Inherited retinal diseases are the most common cause of blindness in the working-age population in Australia

Background: This study examined the frequency of inherited retinal diseases (IRDs) as the reason for blindness registrations over the last two decades and the demographic and clinical phenotypes of inherited retinal disease (IRD)-related registrations. Materials and methods: Retrospective, observational study of individuals registered with a state-wide blind and vision-impaired registry. Low-vision or blindness-only (<= 20/200 or <= 20 degrees) certificates issued to children (0-15 years), working-age (16-64 years) and older-age (65 and older) adults were assessed. Sex and age distributions were examined for the top 20 reasons for certification. Demographic and clinical features of specific phenotypes of IRDs listed in the registry were examined. Results: Amongst 11824 low-vision certificates issued between July 1995 and January 2017, 679 (5.7%) listed an IRD as the reason for registration. In individuals with blindness-only certification (N=4919), IRDs was the second most common diagnosis (8.3%), overtaking glaucoma (8.1%) and diabetic retinopathy (5.4%). IRD was the second most common reason for low-vision certification amongst children (11.6%) and the most common reason amongst working-age population (23.3%). The mean +/- SD age for IRD-related blindness-only certification was 46 +/- 20 years. The top three phenotypes of IRD-related low-vision certification were non-syndromic retinitis pigmentosa (54%), Stargardt disease (12%) and macular dystrophy (8%). Conclusion: Our findings of IRDs as a common cause of blindness in all ages justify continued funding for providing low-vision services and developing treatments for these conditions.