Dark Atrophy: An Optical Coherence Tomography Angiography Study

Abstract

Purpose: To assess the status of choriocapillaris in eyes with macular atrophy secondary to age-related macular degeneration (AMD) (geographic atrophy [GA]) and Stargardt disease (STGD) using optical coherence tomography angiography (OCTA).

Design: Prospective, observational case series.

Participants: A total of 14 patients (20 eyes) affected by GA and 10 patients (20 eyes) affected by STGD.

Methods: Each patient underwent a complete ophthalmological examination including fundus autofluorescence (FAF), dynamic simultaneous fluorescein angiography (FA) and indocyanine green angiography (ICGA), enhanced-depth imaging optical coherence tomography (EDI-OCT) (HRA+OCT Spectralis, Heidelberg Engineering, Heidelberg, Germany), and OCTA using AngioVue technologies (Optovue Inc, Freemont, CA).

Main outcome measures: An evaluation of the status of choriocapillaris in the 2 groups was performed.

Results: Patients' mean age was 75 years for subjects with GA (median, 76 years; range, 63-88 years) and 61 years for STGD (median, 62 years; range, 40-74 years). Atrophy was bilateral in 42% (n = 6) of subjects with GA and 100% (n = 10) of subjects with STGD. In the early frames, FA displayed hyperfluorescence in the atrophic area in 100% (n = 20) of eyes affected by GA and 20% (n = 4) of eyes affected by STGD; dark choroid was present in 0% of GA eyes and 65% of STGD eyes (n = 13). Atrophy in ICGA late frames was hypofluorescent in 20% (n = 4) of GA eyes and 100% (n = 20) of STGD eyes. A ring at atrophy margins was detected in both FA (90%, n = 18) and ICGA (100%, n = 20) in STGD eyes. Mean subfoveal choroidal thickness was 156 μm (147, 42-362 μm) for GA eyes and 168 μm (167, 55-320 μm) for STGD eyes (P = 0.59). At OCTA evaluation, GA eyes showed persisting, rarefied choriocapillaris in correspondence of retinal pigment epithelium (RPE) atrophy in 80% (n = 16) of cases, whereas eyes affected by STGD had disappearance of this tissue in 100% (n = 20; P < 0.0001).

Conclusions: Analysis of macular atrophy by OCTA in patients with STGD revealed an extensive loss of choriocapillaris in the central area with persisting tissue at its margins, whereas in those with GA the area of RPE loss showed persistent but rarefied choriocapillaris.