Glasses Do Not Reduce Amblyopia Risk for Children With Astigmatism

While children with moderate astigmatism are prescribed eyeglasses for multiple reasons — including to reduce eye strain — a 12-year study challenges previous thinking that spectacle correction can head off strabismus or amblyopia in these patients. The research shows 4-year follow-up rates for amblyopia were marginally higher for those who wore glasses than those who were just observed, according to data published in American Journal of Ophthalmology.

The Mayo Clinic’s Department of Ophthalmology and Department of Quantitative Health Sciences reviewed charts of children 1 to <7 years of age with bilateral astigmatism of +1.25 to +3.25 D. The investigation included participants with at least 18 months of follow-up, and who were 4 to <10 years of age at the last examination. Inclusion criteria in the population base of 1235 was rigorous — excluded were those with amblyopia or strabismus at diagnosis, anisometropia ≥1.00 D, myopia ≥-3.00 D, and hyperopia ≥+3.00 D. Complete examinations included cycloplegic refraction, with spectacle correction at the discretion of 2 examiners.

This analysis demonstrated that after 4 years, Kaplan-Meier rate for amblyopia onset was 10.3% for 58 patients in the spectacle-wearing group and 8.3% for 27 participants in the observation cohort. Strabismus developed in 7.1% of each group. “While there is little doubt that children presenting with astigmatism and amblyopia should be managed with astigmatic spectacle correction, there is scant empirical evidence as to whether astigmatic children without amblyopia at diagnosis would benefit from optical correction,” the study explains.

Amblyopia occurred more often in children with higher mean refractive cylinder at diagnosis, independent of whether they were in the eyeglass-treated (13.8%) or observation (11.1%) group, compared with participants who had lower cylinder in the treated (6.9%) or observation (5.5%) cohort.

Eyeglasses did not significantly impact outcomes in 2 age subgroups. For patients 1 to <4 years of age who wore spectacles, 14.2% developed amblyopia, compared with 6.3% of those observed (P =.62). In children 4 to <7 years of age who wore glasses, 8.1% acquired amblyopia, as well as 9.1% of kids who were observed (P =.95).

The retrospective study examined charts at a single center from January 1, 2005 to December 31, 2016. Eyeglass wearing compliance could not be assessed; a limitation of this analysis. Also, the 2 cohorts displayed differing baseline variables — for example, spectacle wearers had a mean age of 4.31 years at diagnosis compared with 3.56 years for those observed, and the treated cohort also had greater astigmatism at diagnosis, 2.00 DC, compared with the observed group, 1.73 DC. Larger randomized studies are indicated, the research added.

This investigation is the first to compare correction with observation in participants that have moderate astigmatism, normal visual function,  and no strabismus or amblyopia at baseline. A growing number of screening programs in the US have generated more referrals to clinicians for astigmatism correction, and the “inference from the conclusions of this study is that some of these children who are asymptomatic may be at risk of overtreatment,” the analysis explains.

Reference

Wang JY, Hodge DO, Mohney BG, et al. Glasses versus observation for moderate bilateral astigmatism in 1- to <7-year-olds. Am J Ophthalmol. Published online August 2, 2021. doi:10.1016/j.ajo.2021.07.029