Reduced Size of Telangiectatic Capillaries After Intravitreal Injection of Anti-Vascular Endothelial Growth Factor Agents in Diabetic Macular Edema

Abstract

Intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) agents reduces microaneurysms in patients with diabetic macular edema (DME). However, residual anti-VEGF-resistant telangiectatic capillaries (TelCaps) have been reported. In this study, we investigated changes in the size of TelCaps after intravitreal injection of anti-VEGF agents in DME. Indocyanine green angiography (IA) and optical coherence tomography were performed before and 3 months after the intravitreal injection of anti-VEGF agents (pro re nata regimen after three monthly loading doses) in 12 eyes of 12 patients (7 males and 5 females, mean age 65.2 ± 8.8 years) with DME. The number and size of TelCaps within a 6-mm diameter macular region of the edema were measured using optical coherence tomography B-scan images overlaid on IA images. There were significant reductions in the number and size of TelCaps between the baseline and 3 months after anti-VEGF agent administration (P < 0.05 and P < 0.0001, respectively). The maximum corrected visual acuity (logMAR visual acuity) and the central macular thickness after anti-VEGF therapy were significantly improved (P < 0.01 and P < 0.02, respectively). The TelCaps remaining after loading three consecutive anti-VEGF agents had a significantly larger mean size at baseline than the TelCaps that resolved after the treatment (P < 0.03). Our study demonstrated that intravitreal injection of anti-VEGF agents could reduce TelCap size in patients with DME. We propose that larger-sized TelCaps detected by IA might be useful predictors of refractory DME, which could thus be principal targets of laser photocoagulation.