Evaluation of Macula and Optic Disc of Adult Amblyopia Patients with Diverse Etiologies using Optical Coherence Tomography Angiography.

Purpose: To compare macula and optic-disc optical coherence tomography angiography (OCTA) metrics of adult amblyopic eyes with healthy controls and investigate whether these differ according to amblyopia etiology.

Methods: This cross-sectional study included 35 unilateral amblyopic adults (n = 35 eyes) and 35 age-matched healthy controls (n = 35 eyes). Amblyopia subgroups consisted of anisometropic (n = 12 eyes), strabismic (n = 12 eyes), and combined-mechanism amblyopia (n = 11 eyes). Foveal avascular zone area (FAZA), vessel density (VD), and retinal thickness were obtained using OCTA. Retinal thicknesses were measured at the fovea, parafovea, perifovea, and retinal nerve fiber layer. Foveal, parafoveal, perifoveal, whole-macula, intradisc, peripapillary, and whole-disc VD were recorded. Groups were compared regarding OCTA metrics after adjusting for axial length, spherical equivalent, age, gender, and signal quality index using a one-way analysis of covariance test.

Results: Amblyopic eyes had significantly lower foveal, parafoveal, perifoveal, whole-macula VD in superficial capillary plexus (SCP), and deep capillary plexus (DCP) than control eyes after adjusting for confounders (P < 0.05 for all). All amblyopia subgroups had significantly lower parafoveal, perifoveal, and whole-macula VD in SCP and DCP than control eyes after adjusting for confounders (P < 0.05 for all). There was no significant difference in retinal thickness, FAZA, intradisc VD, peripapillary VD, and whole-disc VD between amblyopic and control eyes, as well as amblyopia subgroups and control eyes.

Conclusion: These results suggest that effect of amblyopia on macular microvasculature should be considered when interpreting OCTA metrics of adults with concomitant diseases. It also supports that adult amblyopic eyes of different etiology have similar microvascular features.