The Effect of Pathological Retinal Changes on Retinal Capillary Circulation in Myopic Patients

Myopia is a common ocular disorder worldwide, leading to degenerative changes in the retina which is highly susceptible to vascular impairment. The aim of the study was to investigate the effects of pathological retinal changes on the retinal capillary structures using optical coherence tomography angiography (OCTA) in myopic patients.

Thirty-two patients with high myopia (HM), 29 patients with pathological myopia (PM), and 38 healthy subjects with emmetropia (EM) were enrolled in this study. OCTA was performed to measure the following parameters: Foveal avascular zone (FAZ) area; FAZ perimeter; FAZ acircularity index (AI); and superficial, deep, and radial peripapillary capillary (RPC) vessel densities. Axial length (AL), spherical equivalent, and anterior chamber depth were evaluated.

Significant differences in the mean AL values were observed between the EM group and the other groups (p<0.001 for all); however, no significant differences were observed between the HM and PM groups (p=0.135). Significant differences in FAZ parameters, except for AI, were found among the three groups (p<0.05 for all). In all regions, except for the fovea and inside disc, the capillary plexus vessel densities were significantly lower in the PM group than in the other groups and were lower in the HM group than in the EM group (p<0.05 for all).

Significant differences identified in capillary densities between the HM and PM groups, both of which present similar AL measurements, suggest that pathological retinal findings have significant effects on retinal perfusion independent of the effect of AL.