Abstract
Purpose :
To explore the frequency, extent, and anatomical features of collateral retinal vasculature in eyes with BRVO undergoing long term treatment with anti-vascular endothelial growth factor (VEGF) therapy.
Methods :
In this retrospective study, a consecutive group of patients with diagnosis of BRVO were studied after Institutional Review Board approval. Inclusion criteria included BRVO diagnosis, availability of good quality ultra-widefield fluorescein angiography at baseline and during chronic phase of disease (>6months), and a minimum of one year follow up. Eyes with retinal problems such as diabetic retinopathy, trauma, prior retinal surgery, or macular degeneration were excluded. A subgroup of patients underwent OCTA imaging during study period.
Results :
A total of 39 eyes from 38 patients met inclusion criteria and were enrolled in the study. LogMAR visual acuity at presentation was 0.371. Average follow up duration was 75.2 months. Ultra-widefield fluorescein angiography was performed 1-4 times during follow up period. BRVO was located in superior hemispheres in 27 eyes and in inferior hemispheres in 12 eyes. Collateral vessels were visible on UWFA in 35/39 eyes. Collaterals located within perifoveal area were associated with late leakage on UWFA. In 32/39 eyes collaterals were visible outside perifoveal capillary network on UWFA. In 26/39 eyes vascular changes including BRVO, silver wiring, copper wiring, arteriolar narrowing, vascular tortuosity, peripheral non-perfusion, and microaneurysms were detected in the opposite eye using Nidek OCTA.
In 18/39 eyes macular OCTA was performed. Variable degrees of disruption in superficial (SCP) and deep capillary plexus (DCP) were present in 16/18 eyes. Prominent finding in macular OCTA was sectoral disorganization, tortuosity associated with increased or decreased vascular density, constriction or enlargement of foveal avascular zone . All OCTAs with these findings had noticeable shunt vessels on FA, however OCTA often had greater extent and sectoral variation on mostly DCP segmentation than noted on FA.
Conclusions :
In eyes with BRVO undergoing long term anti-VEGF therapy, collateral vessels develop in the macular and extramacular vasculature. OCTA can demonstrate extensive vascular remodeling, including anastomosis and other patterns, in the superficial and deep perifoveal capillary circulations.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.