Hemodynamic Instability and Retinal Vein Occlusion in Glaucoma: Comparative Analysis of Heart Rate Variability and Choroidal Perfusion

PurposeTo assess the hemodynamic and structural differences between glaucoma patients who developed retinal vein occlusion (RVO) and those who did not. Study DesignRetrospective, single-center, cross-sectional study MethodsThis study included glaucoma patients who underwent a heart rate variability (HRV) test between January 2018 and July 2024. Patients were subdivided into RVO and non-RVO groups. Baseline mean deviation (MD) and pattern deviation (PSD) of the visual field and optical coherence tomography parameters were analyzed. ResultsTwenty-nine glaucoma patients with RVO and 34 glaucoma patients without RVO were included. Baseline MD and PSD had no difference (MD: -5.98 {+/-} 9.05 vs. -3.70 {+/-} 4.70, p=0.114; PSD: 3.88 {+/-} 3.78 vs. 3.98 {+/-} 3.96, p=0.883). HRV parameters, specifically Standard Deviation of NN interval (SDNN) and root-mean-square of successive differences (rMSSD), were significantly lower in the RVO group (SDNN: 22.12 {+/-} 8.27 vs. 36.71 {+/-} 24.74, p=0.002; rMSSD: 16.34{+/-}9.55 vs. 29.87{+/-}31.58, p=0.022). Statistically significant choroidal vascularity index difference was also observed between groups (64.62{+/-}7.38 vs. 67.49{+/-}5.90, p=0.045). Multivariate logistic regression analysis identified hypertension medication use (p=0.019) and SDNN (p=0.003) as factors associated with RVO development in glaucoma patients. ConclusionThis is the first reported study to analyze the association between hemodynamic instability and RVO development in glaucoma patients. Our results showed that RVO patients had lower HRV parameters, with SDNN being significantly associated with RVO development. We believe that HRV can be an indicator for identifying glaucoma patients at risk for RVO, though further studies are needed to validate this association.