Results of an epidemiological study on drug-treated intraocular hypertension in Belgium

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).