Link Between Baseline Peripheral Vascular Leakage and Treatment Response in Patients with Central Retinal Vein Occlusion: A Pilot Study

Purpose: To explore the potential link between quantitative measures of retinovascular function and response to intravitreal bevacizumab in patients with central retinal vein occlusion (CRVO). Patients and Methods: This retrospective, observational cohort study included 28 eyes with CRVO that satisfied the following inclusion criteria: age over 18 years; bevacizumab treatment for at least 4 months; best corrected visual acuity (BCVA) measurements at baseline and post-treatment; and pre-treatment ultra-wide field fluorescein angiography (UWF-FA). The RETICAD software was used for quantitative analysis of baseline UWF-FA, generating measures of blood flow, perfusion, and blood-retina barrier (BRB) in the central and peripheral retina. Responders and non-responders were defined based on BCVA stratification method developed by the DRCR network. Baseline differences between responders and non-responders were assessed using the Wilcoxon Rank Sum test. The discriminative performance of baseline measures in distinguishing responders from non-responders was evaluated using logistic regression. Results: At baseline, responders had significantly higher peripheral leakage (p = 0.034), but not central leakage (p = 0.444), compared to non-responders. No significant baseline differences were observed in perfusion or blood flow. The highest discriminative performance for treatment response was observed for baseline BRB leakage in the nasal-peripheral and inferior-peripheral regions (AUC = 0.77 and 0.75, respectively). Baseline blood flow, perfusion, central macular thickness (CMT), and BCVA demonstrated lower discriminative performance. Conclusion: High peripheral BRB leakage at baseline may be associated with an increased likelihood of benefiting from bevacizumab treatment. While this pilot study highlights the potential of quantitative UWF-FA analysis to guide CRVO therapy, these findings require validation in a larger, prospective, multicenter study with a standardized treatment protocol. Keywords: central retinal vein occlusion, blood-retina barrier leakage, ultra-wide field fluorescein angiography, image analysis, anti-VEGF treatment response