1. Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
2. Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Tennessee Health Science Center, Memphis, TN 38163, USA
3. Department of Preventive Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA
4. Clinical Research Center, University of Tennessee Health Science Center, Memphis, TN 38163, USA