Prevalence and causes of visual impairment and blindness among adults with diabetes mellitus aged 40 years and older receiving treatment at government health facilities in the Mopani District, South Africa

Abstract

This article presents part of the findings of a study conducted to assess the prevalence and causes of visual impairment (VI) and blindness among adults with diabetes mellitus (DM) receiving treatment at the government health facilities in the Mopani District, South Africa.  This health facility-based cross-sectional study was conducted among 225 Black South African diabetics (161 females and 64 males) aged 40-90 years (mean= 61.50 ± 10.49) years at seven different health care facilities. All the participants were examined for VI using an auto-refractor, pinhole disc, an ophthalmoscope, and a logMAR chart. Visual impairment was defined as visual acuity (VA) of worse than 6/9.5 but better and equal to 3/60, and blindness as VA of worse than 3/60 to no light perception. The prevalence of uncompensated VI and blindness in the right eyes was 70.6 and 3.6%, respectively. In the left eyes, the prevalence was 72 and 3.1% for VI and blindness respectively. The prevalence of blindness remained the same after optical compensation. The leading causes of uncompensated VI and blindness in both eyes were uncorrected refractive error (RE) (49.5%), cataract (24.7%), diabetic retinopathy (3.8%) and glaucoma (2.2%). Following optical compensation, the prevalence of compensated VI and blindness in the right eyes was 41.3 and 3.6%, respectively and in the left eyes, the prevalence was 42.2 and 3.1%, respectively. Uncompensated RE and cataract were the common causes of VI and blindness in this sample. The socio-economic status of this population might have contributed to these findings. These results indicate the need for affordable vision examination and spectacles provision as well as cataract surgery services in this population.