1. Depatment of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma;
2. Harold Hamm Diabetes Center, Oklahoma City, Oklahoma;
3. Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts; and
4. Departments of Ophthalmology, Biochemistry & Molecular Medicine, Maisonneuve-Rosemont Hospital Research Centre, University of Montreal, Montreal, Quebec, Canada