Low vision in Nigerians with diabetes mellitus

To determine the prevalence and causes of low vision in diabetes mellitus patients in Nigeria.

All consecutive new patients seen at the Diabetic Eye Clinic, Nnamdi Azikiwe University Teaching Hospital Nnewi Nigeria, between March 1997 and September 1998 were the subjects of the study. Examination methods included interviewer-administered structured questionnaire, visual acuity test, external eye examination, refraction, tonometry, gonioscopy, binocular indirect ophthalmoscopy and slit lamp fundus examination with 78D non-contact lens.

Of the 100 new patients examined, 47 (47%) did not know that diabetes could lead to visual loss; 53 (53%) had not been examined by any eye health worker. Eighteen patients (18%) were bilaterally blind and 26 (26%) had monocular blindness; visual impairment was present in the better eyes of 30 patients (30%), with 20 (20%) having bilateral visual impairment. Glaucoma, cataract, diabetic retinopathy, central retinal vein occlusion, age-related macular degeneration, and leukoma were the causes of blindness. Visual impairment was due to diabetic macular edema, ametropia, cataract, age-related macular degeneration, glaucoma, uveitis and branch retinal vein occlusion.

The causes of low vision in the patients are treatable and visual defects from them are thus avoidable. It is recommended that (a) all diabetics be made aware that diabetic complications cause visual loss; (b) laser photocoagulation facilities be provided for treating diabetic retinopathy.