The effect of treatment on retinal microvasculature in children with unilateral amblyopia

To assess whether the abnormal retinal microvasculature in unilateral amblyopia changes following amblyopia treatment.

A total of 70 patients with unilateral amblyopia (4-12 years of age) were initially recruited. Of these, 33 completed follow-up assessments after 6 months of amblyopia treatment. The retinal thickness and microvascular metrics were measured at baseline and after treatment. The interocular differences and longitudinal changes after treatment were analyzed. Partial correlation analysis was performed to explore the associations between best-corrected visual acuity improvements and changes in retinal metrics after treatment.

The central retinal thickness, thickness of the ganglion cell-inner plexiform layer, and vessel density index were greater in amblyopic eyes (P < 0.001, P < 0.001, P < 0.001, resp.), whereas the area and circularity of the foveal avascular zone were smaller in amblyopic eyes (P = 0.014, P < 0.001, resp.). Better (lower logMAR) visual acuity was associated with greater circularity of the foveal avascular zone in amblyopic eyes (r = -0.326; P = 0.007). The circularity significantly increased after amblyopia treatment in both eyes (P < 0.001, P = 0.027), and the changes in circularity in amblyopic eyes were associated with visual acuity improvements (r = -0.476; P = 0.008).

Patients with unilateral amblyopia showed interocular differences in retinal microstructure. Foveal avascular zone shape was more irregular in amblyopic eyes and associated with the severity of amblyopia, which tended to improve and become more regular with visual acuity improvements after amblyopia treatment.