Some epidemiological aspects of drug-treated intraocular hypertension in Belgium were established in 1992 from questionnaires filled in by 1513 patients who attended a sample of 209 pharmacies open to the public.

The mean age of the patients was 67 years (range : 3-95).

After standardization for age, the prevalence of diabetes mellitus among patients was found to be 1.7 times higher than in the general population.

Family history of glaucoma and/or blindness was reported by 28% of the patients.

Beta-blocker eye drops were used by 96% of the sample.

An ophthalmologist was consulted more than four times a year by 24% of the patients who had been drug-treated for less than one year ; the proportion, however, decreases to 11% for those treated for at least five years.

The annual consumed dose of eye drops containing parasympathomimetics, beta-blockers, and epinephrine or dipivefrine was 12.4,13.6, and 12.3 bottles, respectively, and that of ointments containing parasympathomimetics was 9.9 tubes.

From these results and using sales figures, the prevalence of drug-treated intraocular hypertension was found to be 77 per 10,000 inhabitants (95% CI : 31-123).