Midperipheral Microvascular Defects and Their Associations With Vitreoretinal Abnormalities in Early-Stage Familial Exudative Vitreoretinopathy.

Purpose: To investigate microvascular growth defects in the temporal midperipheral retina and their correlations with vitreoretinal microstructural abnormalities (VRMAs) in early-stage familial exudative vitreoretinopathy (FEVR).

Methods: We enrolled 127 patients (127 eyes) with early-stage FEVR and 31 healthy subjects (31 eyes). Widefield optical coherence tomography angiography was conducted for all enrolled eyes. Vessel density (VD), vessel diameter index (VDI), and vessel index (VI; VD/VDI) of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in temporal midperiphery were further evaluated. The distance from the vessel sprouting point of the optic disc to the avascular area margin (Optic-AVA) was measured to assess retinal vascular dysplasia.

Results: In early-stage FEVR, 61.42% of eyes showed retinal microvascular abnormalities (MVAs) in the temporal midperiphery, all combined with VRMAs. Common MVAs presented disordered vascular anastomoses in the SCP and capillary loss in the DCP, corresponding to deficient neuroretina. The preretinal vasculature (PRV) was detected in 36 eyes. VD and VI were lower in FEVR eyes compared to controls, whereas the VDI in the SCP was larger (all P < 0.001). Optic-AVA was positively correlated with VD and VI in both plexuses and negatively correlated with the VDI in the SCP. PRV existence was independently correlated with decreased VI in the DCP (odds ratio [OR] = 0.322; P < 0.001), and VRMA existence was independently correlated with decreased VI in SCP and DCP (SCP OR = 0.282, P = 0.010; DCP OR = 0.562, P = 0.002).

Conclusions: MVAs in the temporal midperipheral retina were revealed. Microvascular loss may be correlated with Optic-AVA reduction, PRV, and the presence of VRMAs.