Peripapillary Retinal Nerve Fiber Layer Thickness in Patients with Unilateral Retinal Vein Occlusion

Background: Retinal vein occlusion (RVO), including branch (BRVO) and central retinal vein occlusion (CRVO), can lead to vision loss and optic nerve damage. Understanding changes in peripapillary retinal nerve fiber layer (pRNFL) thickness in affected and fellow eyes is crucial for managing these conditions. Objective: This study evaluated longitudinal changes in pRNFL thickness in eyes with BRVO and CRVO, and their fellow eyes, compared with normal controls. Methods: In this retrospective case-control study, 68 patients with newly diagnosed unilateral RVO (42 BRVO, 26 CRVO) and 45 controls were included. pRNFL thickness was measured at baseline, 6, 12, and 24 months using spectral-domain optical coherence tomography (SD-OCT) in six sectors. Baseline characteristics like age, gender, hypertension, and diabetes were recorded. Statistical analyses were conducted using SPSS 23.0, with one-way ANOVA, Pearson’s chi-square test, paired t-tests, and repeated-measures ANOVA. Results: At baseline, BRVO-affected eyes had a global pRNFL thickness of 119.15 ± 17.71 μm, higher than fellow eyes at 104.52 ± 10.46 μm (p < 0.001). CRVO-affected eyes had a baseline pRNFL of 136.04 ± 36.33 μm, compared to 99.93 ± 13.59 μm in fellow eyes (p < 0.001). At 24 months, only the temporal sector in CRVO eyes showed significant pRNFL differences. Global pRNFL thickness in fellow eyes of both BRVO and CRVO groups decreased significantly at 24 months, with no significant change in the control group. Fellow eyes of the CRVO group had significantly lower pRNFL thickness at 12 and 24 months compared to BRVO and control groups. Conclusion: Both BRVO and CRVO affect pRNFL thickness in fellow eyes, with CRVO showing more susceptibility to damage. This suggests a shared vascular abnormality between RVO and glaucoma, highlighting the importance of careful pRNFL monitoring, particularly in CRVO patients.