John P Thompson1, Constance L Fry2. 1. Department of Ophthalmology, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, MC 6230, San Antonio, TX, 78229, USA. thompsonj5@livemail.uthscsa.edu. 2. Department of Ophthalmology, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, MC 6230, San Antonio, TX, 78229, USA.