Abstract
Purpose :
To compare longitudinal changes in en-face images derived from optical coherence tomography (OCT) to hypo- and hyper-autofluorescent (hypoAF, hyperAF) areas on short-wavelength autofluorescence (SW-AF) in recessive Stargardt disease (STGD1).
Methods :
At baseline, wide-field, swept source OCT cube scans (12x9 mm, 256 B-scans, 512 A-scans, DRI-OCT, Topcon, Inc) were obtained from 16 eyes (16 patients) aged 11 to 70 yrs with genetically confirmed STGD1.[1] OCT scans using a 20°x 20° protocol (6x6 mm), and SW-FAF images (30° and 55°), were also obtained using Spectralis HRA+OCT (Heidelberg Eng) .The automated segmentation of the inner/outer segment (IS/OS) junction, the OS/retinal pigment epithelium (OS/RPE), and RPE/BM boundaries were manually corrected and en-face images were generated with these boundaries as references using commercial and special purpose software (ATL 3D-Suite).[2] For each eye, the area of the central macular lesion/atrophy on a subRPE slab Fig. 1, left) positioned below the RPE, and on an IS/OS band slab (Fig. 1, right), were compared to the central hypo- and hyperAF areas on the SW-AF image (Fig. 2) using ImageJ. Baseline results were compared to repeat measurements obtained from 11 of the patients over a period ranging from 11-29 months (mdn: 24 mos).
Results :
RPE atrophy was visualized as a central hyper-reflective area on the subRPE slab, and IS/OS junction loss as an abnormal reflective area on the IS/OS slab. Compared to baseline, there was a significant increase in the central hyper-reflective area and in the area attributed to a loss of IS/OS junction in 9 of 11 eyes. The loss of IS/OS area was significantly larger (Fig. 1). For SW-AF, the central areas of hypo- and hyper-AF were increased in 10 of 11 eyes (Fig. 2). The area of abnormal AF was larger than the area of hypo-AF. Bland-Altman plots showed similarity between the en face subRPE and central hypo-AF measurements, and between the en-face IS/OS and abnormal AF measurements . In addition on SW-AF the number of retinal flecks were increased in 4 eyes.
Conclusions :
Evidence of disease progression in STGD1 at the level of the outer retina can be detected over a 2 year period using en-face images derived from OCT scans and fundus AF.1. Greenstein et al. IOVS 2017; 2.Fortune et al. IOVS 2014
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.