Impact of posterior vitreous detachment on clinical outcomes in eyes with branch retinal vein occlusion

Purpose: To investigate posterior vitreous detachment (PVD) status in eyes with branch retinal vein occlusion (BRVO) and its relationship to structural and treatment outcomes. Methods: Retrospective cohort study of eyes with treatment-naïve BRVO diagnosed within one year of onset from 2009 through 2021, with at least one year of follow-up. Eyes were stratified by PVD status on optical coherence tomography at presentation. Outcomes included cystoid macular edema (CME) prevalence, central subfield thickness (CST), and number of intravitreal injections. Results: Of 88 eyes, 33 (37.5%) had complete PVD and 55 (62.5%) did not. Patients with complete PVD were older (median 75 vs 67 years; p=0.02) and had a lower prevalence of hypertension (66.7% vs 89.1%; p=0.01). At one year, CME was less frequent in eyes with complete PVD (65.6% vs 88.9%; p=0.01), after adjustments for hypertension, baseline CME, and CST. Eyes with complete PVD had lower median CST (277.5 vs 301.0 μm; p=0.045) and required fewer median injections (4.0 vs 7.0; p=0.01) at one year, after adjustments for baseline CME and CST, but not hypertension. A significant interaction between baseline CST and PVD status was observed for one-year injection burden (p=0.03), with complete PVD associated with fewer injections at lower CST, but more injections at higher CST. Conclusion: In eyes with BRVO, complete PVD at presentation was associated with lower one-year CME prevalence, CST, and injection burden. The relationship between PVD status and injection burden varied by baseline CST, suggesting PVD status and CST may provide complementary information regarding treatment burden.