1. Professor and Chairman, Department of Ophthalmology, College of Medicine, King Saud University, P.O. Box 55307, Riyadh 11534, Saudi Arabia
2. Head, Section of Pediatric Infectious Diseases, Department of Pediatrics, MBC 58, King Faisal Specialist Hospital and Research Centre, P.O. Box 3354, Riyadh 11211, Saudi Arabia