Outer retinal corrugations in age-related macular degeneration

Optical coherence tomography (OCT) abnormalities of age-related macular degeneration (AMD) have not been fully characterized because of the complex morphology and a lack of correlative histologic studies. Expansion of our ability to interpret increasing attributes brings us closer to the goal of in vivo histologic analysis of the eye by OCT.

To describe a new outer retinal finding of AMD using spectral-domain (SD) OCT and suggest histopathologic correlates.

Twenty-five eyes of 16 patients with AMD with severe atrophy due to either choroidal neovascularization (CNV) or geographic atrophy (GA) and 53 donor eyes of 53 patients with late AMD were included. Imaging studies were conducted at a referral retinal practice and histopathology was done at a university research laboratory.

Findings in the outer retina were evaluated in SD-OCT images in eyes with atrophy of the retinal pigment epithelium (RPE) and compared with histopathologic findings in eyes with GA or CNV that also showed loss of the RPE.

Spectral-domain OCT and histologic characteristics of the outer retina.

The mean (SD) age of the 16 patients was 82.7 (7.9) years. Twenty eyes had CNV and 5 eyes had GA. The mean best-corrected visual acuity was 0.800 logMAR (interquartile range, 0.350-1.000 logMAR), a Snellen equivalent of 20/126. A curvilinear hyperreflective density was identified above the Bruch membrane line within the atrophic area in the SD-OCT images. At the internal border, the material was contiguous with the outer portion of the RPE band. Below the material was a relatively hyporeflective space. The material was thrown into folds in cases with atrophy following CNV or was seen as a sheet with numerous bumps in eyes with GA. Review of histopathologic findings of eyes with advanced GA and CNV revealed a rippled layer of basal laminar deposits in an area of RPE atrophy that was located in the same level as the curvilinear line seen in the OCT images.

We have described a new entity, termed outer retinal corrugations, which may correspond to histological findings of basal laminar deposits, extracellular deposits that persist in eyes with late AMD. Observation of this undulating band does not necessarily mean there is exudation or leakage; as a consequence, these patients do not need treatment based on this solitary finding.