Autofluorescence Imaging of RPE Tears

Abstract

Abstract: : Purpose: To use autofluorescence (AF) imaging of the human fundus to determine initial RPE damage and subsequent resurfacing of denuded inner Bruch’s membrane (BM) after RPE tears; and the presence or absence of fluorophores, including A2E, within deeper layers of human BM in situ. Methods: 16 eyes of 13 patients with RPE tears, confirmed on clinical exam and/or fluorescein angiography, underwent standard AF imaging of the fundus using a fundus camera based system with a low pass excitation filter (wavelength: 580 nm) and emission filter (wavelength: 695 nm). Optical coherence tomography (OCT) imaging was obtained in 15 of the 16 eyes. Results: The mean visual acuity post retinal pigment epithelial tear was 20/200 (range: 20/30 to 5/400). Final visual acuity has a bimodal distribution with a small peak at 20/50 and a larger peak at 20/200. Tears developed spontaneously in 6 eyes, after photodynamic therapy alone in 4 eyes, after combination photodynamic therapy and intravitreal triamcinolone acetonide in 5 eyes, and after thermal laser in 1 eye. A pigment epithelial detachment preceded the development of a tear in 9 of the 9 eyes with prior imaging. AF images reveal characteristic hypo AF within the bed of the RPE tear with hyper AF occasionally seen along the deeper major choroidal vessels. Hyper AF was present along the edge of the tear; OCT confirmed that this represented rolled RPE. Chronic tears exhibited a time–dependent increase in AF within the bed of the tear, at reduced levels compared to the surrounding tissue, consistent with partial RPE healing within the bed. Conclusions: AF imaging can confirm the diagnosis of suspected RPE tear noninvasively and can be used to demonstrate rolling of the RPE and partial resurfacing of the bed. VA can recover in select eyes with partial resurfacing. AF imaging suggests that fluorophore–laden RPE at the edge of the defect divide and migrate to partially resurface BM. AF signaling within the tear bed demonstrates that deeper layers of human BM do not contain significant levels of fluorophores such as A2E, although autofluorescent material may be present around the large choroidal vessels.

Keywords: age-related macular degeneration • retinal pigment epithelium • imaging/image analysis: clinical