Distribution of Intraocular Pressure in Indigenous Black Africans and Related Risk Factors: A Population-Based Study in Southwest Nigeria

Abstract

Background: Elevated intraocular pressure (IOP) is a major risk factor for glaucoma and is presently the only modifiable risk factor. Even in a healthy population, IOP distribution varies among different racial groups. Objective: To determine the distribution of IOP and factors affecting it, among an indigenous African population in Southwest Nigeria. Methods: A population-based descriptive cross-sectional survey with an analytical component was performed. The study was conducted among participants 16 years and older who were residents of Akinyele Local Government Area of Oyo State and were all black Africans. A multi-stage sampling with probability proportional to size was used to identify the study population. All participants were examined at the local health center in their community, assessing the visual acuity, Goldmann applanation tonometry, central corneal thickness, anterior segment, fundoscopy, weight, height, and blood pressure. Results: A total of 1810 respondents completed the study; male patients accounted for 41.55%. Mean age was 49.43 ± 15.57 years. The mean IOP was 15.91 ± 4.74 mmHg. There was a significant association between elevated IOP and the male gender. Intraocular pressure also had a significant positive correlation with increasing age, systolic blood pressure, and central cornea thickness. There was no significant relationship between IOP and self-reported diabetes mellitus. Conclusion: The mean IOP and distribution in this study were a bit different from that observed in studies in different geographical locations but similar to studies in West Africa. It may be advisable to employ a geographical approach to normal IOP interpretation.