Relationship between anisometropia, patient age, and the development of amblyopia

Characteristics of refractive development in children aged 4 months to 8 years in urban China: A retrospective screening analysis

PURPOSE

To conduct a large retrospective study of screening refractive error in young children.

METHODS

This retrospective study included children aged from 4 months to 8 years in Daxing District, Beijing, who underwent refractive examinations without cycloplegia. It included a cross-sectional assessment of refractive error screening for all children, and a longitudinal component for a subgroup with data available for two to five visits.

RESULTS

A total of 14,987 children were included in the cross-sectional study. In the group <1 year of age, the percentage of children with a spherical equivalent (SE) >+2.00 D or with cylinder <-1.50 D was 15.25% and 33.24%, respectively. These were significantly higher than for the 1- to 4-year-old group (SE 8.1% higher, cylinder 13.2% higher) (χ2 = 53.57, p < 0.001; χ2 = 790.39, p < 0.001). Furthermore, 34.83% of children in the 0-year-old group had amblyopia risk factors (ARFs). In the 4-year-old group, boys had a significantly longer axial length (AL) than girls (differences in the right and left eyes were 0.53 and 0.56 mm, respectively; z = 5.48 p < 0.001, z = 5.80, p < 0.001). AL increased with age, while the AL difference between boys and girls remained stable at 4-8 years of age. The percentage of children aged 5-8 years with myopia in 2020-2021 was significantly higher than that in 2018-2019 (H = 12.44, p = 0.006). In the longitudinal study of 4406 children (up to 12-month follow-up), annual changes in SE were -0.27, -0.06, 0.19 and 0.13 D between 0 and 3 years, and -0.38, -0.58, -0.70 and -0.75 D between 5 and 8 years.

CONCLUSIONS

Children's refractive error varied significantly from ages 4 months to 1 year, with a high proportion having ARFs. Children aged 5-8 years showed a trend towards myopia. The prevalence of myopia in the cross-sectional analysis in 2020-2021 was greater than in 2018-2019. Screening refraction changed minimally over a 12-month period for children aged 1-3 years, but became more myopic for children aged 5-8 years.

Congenital Nasolacrimal Duct Obstruction - Early Diagnosis and Graded Therapeutic Approach as Key Points for Successful Management

PURPOSE

Epiphora in childhood is a frequent symptom that is typically associated with Congenital nasolacrimal duct obstruction (CNLDO). Nevertheless, inflammatory pathologies of the ocular surface as well as inside the eye, or even congenital glaucoma, must be considered in the differential diagnosis.

METHODS

A comprehensive literature review concerning CNLDO was conducted. Different therapeutic steps are categorized and summarized in order to reflect the existing staged therapeutic concept.

RESULTS

For CNLDO, a staged therapeutic concept is applicable, resulting in a cure rate of approximately 95% with only conservative or minimally invasive intervention. This concept includes five steps that encompass therapeutic interventions with increasing complexity. It includes conservative techniques, followed by probing and syringing, transcanalicular approaches without or with lacrimal intubation, and dacryocystorhinostomy which is the ultima ratio.

CONCLUSION

To preserve the topographic anatomy as much as possible, therapeutic recommendations enable stepwise and individualized management of children with CNLDO.

A case of reverse amblyopia in a myopic anisometropic patient: an atypical presentation

We herein report a case of a 4-year-old female patient who presented with anisometropic amblyopia with initial visual acuity recorded at 20/400 OD and 20/100 OS. The patient was recommended for patching. Eighteen months later, the patient presented with visual acuity of 20/60 OD and 20/80 and reverse amblyopia was noted. In settings of amblyopia, where alternate patching may be used, it is most likely that reverse amblyopia, if present, will affect the more myopic eye. However, unexpectedly, in this case, reverse amblyopia occurred in the less myopic eye. With discontinuation of occlusion therapy and continued use of optical correction, the patients reverse amblyopia resolved and the visual equity equalized. To our knowledge, this is the first case described in the literature demonstrating such an occurrence. Awareness of this rare presentation by clinicians is of great importance to aid in correctly diagnosing and treating such patients.

Temporal trend of anisometropia incidence in Chinese school-aged children before and during the COVID-19 pandemic

Objective

To analyze and compare the temporal trends in the incidence of anisometropia among Chinese school-aged children both before and during the COVID-19 pandemic, and to investigate the impact of the pandemic on the incidence of anisometropia.

Methods

We conducted a retrospective study comprising six distinct and independent longitudinal cohorts, each including children aged 6 to 13 years who visited the Joint Shantou International Eye Center between January 2010 and December 2021. Children were grouped into cohorts based on the year of their first eye clinic visit: 2010, 2012, 2014, 2016, 2018, or 2020. Only children without anisometropia at initial visits, followed for 18 ± 6 months, were included. The cumulative incidence and risk factors of anisometropia were analyzed using Kaplan-Meier estimation and Cox proportional hazards regression models. Subgroup analyses were performed based on sex, age groups, initial refractive error status, and initial interocular SE difference. Anisometropic children were further categorized into myopic and non-myopic, with subsequent subgroup analyses conducted.

Results

Of 11,235 children were recruited from six cohorts (2010: n = 1,366; 2012: n = 1,708; 2014: n = 1,896; 2016: n = 2,354; 2018: n = 2,514; 2020: n = 1,397), 869 children developed anisometropia during a mean follow-up of 17.5 ± 3.7 months. After adjustment of confounding factors, we found that the risk of anisometropia remained relatively stable before 2020 but significantly increased in the 2020 cohort (adjusted HR 2.93, 95% CI 2.23 to 3.86; p < 0.001). This trend persisted in studies of spherical anisometropia (adjusted HR 2.52, 95% CI 1.60 to 3.97; p < 0.001) and cylindrical anisometropia (adjusted HR 2.91, 95% CI 1.69 to 3.62; p < 0.001). Older age and a greater initial difference in SE between the two eyes were also significantly associated with a higher risk of developing anisometropia (p < 0.001). Subgroup analyses consistently showed increased risk in the 2020 cohort.

Conclusion

This study reveals a concerning rise in anisometropia incidence among Chinese school-aged children during the period of the COVID-19 pandemic. These findings highlight the worrisome rise in anisometropia risk during the COVID-19 pandemic and emphasize the importance of early detection and management to safeguard children's visual health.

Factors associated with progressive anisometropia after bilateral intraocular lens implantation in patients with pediatric cataract

OBJECTIVES

To identify factors associated with progressive anisometropia after bilateral intraocular lens (IOL) implantation in patients with pediatric cataract.

METHODS

Clinical and standardized questionnaire data were collected for Sixty-eight patients with pediatric cataract (136 eyes) who underwent bilateral IOL implantation and at least 1 year of follow-up. Univariate and multivariate linear regression models were used to identify factors associated with postoperative anisometropia.

RESULTS

The median age at IOL implantation was 3.2 years (range: 1-12.4 years), and median follow-up time was 5.7 years (range: 1.1-14 years). At 1 month postoperatively and at the last follow-up, there were 19 (27%) and 31 (46%) cases of anisometropia ≥1 D, 9 (13%) and 15 (22%) cases of anisometropia ≥2 D, and 2 (3%) and 9 (13%) cases of anisometropia ≥3 D, respectively. Compared with 1 month postoperatively, the amount of anisometropia increased in 45 (67%) patients. Greater anisometropia one year or more after bilateral IOL implantation was associated with larger intereye difference in IOL power (P = 0.032, 95%CI 0.013 to 0.285), intereye difference in preoperative axial length (P = 0.018, 95%CI -1.247 to -0.123), presence of strabismus (P = 0.017, 95%CI 0.063-0.601), anisometropia at 1 month postoperatively (P = 0.001, 95%CI 0.126-0.478), and intereye difference in axial length at the last follow-up (P = 0.047, 95%CI 0.005-0.627).

CONCLUSION

Anisometropia might progress after bilateral IOL implantation in patients with pediatric cataract. Greater intereye difference in IOL power, presence of strabismus might increase the potential of progressive anisometropia.

Cost-effectiveness of Universal School- and Community-Based Vision Testing Strategies to Detect Amblyopia in Children in Ontario, Canada

IMPORTANCE

Screening for amblyopia in primary care visits is recommended for young children, yet screening rates are poor. Although the prevalence of amblyopia is low (3%-5%) among young children, universal screening in schools and mandatory optometric examinations may improve vision care, but the cost-effectiveness of these vision testing strategies compared with the standard in primary care is unknown.

OBJECTIVE

To evaluate the relative cost-effectiveness of universal school screening and mandated optometric examinations compared with standard care vision screening in primary care visits in Toronto, Canada, with the aim of detecting and facilitating treatment of amblyopia and amblyopia risk factors from the Ontario government's perspective.

DESIGN, SETTING, AND PARTICIPANTS

An economic evaluation was conducted from July 2019 to May 2021 using a Markov model to compare 15-year costs and quality-adjusted life-years (QALYs) between school screening and optometric examination compared with primary care screening in Toronto, Canada. Parameters were derived from published literature, the Ontario Schedule of Benefits and Fees, and the Kindergarten Vision Testing Program. A hypothetical cohort of 25 000 children aged 3 to 5 years was simulated. It was assumed that children in the cohort had irreversible vision impairment if not diagnosed by an optometrist. In addition, incremental costs and outcomes of 0 were adjusted to favor the reference strategy. Vision testing programs were designed to detect amblyopia and amblyopia risk factors.

MAIN OUTCOMES AND MEASURES

For each strategy, the mean costs per child included the costs of screening, optometric examinations, and treatment. The mean health benefits (QALYs) gained were informed by the presence of vision impairment and the benefits of treatment. Incremental cost-effectiveness ratios were calculated for each alternative strategy relative to the standard primary care screening strategy as the additional cost required to achieve an additional QALY at a willingness-to-pay threshold of $50 000 Canadian dollars (CAD) ($37 690) per QALY gained.

RESULTS

School screening relative to primary care screening yielded cost savings of CAD $84.09 (95% CI, CAD $82.22-$85.95) (US $63.38 [95% CI, US $61.97-$64.78]) per child and an incremental gain of 0.0004 (95% CI, -0.0047 to 0.0055) QALYs per child. Optometric examinations relative to primary care screening yielded cost savings of CAD $74.47 (95% CI, CAD $72.90-$76.03) (US $56.13 [95% CI, $54.95-$57.30]) per child and an incremental gain of 0.0508 (95% CI, 0.0455-0.0561) QALYs per child. At a willingness-to-pay threshold of CAD $50 000 (US $37 690) per QALY gained, school screening and optometric examinations were cost-effective relative to primary care screening in only 20% and 29% of iterations, respectively.

CONCLUSIONS AND RELEVANCE

In this study, because amblyopia prevalence is low among young children and most children in the hypothetical cohort had healthy vision, universal school screening and optometric examinations were not cost-effective relative to primary care screening for detecting amblyopia in young children in Toronto, Canada. The mean added health benefits of school screening and optometric examinations compared with primary care screening did not warrant the resources used.

Photoscreening for amblyopia risk factors assessment in young children: A systematic review with meta-analysis

PURPOSE

Amblyopia is a leading cause of preventable and treatable vision loss in the pediatric population. Instrument-based screening of amblyopia-risk factors is being widely adopted but the audit of its results is still lacking. We sought to review the existing evidence regarding the outcomes of photoscreening applied to children under the age of three years.

METHODS

A three-database search (Pubmed, ISI Web of Science, and Scopus) was performed from inception to March 2021. A meta-analysis of proportions was conducted to summarize the referral rate, untestable rate and positive predictive value (PPV).

RESULTS

Thirteen studies were selected among 705 original abstracts. The quantitative analysis included twelve studies enrolling 64,041 children. Of these, 13% (95%CI: 7-19%) were referred for further confirmation of the screening result. Astigmatism was the most common diagnosis both after screening and after ophthalmologic assessment of referred children. The pooled untestable rate and PPV were 8% (95%CI: 3-15%) and 56% (95%CI: 40-71%), respectively.

CONCLUSION

There is no global consensus on the optimal age, frequency or what magnitude of refractive error must be considered an amblyopia-risk factor. Optimization of referral criteria is therefore warranted.

Anisometropia and refractive status in children with congenital nasolacrimal duct obstruction-a prospective observational study

PURPOSE

To assess the refractive status and anisometropia in children with unilateral and bilateral congenital nasolacrimal duct obstruction (CNLDO).

METHODS

Consecutive children newly diagnosed with CNLDO were prospectively enrolled from November 2017 to May 2019. A complete ophthalmic evaluation including cycloplegic refraction was performed followed by appropriate intervention. Patients were followed for 6 months, and cycloplegic refraction was performed at each visit. The final refractive error was defined as the refractive error obtained from the most recent visit. Amblyogenic risk factors were assessed based on 2013 referral criteria of the American Association for Pediatric Ophthalmology and Strabismus (AAPOS).

RESULTS

A total of 308 patients with CNLDO were enrolled: 205 (67%) unilateral cases and 103 (33%) bilateral cases. In unilateral cases, the affected eye and unaffected fellow eye showed statistically significant difference in terms of sphere (P < 0.001), cylinder (P = 0.019), and spherical equivalent (P < 0.001); there was no interocular difference in bilateral cases (P > 0.05). Anisometropia was more prevalent in unilateral cases than in bilateral cases (11.2% vs 1.9%; P = 0.005). Based on the 2013 AAPOS referral criteria, 3.9% of the unilateral and 3.9% of bilateral cases exhibited amblyogenic risk factors. Later age of presentation was associated with higher rate of anisometropia (53.8% in the age group >48 months).

CONCLUSIONS

In our study cohort, unilateral CNLDO was associated with a higher prevalence of anisometropia compared with bilateral CNLDO. The affected eye in unilateral CNLDO had higher prevalence of refractive error.

Visual outcomes of photorefractive keratectomy in non-children with anisometropic amblyopia: One-year Follow-up Outcomes

OBJECTIVE

To evaluate the safety, efficiency, short term stability, and sensory results of photorefractive keratectomy (PRK) in anisometropic in non-compliant children with correction.

METHODS

Twelve eyes of 12 children with an age range: 6-17 years and anisometropic amblyopia who underwent PRK under general anesthesia to correct the dioptric difference between the eyes were included in this study. A complete ophthalmic assessment including refractive status, uncorrected and corrected distance visual acuity (UDVA & CDVA), and binocular vision status using the Worth 4-dot test and stereopsis were performed before and 1, 3, 6, and 12 months after PRK.

RESULTS

The mean preoperative CDVA was 0.34 ± 0.24 LogMAR which showed a statistically significant improvement at 12 months (0.20 ± 0.19, p = 0.024) after surgery compared to the preoperative assessment. (p = 0.003) The mean preoperative UDVA was 0.63 ± 0.24 LogMAR that increased to 0.44 ± 0.24, 0.32 ± 0.16, 0.25 ± 0.19, and 0.25 ± 0.19 LogMAR at 1, 3, 6, and 12 months after PRK, respectively. One to three lines improvement in UDVA and CDVA was seen in 10 (83.4%) and 8 eyes (66.7%); while one line UDVA and CDVA loss was seen in one (8.3%) and one (8.3%) eye and unchanged UDVA and CDVA was seen in 1 (8.3%) and 3 eyes (25%), respectively. The mean preoperative stereoacuity was 341.9 ± 245.7 s of arc, which significantly improved to 166.6 ± 87.5 s of arc 12 months after PRK. (p = 0.012).

CONCLUSION

PRK was an effective surgical alternative to improve visual acuity and stereopsis in anisometropic children who did not cooperate with conventional methods of amblyopia therapy.

Stereoacuity after Successful Occlusion Therapy in Children with Anisometropic Amblyopia

Purpose: To compare the stereoacuity between patients with anisometropic amblyopia who were treated and achieved normal visual acuity (VA) and normal children and evaluate the factors associated with stereoacuity.Methods: We retrospectively reviewed the records of 37 pediatric patients with anisometropic amblyopia who recovered to normal VA with glasses and occlusion treatment (amblyopia group) and 34 normal children (control group). The Worth 4-dot test, Lang II test, Titmus test, and TNO test were performed to measure stereoacuity. Clinical characteristics were compared between the two groups, and factors affecting stereoacuity outcomes were also analyzed in the amblyopic group.Results: The mean age at diagnosis of amblyopia was 5.3 ± 1.4 years, and the mean VAs at diagnosis were 0.41 ± 0.24 and 0.06 ± 0.07 in amblyopic and fellow eyes, respectively. The mean duration of occlusion was 19.00 ± 9.44 months, and VA of amblyopic eyes improved to 0.04 ± 0.04 after occlusion treatment. The patient characteristics did not differ significantly between the two groups, except for the final VA of the amblyopic eye. The final mean logarithm of minimal angle of resolution VA of the amblyopic eye in the amblyopia group was significantly worse than that in the control group. The number of patients with normal stereoacuity was significantly lower in the amblyopia group than in the control group on Lang II, Titmus, and TNO tests. Factors associated with poor stereoacuity were severe amblyopia in the Lang II test and poor post-treatment VA of the amblyopic eye in the Titmus test.Conclusions: Stereoacuity was worse in the amblyopia group than in the control group, despite normal visual development. The depth of amblyopia and post-treatment VA were associated with stereoacuity outcomes. Thus, VA improvement should be closely monitored in the amblyopic eye to obtain good stereoacuity.

Refinement strategies in photoscreening for the detection of amblyopia risk factors in 12-to-24-month-old children

PURPOSE

To establish an appropriate clinical protocol for early photoscreening in 12-to-24-month-old children at pediatric well-baby clinics.

METHODS

This prospective study included a total of 277 children aged 12-24 months who visited a pediatric well-baby clinic. All participants underwent: 1) inquiry of medical history; 2) photoscreening with PlusoptiX A12; and 3) comprehensive ophthalmologic examinations. The optimal referral cut-off point for PlusoptiX was determined by receiver operating characteristic analyses. A high-risk subgroup was defined as having a birth weight <3000 g or a history of major systemic diseases, based on the results of multivariable risk factor analysis from children's medical history. A strategy of selective photoscreening focusing on the high-risk subgroup was evaluated. The main outcome measures included sensitivity, specificity, and positive and negative predictive values.

RESULTS

The prevalence of amblyopia risk factors in our study population was 12.3%. A total of 172 children (62.1%) were assigned to the high-risk subgroup. Compared with the nonselective photoscreening of all 277 children, selective photoscreening of the high-risk children yielded a higher positive predictive value (59.6% vs. 46.7%, p = 0.001) while showing no difference in sensitivity (82.3% vs. 85.3%, p = 0.32), specificity (92.2% vs, 86.4%, p = 0.05), and negative predictive value (97.4% vs. 97.6%, p = 0.50).

CONCLUSION

At pediatric well-baby clinics, selective photoscreening among 12-to-24-month-old children with a birth weight <3000 g or a history of major systemic diseases helped reducing the number of children need to be screened and conserving medical resources yet identifying children at risk for timely eye care.

Guide de pratique clinique fondé sur des données probantes pour l'examen périodique de la vue chez les enfants de 0 à 5 ans au Canada

CONTEXTE

Étant donné que les maladies oculaires avant l'âge de 5 ans sont courantes, une certaine forme de dépistage des troubles de la vision devrait être effectuée chez les enfants avant qu'ils ne fréquentent l'école primaire. Cependant, l'absence de recommandations nationales cohérentes crée de la confusion chez les patients, les professionnels des soins oculovisuels et les gouvernements. MéTHODES: L'objectif de ce document est de fournir des recommandations quant aux types d'examens oculaires à pratiquer chez les enfants en bonne santé de 0 à 5 ans ainsi que sur le moment et la périodicité de tels examens. Une recension des écrits a produit 403 articles. Un comité d'experts multidisciplinaire (composé de deux optométristes, d'un ophtalmologiste effectuant des examens complets de la vue, d'un ophtalmologiste pratiquant en pédiatrie, d'un médecin de famille et d'un pédiatre) a établi de façon indépendante les articles jugés essentiels à la question clinique. Les articles se prêtant à un classement [n = 16] ont ensuite été soumis à une évaluation critique indépendante par un groupe externe, lequel a fourni un profil « GRADE » des articles à utiliser et leur a attribué une cote.

RECOMMANDATIONS

En plus du dépistage de routine effectué par les professionnels de première ligne, un examen complet de la vue mené par un professionnel possédant l'expertise nécessaire à la détection des facteurs de risque de l'amblyopie (comme un ophtalmologiste ou un optométriste) est requis durant la petite enfance. Les conclusions confirment l'importance de la détection précoce de l'amblyopie avant 36 mois et au plus tard 48 mois par le dépistage assorti d'au moins un examen complet de la vue avant l'âge de 5 ans.

CONCLUSIONS

Le dépistage de la vue effectué chez les bébés et les enfants par les fournisseurs de soins de première ligne au cours des consultations de routine et des vaccinations périodiques est un élément essentiel de la détection des maladies oculaires. Toutefois, le potentiel de détection précoce est limité et un examen oculovisuel complet est également recommandé avant que l'enfant n'entre à l'école. Si l'amblyopie, le strabisme ou une autre pathologie oculaire est détecté ou soupçonné, et que le problème dépasse le champ de compétences du professionnel qui examine le patient, celui-ci peut être dirigé vers le spécialiste approprié, ce qui permet d'amorcer le traitement en temps opportun.

Evidence-based clinical practice guidelines for the periodic eye examination in children aged 0-5 years in Canada

BACKGROUND

As eye disease before age 5 years is common, some form of vision screening should be performed on children before attending primary school. However, the lack of consistent national recommendations creates confusion for patients, eye care professionals, and governments alike.

METHODS

The objective of this document is to provide guidance on the recommended timing, intervals, and types of ocular assessments for healthy children aged 0-5 years. A literature search yielded 403 articles. A multidisciplinary expert committee (comprising 2 optometrists, a comprehensive ophthalmologist, a pediatric ophthalmologist, a family physician, and a pediatrician) independently determined those articles deemed to be key to the clinical question. Articles that were gradable (n = 16) were then submitted for independent critical appraisal by an external review group, which provided a Grading of Recommendations Assessment, Development and Evaluation profile of the reviewed articles to use for assigning a grade of evidence.

RECOMMENDATIONS

In addition to routine screening by a primary health care professional, a comprehensive eye examination by an individual with the expertise to detect risk factors for amblyopia-such as an ophthalmologist or optometrist-is required in early childhood. The findings support the importance of early detection of amblyopia before 36 months and no later than 48 months of age via screening with at least 1 comprehensive eye examination before age 5 years.

CONCLUSIONS

Vision screening performed by primary health care providers during routine well-baby/child visits and scheduled vaccinations is an essential part of the detection of ocular disease. However, this early detection potential is limited, and a full oculovisual assessment is also recommended before the child entering the school system. If amblyopia, strabismus, or other eye pathology is detected or suspected that is beyond the scope of the eye care professional examining the patient, a referral to the appropriate specialist can be made, allowing treatment to be initiated in a timely fashion.

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.

Threshold Values of Myopic Anisometropia Causing Loss of Stereopsis

Purpose

The aim of the study was to determine the threshold values of myopic anisometropia that lead to the loss of stereoacuity in most of patients.

Materials and Methods

Forty healthy subjects were included in the study. The inclusion criteria were as follows: lack of any functional or morphological ophthalmological disorders, or detectable damage to the visual system, anisometropia equal or less than 0.25 D in a spherical equivalent, and full stereoscopic vision for near and for distance. Myopic anisometropia was evoked by placing different focusing lenses in front of the right eye of the subject in the trial frame. Stereoscopic vision was assessed with the use of the Titmus test (dots) (Stereo Fly Test Stereo Optical Co. Inc.) for near and the Randot test for distance (Distance Randot Stereotest Stereo Optical Co. Inc.).

Results

The threshold values for different types of myopic anisometropia for the loss of stereopsis in more than 50% of patients were determined. For near, this value was 3 D for sphere and “against the rule astigmatism” and 4 D for “with the rule astigmatism”. For distance, the values were 2 D for sphere and “against the rule astigmatism” and 3 D for “with the rule astigmatism.” Conclusions. Myopic anisometropia of more than 2 D can cause a significant impairment of binocular vision. Stereoacuity at distance is more sensitive to myopic anisometropia than stereoacuity at near. Myopic anisometropia involving “against the rule” astigmatism potentially affects binocularity more than anisometropia with regular astigmatism. A prompt correction of anisometropia of more than 2 D is needed in children to prevent the development of amblyopia.

Preschool Vision Screening: Where We Have Been and Where We Are Going

PURPOSE

To discuss the evolution of instrument-based screening to detect amblyopia and its risk factors, and to summarize the importance of preschool vision screening.

DESIGN

Expert commentary.

METHODS

Author experiences were supplemented by a review and interpretation of pertinent medical literature.

RESULTS

Amblyopia remains a public health problem, as it is a common cause of monocular visual impairment. As a disease, amblyopia detection is best obtained by appropriate vision screening rather than by yearly mandated comprehensive eye examinations for all children; the US Preventative Services Task Force (USPSTF) recently reaffirmed their recommendations for vision screening in preschool children. Vision screening devices have evolved over the past 4 decades ranging from photoscreeners that use instantaneously developing film, to autorefractors that detect amblyopia risk factors, to nerve fiber layer scanners that detect the microtropia that nearly always accompanies amblyopia. When it is detected early, effective treatment for amblyopia can be initiated.

CONCLUSIONS

Amblyopia is a reversible cause of vision loss in children. Vision screening devices and screening programs have been extensively studied-experts and literature agree: vision screening devices and programs are cost-effective, are efficient, and are effective methods for amblyopia detection. The authors support the regular use of instrument-based vision screening in the medical home for all children until they reach a developmental stage where they can participate reliably in optotype-based vision screening.

Comparison of the efficacy of Lea Symbol chart and Sheridan Gardiner chart for preschool vision screening

Purpose:

To compare the efficacy of Lea symbols (LS) chart and Sheridan Gardiner (SG) chart for vision screening among preschool children, in a semi-urban district of South India.

Methods:

Vision screening was conducted among 260 preschool children aged 3–5 years in cluster sampled kindergartens using LS chart and SG chart. Pass/fail scores and time taken for visual acuity (VA) estimation were compared. VA scores and time taken were compared using unpaired t-test. Sensitivity, specificity, and positive and negative predictive values were compared between the charts.

Results:

There was a significant difference between LS and SG charts in the VA score in both the eyes (P = 0.04). LS showed 76.09% pass score and 23.90% fail score, whereas SG showed 87.65% pass score and 12.35% fail score with a cutoff value of > 0.3 log MAR. Time for screening using LS was higher, when compared to SG, both for the right eyes (P < 0.001) and the left eyes (P < 0.001). The sensitivity of the LS was 94.74% (95% confidence interval [CI]: 70.13%–81.06%) and that of SG was 52.63% (95% CI: 45.29%–59.8%). The specificity of LS was 66.67% (95% CI: 90.26%–97.30%) and SG was 83.33% (95% CI: 70.12%–91.30%).

Conclusion:

LS chart showed better sensitivity and negative predictive value when compared to SG chart. However, SG chart showed better specificity and positive predictive value, and screening was less time-consuming. Considering the high sensitivity and negative predictive value, LS is the preferred tool, when compared to SG chart in preschool vision screening in our population.

Anisometropia and refractive status in children with unilateral congenital nasolacrimal duct obstruction

OBJECTIVE:

The objective of the study was to evaluate the refractive status and thereby assess anisometropia in children with unilateral congenital nasolacrimal duct obstruction (CNLDO).

STUDY DESIGN:

This study design was a descriptive cross-sectional study.

PLACE AND DURATION:

this study was conducted at the Department of Pediatric Ophthalmology and Strabismology, Al-Shifa Trust Eye Hospital, Rawalpindi; from August 2013 to July 2014.

METHODOLOGY:

This study assessed consecutive children with unilateral CNLDO. Cycloplegic refraction on all children with CNLDO was performed followed by appropriate intervention. Refractive errors of the affected and normal eyes were compared.

RESULTS:

One hundred and twenty-four children with a mean age of 29.69 ± 21.12 months (range, 2 months to 8 years) were studied. Based on spherical equivalent (SE), hypermetropia was more common in the affected eyes (P < 0.001). Anisometropia of >1.5 diopters (D) was present in n = 17 (13.7%). Interocular difference was significant for spherical error and SE (P < 0.001) but not cylindrical errors.

CONCLUSION:

Unilateral CNLDO is associated with statistically significant anisometropia, especially anisohypermetropia which has amblyogenic potential. It is vital to perform cycloplegic refraction routinely and counsel parents regarding prognosis and regular follow-ups.

The burden of pure anisometropic amblyopia: a cross-sectional study on 2800 Iranians

PURPOSE

To assess the proportion of pure anisometropic amblyopia in a sample Iranian (white) population.

METHODS

A total of 2800 consecutive individuals who presented at a referral eye clinic for any reason were examined for the presence of pure anisometropic amblyopia. Anisometropia was reported when a spherical equivalent refraction difference of at least 1.0 D with or without a cylinder refraction difference of at least 1.0 D was present between the two eyes. Amblyopia was defined as the best-corrected visual acuity of 20/30 or worse or a two-line interocular visual acuity difference between eyes that could not be attributed to any structural ocular pathology or visual pathway abnormality.

RESULTS

Subjects were 1528 females and 1272 males with a mean age of 30.25 ± 14.93 years (range, 5-65). Amblyopia was diagnosed in 192 cases (6.9%), significantly more frequent among females (7.9 vs. 5.7%, p = 0.02). Pure anisometropic amblyopia was present in 6.1% of the study population, significantly more common in patients with spherical hyperopic anisometropia (37.7%) compared to patients with spherical myopic anisometropia (21.3%), cylindrical myopic anisometropia (4.1%), and cylindrical hyperopic anisometropia (15%) (p < 0.001).

CONCLUSIONS

Pure anisometropic amblyopia is a common finding in Caucasians seeking eye care, particularly when anisometropia is of spherical hyperopic subtype.

[Minimally invasive diagnostics and therapy of congenital nasolacrimal duct obstruction]

BACKGROUND

One of the most frequent issues in pediatric ophthalmology concerns congenital nasolacrimal duct obstruction (CNLDO). Typically, irritation of the medial eyelid angle occurs during the first days of life and later increased epiphora appears as tear production is still reduced in young infants. In the case of intrasaccal or postsaccal nasolacrimal duct stenosis, a chronic dacryocystitis develops.

METHODS

Modern minimally invasive diagnostics and therapy of CNLDO are reviewed by means of a search of the recent literature and reflection of own experiences.

RESULTS

An early diagnosis of CNLDO is desirable. If conservative therapeutic approaches fail, invasive procedures have to be considered. Probing and high pressure syringing of the nasolacrimal ducts remains the therapy of choice. Further therapy options, such as balloon dacryoplasty and dacryoendoscopy are also available. Additionally, due to improvement of the surgical techniques a minimally invasive approach is possible even for dacryocystorhinostomy; nevertheless, this procedure should be considered only as a last resort.

CONCLUSION

Precise classification of CNLDO and knowledge about the possible treatment options are important. Lacrimal surgery in childhood is dominated by transcanalicular procedures. Advanced minimally invasive techniques, such as dacryoendoscopy or modern autostable intubation sets have to be emphasized. All therapeutic interventions can be summarized using a staged therapeutic concept, which should be used individually and patient-centered.

Refractive Errors and Amblyopia in the UCLA Preschool Vision Program; First Year Results

PURPOSE

To report the outcomes of full ophthalmic examination for preschool children in LA County who failed screening with the Retinomax Autorefractor.

DESIGN

Retrospective, cross-sectional study.

METHODS

Between August 2012 and May 2013, the University of California Los Angeles (UCLA) preschool vision program screened 11 260 preschool children aged 3-5 years in Los Angeles County using the Retinomax Autorefractor only. Of those, 1007 children who failed the screening were examined by an ophthalmologist on the UCLA Mobile Eye Clinic. Data from the eye examination were recorded for all children. Amblyopia was defined as unilateral if there was ≥2 line interocular difference in the best-corrected visual acuity (BCVA) and as bilateral if BCVA was <20/50 for children <4 years old and <20/40 for children ≥4 years old.

RESULTS

Glasses were prescribed for 740 (74%) of those examined. Uncorrected visual acuity for all examined children was 0.4 ± 0.2 (logMAR mean ± SD), and BCVA was 0.2 ± 0.1. Of the 88% who underwent cycloplegia, 58% had hyperopia (spherical equivalent [SE] ≥+0.50 diopter [D]), mean of +2.50 D, and 21% had myopia (SE ≤-0.50 D), mean of -1.40 D. A total of 69% had astigmatism ≥1.50 D, mean of 1.97 D (range 0-5.75). Spherical and cylindrical anisometropia ≥1.00 D were each found in 26% of those examined. Refractive amblyopia was found in 9% of those examined, or 0.8% of the original population. Of the amblyopic subjects, 77% were unilateral.

CONCLUSIONS

Screening of preschoolers with the Retinomax led to diagnosis and early treatment of uncorrected refractive errors and amblyopia. By treating children early, amblyopia may be prevented, quality of life improved, and academic achievements enhanced.

Validation of photoscreening technology in the general pediatrics office: a prospective study

BACKGROUND

Photoscreening instruments have been widely validated in pediatric ophthalmology clinics and field studies; however, validation by general pediatricians is lacking. We performed the first prospective, multisite evaluation of a commercially available photoscreener in the medical home.

METHODS

Eleven practices in Middle Tennessee recruited over 3,100 children between 12 months and 5 years to be screened at well-child examinations. Participants were those who received a "refer" result; controls received a "pass." Referred children received a comprehensive eye examination with cycloplegic retinoscopy. A subset of control children underwent eye examinations in an attempt to determine sensitivity and specificity.

RESULTS

The overall referral rate was 10%. Amblyopia risk factors (ARFs) were confirmed in 47% of referred children, with positive predictive values (PPVs) of 77.8% for suspected hyperopia, 60% for myopia, 50% for anisometropia, and 44.8% for astigmatism by the 2013 guidelines of the American Association of Pediatric Ophthalmology and Strabismus Vision Screening Committee. Using the 2003 guidelines, the overall PPV was 60.3%; PPVs were determined for suspected hyperopia (77.8%), myopia (60%), anisometropia (67.6%), and astigmatism (61.2%). Of referred children who received follow-up, 18 (13.2%) had amblyopia. PPVs for children ≤36 months (n = 79) did not differ from those 37-72 months (n = 57). No child who passed screening and had a follow-up examination had any ARFs.

CONCLUSIONS

Our results replicate those of previously published field studies and support recent United States Preventive Services Task Force and American Academy of Pediatrics position statements. They provide prospective evidence that photoscreening is an effective tool for children aged 12-72 months.

The Use of a Mobile Van for School Vision Screening: Results of 63 841 Evaluations

PURPOSE

To present data from an established mobile screening program for children in the amblyogenic age group using gold-standard examination techniques by eye care professionals.

DESIGN

Retrospective 12-year, cross-sectional study.

METHODS

setting: Single center.

STUDY POPULATION

All children enrolled in pre-kindergarten, kindergarten, and first grades in public schools in Cleveland, Ohio were eligible for evaluations. intervention procedure: An ophthalmic technician and/or optometrist examined children in a customized van that visits all elementary schools. The initial screening included testing of monocular near and distance visual acuity, stereoacuity, ocular alignment, motility, pupils, and external abnormalities. Children meeting the 2003 American Academy of Pediatrics vision screening referral criteria underwent cycloplegic retinoscopy and ophthalmoscopy by the on-site optometrist and received glasses. In addition, these children were referred to pediatric ophthalmology for ongoing care.

MAIN OUTCOME MEASURE

Determination of the proportion of children with refractive errors, amblyopia, and/or strabismus.

RESULTS

Between 2002 and 2014, 63 841 evaluations were performed, representing approximately 55% of eligible children. Overall, 6386 (10.0%) of children met 1 or more referral criteria: 5355 (8.39%) received glasses, 873 (1.37%) had amblyopia, and 1125 (1.76%) had strabismus. Over the 12-year period, there was no statistically significant change in the prevalence of strabismus (1.73%-2.24%, P = .91) or amblyopia (0.9%-2.08%, P = .13) among first grade students.

CONCLUSIONS

Amblyopia, strabismus, and refractive errors are common in young children. During the study period, the rates of amblyopia and strabismus remained stable, indicating the need for continued vision screening and treatment services. A van-based model, traveling directly to schools, appears to be effective in reaching young children in underserved communities.

Refractive Changes in Amblyopic Children with High Anisometropia

PURPOSE

To demonstrate the refractive changes of amblyopic children attributed to high anisometropia in the myopia endemic in Taiwan.

METHODS

Amblyopic children younger than 10 years with myopic or hyperopic anisometropia 3 diopters (D) or more who had follow-up for more than 2 years and had final visual acuity of 20/30 or better in the amblyopic eye were included.

RESULTS

The average age on the first visit was similar for the 13 myopic children (5.5 years) and 17 hyperopic children (5.3 years). Initially, the mean anisometropia was significantly different (myopic, 7.25 D vs. hyperopic, 3.89 D), but the visual acuity of the amblyopic eye (logarithm of the minimum angle of resolution) was similar between both groups at baseline (0.50 vs. 0.57). Myopization of the sound eye surpassed that of the amblyopic eye in the myopic group, which resulted in a yearly reduction of anisometropia of 0.51 D. However, hyperopia decreased synchronously in both eyes of the hyperopic children. The final degree of anisometropia was not significantly different between the two groups (4.07 D vs. 3.62 D).

CONCLUSIONS

Growing up in a country with a high prevalence of myopia, children with myopic and hyperopic anisometropia in this study inevitably had myopization in both eyes. Myopic anisometropia decreases significantly over time, but hyperopic anisometropia remains constant.

Vision photoscreening of infants and young children in a primary care pediatric office: can it identify asymptomatic treatable amblyopic risk factors?

OBJECTIVE

The purpose of this study was to assess the feasibility and accuracy of vision photoscreening a large cohort of asymptomatic children age 6 months to 6 years.

METHODS

Photoscreening was performed at the 6 and 18 months and annually at the 2- to 5-year scheduled pediatric health assessment visits.

RESULTS

A total of 1976 children underwent photoscreening for amblyopic risk factors during an 18-month period; 167 of them (8.5%) screened positive. Of the 94 study children who were evaluated by a pediatric ophthalmologist, 25 required intervention at their initial visit (26.6%). Ten children were diagnosed with amblyopia, representing 0.5% of all children screened.

CONCLUSION

Vision photoscreening of 1976 young children identified 10 with previously undiagnosed amblyopia and an additional 15 with treatable pre-amblyopic risk factors. It is unlikely that any of these children with serious refractive errors would have been detected without the use of in-office vision photoscreening.

The prevalence of amblyogenic factors in children with persistent congenital nasolacrimal duct obstruction

BACKGROUND

To evaluate the prevalence of amblyopia risk factors in children that underwent probing for persistent congenital nasolacrimal duct obstruction (CNLDO).

METHODS

The medical records of children with CNLDO (after 1 year of age) that underwent probing were reviewed. Amblyopia risk factors, based on the American Association for Pediatric Ophthalmology and Strabismus referral criteria in 2013, were sought in the patientsʹ records before probing. The proportion of the patients with anisometropia >1.5 diopters (D) was separately calculated. In unilateral cases of CNLDO, sphere, astigmatism, and spherical equivalent of the eyes with CNLDO were compared with contralateral eyes in order to assess the effect of CNLDO on refractive error. In the follow-up examinations, the success of the probing or the need for additional procedures (Crawford intubation, Monoka intubation, or dacryocystorhinostomy) was evaluated. The prevalence of anisometropia between 'successful probing' and 'failed probing' groups was compared.

RESULTS

A total of 433 cases were included in the study. 41 cases (9.46 %) had amblyopia risk factors. Twenty-four cases (5.5 %) had anisometropia >1.5 D (spherical or cylindrical). In unilateral cases of CNLDO, the sphere and spherical equivalent of the eyes with CNLDO were significantly greater than those of the contralateral eyes (p < 0.001 for both). Thirty-nine patients (9 %) required other interventions due to failure of probing (failed probing group). There were significantly more anisometropia prevalence in this group, compared with the successful probing group, at the initial examination (p = 0.03).

CONCLUSIONS

The findings of greater prevalence of anisometropia >1.5 D (compared with the prevalence in the general population) and significantly greater sphere and spherical equivalents in the eye with CNLDO (compared with contralateral eye) in unilateral cases with CNLDO, suggested some relationships between anisometropia and long-term untreated CNLDO. The finding of more anisometropia in failed probing cases may support the theory of structural abnormality as an explanation for the possible relationship between congenital nasolacrimal duct obstruction and anisometropia.

Preschool vision screening: update on guidelines and techniques

PURPOSE OF REVIEW

To discuss the current preschool vision screening (PVS) guidelines and review some of the newest vision screening techniques. The different vision screening practices and barriers to screening are discussed.

RECENT FINDINGS

Vision screening guidelines, which have been developed in response to the advances in technology and increased understanding of the developing visual system, have been recently updated by some of the major medical organizations that endorse vision screening. With advances in vision screening technology, there is a growing trend for screening at younger ages.

SUMMARY

PVS has been widely endorsed by various medical organizations as an effective way to detect preventable and treatable vision problems of childhood. Although PVS is widely recommended, actual screening rates remain low. There are several real and perceived barriers to screening which often prevents successful screening programs. Current vision screening guidelines take into account the recent advances in technology. With the development of new devices, vision screening can effectively be performed at younger ages.

The relationship between anisometropia and amblyopia

This review aims to disentangle cause and effect in the relationship between anisometropia and amblyopia. Specifically, we examine the literature for evidence to support different possible developmental sequences that could ultimately lead to the presentation of both conditions. The prevalence of anisometropia is around 20% for an inter-ocular difference of 0.5D or greater in spherical equivalent refraction, falling to 2-3%, for an inter-ocular difference of 3D or above. Anisometropia prevalence is relatively high in the weeks following birth, in the teenage years coinciding with the onset of myopia and, most notably, in older adults starting after the onset of presbyopia. It has about one-third the prevalence of bilateral refractive errors of the same magnitude. Importantly, the prevalence of anisometropia is higher in highly ametropic groups, suggesting that emmetropization failures underlying ametropia and anisometropia may be similar. Amblyopia is present in 1-3% of humans and around one-half to two-thirds of amblyopes have anisometropia either alone or in combination with strabismus. The frequent co-existence of amblyopia and anisometropia at a child's first clinical examination promotes the belief that the anisometropia has caused the amblyopia, as has been demonstrated in animal models of the condition. In reviewing the human and monkey literature however it is clear that there are additional paths beyond this classic hypothesis to the co-occurrence of anisometropia and amblyopia. For example, after the emergence of amblyopia secondary to either deprivation or strabismus, anisometropia often follows. In cases of anisometropia with no apparent deprivation or strabismus, questions remain about the failure of the emmetropization mechanism that routinely eliminates infantile anisometropia. Also, the chronology of amblyopia development is poorly documented in cases of 'pure' anisometropic amblyopia. Although indirect, the therapeutic impact of refractive correction on anisometropic amblyopia provides strong support for the hypothesis that the anisometropia caused the amblyopia. Direct evidence for the aetiology of anisometropic amblyopia will require longitudinal tracking of at-risk infants, which poses numerous methodological and ethical challenges. However, if we are to prevent this condition, we must understand the factors that cause it to develop.

Prevalence of anisometropia and its association with refractive error and amblyopia in preschool children

AIM

To determine the age and ethnicity-specific prevalence of anisometropia in Australian preschool-aged children and to assess in this population-based study the risk of anisometropia with increasing ametropia levels and risk of amblyopia with increasing anisometropia.

METHODS

A total 2090 children (aged 6-72 months) completed detailed eye examinations in the Sydney Paediatric Eye Disease Study, including cycloplegic refraction, and were included. Refraction was measured using a Canon RK-F1 autorefractor, streak retinoscopy and/or the Retinomax K-Plus 2 autorefractor. Anisometropia was defined by the spherical equivalent (SE) difference, and plus cylinder difference for any cylindrical axis between eyes.

RESULTS

The overall prevalence of SE and cylindrical anisometropia ≥1.0 D were 2.7% and 3.0%, for the overall sample and in children of European-Caucasian ethnicity, 3.2%, 1.9%; East-Asian 1.7%, 5.2%; South-Asian 2.5%, 3.6%; Middle-Eastern ethnicities 2.2%, 3.3%, respectively. Anisometropia prevalence was lower or similar to that in the Baltimore Pediatric Eye Disease Study, Multi-Ethnic Pediatric Eye Disease Study and the Strabismus, Amblyopia and Refractive error in Singapore study. Risk (OR) of anisometropic amblyopia with ≥1.0 D of SE and cylindrical anisometropia was 12.4 (CI 4.0 to 38.4) and 6.5 (CI 2.3 to 18.7), respectively. We found an increasing risk of anisometropia with higher myopia ≥-1.0 D, OR 61.6 (CI 21.3 to 308), hyperopia > +2.0 D, OR 13.6 (CI 2.9 to 63.6) and astigmatism ≥1.5 D, OR 30.0 (CI 14.5 to 58.1).

CONCLUSIONS

In this preschool-age population-based sample, anisometropia was uncommon with inter-ethnic differences in cylindrical anisometropia prevalence. We also quantified the rising risk of amblyopia with increasing SE and cylindrical anisometropia, and present the specific levels of refractive error and associated increasing risk of anisometropia.

Guidelines for automated preschool vision screening: a 10-year, evidence-based update

In 2003 the American Association for Pediatric Ophthalmology and Strabismus Vision Screening Committee proposed criteria for automated preschool vision screening. Recent literature from epidemiologic and natural history studies, randomized controlled trials of amblyopia treatment, and field studies of screening technologies have been reviewed for the purpose of updating these criteria. The prevalence of amblyopia risk factors (ARF) is greater than previously suspected; many young children with low-magnitude ARFs do not develop amblyopia, and those who do often respond to spectacles alone. High-magnitude ARFs increase the likelihood of amblyopia. Although depth increases with age, amblyopia remains treatable until 60 months, with decline in treatment effectiveness after age 5. US Preventive Services Task Force Preventative Services Task Force guidelines allow photoscreening for children older than 36 months of age. Some technologies directly detect amblyopia rather than ARFs. Age-based criteria for ARF detection using photoscreening is prudent: referral criteria for such instruments should produce high specificity for ARF detection in young children and high sensitivity to detect amblyopia in older children. Refractive screening for ARFs for children aged 12-30 months should detect astigmatism >2.0 D, hyperopia >4.5 D, and anisometropia >2.5 D; for children aged 31-48 months, astigmatism >2.0 D, hyperopia > 4.0 D, and anisometropia >2.0 D. For children >49 months of age original criteria should be used: astigmatism >1.5 D, anisometropia>1.5 D, and hyperopia >3.5 D. Visually significant media opacities and manifest (not intermittent) strabismus should be detected at all ages. Instruments that detect amblyopia should report results using amblyopia presence as the gold standard. These new American Association for Pediatric Ophthalmology and Strabismus Vision Screening Committee guidelines will improve reporting of results and comparison of technologies.

Associations of anisometropia with unilateral amblyopia, interocular acuity difference, and stereoacuity in preschoolers

PURPOSE

To evaluate the relationship of anisometropia with unilateral amblyopia, interocular acuity difference (IAD), and stereoacuity among Head Start preschoolers using both clinical notation and vector notation analyses.

DESIGN

Multicenter, cross-sectional study.

PARTICIPANTS

Three- to 5-year-old participants in the Vision in Preschoolers (VIP) study (n = 4040).

METHODS

Secondary analysis of VIP data from participants who underwent comprehensive eye examinations, including monocular visual acuity testing, stereoacuity testing, and cycloplegic refraction. Visual acuity was retested with full cycloplegic correction when retest criteria were met. Unilateral amblyopia was defined as IAD of 2 lines or more in logarithm of the minimum angle of resolution (logMAR) units. Anisometropia was defined as a 0.25-diopter (D) or more difference in spherical equivalent (SE) or in cylinder power and 2 approaches using power vector notation. The percentage with unilateral amblyopia, mean IAD, and mean stereoacuity were compared between anisometropic and isometropic children.

MAIN OUTCOMES MEASURES

The percentage with unilateral amblyopia, mean IAD, and mean stereoacuity.

RESULTS

Compared with isometropic children, anisometropic children had a higher percentage of unilateral amblyopia (8% vs. 2%), larger mean IAD (0.07 vs. 0.05 logMAR), and worse mean stereoacuity (145 vs. 117 arc sec; all P<0.0001). Larger amounts of anisometropia were associated with higher percentages of unilateral amblyopia, larger IAD, and worse stereoacuity (P<0.001 for trend). The percentage of unilateral amblyopia increased significantly with SE anisometropia of more than 0.5 D, cylindrical anisometropia of more than 0.25 D, vertical and horizontal meridian (J0) or oblique meridian (J45) of more than 0.125 D, or vector dioptric distance of more than 0.35 D (all P<0.001). Vector dioptric distance had greater ability to detect unilateral amblyopia than cylinder, SE, J0, or J45 (P<0.001).

CONCLUSIONS

The presence and amount of anisometropia were associated with the presence of unilateral amblyopia, larger IAD, and worse stereoacuity. The threshold level of anisometropia at which unilateral amblyopia became significant was lower than current guidelines. Vector dioptric distance is more accurate than spherical equivalent anisometropia or cylindrical anisometropia in identifying preschoolers with unilateral amblyopia.

Instrument-based pediatric vision screening policy statement

A policy statement describing the use of automated vision screening technology (instrument-based vision screening) is presented. Screening for amblyogenic refractive error with instrument-based screening is not dependent on behavioral responses of children, as when visual acuity is measured. Instrument-based screening is quick, requires minimal cooperation of the child, and is especially useful in the preverbal, preliterate, or developmentally delayed child. Children younger than 4 years can benefit from instrument-based screening, and visual acuity testing can be used reliably in older children. Adoption of this new technology is highly dependent on third-party payment policies, which could present a significant barrier to adoption.

Childhood vision screening in Canada: public health evidence and practice

OBJECTIVES

Best practice guidelines recommend vision testing in children 3 to 5 years of age for the prevention of amblyopia; however, universal vision screening is controversial. In Canada, amblyopia screening can be the responsibility of physicians, optometrists, and/or Public Health. We review the evidence underlying preschool vision screening for amblyopia using an Evidence-based Public Health (EBPH) approach, and consider implications for the Public Health provision of universal screening programs for amblyopia in Canadian jurisdictions in light of present practices.

METHODS

We searched the literature to address each major screening criterion (disease, test, treatment, program requirements) necessary to support preschool vision screening for amblyopia. We also reappraised papers cited in two systematic reviews related to the impact of vision screening. The Chief Medical Officer of Health of each province/territory was sent a short survey asking whether there currently was a Public Health preschool vision screening program in place and if so, for specifics about the program.

RESULTS

An EBPH approach to the literature with respect to the criteria for screening and available intervention studies support amblyopia screening by Public Health. There is a public health divide in amblyopia screening practice in Canada; while some provinces maintain organized programs, others have chosen to delegate the task to other professionals, without a concurrent surveillance function to monitor disparities in uptake.

CONCLUSIONS

Amblyopia deserves attention from Public Health. Efforts should be made to maintain existing programs, and provinces without organized screening programs should reconsider their role in the prevention of inequities with regard to preventable blindness in Canadian children.

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

OBJECTIVE

To investigate risk factors associated with unilateral or bilateral decreased visual acuity (VA) in preschool children.

DESIGN

Population-based, cross-sectional prevalence study.

PARTICIPANTS

Population-based samples of 6504 children ages 30 to 72 months from California and Maryland.

METHODS

Participants were preschool African-American, Hispanic, and non-Hispanic white children from Los Angeles, California, and Baltimore, Maryland. Data were obtained by a parental interview and a detailed ocular examination. Logistic regression models were used to evaluate the independent associations between demographic, behavioral, and clinical risk factors with unilateral and bilateral decreased VA.

MAIN OUTCOME MEASURES

Odds ratios (ORs) for various risk factors associated with interocular difference (IOD) in VA of ≥2 lines with ≤20/32 in the worse eye, or bilateral decreased VA <20/40 or <20/50 if <48 months of age.

RESULTS

In multivariate logistic regression analysis, 2-line IOD with a VA of ≤20/32 was independently associated with Hispanic ethnicity (OR, 2.05), esotropia (OR, 8.98), spherical equivalent (SE) anisometropia (ORs ranging between 1.5 and 39.7 for SE anisometropia ranging between 0.50 to <1.00 diopters [D] and ≥2.00 D), and aniso-astigmatism in J0 or J45 (ORs ranging between 1.4 and ≥5.3 for J0 or J45 differences ranging between 0.25 to <0.50 D and ≥1.00 D). Bilateral decreased VA was independently associated with lack of health insurance (OR, 2.9), lower primary caregiver education (OR, 1.7), astigmatism (OR, 2.3 and 17.6 for astigmatism 1.00 to <2.00 D and ≥2.00 D), and SE hyperopia ≥4.00 D (OR, 10.8).

CONCLUSIONS

Anisometropia and esotropia are risk factors for IOD in VA. Astigmatism and high hyperopia are risk factors for bilateral decreased VA. Guidelines for the screening and management of decreased VA in preschool children should be considered in light of these risk associations.

FINANCIAL DISCLOSURE(S)

The authors have no proprietary or commercial interest in any of the materials discussed in this article.

To prescribe or not to prescribe? Guidelines for spectacle prescribing in infants and children

This paper discusses the considerations for prescribing a refractive correction in infants and children up to and including school age, with reference to the current literature. The focus is on children who do not have other disorders, for example, binocular vision anomalies, such as strabismus, significant heterophoria or convergence excess. However, refractive amblyogenic factors are discussed, as is prescribing for refractive amblyopia. Based on this discussion, guidelines are proposed, which indicate when to prescribe spectacles and what amount of refractive error should be corrected. It may be argued that these are premature because there are many questions that remain unanswered and we do not have the quality of evidence that we would like; the clinician, however, must make decisions on whether and what to prescribe when examining a child. These guidelines are to aid clinicians in their current clinical decision making.

Prevalence of strabismic binocular anomalies, amblyopia and anisometropia. Rehabilitation Faculty of Shahid Beheshti Medical University

Purpose

Manifest strabismus such as constant and alternative esotropia and exotropia, not only cause cosmetic problem in patients but also induce disorders such as amblyopia. These anomalies can lead to academic failure in students and reduce efficiency in other jobs. Therefore, determining the prevalence of binocular anomalies is important. The purpose of this study is to determine the prevalence of strabismic binocular anomalies, amblyopia and anisometropia in patients examined in optometry clinic of the rehabilitation faculty of Shahid Beheshti Medical University in 2008/2009.

Methods

In this study, files of 600 patients were evaluated. Cycloplegic refraction was performed in infants, elementary and middle school children and other patients had noncylcoplegic refraction. Anisometropia was defined as a difference of 1.00D or more between two eyes. Amblyopia was diagnosed as a reduction of best corrected visual acuity (BCVA) to 20/30 or less in one eye or 2-line difference in the absence of pathological causes. Cover test was performed to investigate of strabismus.

Results

The prevalence of strabismic binocular anomalies, amblyopia and anisometropia were respectively: anisometropia in 64 patients (10.67%), anisometropic amblyopia in 9 patients (1.5%), anisometropic amblyopia with exotropia in 1 patient (0.17%), anisometropic amblyopia with esotropia in 1 patient (0.17%), bilateral amblyopia in 5 patients (0.83%), esotropia in 2 patients (0.33%), exotropia in 1 patients (0.17%) and convergence insufficiency in 2 patients (0.33%).

Discussion

The results show that the prevalence of anisometropia was higher than shown in previous studies but prevalence of convergence insufficiency, esotropia and exotropia was lower than previous studies.

Prevalence of amblyogenic risk factors in siblings of patients with accommodative esotropia

PURPOSE

To prospectively describe the prevalence of amblyogenic risk factors in the siblings of patients with accommodative esotropia.

METHODS

We examined 81 proband children with accommodative esotropia and 115 siblings ages 10 years or younger in our clinical practice. Criteria for significant ocular findings in siblings included any of the following: spherical refractive error > or = +3.5 D in either eye; astigmatism in either eye > or =1.0 D or 1.5 D depending on the axis; anisometropia > or =1.5 D; and/or any strabismus.

RESULTS

In siblings, 42.6% (95% CI: 34.0%-51.7%) had significant ocular findings: strabismus, 14.8% (95% CI: 8.3%-21.3%); hyperopia > or =3.5 D, 23.5% (95% CI: 16.6%-32.1%); astigmatism > or =1 D or 1.5 D (depending on axis), 13.9% (95% CI: 8.7%-21.5%); and anisometropia > or =1.5 D, 7.0% (95% CI: 3.4%-13.3%).

CONCLUSIONS

Siblings of children with accommodative esotropia have a high prevalence of amblyogenic risk factors. This study offers additional data and rationale for providing comprehensive eye exams for children with a family history of strabismus.

Associations between anisometropia, amblyopia, and reduced stereoacuity in a school-aged population with a high prevalence of astigmatism

PURPOSE

To describe the relation between magnitude of anisometropia and interocular acuity difference (IAD), stereoacuity (SA), and the presence of amblyopia in school-aged members of a Native American tribe with a high prevalence of astigmatism.

METHODS

Refractive error (cycloplegic autorefraction confirmed by retinoscopy), best corrected monocular visual acuity (VA; Early Treatment Diabetic Retinopathy Study logMAR charts), and best corrected SA (Randot Preschool Stereoacuity Test) were measured in 4- to 13-year-old Tohono O'odham children (N = 972). Anisometropia was calculated in clinical notation (spherical equivalent and cylinder) and in two forms of vector notation that take into account interocular differences in both axis and cylinder magnitude.

RESULTS

Astigmatism >or= 1.00 D was present in one or both eyes of 415 children (42.7%). Significant increases in IAD and presence of amblyopia (IAD >or= 2 logMAR lines) occurred, with >or=1 D of hyperopic anisometropia and >or=2 to 3 D of cylinder anisometropia. Significant decreases in SA occurred with >or=0.5 D of hyperopic, myopic, or cylinder anisometropia. Results for vector notation depended on the analysis used, but also showed disruption of SA at lower values of anisometropia than were associated with increases in IAD and presence of amblyopia.

CONCLUSIONS

Best corrected IAD and presence of amblyopia are related to amount and type of refractive error difference (hyperopic, myopic, or cylindrical) between eyes. Disruption of best corrected random dot SA occurs with smaller interocular differences than those producing an increase in IAD, suggesting that the development of SA is particularly dependent on similarity of the refractive error between eyes.

The age-dependent effect of anisometropia magnitude on anisometropic amblyopia severity

INTRODUCTION

Anisometropia is an important cause of amblyopia. The relationship between anisometropia depth and amblyopia magnitude is not well characterized, as previous studies have been limited to patients identified because of their amblyopia. We analyzed results from anisometropic patients identified with photoscreening to eliminate this selection bias.

METHODS

We performed a retrospective observational study of preschool children with anisometropia >1.0 D identified during a statewide photoscreening program. Nine hundred seventy-four children with anisometropia were detected over a 9-year period. Visual acuity, cycloplegic refraction data, and patient age from a formal follow-up examination were analyzed. Effect of anisometropia magnitude on amblyopia was measured by ordinal logistic regression, taking age into account.

RESULTS

Six hundred forty (65.7%) children had amblyopia > or =2 lines. Three hundred sixty-four (37.4%) had > or =4 lines amblyopia. There was a statistically significant increase in risk of amblyopia with increasing magnitude of anisometropia. Calculated odds ratios for amblyopia with maximal meridional anisometropia of > or =2 to <4 D compared with >1 to <2 D was 2.13 (95% CI [1.63, 2.78], p < 1 x 10(-7)), and 2.34 (95% CI [1.67, 3.28], p < 1 x 10(-6)) when comparing > or =4 D to > or =2 to <4 D. Odds ratios for spherical equivalent anisometropia were also highly statistically significant.

CONCLUSIONS

Children with higher magnitudes of anisometropia had higher prevalence and greater depth of amblyopia. Older children had an increased risk of amblyopia compared with younger children for moderate levels of anisometropia. Low magnitude anisometropia in young children may not predispose to amblyopia; these findings have implications for vision screening criteria at various ages.

Diagnosis and treatment of refractive errors in the pediatric population

PURPOSE OF REVIEW

The diagnosis and successful treatment of visually significant refractive errors in children are a subject of continued study and debate.

RECENT FINDINGS

Treatment of significant refractive errors is widely accepted to reduce lifelong vision loss from amblyopia. Children aged 3-5 years may be screened for unexplained vision loss, refractive errors and amblyogenic factors using traditional eye charts as well as newer modalities such as autorefractors and photoscreeners. The accuracy of various screening methods is variable throughout the literature. Debate remains as to who is best suited to administer vision screening tests. Compliance with follow-up with an eye-care professional once a child is identified with an amblyogenic factor remains suboptimal. Treatment of significant refractive errors in certain populations of pediatric patients with refractive surgery shows promise but requires further study.

SUMMARY

The timely diagnosis of significant refractive errors in children remains a significant challenge, especially for ages 3-5 years, but treatment may provide significant improvement of visual acuity and quality of life.

Does assessing eye alignment along with refractive error or visual acuity increase sensitivity for detection of strabismus in preschool vision screening?

PURPOSE

Preschool vision screenings often include refractive error or visual acuity (VA) testing to detect amblyopia, as well as alignment testing to detect strabismus. The purpose of this study was to determine the effect of combining screening for eye alignment with screening for refractive error or reduced VA on sensitivity for detection of strabismus, with specificity set at 90% and 94%.

METHODS

Over 3 years, 4040 preschool children were screened in the Vision in Preschoolers (VIP) Study, with different screening tests administered each year. Examinations were performed to identify children with strabismus. The best screening tests for detecting children with any targeted condition were noncycloplegic retinoscopy (NCR), Retinomax autorefractor (Right Manufacturing, Virginia Beach, VA), SureSight Vision Screener (Welch-Allyn, Inc., Skaneateles, NY), and Lea Symbols (Precision Vision, LaSalle, IL and Good-Lite Co., Elgin, IL) and HOTV optotypes VA tests. Analyses were conducted with these tests of refractive error or VA paired with the best tests for detecting strabismus (unilateral cover testing, Random Dot "E" [RDE] and Stereo Smile Test II [Stereo Optical, Inc., Chicago, IL]; and MTI PhotoScreener [PhotoScreener, Inc., Palm Beach, FL]). The change in sensitivity that resulted from combining a test of eye alignment with a test of refractive error or VA was determined with specificity set at 90% and 94%.

RESULTS

Among the 4040 children, 157 were identified as having strabismus. For screening tests conducted by eye care professionals, the addition of a unilateral cover test to a test of refraction generally resulted in a statistically significant increase (range, 15%-25%) in detection of strabismus. For screening tests administered by trained lay screeners, the addition of Stereo Smile II to SureSight resulted in a statistically significant increase (21%) in sensitivity for detection of strabismus.

CONCLUSIONS

The most efficient and low-cost ways to achieve a statistically significant increase in sensitivity for detection of strabismus were by combining the unilateral cover test with the autorefractor (Retinomax) administered by eye care professionals and by combining Stereo Smile II with SureSight administered by trained lay screeners. The decision of whether to include a test of alignment should be based on the screening program's goals (e.g., targeted visual conditions) and resources.

Prevalence of hyperopia and associations with eye findings in 6- and 12-year-olds

PURPOSE

To describe the prevalence of hyperopia and associated factors in a representative sample of Australian schoolchildren 6 and 12 years old.

DESIGN

Population-based cross-sectional study.

PARTICIPANTS

Schoolchildren ages 6 (n = 1765) and 12 (n = 2353) from 55 randomly selected schools across Sydney.

METHODS

Detailed eye examinations included cycloplegic autorefraction, ocular biometry, cover testing, and dilated fundus examination. Information on birth and medical history were obtained from a parent questionnaire.

MAIN OUTCOME MEASURES

Moderate hyperopia defined as spherical equivalent (SE) refraction of > or =+2.00 diopters (D), and eye conditions including amblyopia, strabismus, astigmatism, and anisometropia.

RESULTS

Prevalences of moderate hyperopia among children ages 6 and 12 were 13.2% and 5.0%, respectively; it was more frequent in children of Caucasian ethnicity (15.7% and 6.8%, respectively) than in children of other ethnic groups. Compared with children without significant ametropia (-0.49 < or = SE refraction < or = +1.99 D), the prevalence of eye conditions including amblyopia, strabismus, abnormal convergence, and reduced stereoacuity was significantly greater in children with moderate hyperopia (all Ps < 0.01). Maternal smoking was significantly associated with moderate hyperopia among 6-year-olds (P = 0.03), but this association was borderline among 12-year-olds (P = 0.055). Early gestational age (<37 weeks) and low birth weight (<2500 g) were not statistically significant predictors of moderate hyperopia in childhood.

CONCLUSIONS

Moderate hyperopia was strongly associated with many common eye conditions, particularly amblyopia and strabismus, in older children. Birth parameters did not predict moderate hyperopia.