Abstract
Purpose:
Stargardt disease (SD), the most common hereditary macular dystrophy, is a rare disease caused by mutations in the ABCA4 gene. In the literature, only scarce epidemiologic data are available to document on the natural course of SD. The objective of this study was to measure the progression of the disease using a variety of clinical parameters and to better understand the disease burden as derived from quality of life (QoL) scales.
Methods:
Single center retrospective observational clinical study on an existing cohort of 148 French patients with SD followed in the Centre Hospitalier National d’Ophtalmologie (CHNO) des Quinze-Vingts. 26 patients genotyped with at least one pathogenic mutant ABCA4 allele on each chromosome and followed with at least two recorded visits were included. Clinical data including best corrected visual acuity changes (BCVA), fundus examination, visual field (Goldmann kinetic perimetry and Static periletry [Octopus]), optical coherence tomography (OCT), fundus autofluorescence (FAF), and electroretinography (Full-field ERG and Multifocal-ERG) were collected during an initial visit and follow-up visit(s) (FUV1 / FUV2). Quality of life (QoL) was evaluated using 2 questionnaires: Hospital Anxiety and Depression scale (HADS) and Visual Function Questionnaire 25 (NEI-VFQ-25).<br /> <br />
Results:
Preliminary descriptive data (57% Male) showed that the mean age of the cohort was 34.2 years (median 32.5) at baseline visit. The mean age at symptoms onset was 17.2 (10 to 29 years, median 17.5). At inclusion, 54% patients were categorized as SD type 1, 31% as type 2 and 15% as type 3, according to the classification based on the ERG phenotype (Lois et al, Arch Ophthalmol., 2001. At FU V1, (average of 2.7 years after the initial visit), 42% patients were type 1, 33% type 2 and 25% type 3.<br /> Absolute mean change in BCVA from inclusion to first visit of follow-up was 1.9 ± 4.2 ETDRS letters. No significant changes were noted on the QoL scales and on the other clinical parameters studied during the follow-up period.
Conclusions:
On review of these preliminary data no evidence of significant clinical disease progression or QoL change was observed in our cohort during the follow-up interval. This may be due to the advanced stage of the disease at the time of initial visit. It is expected that more evidence of progression may have been seen if the cohort had been observed from earlier stage of the disease.