Optical Coherence Tomography Analysis of Macular Thickness in Children with Amblyopia

Purpose: To compare central, inner and outer ring macular thickness measured with optic coherence tomography (OCT) in children with unilateral amblyopia. To analyze the differences in retinal structure among strabismic, anisometropic and combined (strabismus + anisometropia) amblyopia. Background: Amblyopia is a reduction of visual acuity in one or both eyes due to an abnormal visual input during the development of the visual system. It is mainly caused by strabismus, anisometropia or high bilateral refractive errors, and visual deprivation. Although it has been always said that the amblyopic eye is an otherwise healthy eye, the imaging techniques developed lately, especially OCT and angio OCT, may show differences in retinal structures that could have a role in the development of amblyopia and/or its response to treatment. Methods: Retrospective review of amblyopic children followed up in our hospital. 60 children with unilateral amblyopia due to anisometropia and/or strabismus, with a good quality OCT exam, were included. We analyzed 9 thickness measurements: central macular thickness (1mm ring) and 4 sectors in inner (3mm) and outer (6mm) rings. Results: Data from 60 children is included. Mean retinal thickness at the central 1mm ring was 249.15µm for amblyopic eyes vs 238.3µm for fellow eye (p=0.000). For the thickness in the other 8 sectors for inner and outer rings no statistically significant differences were found. The central retina measurement was thicker in the anisometropic amblyopia group (p=0.003), but no statistically significant difference was found in the strabismic (p=0.066) and combined group (p=0.055). Conclusions: Central retinal thickness was significantly greater in amblyopic eyes compared to fellow eyes. This difference in thickness is also statistically significant in patients with anisometropia but not in those with strabismus or strabismus + anisometropia. Further studies with more patients are recommended.