Biomarkers of macular neovascularisation activity using optical coherence tomography angiography in treated stable neovascular age related macular degeneration

Abstract

Purpose : Biomarkers of activity of macula neovascularisation (MNV) in those deemed stable with conventional structural optical coherence tomography (OCT) could help to determine the requirement for further treatment and their associated monitoring interval for further visits. The aim of this study was to describe features of disease activity of treated stable MNV due to neovascular age related macular degeneration (nAMD) using optical coherence tomography angiography (OCTA).

Methods : 32 eyes of 32 patients with nAMD were included in this prospective, observational study. These patients were undergoing treatment with aflibercept on a treat-and-extend regimen. They were identified as attending a 16-week interval treatment visit and had been assessed as clinically stable based on clinical evaluation (visual acuity assessment, clinical examination and structural OCT assessment). All patients then underwent macular OCT imaging and OCT angiography on the same day (Spectralis, Heidelberg Engineering, Heidelberg, Germany). These images were analysed by the Moorfields Eye Hospital Reading Centre, London, United Kingdom.

Results : Evaluation of structural OCT confirmed no evidence of subretinal or intraretinal edema, but presence of subretinal hyperreflective material (13, 40.6%), pigment epithelial detachment (31, 96.9%), outer retinal tubulation (10, 31.3%) and macula atrophy (19, 59.4%). 31/32 OCTA images were gradeable (1 had significant signal attenuation); 28/32 (87.5%) OCTA images were noted to have signal artefacts. The mean MNV size was 3.6 ± 4.6mm and 29 (93.5%) and 27 (87.1%) had detectable MNV blood flow. 29 (93.5.%) subjects had MNV maturity including 10 non-specific, 10 tangle, 3 deadtree and no medusa or seafan phenotypes. MNV halo and MNV central feeder vessel were noted in 18 (58.1%) and 19 (61.3%) of subjects respectively; only 1 (3.2%) subject was noted to have a MNV capillary fringe.

Conclusions : CNV blood flow is still detectable using OCTA in the majority of subjects in this study. The majority of MNV were of mature phenotype. OCTA features associated with this clinically stable MNV activity included MNV maturity, feeder vessel, halo and absence of capillary fringe. These features could be helpful as possible OCTA biomarkers of disease activity and help inform treatment decisions with anti-vascular endothelial growth factor agents.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.