 in participants with a visual acuity of better than 0.63, 14.56 ± 3.76 in the amblyopic group, and 15.14 ± 3.65 in participants with a visual acuity of 0.63 or worse without amblyopia. In a linear regression model, sex, and socioeconomic status significantly predicted planning performance (P <.0001), whereas amblyopic status did not (P = .20).

CONCLUSIONS

Amblyopia may affect visuospatial perception, but no such relationships could be found for higher cognitive functions that strongly depend on visuospatial processing. Thus, in adulthood, individuals with amblyopia are unaffected in their visuospatial cognitive abilities, as required by the ToL test. [J Pediatr Ophthalmol Strabismus. 2019;56(6):397-401.].

Choosing appropriate tools and referral criteria for vision screening of children aged 4-5 years in Canada: a quantitative analysis

OBJECTIVES

To assess the diagnostic accuracy of five vision screening tools used in a school setting using sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV).

DESIGN

We compared the results of the five best evidence-based screening tools available in 2014 to the results of a comprehensive eye exam with cycloplegic refraction by a licenced optometrist. Screening included Cambridge Crowded Acuity Cards, Plusoptix S12 and Spot photoscreeners, Preschool Randot Stereoacuity Test and the Pediatric Vision Scanner (PVS). Referral criteria followed AAPOS (2013) guidelines and published norms.

SETTING

A large school in Toronto, Canada, with 25 split classrooms of junior kindergarten (JK: 4 year olds) and senior kindergarten (SK: 5 year olds) children.

PARTICIPANTS

Over 2 years, 1132 eligible children were enrolled at the school. After obtaining parental consent, 832 children were screened. Subsequently, 709 children had complete screening and optometry exam data.

MAIN OUTCOME MEASURES

The presence/absence of a visual problem based on optometrist's assessment: amblyopia, amblyopia risk factors (reduced stereoacuity, strabismus and clinically significant refractive errors) and any other ocular problem (eg, nystagmus).

RESULTS

Overall, 26.5% of the screened children had a visual problem, including 5.9% with amblyopia. Using all five tools, screening sensitivity=84% (95% CI 78 to 89), specificity=49% (95% CI 44 to 53), PPV=37% (95% CI 33 to 42), and NPV=90% (95% CI 86 to 93). The odds of having a correct screening result in SK (mean age=68.2 months) was 1.5 times those in JK (mean age=55.6 months; 95% CI 1.1 to 2.1), with sensitivity improved to 89% (95% CI 80 to 96) and specificity improved to 57% (95% CI 50 to 64) among SK children.

CONCLUSIONS

A school-based screening programme correctly identified 84% of those kindergarten children who were found to have a visual problem by a cyclopleged optometry exam. Additional analyses revealed how accuracy varies with different combinations of screening tools and referral criteria.

Eye Conditions in Infants and Children: Vision Screening and Routine Eye Examinations

Vision problems in children are relatively common, with refractive error, strabismus, and/or amblyopia affecting between 5% to 10% of preschool-age children. Amblyopia is most concerning in the pediatric population because the visual system can develop poorly, potentially causing unilateral or bilateral vision impairment, which may or may not be correctable. Because of this, most pediatric vision screening recommendations focus on screening for amblyopia or the risk factors for amblyopia, including anisometropia, high refractive errors, and strabismus. The U.S. Preventive Services Task Force (USPSTF) recommends screening children for amblyopia and its risk factors at least once between ages 3 and 5 years. However, the joint policies of the American Academy of Pediatrics (AAP), American Academy of Ophthalmology (AAO), American Association for Pediatric Ophthalmology and Strabismus (AAPOS), and American Association of Certified Orthoptists (AACO) recommend screening starting in the newborn period and continuing through adolescence. These groups advocate for instrument screening in younger children and children who are developmentally delayed because the use of eye charts can be difficult in these children. In general, children with abnormal screening results should be referred to an ophthalmology subspecialist for further evaluation.

Eye Conditions in Infants and Children: Amblyopia and Strabismus

Amblyopia is a developmental disorder of the central nervous system. It occurs in infancy or early childhood when the visual system is susceptible to issues that interrupt development. In the United States, up to 2% of infants and children ages 6 to 71 months have amblyopia. Risk factors for amblyopia include hyperopia, astigmatism, and myopia. Risk factors are more common in children who are premature or small for gestational age. Management of amblyopia in children includes optical correction of refractive errors, occlusion therapy (patching), pharmacotherapy, and surgery. Strabismus occurs when one eye can focus on an object or a point but the other eye turns inward toward the nose (esotropia), upward (hypertropia), downward (hypotropia), or outward toward the temple (exotropia). The patient may report diplopia or vision loss and may present with compensating posture such as a head tilt. Nonsurgical (ie, eyeglasses, prisms, onabotulinumtoxinA) and surgical management options are available to manage strabismus.

How Many Plusoptix S04 Measures Yield the Most Sensitive Amblyopia Screening?

PURPOSE

To analyze how the Plusoptix S04 (Plusoptix, Atlanta, GA), a widely used technology for amblyopia screening, predicts amblyopia.

METHODS

A total of 1,547 children aged 3 to 4 years underwent a non-invasive eye examination in a whole population screening. The Plusoptix was measured binocularly three consecutive times. Seven models were developed: the first (P1), second (P2), and third (P3) measure of Plusoptix, the mean of P1, P2, and P3 (Pmean123), the maximal value of P1, P2, and P3 (Pmax123), the mean of P1 and P2 (Pmean12), and the maximal value of P1 and P2 (Pmax12).

RESULTS

Internal consistency was excellent for sphere, cylinder (alpha = 0.92 vs 0.97), aniso-sphere, and aniso-cylinder (alpha = 0.87 vs 0.86). All models predicted amblyopia (P < .001); there was 2.3% new diagnosis and 5.1 events per variable. A bootstrap analysis with 1,000 samples confirmed the stability of the model. Astigmatism (P < .001; odds ratio [OR] = 2.1 to 3.6) and aniso-sphere (P < .001; OR = 3.6 to 9.0) predicted amblyopia. Although sphere, when measurable, did not predict amblyopia (P > .19; OR = 1.2 to 1.3), the likelihood of amblyopia presence was 100 times higher when the Plusoptix displayed "hyper." All receiver operating characteristic (ROC) curves were significant (P < .001), with no differences between them (all P > .16). Adjusting the cut-off from ROC curves for the highest sensitivity, Pmax12 referred 31.9% and 16.1% fewer patients than P1 and Pmean12, respectively. A third measure revealed accommodation-related false-negative results; therefore, adding measurements showed no benefit.

CONCLUSIONS

This was the first study to assess the Plusoptix's prediction of amblyopia. When aiming for maximal sensitivity, the Plusoptix refers many children (> 20% children in all models). The first measure refers more children than two measures. Non-measurable results must be considered abnormal because the chance of amblyopia presence was high. [J Pediatr Ophthalmol Strabismus. 2019;56(5):305-312.].

Comparison of amblyopia in schoolchildren in Ireland and Northern Ireland: a population-based observational cross-sectional analysis of a treatable childhood visual deficit

OBJECTIVES

This study reports the prevalence of persistent amblyopia (post-traditional treatment age) in schoolchildren in the Republic of Ireland (henceforth Ireland) and Northern Ireland (NI), UK; populations with broadly similar refractive and genetic profiles but different eye-care systems.

DESIGN

This is a population-based observational study of amblyopia and refractive error.

SETTING

Recruitment and testing in primary and post-primary schools in Ireland and NI.

PARTICIPANTS

Two groups identified through random cluster sampling to represent the underlying population; Ireland 898 participants (12-13 years old) and NI 723 participants (295 aged 9-10 years old, 428 aged 15-16 years old).

MAIN OUTCOME MEASURES

Monocular logMAR visual acuity (presenting and pinhole), refractive error (cycloplegic autorefraction), ocular alignment (cover test) and history of previous eye care. These metrics were used to determine prevalence and type of amblyopia and treatment histories.

RESULTS

Children examined in NI between 2009 and 2011 had a significantly lower amblyopia prevalence than children examined in Ireland between 2016 and 2018 (two-sample test of proportions, p<0.001). Using a criteria of pinhole acuity 0.2logMAR (6/9.5 Snellen) plus an amblyogenic factor, 4 of 295 participants aged 9-10 years old (1.3%, 95% CIs 0.4 to 3.6) and 3 of 428 participants aged 15-16 years old (0.7%, 95%CIs 0.2 to 2.2) were identified in NI. The corresponding numbers in Ireland were 40 of 898 participants aged 12-13 years old (4.5%, 95% CI 3.2 to 6.1). In NI strabismic amblyopia was the most prevalent type of persistent amblyopia, whereas anisometropic was predominant in Ireland. In Ireland, amblyopia was associated with socioeconomic disadvantage (OR=2.2, 95%CIs 1.4 to 3.6, p=0.002) and poor spectacle compliance (OR 2.5, 95% CIs 2.0 to 3.2, p<0.001).

CONCLUSIONS

Amblyopia prevalence persisting beyond traditional treatment ages was significantly lower among NI children compared with Ireland. Uncorrected anisometropia, compliance with spectacle wear and socioeconomic disadvantage were contributing factors in Ireland. Children without obvious visible eye defects were less likely to access eye care in Ireland, resulting in missed opportunities for intervention where necessary.

Fellow Eye Deficits in Amblyopia

Amblyopia is a neurodevelopmental disorder of the visual system, as a result of discordant visual experience during infancy or early childhood. Because amblyopia is typically defined as monocularly reduced visual acuity accompanied by one or more known amblyogenic factors, it is often assumed that the fellow eye is normal and sufficient for tasks like reading and eye-hand coordination. Recent scientific evidence of ocular motor, visual, and visuomotor deficits that are present with fellow eye monocular viewing and with binocular viewing calls this assumption into question. This clinical update reviews the research that has revealed fellow ocular motor and visual deficits and the effect that these deficits have on an amblyopic child's visuomotor and visuocognitive skills. We need to understand how to prevent and rehabilitate the effects of amblyopia not only on the nonpreferred eye but also on the fellow eye.

Comparison of higher order aberrations in amblyopic and non-amblyopic eyes in pediatric patients with anisometropic amblyopia

Purpose

To compare the ocular higher order aberrations (HOAs) for the physiologic pupil size in amblyopic and non-amblyopic eyes of patients with anisometropic amblyopia in pediatric age group.

Methods

Children between 5 and 15 years age having treatment naïve anisometropic amblyopia; after a detailed examination by a pediatric ophthalmologist; underwent assessment of wavefront aberrations for both amblyopic and non-amblyopic eyes at their physiologic pupil sizes using i-Trace ray tracing wavefront aberrometer. The axial lengths were also measured using IOL Master 500. The RMS values of the total ocular higher order aberrations (HOAs) and those arising from internal and corneal components of the two eyes were tabulated and compared to look for differences. Comparison of total ocular aberrations for pre-determined refractive error groups was also done for amblyopic and non-amblyopic eyes separately.

Results

Eighty-eight eyes of 44 subjects were included for analysis. Mean pupil size was comparable in between amblyopic and non-amblyopic eyes (3.98 mm vs. 4.07 mm, P = 0.346). The mean axial lengths of the two eyes were comparable (amblyopic eyes 23.13 mm vs. non-amblyopic eyes 22.88 mm, P = 0.419). Significant differences in total HOAs and those arising from the internal optics (except spherical aberrations) of the eye were noted between the two eyes. There were no differences in the corneal HOAs. The total HOAs were comparable amongst the various refractive error groups for amblyopic and non-amblyopic eyes individually.

Conclusion

There are significant differences in ocular HOAs between amblyopic and non-amblyopic eyes in children with anisometropic amblyopia.

Amblyopia risk factors in congenital nasolacrimal duct obstruction: A longitudinal case-control study

Purpose

To investigate longitudinal changes in risk factors for amblyopia in children treated with congenital nasolacrimal duct obstruction (CNLDO).

Methods

Retrospective observational case control study. A total of 446 children under 4 years of age who underwent probing and/or intubation for CNLDO between January 2004 and January 2018, and 446 age-matched controls were included. Cycloplegic refraction and ocular alignment were investigated at the time of treatment and after at least one year of symptom improvement. Children were classified as having amblyopia risk factors on the basis of the American Association for Pediatric Ophthalmology and Strabismus guideline in 2013.

Main outcome measures

The prevalence of amblyogenic refractive errors, and determinants associated with the presence of amblyogenic refractive errors in CNLDO patients.

Results

The prevalence of amblyogenic refractive errors in CNLDO patients (5.4%) was similar to that of the control group (6.5%) (P = 0.571). After one year of symptom improvement in CNLDO patients, the prevalence of amblyogenic refractive errors was 4.7%. There was no difference in the prevalence of amblyogenic refractive errors between unilateral and bilateral CNLDO patients. Multivariate analysis revealed that manifest strabismus was the only risk factor related with the presence of amblyogenic refractive errors (odds ratio = 6.383, confidence interval = 1.205–33.826, P = 0.029).

Conclusions

This study found no evidence to suggest that the prevalence of amblyopia risk factors is higher in CNLDO patients compared with normal controls. Manifest strabismus was the only determinant associated with the presence of amblyogenic refractive errors.

Amblyopia Elimination Project: Pediatric Medical Home-Based Community Vision Screening

PURPOSE

To examine whether facilitating access to instrument-based screening equipment will increase the total number of high-quality, age-appropriate vision screenings provided to the preschool aged population.

METHODS

The goal of the Naples Lions Amblyopia Elimination Project was to place a SPOT Vision Screener (Welch Allyn, Skaneateles Falls, NY) in every pediatric medical home using philanthropic dollars. Participating medical homes agreed to provide data on the number of children screened, number of referrals made, criteria for referral, and follow-up notes regarding examination outcomes.

RESULTS

In 2012, only 4 of the 23 pediatric medical homes in Collier County were using instrument-based vision screening equipment. By 2017, 19 of the 25 pediatric medical homes (76%) used SPOT Vision Screeners. In 2017, 6,052 preschool children were screened in these 19 pediatric medial homes.

CONCLUSIONS

The concept for this community-based philanthropic effort is original in its design and implementation and is a significant step forward in the goal to eliminate preventable permanent vision loss in children. [J Pediatr Ophthalmol Strabismus. 2019;56(3):146-150.].

Late Ophthalmologic Referral of Anisometropic Amblyopia: A Retrospective Study of Different Amblyopia Subtypes

INTRODUCTION

Amblyopia requires a timely diagnosis and treatment to attain maximum vision recovery. Specialty literature is lacking on how early amblyopia is referred. We aimed to understand if there are mean age differences at first referral for ophthalmologic tertiary center consultation among non-amblyopic and different types of amblyopia, in a context of lack of population screening.

MATERIAL AND METHODS

In this retrospective model, the sample corresponded to all children born in Braga Hospital during 1997 - 2012 (3 - 18 years-old), with an ophthalmologic consultation in 2014. Data was collected from the clinical records and children were divided in a non-amblyopic versus amblyopic group. The amblyopic group was subdivided in strabismic versus refractive (anisometropic/bilateral).

RESULTS

The sample had a total of 1665 participants, 1369 (82.2%) without amblyopia and 296 (17.8%) with amblyopia. Among amblyopia: 67.9% (n = 201) refractive, 32.1% (n = 95) strabismic. Within refractive amblyopia: 63.7% (n = 128) anisometropic and 36.3% (n = 73) bilateral. The mean age at first consultation was 6.24 ± 3.90 years-old: 6.39 ± 3.98 for non-amblyopic and 5.76 ± 3.58 for amblyopic. Among amblyopia subgroups, there were significant differences in mean age at first consultation (F3,1250 = 8.45; p < 0.001; η2 = 0.020). Strabismic and bilateral refractive amblyopia were referred earlier, when compared to non-amblyopia or anisometropic amblyopia (p < 0.05). Anisometropic amblyopia had the highest first consultation mean age: 6.92 ± 3.57 years-old.

DISCUSSION

Without specific pre-school screening, children with amblyopia were referred to their first ophthalmologic evaluation significantly later than desired, especially anisometropic amblyopia, with a postschool mean age for first consultation.

CONCLUSION

Recognizing high-risk children is essential for earlier referral and helps minimize future visual handicap.

High-Definition Optical Coherence Tomography of the Macula in Deprivational Amblyopia

BACKGROUND AND OBJECTIVE

This study evaluated macular thickness in deprivational amblyopia and compared it to matched controls.

PATIENTS AND METHODS

The authors present a cross-sectional study of patients with amblyopia from pediatric cataract and matched controls. Macular high-definition optical coherence tomography scans of each eye were acquired. Central macular thickness (CMT) and parafoveal thicknesses at 500 μm, 1,000 μm, and 1,500 μm in the nasal, temporal, inferior, and superior locations were measured.

RESULTS

Thirty-four eyes were included: 14 eyes with deprivational amblyopia and 20 controls. In amblyopes, the mean age was 10.06 years ± 3.89 years and logMAR visual acuity (VA) was 0.41 ± 0.53, whereas in the control group, mean age was 8.96 years ± 1.89 years and mean logMAR VA was 0.03 ± 0.05. The macula in deprivational amblyopia was significantly thicker centrally compared to controls (P = .0013), but only tended to be thicker at 500 μm and thinner at 1,000 μm and 1,500 μm. Male gender, poorer VA, and hyperopic refraction positively correlated with CMT (P = .011, P = .018, and P = .038, respectively).

CONCLUSION

Eyes with deprivational amblyopia had increased CMT compared to controls, and this correlated with the severity of amblyopia. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:198-204.].

Prevalence of amblyopia and strabismus in Hani school children in rural southwest China: a cross-sectional study

PURPOSE

To determine the prevalence rate of amblyopia and strabismus in Chinese Hani ethnic school-aged children.

METHODS

All grade 1 and grade 7 students in Mojiang Hani Autonomous County, located in southwest China, were invited for comprehensive eye examinations performed by experienced ophthalmologists and optometrists, including visual acuity, ocular alignment and movements, cycloplegic autorefraction, anterior segment and fundus examinations. Standard definitions of amblyopia and strabismus were applied to calculate their prevalence rate.

RESULTS

A total of 1656 (91.0% response rate) grade 1 Hani students and 1394 (92.8% response rate) grade 7 Hani students participated in the study. Amblyopia was present in 25 Hani students (0.82%, 95% CI 0.55% to 1.20%), with no significant differences in grade (p=0.42) and gender (p=0.69). Among these 25 amblyopic children, 17 had unilateral amblyopia and eight had bilateral amblyopia, including 16 anisometropic, eight binocular refractive and one strabismic. Strabismus was found in 59 Hani students (1.93%, 95% CI 1.50% to 2.48%), including 47 with intermittent exotropia, six with constant exotropia, five with constant esotropia and one with unilateral superior oblique palsy. The prevalence rate of strabismus was higher in grade 7 students than grade 1 students with borderline significance (2.44%vs1.50%, p=0.07), but was similar by gender (2.16% in boys vs 1.68% in girls, p=0.36).

CONCLUSION

The prevalence of amblyopia and strabismus in Chinese Hani school children are both lower than that previously reported for Chinese Han children in China and for many other racial/ethnic populations from non-China studies. Refractive error is the major cause for amblyopia and intermittent exotropia is the primary strabismus type.

A new counterintuitive training for adult amblyopia

Objectives

The aim of this study was to investigate whether short-term inverse occlusion, combined with moderate physical exercise, could promote the recovery of visual acuity and stereopsis in a group of adult anisometropic amblyopes.

Methods

Ten adult anisometropic patients underwent six brief (2 h) training sessions over a period of 4 weeks. Each training session consisted in the occlusion of the amblyopic eye combined with physical exercise (intermittent cycling on a stationary bike). Visual acuity (measured with ETDRS charts), stereoacuity (measured with the TNO test), and sensory eye dominance (measured with binocular rivalry) were tested before and after each training session, as well as in follow-up visits performed 1 month, 3 months, and 1 year after the end of the training.

Results

After six brief (2 h) training sessions, visual acuity improved in all 10 patients (0.15 ± 0.02 LogMar), and six of them also recovered stereopsis. The improvement was preserved for up to 1 year after training. A pilot experiment suggested that physical activity might play an important role for the recovery of visual acuity and stereopsis.

Conclusions

Our results suggest a noninvasive training strategy for adult human amblyopia based on an inverse-occlusion procedure combined with physical exercise.

Analysis of Macular Vessel Density and Foveal Avascular Zone Using Spectral-Domain Optical Coherence Tomography Angiography in Children With Amblyopia

PURPOSE

To quantify the foveal avascular zone and the whole, parafoveal, and foveal vessel density of superficial and deep capillary plexus in amblyopic eyes and age-matched controls and to compare the measurements.

METHODS

This cross-sectional study involved 49 eyes from 17 patients with amblyopia and 21 healthy children (aged 6 to 16 years). Optical coherence tomography angiography was performed for all participants and superficial capillary plexus, deep capillary plexus, and foveal avascular zone were evaluated. Data from amblyopic eyes, fellow eyes with unilateral amblyopia, and control eyes were compared using the Mann-Whitney U test.

RESULTS

The mean patient age was 8.6 ± 2.5 years in the amblyopia group and 9.6 ± 2.9 years in the control group. The mean foveal avascular zone measurements were 0.251 ± 0.1 mm² in the amblyopia group and 0.291 ± 0.1 mm² in the control group. The whole, foveal, and parafoveal vessel densities of superficial capillary plexus were 48.8% ± 3.7%, 23.8% ± 8.8%, and 50.9% ± 4.6% in the amblyopia group and 48.4% ± 2.5%, 19.3% ± 5.4%, and 51.3% ± 2.7% in the control group. The whole, foveal, and parafoveal vessel densities of deep capillary plexus were 51.8% ± 4.3%, 37.6% ± 5.8%, and 54.8% ± 4.2% in the amblyopia group and 54.4% ± 3.2%, 34.9% ± 7.4%, and 56.8% ± 3.2% in the control group. No statistically significant difference was detected in all measurements.

CONCLUSIONS

Assessment of the foveal avascular zone and vessel density of superficial capillary plexus and deep capillary plexus with optical coherence tomography angiography revealed no difference between amblyopic eyes, controls, and fellow eyes of patients with unilateral amblyopia. [J Pediatr Ophthalmol Strabismus. 2019;56(1):55-59.].

Comparison of predicted and measured axial length for ophthalmic lens design

Ocular parameters have been applied to ophthalmic lens designs in order to satisfy individual wearers. An axial length (AL) of them can be used in individual ophthalmic lens designs. Our aim was to propose a reliable formula that predicts an individual’s AL using the corneal radius and refractive error, and to demonstrate the applicability of this formula. A total of 348 subjects underwent keratometry, objective and subjective refraction, and AL measurement. The formula of calculated AL for prediction obtained from the original Gullstrand simplified schematic eye: calculated AL = (24.00 × aveK/7.80)—(SE × 0.40), where aveK and SE denote average corneal radius and spherical equivalent, respectively. Calculated AL was 24.50 ± 1.83 mm, which was 0.18 ± 0.47 mm longer than the measured value of 24.32 ± 1.73 mm (p < 0.001). The proportion showing the differences between the calculated and measured ALs were 284 eyes (40.8%) for 0.00–0.25 mm, 525 eyes (75.4%) for less than 0.50 mm, 665 eyes (95.5%) for less than 1.00 mm, and 31 eyes (4.5%) for more than 1.01 mm. Correlation coefficient showed a very high correlation between calculated and measured ALs (r = 0.967, p < 0.001), and higher in the myopic than in the hyperopic group. The mean difference was 0.18 mm; the 95% limit of agreement was +1.10—-0.75 mm in all groups. Agreement was better in hyperopic eyes than myopic eyes. Prediction from calculation of AL with a formula using the corneal radius and SE provides an alternative method to direct measurements of AL, especially in the restricted environment, which can’t use biometric equipment for personalized ophthalmic lens design.

Atypical presentation of Best Disease

CLINICAL CASE

A 43-year-old man was treated for reduced visual acuity, initially attributed to strabismic amblyopia. On fundus examination, bilateral neurosensory detachments (NSD) were observed in posterior pole, surrounded by deposits of lipofuscin. His 3-year-old son was also examined and circumscribed NSD was observed with the presence of pseudohypopyon in OD and a fibrosis scar in OS. The Arden ratio were decreased in electrooculography (EOG) in both patients, and genetic studies revealed a single mutation of the BEST1 gene.

DISCUSSION

The existence of extensive bilateral NSD may be an unusual form of presentation of Best disease. Family history, EOG, and genetic study supported this diagnosis.

Binocular contrast summation and inhibition depends on spatial frequency, eccentricity and binocular disparity

PURPOSE

When central vision is compromised, visually-guided behaviour becomes dependent on peripheral retina, often at a preferred retinal locus (PRL). Previous studies have examined adaptation to central vision loss with monocular 2D paradigms, whereas in real tasks, patients make binocular eye movements to targets of various sizes and depth in 3D environments.

METHODS

We therefore examined monocular and binocular contrast sensitivity functions with a 26-AFC (alternate forced choice) band-pass filtered letter identification task at 2° or 6° eccentricity in observers with simulated central vision loss. Binocular stimuli were presented in corresponding or non-corresponding stereoscopic retinal locations. Gaze-contingent scotomas (0.5° radius disks of pink noise) were simulated independently in each eye with a 1000 Hz eye tracker and 120 Hz dichoptic shutter glasses.

RESULTS

Contrast sensitivity was higher for binocular than monocular conditions, but only exceeded probability summation at low-mid spatial frequencies in corresponding retinal locations. At high spatial frequencies or non-corresponding retinal locations, binocular contrast sensitivity showed evidence of interocular suppression.

CONCLUSIONS

These results suggest that binocular vision deficits may be underestimated by monocular vision tests and identify a method that can be used to select a PRL based on binocular contrast summation.

Assessing amblyopia treatment using multifocal visual evoked potentials

BACKGROUND

To evaluate the effect of occlusion treatment for anisometropic amblyopia using multifocal visual evoked potentials (mfVEPs).

METHODS

The patients for this study comprised 19 patients (mean age 6.05 ± 1.65 years) with anisometropic amblyopia underwent mfVEP analysis using the RETIscan® system before and after occlusion treatment. After dividing the area into six ring areas and four quadrants, we analyzed the amplitudes and latencies of the mfVEPs.

RESULTS

The amplitudes of ring 1 (central field) in amblyopic eyes after treatment were significantly higher than those in the other rings (p = 0.001). The mfVEP amplitudes in each of the six rings between amblyopic eyes and fellow eyes at diagnosis and after occlusion treatment showed no significant differences. In quadrant 1 the amplitudes of the amblyopic eyes and fellow eyes were significantly different at the time of diagnosis (p = 0.005), whereas after occlusion treatment there was no significant difference (p = 0.888). The amplitudes for each of the six rings at diagnosis and after occlusion treatment in amblyopic eyes versus fellow eyes showed no significant difference. There were also no differences in the amplitudes in each of the four quadrants at the time of diagnosis and after occlusion treatment in amblyopic eyes versus fellow eyes. No significant difference was found in the comparison of latency values in each of the six rings or in each of the four quadrants at diagnosis and after occlusion treatment in amblyopic eyes versus their fellow eyes.

CONCLUSIONS

The amplitudes of quadrant 1 in amblyopic eyes compared with those of the fellow eyes at diagnosis were increased after occlusion treatment. Changes of the difference between amblyopic eyes and fellow eyes in quadrant 1 after occlusion treatment could be a useful, objective method for monitoring improvement in visual acuity.