The impact of visual impairment on health-related quality of life in rural Africa

Purpose: To assess the impact of visual impairment (VI) on utility values in Sub-Saharan Africa and compare findings with other studies from low- and high-income countries. Methods: Patients with normal vision and various levels of VI were recruited from a secondary eye clinic in rural Kenya and interviewed using time trade-off (TTO). VI was classified using the World Health Organization definition of (normal vision, visual acuity ≥20/60, VI 20/80-20/200, severe VI 20/240-20/400, and blindness <20/400). Results: Mean age of the total sample (N=303) was 50.3 years (standard deviation, SD, ±18.17 years), and 51.5% of patients were male. Most were small-scale farmers and illiteracy was high at 40%. Mean TTO scores per group were: normal vision 0.93 (SD±0.10), VI 0.88 (SD±0.14), severe VI 0.86 (SD±0.13), blindness 0.73 (SD±0.17; p≤0.001). Lower TTO scores were independently associated with worse visual acuity (p≤0.001), longer duration of disease (p≤0.001) and illiteracy (p=0.011), but not with cause of VI, age, sex, marital status, socioeconomic status, or systemic comorbidities in multivariate analyses. Overall, TTO scores were considerably higher than those reported from high-income countries at similar levels of VI. Conclusion: In this rural African population, duration and extent of vision loss, rather than cause, socioeconomic factors and comorbidities affected vision-related quality of life. Our findings underline the importance of providing sight-restoring treatment as timely as possible and the necessity of enhancing rehabilitation efforts for those with non-curable eye diseases.