Steps towards a better understanding of the development of Fibrosis and Atrophy in Neovascular Age-Related Macular Degeneration

Abstract

Purpose : Fibrosis and macular atrophy remain important causes of progressive visual loss in anti-vascular endothelial growth factor (anti-VEGF) treated neovascular age-related macular degeneration (nAMD). Hyper-reflective material (RM) and hypertransmission of optical coherence tomography (OCT) signal into the choroid (HyperTC) based on spectral domain OCT (SD-OCT) are considered proxies for fibrosis and macular atrophy. Detailed characterisation of these features would contribute better understanding the natural progress to fibrotic shift and/or atrophy. Here we report the frequency and features of HRM and HyperTC at baseline (M0) and 18 months (M18) in a subset of data accrued from longitudinal studies and clinical trials in anti-VEGF treated eyes.

Methods : The most affected B-scan of SD-OCT volume scans of 381 eyes from the Early Detection of neovascular AMD study (EDNA) were selected. HRM was graded as undefined or defined and HyperTC as intermittent or continuous. The maximum length and height of HRM and the maximum length of HyperTC were measured at M0 and M18. Continuous data were summarized by medians and interquartile ranges, and categorical data were summarized by counts and percentages.

Results : Of the 381 eyes graded at M0, 362 (95.0%) had HRM of which 33.7% was classified as defined. The median length and height of HRM were 2277µm (1446-3204) and 186µm (123-273), respectively. By M18 the number of eyes with HRM reduced to 331 (86.9%) which of 40.5% was defined. The median length reduced to 1931µm (1126-2901) and the median height to 129µm (90-204.5) by M18. HyperTC was present in 112 (29.4%) at M0 and the median length was 1315µm (716-2246) of which 46.4% was classified as continuous. By M18 the frequency of HyperTC increased to 236 (61.9%) of which 54.2% was continuous. The median length of HyperTC increased to 1508µm (926-2416) by M18.

Conclusions : Persistence of HRM is common in treated nAMD and new onset HyperTC occurs in around half by M18. Characterization of time to development of HRM and HyperTC and better classification of the textural characteristics of HRM can help with defining new clinical trial endpoints for therapies aimed at preventing fibrosis and macular atrophy.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.