Isoametropic amblyopia due to high hyperopia in children

Abstract

Purpose To identify children with isoametropic amblyopia due to moderate to high hyperopia and evaluate associated findings and visual acuity outcome. Methods Charts from two university's pediatric ophthalmology clinics were reviewed retrospectively. Healthy children with ≥+4.5 D spherical equivalent who did not have anisometropia ≥ 1.5 D were selected for data collection. The charts of qualifying children with bilateral amblyopia (visual acuity of 20/40 or less) were further analyzed. Results Identified were 418 children with the above set of criteria for hyperopia; 36 of these children had isoametropic amblyopia (bilateral amblyopia). This gives an estimated prevalence of isoametropic amblyopia of 8.6% in children with at least 4.5 D of hyperopia in one or both eyes. The children with isoametropic amblyopia presented at a later age (5 years, 1 month) than the overall group of hyperopes (3 years, 5 months). Strabismus was less prevalent in this group (64%) than in the entire population of children with high hyperopia (81%). These children's amblyopia responded well to treatment with glasses, and patching in 13 (36%) cases. Surgical intervention for residual strabismus was necessary in very few cases (2 of 36, 5.5%). Conclusion Children with hyperopia ≥ 4.5 D have an increased risk of amblyopia and strabismus that further threatens their future visual function. Isoametropic amblyopia is a real risk in these children. Based on these results, hyperopic correction should be prescribed for children with ≥4.5 D of hyperopia even if no strabismus or fixation preference is detected, to reduce this risk. Screening programs should also be in place to identify these children at an early age.