Causes of blindness in Northern Tanzania: a hospital and rural health centre based study.

Abstract

To identify the main causes of blindness in Northern Tanzania. Ophthalmic patients at the Kilimanjaro Christian Medical Centre and on outreach clinics in the Kilimanjaro region of Northern Tanzania were examined. The cause of blindness was documented for any eye seeing less than 3/60 Snellen. If more than one factor contributed to the visual loss, the single factor deemed to be the most visually disabling was documented. 1045 blind eyes of 781 patients were examined. 264 patients were bilaterally blind. The main cause of bilateral blindness was cataract [39%]. The other chief causes of blindness were glaucoma, trauma and corneal scarring. The most important cause of corneal scarring, approximately half the cases, was microbial keratitis. Refractive error alone was responsible for 4.2% of bilateral blindness, of which 2.7% was uncorrected post-cataract surgery aphakia. Treatable causes of blindness, including cataract and refractive error account for over a third of all blindness in Northern Tanzania. Trauma, glaucoma and microbial keratitis are other important causes of blindness in the region.