Ophthalmologist Dr. Yu-Guang (IMAGE) UT Southwestern Medical Center Caption Ophthalmologist Dr. Yu-Guang He is a principal investigator in a nationwide study investigating whether taking modified combinations of vitamins, minerals and fish oil products can slow age-related macular degeneration vision loss. Credit UT Southwestern Medical Center Usage Restrictions Please use credit line. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.