Abstract
Purpose :
To assess changes in subretinal volume over time in age-related macular degeneration (AMD) using optical coherence tomography (OCT).
Methods :
105 eyes of 105 patients were imaged using Topcon (3D OCT-1000) over two years. These eyes were divided into 3 groups: group 1 were non-progressors (NP) who did not progress from early/intermediate to wet (neovascular) AMD (n = 40), group 2 were those who progressed (P) to wet AMD (n = 31), and group 3 were healthy control eyes (n = 34). The OCTs were reviewed around year 1 and year 2 timepoints before the development of CNV in group 2. OCT analysis was performed using the Orion software, which supports inner retinal layers and thicknesses as well as subretinal measures between the RPE and Bruch’s. Volumetric measurements were made over a 6mm diameter circle centered at the fovea, and all cases were reviewed for segmentation errors.
Results :
Across all timepoints, the subretinal volumes differed significantly between the AMD groups and the controls, but not within the AMD groups. No other volumetric measures showed any significant difference between diseased and control groups. Subretinal volume showed greater increases over time in the group that converted to wet AMD, althouth the increased rate of change was not significant. Total retinal volume (TRV - ILM to RPE) remained fairly constant over time.
Conclusions :
TRV as measured from the ILM to the RPE is not necessarily a useful parameter in diagnosing or following AMD. More important are measurements of the subretinal volume that increases in both dry and wet AMD. The rate of change of the increase appears relevant to conversion from dry to wet AMD, but further analysis and perhaps alternate measures will be needed to investigate predictive efficacy.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.