Multimodal imaging features of retinal neovascularization in response to 3 anti-VEGF injections.

Abstract

Objective: To analyze longitudinal changes of retinal neovessels (NV) in eyes with proliferative diabetic retinopathy (PDR) after 3 monthly intravitreal injections (IVI) of ranibizumab by means of different imaging modalities, particularly focusing on optical coherence tomography (OCT) and OCT-angiography (OCT-A) features.

Methods: Prospective, monocentric study, Luigi Sacco Hospital, Milan. Consecutive patients with PDR were enrolled. All patients underwent color fundus photography (CFP), fluorescein angiography (FA), SD-OCT, and OCT-A at baseline (t0) and after 3 monthly IVI of ranibizumab (t1). Neovessels (NVs) were classified as flat, elevated, flat-elevated, or table-top using OCT scans and further analyzed on FIJI. Qualitative and quantitative NV characteristics were evaluated. Vessel density (VD) was calculated as the mean of all the white pixels of the NV and expressed as a percentage of the area of the NV (VD = NV area × 100).

Results: Thirty-six NVs in 10 patients were studied. The regression of NVs at t1 was partial in 66.7% of cases and complete in 33.3%. Table-top NV demonstrated more frequently a complete regression (P = .03). A significant reduction of the NV area, perimeter, and VD was observed at t1 (P < .001). NVs that showed a complete regression had higher mean VD values at t0 compared with NVs, which showed a partial regression (P = .02). Flat NVs had more frequently a complete vitreous attachment, while table-top showed more often a partial vitreous detachment with focal NV adhesion (P < .05). A complete regression was more often observed for NVs with a partial vitreous detachment and focal NV adhesion at t0 (10/12), while most of the NVs with a complete vitreous attachment showed a partial regression (18/24) (P < .001).

Conclusions: The table-top configuration of the neovessel, higher VD values at baseline, and the presence of a focal adhesion of the vitreous over the NV were factors associated with a higher risk of complete regression of the NV in response to 3 monthly IVI of ranibizumab.