New epidemiologic approach to intraocular pressure in an Antananarivo population

Purpose: The Malagasy population is a mixture from many ethnic origins. The Merina population is generally of Asiatic origin. The purpose of this stud y was to report the main characteristics of Merina intraocular pressure and their risk factors. Methods: Screening was conducted in 1507 apparently healthy subjects with n o known ocular disease (such as glaucoma) living in Antananarivo. Intraocul ar pressure was measured with a Goldmann tonometer. Results: Males predominated (54.81%). The distribution of aplanation pressu re followed an asymmetrical Gaussian pattern. In the Merina population, mea n intraocular pressure was low (13.50+/-3.5mmHg, m+/-SD) and increased with age. There was no difference by gender. The prevalence of ocular hypertens ion was 1.43%. It was slightly higher in females and increased to the age o f 50 years, then decreased. Among possible risk factors, only familial glau coma was significantly frequent. Conclusion: The mean intraocular pressure in the Merina population is lower than the accepted statistical mean and is similar in both sexes. The preva lence of intraocular hypertension is also low but glaucoma develops early. Some of our data are similar to those observed in western populations (mean intraocular pressure increases with age). Other points are similar to the Asian population (low mean intraocular pressure and low frequency of intrao cular hypertension and its progression after 50 years).