The Progression of Stargardt Disease (ProgStar) as determined by spectral-domain optical coherence tomography over a 24-month period (ProgStar Report No. 19)

Introduction: To evaluate the progression of atrophy as determined by spectral-domain optical coherence tomography (SD-OCT) in patients with molecularly confirmed ABCA4-associated Stargardt disease type 1 (STGD1) over a 24-month period in a multicenter prospective cohort study. Methods: SD-OCT images from 428 eyes of 236 patients were analyzed. Change of mean thickness (MT) and intact area were estimated after semi-automated segmentation for the following individual layers in the central subfield (CS), inner ring (IR) and outer ring (OR) of the ETDRS grid: retinal pigment epithelium (RPE), outer segments (OS), inner segments (IS), outer nuclear layer (ONL) inner retina (IR) and total retina (TR). Results: Statistically significant decreases of all outer retinal layers (RPE, OS, IS, and ONL) could be observed over a 24-month period both in decline of mean retinal thickness and intact area (p.0001, respectively); whereas the inner retina showed an increase of retinal thickness in the central subfield and inner ring and remained unchanged in the outer ring. Conclusions: Significant loss could be detected in outer retinal layers by SD-OCT over a 24-month period in patients with STGD1. Loss of thickness and/or intact area of such layers may serve as potential endpoints for clinical trials that aim to slow down the disease progression of STGD1.