The Epidemiology of Stargardt Disease in the United Kingdom.

PURPOSE: To establish the incidence of Stargardt disease (STGD) in the United Kingdom and define baseline characteristics of newly diagnosed patients. DESIGN: Prospective epidemiologic study undertaken under the auspices of the British Ophthalmological Surveillance Unit (BOSU). PARTICIPANTS: New incident cases of STGD in the United Kingdom reported by ophthalmologists to BOSU during a 12-month period, from June 1, 2012, to June 1, 2013. METHODS: Once a new case of STGD was reported, an incident questionnaire was sent to the reporting ophthalmologist, followed by a follow-up questionnaire (when required) 6 months later. MAIN OUTCOME MEASURES: Patient demographics, baseline characteristics including visual acuity, and findings on slit-lamp biomicroscopy, as well as diagnostic technologies undertaken at baseline and their findings, including electrophysiology, fundus autofluorescence, fluorescein angiography, and genetic testing. RESULTS: A total of 81 new cases of STGD were reported during the 12-month period of the study; baseline data were obtained on 70 (86%) of these. These results suggest an annual incidence in the United Kingdom of between 0.110 and 0.128 per 100 000 individuals. The median age of patients at presentation was 27 years, the majority were British (77%), and most (90%) were symptomatic, with a median visual acuity of 0.52 logMAR (Snellen equivalent 20/66). CONCLUSIONS: Even considering possible limitations related to incomplete ascertainment, this is the first prospective epidemiology study that provides indication of the incidence of STGD in the United Kingdom. The incidence of STGD estimated herein appears to be lower than that repeatedly quoted in the literature. Fundus autofluoresence and electrophysiology testing are most commonly used for the evaluation of patients with STGD.