Volumetric High-Resolution Optical Coherence Tomography Reveals Longitudinal Changes in Subretinal Drusenoid Deposits in Intermediate Dry Age-related Macular Degeneration

Abstract

Purpose : To demonstrate the utility of a high-resolution spectral domain optical coherence tomography (OCT) prototype device combined with 3D motion correction and volume fusion for assessing natural progression of subretinal drusenoid deposits (SDDs) in eyes with intermediate dry age-related macular degeneration (AMD).

Methods : A total of 5 participants (5 eyes) with intermediate dry AMD were analyzed for qualitative changes in SDD presentation. Subjects were between 62 and 87 years old, with a mean age of 75 years; 4 females and 1 male. Subjects were imaged using a high-resolution OCT prototype device developed at MIT (2.7 µm axial resolution) on at least 2 visits with an average interval of 6.2 months (range 2.5-19 months). Raster scans over a 6mm x 6mm field-of-view (500 x 500 A-scans) combined with 3D motion correction and volume fusion were used to generate en-face projections (average of 50 µm thick slab from 27 µm above Bruch’s membrane). En-face projections were reviewed for longitudinal changes in the presence, characteristics, and localization of SDDs using ImageJ.

Results : OCT images showed all eyes had multiple SDDs of varying types at all time points. SDDs were identified on en-face projections as a hyporeflective ring surrounding a hyperreflective conical center (dot SDDs) or ribbon-like shapes (ribbon SDDs) and confirmed on B-scans. The en-face projections also include visualization of soft drusen, exhibited as hyperreflective regions with inhomogeneous shapes. The en-face projection enabled visualization of the individual progression of SDDs, including growth, shrinkage, fusion, and alterations in shape across timepoints (Fig. 1). The most common trend was SDD growth over imaging sessions.

Conclusions : High-resolution OCT imaging combined with dense, isotropic volume scan protocol and advanced image processing allows for en-face visualization and monitoring of individual SDDs in patients with dry AMD; further studies are needed to demonstrate the clinical applications of this utility.

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

 

Enlarged SDDs visible on en-face projections of high-resolution OCT images acquired over a 12-month interval in a 62-year-old female patient with intermediate dry AMD. Arrows denote SDD shrinkage (magenta), SDD appearance (cyan), SDD fusion (yellow), and SDD growth (green) between Visits 1 and 2.