Abstract
Inherited retinal dystrophies/degenerations (IRDs) are the leading cause of visual impairment and incurable familial blindness in the Western world. Given the clinical and genetic heterogeneity, establishing a molecular diagnosis is especially relevant. The aim of this study was to perform the first nationwide survey to understand the prevalence and current management of IRDs in Portugal. A response was obtained from 26 healthcare providers (HCP) (76.5% response rate). Only 4 respondents reported not managing IRD patients. Most HCPs (68.1%) reported managing up to 100 patients, while three currently manage between 501 and 1000 patients. Based on the Portuguese population, an estimated IRD prevalence of 0.031%, i.e., about 1 in 3000 individuals, was calculated. In most HCPs (86.3%), most patients are adults, and non-syndromic retinitis pigmentosa is the most frequent diagnosis. Only 4 HCPs currently use the national, web-based IRD registry (IRD-PT). However, all but one respondent expressed interest in participating in such a registry. Genetic testing is available in 54.5%, with 58.3% HCPs reporting solved rates between 61-80%, but 4 to 9 months to get a genetic test result in 83.4% of cases. Based on this survey, the prevalence of biallelic RPE65-associated disease in Portugal is 0.00031%, i.e., approximately 1:300,000 individuals. Data from this study provide vital background information on national differences in the diagnosis and management of IRD patients. Nationwide implementation of the IRD-PT registry should be encouraged and supported to provide population-based reference data and to identify patients eligible for current and future therapies.