1. Department of Ophthalmology, College of Health Sciences, Makerere University, P. O. Box 7072, Kampala, Uganda
2. Habib Medical School, Islamic University in Uganda, Uganda
3. Department of Physiology, College of Health Sciences, Makerere University, P. O. Box 7072, Kampala, Uganda
4. Uganda Cancer Institute, P.O.Box, 3935, Kampala, Uganda
5. Department of Medicine, College of Health Sciences, Makerere University, P. O. Box 7072, Kampala, Uganda