Population-based study of presbyopia in rural Tanzania

Abstract

Objective: To determine the prevalence of presbyopia in a rural African population.

Design: Cross-sectional prevalence study.

Participants: One thousand seven hundred nine persons age 40 years and older who resided in 3 villages and randomly selected neighborhoods of Kongwa town, Tanzania.

Methods: Eligible persons were refracted and given best distance correction. Near vision was tested and corrected to the nearest 0.5 diopter. Presbyopia was defined as at least 1 line of improvement on a near visual acuity chart with an addition of a plus lens.

Results: A total of 61.7% of eligible participants were presbyopic. A higher prevalence of presbyopia was associated with increased age, female gender, higher educational level, and residence in town (odds ratio = 3.09; 95% confidence interval: 2.46-3.90). The odds of developing presbyopia increased 16% per year of age from age 40 to 50, but the increase was nonsignificant at 1% per year after age 50. More severe presbyopia was associated with female gender and less with education.

Conclusions: This study provides the first population-based data on prevalence of presbyopia in a large, random sample of older Africans and suggests a high rate of presbyopia. Presbyopia plateaus after age 50, and it is more common in females. In addition, the 3-fold increased odds in town versus village dwellers was unexpected and suggests that research of other factors, including environmental factors, is warranted.