The prevalence of open-angle glaucoma in Iceland.

A compilation of all prescriptions issued for glaucoma medication in Iceland for a 6 months period, together with hospital records of all patients operated on for primary open-angle glaucoma but not on glaucoma medication, were analysed for the prevalence and distribution of glaucoma in Iceland. The glaucoma population consisted of 1916 individuals (991 males and 925 females), amounting to an overall prevalence of 8.3 per thousand population. About 80% of the patients were on glaucoma medication and the remaining had been operated on but had not used drugs. Only 2.6% of the glaucoma population was under 50 years of age. The overall prevalence among those aged 50 and older was 35.3 per 1000, all having primary open angle glaucoma (subsuming glaucoma with pseudoexfoliation of the lens capsule). The prevalence increased with age from 5.7 per 1000 at age 50-59, to 107.5 at age 80 and older. Rates for males were significantly higher than rates for females in all age groups. The rates were highest in regions where ophthalmologists visit health centers regularly. Assuming that the open-angle glaucoma patients in Iceland as a whole have a similar eye status to the patients attending the University Outpatient Glaucoma Clinic, the overall prevalence of GVFD (glaucoma visual field defects) in the population aged 50 and older is 19.1 per thousand. The age specific prevalence of GVFD in Iceland is therefore consistent with results of prevalence studies in neighbouring countries.