PURPOSE: To examine the frequency and causes of visual impairment (VI) in a select population of Danish adults.

METHODS: A total of 3843 adults aged 20-94 years from the Danish General Suburban Population Study (GESUS) were included in the population-based, cross-sectional ophthalmological study, Danish Rural Eye Study (DRES). All DRES participants received a comprehensive general health examination preceding their eye examination, including measurement of best-corrected visual acuity (BCVA) for each eye, bilateral 45° retinal fundus photographs and further ophthalmological examination where indicated.

RESULTS: Overall, 3826 of 3843 participants (99.6%) had bilateral visual acuity measurements. The overall frequency of VI (BCVA <20/40 in the better-seeing eye) was 0.4% (95% confidence interval, CI, 0.2-0.7%; n = 15) among all DRES participants, 0.6% (95% CI 0.3-1.0%; n = 15) among participants >50 years and 3.7% (95% CI 2.1-6.5%; n = 11) in participants >80 years. The primary causes of VI in the better-seeing eye were age-related macular degeneration (AMD) in 46.7% (7/15) and cataract in 26.7% (4/15). A total of 43.3% (n = 115) of participants >80 years were pseudophakic in one or both eyes. The frequency of diabetes (HbA1c ≥ 48 mmol/mol or self-reported diagnosis) was 5.9% (n = 227), including 1.3% (n = 51) newly diagnosed in the GESUS. Of participants determined to have VI due to exudative AMD, 50% had received anti-vascular endothelial growth factor (VEGF) treatment.

CONCLUSION: We report a relatively low frequency of VI among Danish adults over 59 years of age compared with that observed 10-15 years ago, which is both consistent with other recent Scandinavian studies and reflective of our relatively healthy and mobile population sample.