Visual acuity and causes of central visual loss in the adult Danish population 2020-2022. Results from the FORSYN study.

Abstract

Knowledge of visual health in the population is necessary for designing and implementing measures to handle visual handicap. The purpose of the FORSYN (Forekomst af synshandicap og synshjaelpemidler i Danmark) project was to study visual health in the Danish population 2020-2022 after implementation of the recent advances in the management of choroidal and retinal vascular disease. The present study reports visual acuity and causes of central visual loss from this study. A population-representative sample of 10 350 citizens living within 40 kilometres from Aarhus University Hospital were invited to answer a questionnaire about quality of life related to vision, measurement of visual acuity and a non-mydriatic examination of the eyes. The data were corrected for selection bias on the basis of demographic and socioeconomic factors so that the results could be projected to represent the adult Danish population. Population-adjusted visual acuity in ETDRS letters (mean ± SD) differed significantly (p < 0.0001) among the worse eye (84.1 ± 0.25), the better eye (88.4 ± 0.11) and binocularly (89.2 ± 0.15). Social blindness affected 0.22% (95% CI: 0.14%-0.33%) of the population and was in none of the studied persons due to exudative age-related macular degeneration (AMD) or diabetic retinopathy. The most frequent causes of visual loss were atrophic AMD, neuro-ophthalmic disorders and other chorioretinal diseases. Recent advances in the therapy of chorioretinal vascular diseases have been paralleled with a reduction in central vision loss secondary to exudative AMD and diabetic retinopathy in Denmark. The demographic development can be expected to increase the demand for treatments of vision-threatening diseases that mainly affect older persons.