Primary open angle glaucoma as seen at the University Teaching Hospital, Lusaka, Zambia

Abstract

Objective: To determine the prevalence of Primary Open-Angle Glaucoma (POAG) among patients attending
eye clinic at University Teaching Hospital (UTH).

Design: A cross sectional survey.

Methods: The POAG survey was carried out at the eye clinic of the University Teaching Hospital (UTH), Lusaka
from January to December 2013. The clients (n = 1,625) had a full ocular examination and their demographic
information (specifically age, sex, residence and ethnicity) was captured. The ocular examination included
visual acuity and intraocular pressure (IOP) among others. Multivariate logistic regression, stratified by age
group and gender, was used to determine the association between demographic factors and POAG.

Results: Of the 1,714 patients randomly sampled for the study, 89 (5.2%) declined to participate in the study;
hence the response rate of 94.8%. The ages ranged from 20 to 98 years, with a median age of 51 years (IQR
45, 59). The prevalence of POAG was 19.0% (95% CI, 14.6%, 23.8%), distributed as 5.7% (95% CI 3.2, 9.1) in
males and 13.3% (95% CI 11.7, 21.3) for females. Females were more likely to have POAG than males (72.9%
vs. 27.1%; OR 2.78, 95% CI 2.1, 5.8). Surprisingly, age groups younger than 40 years had higher proportion of
POAG compared to the older population (61.6% vs. 38.4%, P<0.001). The main determinants of POAG were
age, sex and Diabetic Retinopathy (DR). There was a significant negative correlation between POAG and HIV
infection (r2 = 0.0269; p<0.001).

Conclusion: The prevalence of POAG in this population of 19.0% was higher and certainly not comparable
to those in black populations in Barbados, St. Lucia, Nigeria, Ghana and South Africa. The striking finding
of this study was that 40.7% of all the identified POAG cases were below the age of 40 years. There was no
association between POAG and HIV infection