Comparing the Retinal Nerve Fiber Layer Thickness and Peripapillary Vasculature in the Fellow Eye of Patients with Unilateral Retinal Vein Occlusion to Normal Controls- an OCT, OCTA based study

Abstract Purpose: To assess the radial peripapillary capillary (RPC) density within fellow eyes of patients having a unilateral RVO utilizing OCTA along with determining the associations between peripapillary microvasculature, retinal nerve fiber layer (RNFL) as well as ganglion cell complex (GCC) thickness. Methods: Fifty- seven cases having a unilateral RVO as well as fifty-seven normal controls were included. Peripapillary OCTA was conducted and the RPC density as well as peripapillary RNFL thickness were automatically calculated. Results: The peripapillary RNFL thickness for RVO fellow eyes showed significantly thinner values as regards the average, superior quadrant, nasal quadrant as well as temporal quadrant (P-value 0.003, 0.026 ,0.005 and ˂0.001 respectively). Also, they showed significantly thinner GCC (P-value ˂0.001) as well as RPC density within the whole image, inferior-hemisphere, nasal quadrant, and temporal quadrant than in normal controls (P-value 0.007, 0.004,0.003 and 0.024 respectively). No significant variations as regards GCC, RNFL thickness as well as RPC density among BRVO or CRVO fellow eyes were documented. RNFL thicknesses show significant positive association with RPC density. Conclusion: When compared to healthy controls, fellow eyes of cases having a unilateral RVO exhibited lower peripapillary microvascular parameters as well as thinner GCC and RNFL. The RNFL was positively correlated to peripapillary VD.