Nationwide incidence and prevalence of inherited retinal disease in Sweden, 2006-2021: a population-based register study.

BACKGROUND

Inherited retinal diseases (IRDs) are a rare but severe cause of vision loss on a population level. This study provides a comprehensive assessment of IRD epidemiology, including incidence, prevalence and patient characteristics in Sweden over two decades.

METHODS

This population-based cohort study used data from the Swedish national administrative registers including the National Patient Register. Patients with a registered diagnosis of IRD between 2006 and 2021 were identified, and age-matched and sex-matched comparators were sampled from the total population. Incidence rates and annual average prevalence stratified by age, sex and diagnostic subgroups were calculated per 100 000 individuals, standardised to the 2021 Swedish population. The sociodemographic and comorbidity profile was compared between patients and comparators.

RESULTS

We identified 6544 IRD prevalent cases in Sweden from 2006 to 2021 and estimated a cumulative overall prevalence of 62.6/100 000 persons. Applying a 5-year washout period (2001-2005), we identified 5599 newly diagnosed IRD cases between 2006 and 2021, estimating an overall average incidence rate of 3.4/100 000 individuals/year. Unspecified IRD accounted for over half of all prevalent cases, followed by retinitis pigmentosa-like conditions (0.6/100 000 persons), pigment epithelial dystrophy (0.1/100 000 persons), unspecified hereditary retinal dystrophy (0.1/100 000 persons), other hereditary retinal dystrophy and vitreoretinal dystrophy.

CONCLUSION

This nationwide population-based study provides the first comprehensive estimates of IRD prevalence and incidence in Sweden. The findings indicate a stable incidence of IRD over the past two decades. These results underscore the need for ongoing surveillance and targeted healthcare planning to address the evolving burden of IRDs.