Abstract
Purpose:
To investigate the mechanism of choroidal neovascularization (CNV) recurrence followed by intravitreal ranibizumab injections based on vascular structural changes of choroidal neovascularization (CNV) using indocyanine green angiography (ICGA)
Methods:
A total of 31 patients with exudative age-related macular degeneration and CNV whose structures were identifiable in ICGA. Patients with either polypoidal choroidal vasculopathy or retinal angiomatous proliferation were excluded. Ranibizumab was injected into the vitreous cavity once a month for 3 months, and then as needed for the following 3 months. Fluorescein angiography (FA) and ICGA were performed at baseline, 3 and 6 months. Vascular structures of CNV were described as arterio-venular (A-Vular) and capillary components, and structural changes were assessed in ICGA.
Results:
Arteriolar components were observed in 29 eyes (94%). Regression of the capillary components was observed in most cases. Two eyes, having purely capillary, components showed complete regression of CNV leaving non-fibrotic scar at 3 months. Although regression of A-Vular component was noted in 14 eyes (48%), complete resolution was not observed. The eyes were categorized into 3 groups according to CNV structural changes- the regressed (group R, 10 eyes, 31%), the matured (group M, 7 eyes, 23%) and the growing (group G, 14 eyes, 45%). In group R, there was no regrowth of CNV found at 6 months. In group M, distinct vascular structures were observed at 3 months and persisted without apparent changes at 6 months. In group G, growth or reperfusion of capillary components from the persisting A-Vular components was noted at 6 months. The BCVA of group G was significantly worse at baseline, 3 and 6 months.
Conclusions:
Capillary components were regressed as well as matured during anti-VEGF treatment. Loading monthly ranibizumab injections for 3 months showed limited efficacy in regressing A-Vular components entirely, which was the underlying reason in CNV recurrence
Keywords: 412 age-related macular degeneration •
748 vascular endothelial growth factor