Effect of intravitreal dexamethasone implant versus ranibizumab on vessel density in branch retinal vein occlusion

Abstract

Purpose: This study aimed to compare the effect of intravitreal dexamethasone implant with that of ranibizumab on vessel density (VD) in eyes with branch retinal vein occlusion (BRVO). Methods: Sixty-three eyes of 63 patients with superotemporal BRVO treated either with intravitreal dexamethasone implant (DEX group, n = 31) or ranibizumab (RNB group, n = 32) were prospectively enrolled. Swept-source optical coherence tomography angiography 6 × 6 mm scans of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in all eyes were analyzed. Results: The mean baseline VD of the SCP and the DCP was similar between groups in all quadrants ( p > 0.05 for all). At 12 months, the VD of the SCP in the parafoveal superior and temporal quadrants was significantly higher in the RNB group than in the DEX group ( p = 0.002 and p = 0.001, respectively). The VD of the DCP in the parafoveal temporal, nasal, and superior quadrants was significantly higher in the RNB group than in the DEX group ( p < 0.05 for all). Further, there was a statistically significant positive correlation between the improvement of visual acuity and increased VD of the SCP and the DCP in the parafoveal temporal quadrant in both groups ( R = 0.589, p = 0.001 and R = 0.455, p = 0 .017, respectively). Conclusion: Our findings support that ranibizumab does not inhibit collateral vessel formation in eyes with superotemporal BRVO compared to dexamethasone implant. VD and vessel formation can positively affect the vision prognosis in long-term follow-up.