Study Of Peripapillary Microvasculature Perfusion Density And Retinal Nerve Fiber Layer Thickness In The Fellow Eyes Of Unilateral Retinal Vein Occlusion

Objective To quantitatively measure the peripapillary microvasculature perfusion density(PD)and retinal nerve fiber laye(r RNFL)thickness in fellow eyes of unilateral RVO and healthy eyes using OCT and optical coherence tomography angiography(OCTA).To compare RNFL thickness and microvascular PD between these two groups,respectively.And to explore the relationship between these two parameters.We aim to explain the phenomenon that unilateral RVO has "an unhealthy fellow eye",and provide reference for revealing the RVO pathogenesis.Methods This research was a case-control study.The fellow eyes of 50 patients with unilateral RVO were enrolled as the experimental group and50 normal controls during the same period were included as the control group in the XXX Hospital.All sectors of peripapillary RNFL thickness maps and all layers of peripapillary blood flow maps were obtained using OCT and OCTA techniques.In this study,the blood flow maps of the retinal nerve fiber layer vascular plexus(NFLVP)were selected.Matlab software was used to manually remove the thick vessels and then calculate the PD of microvasculature.Results The mean RNFL thickness of T sector in the fellow eyes of RVO patients were significantly thinner than in normal controls(75.70±10.35μm vs 80.30±11.87μm,P=0.042,P<0.05).The mean PD of microvasculature around optic nerve head(ONH)was significantly lower than in normal controls(0.196±0.236 vs 0.206±0.185,P=0.028,P<0.05).NS sector,N sector and whole circle RNFL thickness were correlated with peripapillary PD(r=0.432,P=0.002;r=342,P=0.015;r=0.325,P=0.021).There was no difference between CRVO and BRVO in PD of microvasculature and RNFL thickness of all sectors around ONH.Conclusion There were lower peripapillary microvascular PD in RPCP and thinner RNFL thickness of T sector in the fellow eyes of unilateral RVOs.In addition,peripapillary microvascular PD in the fellow eye of unilateral RVO was significantly positively correlated with NS sector,N sector,and the overall RNFL thickness.These two parameters did not significantly differ between CRVO and BRVO subgroups.This indicates that the fellow eye of unilateral RVO is unhealthy though it seems normal.The structure and microcirculation of the retina around the ONH have been changed.Furthermore,there was a significant positive correlation between PD and RNFL thickness in the fellow eye group,which means that the thinning of RNFL thickness and the decrease of the microvascular PD around the ONH both occurred.However,there has no conclusion about which one changes first.In the future,based on the improvement of OCTA technology,combined with quantitative measurement of peripapillary retinal deep capillary parameters and choroidal capillary parameters,it may provide clues for revealing the change law of peripapillary blood flow,and then provide reference for explaining the pathogenesis of RVO.