Amblyopia Prevalence and Risk Factors in Australian Preschool Children

doi:10.1016/j.ophtha.2011.06.024

Ophthalmology

Volume 119, Issue 1, January 2012, Pages 138-144

https://doi.org/10.1016/j.ophtha.2011.06.024 Get rights and content

Purpose

To determine the prevalence of and factors associated with amblyopia in a sample of Australian preschool children.

Design

Population-based, cross-sectional study.

Participants

The Sydney Paediatric Eye Disease Study examined 2461 (73.8% participation) children aged between 6 and 72 months from 2007 to 2009.

Methods

Visual acuity (VA) was assessed in children aged ≥30 months using the Electronic Visual Acuity system, and a subset using the logarithm of the minimum angle of resolution chart. Amblyopia was categorized into unilateral and bilateral subtypes: Unilateral amblyopia was defined as a 2-line difference in reduced VA between the 2 eyes, in addition to strabismus, anisometropia, and/or visual axis obstruction; bilateral amblyopia was defined as bilateral reduced VA with either bilateral visual axis obstruction or significant bilateral ametropia. Information on ethnicity, birth parameters, and measures of socioeconomic status were collected in questionnaires completed by parents.

Main Outcome Measures

Amblyopia.

Results

We included 1422 children aged 30 to 72 months, of whom 27 (1.9%) were found to have amblyopia or suspected amblyopia. Mean spherical equivalent for the amblyopic eyes was +3.57 diopters, with a mean VA of 20/50. Only 3 of the 27 amblyopic children had previous diagnoses or treatments for amblyopia. In regression analysis controlling for age, gender, and ethnicity, amblyopia was significantly associated with hyperopia (odds ratio [OR], 15.3; 95% confidence interval [CI], 6.5–36.4), astigmatism (OR, 5.7; 95% CI, 2.5–12.7), anisometropia (OR, 27.8; 95% CI, 11.2–69.3), and strabismus (OR, 13.1; 95% CI, 4.3–40.4). There were no significant associations of amblyopia with low birthweight (<2500 g), preterm birth (<37 weeks), maternal smoking, age, gender, ethnicity, or measures of socioeconomic status (all P>0.05).

Conclusions

Amblyopia was found in 1.9% of this Australian preschool sample, which is comparable with prevalence rates reported by other recent studies in preschool children. Refractive errors, particularly significant hyperopia and astigmatism, in addition to anisometropia and strabismus, were the major amblyogenic factors. There was a low amblyopia detection rate in this preschool population, which suggests that different strategies are required to improve current vision screening strategies in preschoolers.

Financial Disclosure(s)

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

Section snippets

Participants

The Sydney Paediatric Eye Disease Study (SPEDS) enumerated 3333 eligible children, aged between 6 and 72 months at time of recruitment, via a door-to-door census in 4 randomly selected postcodes (inner city, suburban, outer suburban region) in metropolitan Sydney, stratified by socioeconomic status. A total 2461 of these children (73.8% participation rate) were examined from 2007 to 2009. All examination procedures were approved by the University of Sydney Human Research Ethics committee, and

Results

Of 1422 children included in this report, 27 (1.9%) were identified as amblyopic or suspected cases of amblyopia using the MEPEDS criteria.¹¹ Of these amblyopic children, only 3 (11.1%) had a previous diagnosis of amblyopia and were commenced on temporary patching of the affected eye, atropine treatment, and/or wearing spectacles prescribed by treating ophthalmologists. The remaining 24 children were referred by study investigators to pediatric ophthalmologists for further management.

Table 1

Discussion

The prevalence of amblyopia was 1.9% in this sample of 1422 Australian preschool-aged children, comparable with our previously reported prevalence in older 6-year-old children from Sydney,⁸ and to other preschool studies.10, 11 In the Sydney Myopia Study, a 1.8% amblyopia prevalence was reported in 1739 6-year-old multiethnic school children; those with a previous history of treatment for amblyopia were also included, even if normal by the time of examination, as in the current study. Using

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To characterize the demographics, eye-related comorbidities, clinical characteristics, clinical outcomes, type of amblyopia tests used, and treatment patterns of a large cohort of pediatric, teenage, and adult amblyopic patients from the IRIS (Intelligent Research in Sight) Registry.
In this retrospective electronic health record analysis, we analyzed 456,818 patients, of whom 197,583 (43.3%) were pediatric patients; 65,308 (14.3%), teenagers; and 193,927 (42.5%), adults. Baseline best-corrected visual acuity examination in both eyes was conducted within 90 days prior to index date. Three age cohorts were analyzed based on age at the index date: pediatric (3-12 years), teen (13-17 years), and adult (18-50 years).
At index date, unilateral amblyopia was more common than bilateral amblyopia in all age cohorts (pediatric, 55% vs 45%; teen, 61% vs 39%; adult, 63% vs 37%). In unilateral amblyopic patients, severe amblyopia was more frequent in adults (21%) than in pediatric patients (12%) and teenagers (13%); in bilateral amblyopic patients, severity was comparable in pediatric patients and adults (4% severe in both). The greatest level of visual acuity improvement was demonstrated in pediatric patients with severe unilateral amblyopia at baseline. Pediatric patients showed significant improvement in stereopsis over time at years 1 (P = 0.000033) and 2 (P = 0.000039) at the population level (per χ² test vs baseline).
Our findings highlight the need for more efficacious amblyopia therapies in older, more severe patients with refractory disease.
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Comparing visual outcomes after use of a novel binocular eye-tracking–based home treatment (CureSight; NovaSight, Ltd) with patching.
Prospective, multicenter, randomized, masked, controlled, noninferiority pivotal trial.
One hundred three children 4 to < 9 years with anisometropic, small-angle strabismic or mixed-mechanism amblyopia were randomized 1:1 to either CureSight treatment or patching.
The CureSight treatment uses combined anaglyph glasses and an eye tracker to induce real-time blur around the fellow eye fovea in dichoptic streamed video content. Participants used the device for 90 minutes/day, 5 days/week for 16 weeks (120 hours). The patching group received 2 hours of patching 7 days/week (224 hours). The prespecified noninferiority margin was 1 line.
The primary outcome was the improvement in the amblyopic eye visual acuity (VA), modeled with a repeated measures analysis of covariance. Secondary outcomes included stereoacuity, binocular VA, and treatment adherence rates, analyzed by a 1-sample Wilcoxon test within each group and a 2-sample Wilcoxon test comparing groups. Safety outcomes included the frequency and severity of study-related adverse events (AEs).
CureSight group VA improvement was found to be noninferior to patching group improvement (0.28 ± 0.13 logarithm of the minimum angle of resolution [logMAR] [P < 0.0001] and 0.23 ± 0.14 logMAR [P < 0.0001], respectively; 90% confidence interval [CI] of difference, –0.008 to 0.076). Stereoacuity improvement of 0.40 log arcseconds (P < 0.0001) and improved binocular VA (0.13 logMAR; P < 0.0001) were observed in the binocular treatment group, with similar improvements in the patching group in stereoacuity (0.40 log arcseconds; P < 0.0001) and binocular VA (0.09 logMAR; P < 0.0001), with no significant difference between improvements in the 2 groups in either stereoacuity (difference, 0; 95% CI, –0.27 to –0.27; P = 0.76) or binocular VA (difference, 0.041; 95% CI, –0.002 to 0.085; P = 0.07). The binocular treatment group had a significantly higher adherence than the patching group (91% vs. 83%; 95% CI, –4.0% to 21%; P = 0.011). No serious AEs were found.
Binocular treatment was well tolerated and noninferior to patching in amblyopic children 4 to < 9 years of age. High adherence may provide an alternative treatment option for amblyopia.
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5959 children aged 18–72 months were recruited and screened in Southwestern Ontario at 210 locations over a period of 3 years and 4 months.
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The screening was negative in 5386 children (90.4%), positive in 403 (6.8%), and unreadable in 170 (2.9%); 42% of all screened children were ≤36 months old. The estimated amblyogenic risk factor prevalence of anisometropia was 4.0%, astigmatism was 3.1%, hyperopia was 1.1%, myopia was 0.4%, and strabismus was 0.4%. Of the 403 referred children, 99 (24.5%) completed a formal eye examination based on the responses returned to the study site.
This is the first Canadian study that provides data on amblyogenic risk factors based on a volunteer-led photoscreening program. Photoscreening is an effective screening tool, particularly for pre-school-aged children; however, the lack of mandatory follow-up to ensure that children receive proper treatment based on cycloplegic refraction reduces the efficacy of screening.
Ce rapport avait pour objectif de présenter les résultats définitifs d'un programme de dépistage photographique communautaire chez des enfants de 18 à 72 mois du sud-ouest de l'Ontario, et d’évaluer la prévalence des facteurs de risque amblyogène au sein de cette population.
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5959 enfants âgés de 18 à 72 mois ont fait l'objet d'un recrutement et d'un dépistage dans 210 centres du sud-ouest de l'Ontario sur une période de 3 ans et 4 mois.
On a eu recours à l'appareil Plusoptix S12 pour le dépistage ophtalmique photographique. Le seuil à partir duquel les patients étaient adressés en vue d'un examen supplémentaire correspondait aux critères du fabricant lorsque les caractéristiques de fonctionnement de l'appareil étaient réglées à 4.
Le dépistage a donné des résultats négatifs chez 5386 enfants (90,4 %), positifs chez 403 enfants (6,8 %) et illisibles chez 170 enfants (2,9 %); 42 % de tous les enfants qui ont fait l'objet d'un dépistage étaient âgés de ≤ 36 mois. La prévalence estimée des facteurs de risque amblyogène se chiffrait à 4,0 % dans le cas de l'anisométropie, à 3,1 % dans le cas de l'astigmatisme, à 1,1 % dans le cas de l'hyperopie, à 0,4 % dans le cas de la myopie et à 0,4 % dans le cas du strabisme. Selon les réponses envoyées au centre de l’étude, sur les 403 enfants adressés en vue d'un examen, 99 (24,5 %) ont subi un examen complet de la vue.
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: The Sydney Paediatric Eye Disease Study was supported by the Australian National Health and Medical Research Council (NHMRC) grant number 402425, and the Westmead Millennium Institute, University of Sydney.

: Manuscript no. 2010-1412.

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

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Original articleAmblyopia Prevalence and Risk Factors in Australian Preschool Children

Purpose

Design

Participants

Methods

Main Outcome Measures

Results

Conclusions

Financial Disclosure(s)

Section snippets

Participants

Results

Discussion

Ophthalmology

Ophthalmology

Ophthalmology

Ophthalmology

Lancet

Am J Ophthalmol

Ophthalmology

J AAPOS

J AAPOS

Am J Ophthalmol

The clinical effectiveness and cost-effectiveness of screening programmes for amblyopia and strabismus in children up to the age of 4–5 years: a systematic review and economic evaluation

Health Technol Assess

Prevalence and causes of visual impairment in African-American and Hispanic preschool children: the Multi-Ethnic Pediatric Eye Disease Study

Ophthalmology

Correctable and non-correctable visual impairment in a population-based sample of 12-year-old Australian children

Am J Ophthalmol

Age-specific prevalence and causes of bilateral and unilateral visual impairment in older Australians: the Blue Mountains Eye Study

Clin Experiment Ophthalmol

Causes and associations of amblyopia in a population-based sample of 6-year old Australian children

Arch Ophthalmol

Impact of amblyopia on vision at age 12 years: findings from a population-based study

Eye (Lond)

Prevalence of amblyopia and strabismus in white and African American children aged 6 through 71 months: the Baltimore Pediatric Eye Disease Study

Ophthalmology

Prevalence of amblyopia and strabismus in African American and Hispanic children ages 6 to 72 months: the Multi-ethnic Pediatric Eye Disease Study

Ophthalmology

Prevalence of amblyopia and strabismus in young Singaporean Chinese children

Invest Ophthalmol Vis Sci

The prevalence of strabismus and amblyopia in Japanese elementary school children

Ophthalmic Epidemiol

Detection of strabismus and amblyopia in 1.5- and 3-year-old children by a preschool vision-screening program in Japan

Acta Med Okayama

Comparison of prevalence rates of strabismus and amblyopia in Japanese elementary school children between the years 2003 and 2005

Acta Med Okayama

Screening amblyopia of preschool children with uncorrected vision and stereopsis tests in Eastern Taiwan

Eye (Lond)

Original article
Amblyopia Prevalence and Risk Factors in Australian Preschool Children