1. School of Medicine, Texas A&M University, Bryan, Texas, USA
2. Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
3. Department of Ophthalmology, King Hussein Medical Center, Amman, Jordan
4. Anne Marion Burnett School of Medicine, Texas Christian University, Fort Worth, Texas, USA
5. Department of Ophthalmology, Veteran Affairs North Texas Health Care Medical Center, Dallas, Texas, USA