Abstract
Purpose :
To compare rod and cone sensitivity loss to structural changes on en-face optical coherence tomography (OCT) and fundus autofluorescence (AF) in patients with Stargardt disease (STGD1).
Methods :
Eight patients aged 16-70 yrs. with genetically confirmed STGD1 were enrolled. Spectral domain (SD)-OCT cube scans (9x6mm, 97 B-scans), short-wavelength (SW)-AF, and near-infrared (NIR)-AF images (30 and 55°) were obtained from the better eye. For the OCT, the automated segmentation of the inner/outer segment (IS/OS) junction and RPE/BM boundaries were manually corrected, and en-face images were generated with these boundaries as references using commercial software. RPE atrophy (a central hyper-reflective area on the subRPE slab) and IS/OS junction loss (an abnormal reflective area on the IS/OS slab) were measured using ImageJ. The areas of hypoSW-AF, hyper+hypoSW-AF, and hypoNIR-AF were also measured. Rod and cone system sensitivities were assessed with two-color dark-adapted fundus perimetry (Nidek MP-1S) using a 10-2 grid centered on the fovea (size 3 stimulus, 200-ms duration, 68 points). The rod and cone sensitivity maps were superimposed on SW-AF (Fig.), NIR-AF, and en-face images. Scotopic visual fields were measured in 5 eyes using a Medmont dark-adapted chromatic perimeter (size 5 stimulus, 200-ms duration, 505 nm, 103 points, 144°x72°).
Results :
Five eyes had foveal sparing. For 7 eyes, the area of IS/OS junction loss was larger than that of RPE atrophy (p=0.03), and the hyper+hypoSW-AF area was larger than the hyperreflective area on the subRPE slab (p=0.003). Agreement between the area of IS/OS junction loss and the hyper+hypoSW-AF area was good. For 5 eyes, the hypoNIR area was larger than the hypoSW-AF, but the hyper+hypoSW-AF area was larger than the hypoNIR-AF area (p=0.01). Rod sensitivity was more affected than cone sensitivity (p<0.001) adjacent to areas of RPE atrophy, IS/OS junction loss, and surrounding the hypo-AF areas (Fig.) Rod visual fields for 5 eyes showed rod sensitivity was markedly decreased within the central 20°, but comparable to normal in the periphery.
Conclusions :
Decreased rod and cone sensitivities are associated with photoreceptor and RPE structural changes that extend beyond atrophy in STGD1.
This is a 2020 ARVO Annual Meeting abstract.