1. Tamale Teaching Hospital, Tamale P. O. Box TL 16, Tamale, Ghana
2. Community Health Department, School of Public Health, University of Ghana, Korle-Bu, Ghana
3. Ophthalmology Unit, Department of Surgery, Korle Bu Teaching Hospital, College of Health Sciences, School of Medicine and Dentistry, University of Ghana, Accra, Ghana
4. Korle-Bu Teaching Hospital, Korle-Bu, Ghana
5. St Francis Xavier Hospital, Assin Fosu, Ghana
6. Nursing and Midwifery Training College, Koforidua, Ghana