Abstract
Purpose :
In an eye with GA, we correlated histology with in vivo findings resulting from OCT, near-infrared reflectance (NIR), and autofluorescence (AF) imaging.
Methods :
In an 86-year-old white woman, NIR and eye-tracked OCT B-scans at each of 6 clinic visits and baseline AF were correlated with osmium tannic acid paraphenylenediamine-post-fixed, toluidine-blue-stained epoxy resin sections.
Results :
Clinical imaging showed a small parafoveal multilobular GA, sub-foveal soft drusen, refractile drusen, hyperreflective lines near Bruch membrane (BrM), subretinal drusenoid deposit (SDD), and absence of hyper-AF at the GA margin. Histology showed that soft drusen end-stages included avascular fibrosis containing highly reflective cholesterol crystals corresponding to hyperreflective lines near BrM in OCT and plaques in NIR imaging. SDD was thick, continuous, extracellular, extensive outside the fovea and associated with distinctive retinal pigment epithelium (RPE) dysmorphia and photoreceptor degeneration. A hyporeflective wedge corresponded to ordered Henle fibers without cellular infiltration. The descent of the external limiting membrane (ELM), which delimits GA, was best visualized in high quality OCT B-scans.
Conclusions :
This case informs on the extent, topography, and lifecycle of extracellular deposits. High quality OCT scans are required to reveal all tissue features relevant to AMD progression to GA, especially the ELM descent. Histologically validated signatures of structural OCT B-scans can serve as references for other imaging modalities.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.