Assessment of Papillary and Macular Vascular Changes After Ranibizumab Injection by Optical Coherence Tomography Angiography in Diabetic Retinopathy

Abstract

To evaluate macular and peripapillary vessels changes after Ranibizumab (Lucentis) injection and to identify predictors of visual outcome using optical coherence tomography angiography (OCTA) in diabetic macular edema (DME). This prospective interventional case series study enrolled 53 eyes of 38 patients with naive DME indicated for anti-VEGF injection. All eyes received three monthly intravitreal injections of ranibizumab (0.5 mg/0.05 ml). Swept-source OCT/OCTA imaging was performed at baseline and 1 month after the third injection. The primary outcome was the change in best-corrected visual acuity (BCVA, logMAR). Secondary outcomes included changes in central foveal thickness, foveal avascular zone (FAZ) area, and vascular density (VD) in the superficial, deep capillary plexuses, and radial peripapillary capillaries. There was a noticeable improvement in mean BCVA ( P =0.003), reduction in mean central foveal thickness ( P <0.001) and in FAZ area ( P <0.001). No significant changes were observed in other metrics as VD (all P >0.05). In univariate analysis, visual improvement was associated with lower HbA1c ( P <0.001), shorter diabetes duration ( P <0.001) and nonproliferative diabetic retinopathy ( P <0.03). In multivariate analysis, lower HbA1c was the sole independent predictor of visual improvement. Intravitreal ranibizumab effectively improves vision and treats DME. OCTA reveals a concurrent reduction in FAZ area, suggesting microvascular remodeling. HbA1c control is the most important modifiable factor determining visual outcome, making integrated systemic and ophthalmic management a necessity.