Abstract
Purpose :
To study longitudinal changes in outer retinal structure in patients with early and intermediate age-related macular degeneration (AMD).
Methods :
Ten eyes of 10 patients with soft drusen, with or without pigmentary changes were studied for 6 to 24 months. At each visit registered SD-OCT volume and averaged line scans (Heidelberg Spectralis HRA+OCT), and short-wavelength fundus autofluorescent (SW-AF) images were obtained. Changes in the outer retinal layers were evaluated in the central macular area by measuring the thicknesses of the outer segment (OS) and retinal pigment epithelium (RPE) layers with a computer-aided, semi-automated segmentation technique.[1] Retinal layer thicknesses were compared to results from 35 age-similar control subjects. The number, height and width of drusen (>30µm) were also measured.
Results :
At the initial visit, 4 eyes were classified as intermediate AMD (AREDS risk factor: 50%), 3 as early AMD (AREDS risk factor: 25%), and 3 as exhibiting age-related changes (AREDS risk factor: 12%). Median follow-up intervals for these 3 groups were 10, 14 and 13 months respectively. Average logMAR visual acuities were 0.08 (range 0.0-0.3) and all eyes had foveal fixation. Follow-up evaluations on funduscopy and SW-AF imaging were unchanged as were severity classifications and AREDS risk factors. Visual acuities were stable. At the initial visit, OCT line scans showed significant thinning of the OS layer and thickening of the RPE in regions with drusen in all 4 eyes with intermediate AMD and all 3 eyes with early AMD compared to healthy subjects. Disruptions of the inner segment/outer segment band were seen in 8 of the 10 eyes. At follow-up the thickness of the RPE layer for 2 eyes with intermediate and 2 eyes with early AMD increased; this was accompanied by increased thinning of the OS layer in 1 eye with intermediate AMD and 1 with early AMD. In addition the number, height and width of drusen increased for 3 eyes with intermediate AMD, and one eye with early AMD.
Conclusions :
Disease-related changes of the outer retina in early and intermediate AMD patients, not demonstrable on funduscopy or by clinical classification, were found at follow up using quantitative analysis of SD-OCT scans. 1. Yang et al. Biomed Opt Express 2011.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.