Evaluation of macular microvasculature and foveal avascular zone in patients with retinal vein occlusion using optical coherence tomography angiography

Purposes To quantitatively evaluate the vessel density of macular microvasculature, choriocapillary, and foveal avascular zone (FAZ) in both eyes of patients with unilateral retinal vein occlusion (RVO) using the optical coherence tomography angiography (OCTA) compared with the normal controls. Methods A retrospective review was conducted on 72 patients with unilateral RVO (72 eyes with RVO and 72 RVO fellow eyes) and 72 healthy individuals (72 normal control eyes). The 3 x 3 mm macular angiogram was acquired using the OCTA. The vessel densities of the retinal superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillary plexus (CCP) were measured, and FAZ was quantified. Results The RVO eyes compared to their fellow eyes, and the fellow eyes compared to the normal controls, showed a significantly lower vessel density in both the SCP and DCP in the whole image and parafovea (P < 0.05) and the CCP (P < 0.05), except for the foveal region (P > 0.05). No significant differences between the RVO eyes and the fellow eyes in the FAZ area and perimeter (P > 0.05) were observed, while the acircularity index in the RVO eyes was significantly higher than the fellow eyes (P < 0.05). Additionally, the FD-300 in the RVO eyes was significantly lower than their fellow eyes (P < 0.05). Conclusions The OCTA reveals that the macular microvasculature of the RVO fellow eyes can be impaired in both the superficial and deep retinal layer as well as the choriocapillary, suggesting the influence of systemic factors in the development of RVO.