Purpose: Optical coherence tomography angiography (OCTA) noninvasively images retinal microvasculature. Foveal avascular zone (FAZ) biomarkers can act as indicators of various forms of amblyopia, making them valuable tools for clinicians. The purpose of this study was to assess the effect of amblyopia therapy on the FAZ using OCTA to determine FAZ size in children with untreated amblyopia.
Patients and methods: This two-arm cohort study enrolled 23 children with untreated strabismic or anisometropic amblyopia who underwent OCTA between 2021-2022. Each arm had 23 eyes, with one arm having amblyopic eyes and the other having normal eyes. FAZ area, perimeter, and circularity index were measured before and quarterly during 1 year of occlusion therapy. Differences in avascular zone biomarkers between amblyopic and fellow eyes were compared and linked to demographic and ocular factors.
Results: Similar FAZ areas were found in the amblyopic (0.3 mm2) and nonamblyopic eyes (0.28 mm2) (P = 0.83), with no significant change in either group (P = 0.93). Amblyopic eyes showed a larger FAZ perimeter reduction (0.12 mm2) than fellow eyes (0.02 mm2), but the difference was not statistically significant (P = 0.09). The circularity index in amblyopic eyes matched with fellow eyes (0.67 mm2), P = 0.38. Initial visual acuity and strabismus correlated with changes in the follow-up FAZ area.
Conclusion: Amblyopia treatment did not significantly alter FAZ area in this cohort. Perimeter variations between amblyopic and fellow eyes require further study. The conclusions were limited by the sample size and lack of randomization.
Keywords: amblyopia; biomarkers; foveal avascular zone; occlusion therapy; optical coherence tomography angiography.
© 2023 Sesma et al.