1. Department of Ophthalmology, College of Medicine, King Saud University, P.O. Box 245, Riyadh 11411, Saudi Arabia
2. Department of Ophthalmology, Padova University Hospital, Via Giustiniani 2, 35128 Padova, Italy
3. Medical College of Georgia and College of Graduate Studies at the Georgia Health Sciences University, Augusta, GA 30912, USA