Purpose
Stargardt Disease (SD), caused ABCA4 gene mutations, is the most prevalent juvenile-onset inherited retinal disease. As SD is rare (estimated prevalence 1/10,000) with no approved treatment, we sought to better understand the SD patient journey from disease onset to clinical diagnosis and management across the world.
Methods
28 in-depth interviews (IDIs) were conducted among clinicians/researchers working on SD for at least 5 years and 18 representatives of patient associations focusing on SD in 21 countries. The moderation of the IDIs was based on a semi-directive guide including common questions. All IDIs were audio-recorded and the data collected was analyzed descriptively following a common analysis grid.
Results
Preliminary data analysis based on 22 clinicians/researchers and 10 representatives of patients association, IDIs conducted in France, Germany, Italy, Spain, China, Malaysia, South Korea, Argentina, Brazil, Mexico, Colombia, Chile, Venezuela, USA, and Canada showed variability in the delay between the time of symptoms onset and diagnosis. The average delay is 6-12 months in Europe, 1-2 years in North America and 5-6 years in Asia and Latin America. The differences are mainly due to low disease awareness, particularly among general practitioners/pediatricians, and delayed access to specialists often attributed to costs and geographical distance. No SD guidelines are currently available and few therapeutic strategies are in place. Clinical diagnosis is based on funduscopy, visual field, OCT, ERG and family history. Confirmatory genotyping is systematically proposed in France, Germany, Italy, and North America with about 85% of patients tested. The percentage of genotyped patients drops to 30% in China, Mexico and Spain and 10% in Brazil, Argentina and Malaysia. No genotyping is performed in the remaining countries, being considered neither a priority nor required for diagnosis. Additional barriers to genotyping include cost and lab access.
Conclusions
SD patients experience different patient journeys. The variable presentation of the disease, accessibility to specialists and costs also impact these differences. Genotyping for SD is not considered a priority in many countries. The availability of an effective therapy, consensus guidelines including recommendations for genotyping, and raising awareness would reduce delays to diagnosis and help to harmonize the management of SD patients across the globe.