Purpose: The present study was performed as part of an epidemiological study, the Inter99 Eye Study. The aim of the study was to describe refractive errors and visual acuity (VA) in a suburban Danish population.
Methods: The Inter99 Eye Study comprised 970 subjects aged 30-60 years and included a random control group as well as groups at high risk for ischaemic heart disease and diabetes mellitus. The present study presents VAs and refractive data from the control group (n = 502). All subjects completed a detailed questionnaire and underwent a standardized general physical and ophthalmic examination including determination of best corrected VA and subjective refractioning.
Results: Visual acuity </= 0.05 was found in one eye of one subject and VA </= 0.3 in 11 eyes of 11 subjects. The main cause of reduced visual function was strabismic amblyopia. Myopia (</= - 0.5 D, spherical equivalent refraction) was present in 33.1% of right eyes of the total population but in 56.8% of subjects with a university degree.
Conclusions: Strabismic amblyopia was a significant cause of unilateral visual impairment. Myopia was approximately twice as frequent in subjects with a university degree as in the remaining study population.