Optical coherence tomography angiography visualizes morphological changes in choroidal neovascularization after anti-VEGF therapy: Monthly loading-phase versus Pro-Re-Nata regimen.

Abstract

Purpose : To compare the morphological neovascular network changes after anti-vascular endothelial growth factor (anti-VEGF) therapy in treatment-naive and previous treated patients with age-related macular degeneration (AMD), by means of optical coherence tomography angiography (OCTA).

Methods : Consecutive patients with neovascular AMD underwent multimodal imaging, including OCTA (AngioPlex, CIRRUS HD-OCT model 5000; Carl Zeiss Meditec, Inc, Dublin, OH) at baseline and in the three following months. Treatment naive AMD patients undergoing anti-VEGF loading phase by three monthly injections were included in Group A, while previously treated patients, followed monthly and treated according the PRN regimen were included in Group B. High flow networks in the choriocapillaris segmentation of OCTA were analyzed at baseline and at each follow up visit. OCTA changes were correlated with best-corrected visual acuity (BCVA) and exudation signs on structural spectral domain OCT (SD-OCT).

Results : Twenty-two eyes of twenty-one patients were enrolled: 9 eyes of AMD treatment-naive patients and 13 eyes of AMD patients treated by anti-VEGF therapy were included (mean age 78.91). Mean follow-up was of 3±1 months. Baseline overall BVCA was 62.66 letters (Snellen equivalent » 20/50). In all cases baseline OCTA images showed a high flow, ramified neovascular network. Follow up images demonstrated a statistically significant association between Group A (induction anti-VEGF period) and the persistence of tiny ramifications within the neovascular network on OCTA images (p=0.04). Previously treated patients (Group B) were more likely to present, on OCTA images, with large caliber vessels (p=0.05) and less likely to have tiny ramifications (p=0.035) during follow up. Moreover, eyes enrolled in Group A presented with a greater letter gain during follow up (p=0.05), compared with Group B.

Conclusions : Qualitative OCTA analysis of anti-VEGF treatment-response in patients in the induction period versus previously treated patients shows that morphological changes within the neovascular membrane are intrinsically correlated with BCVA. OCTA may help to accurately evaluate treatment response and to recognize morphological changes usually associated with CNV exudative activity.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.