Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

Purpose: Identification of sensitive biomarkers is essential to determine potential effects of emerging therapeutic trials for Stargardt disease. This study aimed to describe the natural history of late-onset Stargardt, and demonstrates the accuracy of retinal pigment epithelium (RPE) atrophy progression as an outcome measure. Methods: We performed a retrospective cohort study collecting multicenter data from 47 patients (91 eyes) with late-onset Stargardt, defined by clinical phenotype, at least one ABCA4 mutation, and age at disease onset ≥ 45 years. We analyzed RPE atrophy progression on fundus autofluorescence and near-infrared reflectance imaging using semiautomated software and a linear mixed model. We performed sample size calculations to assess the power in a simulated 2-year interventional study and assessed visual endpoints using time-to-event analysis. Results: Over time, progression of RPE atrophy was observed (mean: 0.22 mm/year, 95% confidence interval [CI]: 0.19-0.27). By including only patients with bilateral RPE atrophy in a future trial, 32 patients are needed to reach a power of 83.9% (95% CI: 83.1-84.6), assuming a fixed therapeutic effect size of 30%. We found a median interval between disease onset and visual acuity decline to 20/32, 20/80, and 20/200 of 2.74 (95% CI: 0.54-4.41), 10.15 (95% CI: 6.13-11.38), and 11.38 (95% CI: 6.13-13.34) years, respectively. Conclusions: We show that RPE atrophy represents a robust biomarker to monitor disease progression in future therapeutic trials. In contrast, the variability in terms of the course of visual acuity was high.

Original publication

DOI

10.1167/iovs.16-19833

Type

Journal article

Journal

Invest Ophthalmol Vis Sci

Publication Date

01/10/2016

Volume

57

Pages

5186 - 5191

Keywords

ATP-Binding Cassette Transporters, Aged, Aged, 80 and over, DNA, DNA Mutational Analysis, Disease Progression, Electroretinography, Female, Fluorescein Angiography, Follow-Up Studies, Fundus Oculi, Humans, Macular Degeneration, Male, Middle Aged, Mutation, Phenotype, Retinal Pigment Epithelium, Retrospective Studies, Time Factors, Tomography, Optical Coherence, Visual Acuity