1 Guohua Li is from the Center for Injury Epidemiology and Prevention, Columbia University, and the Departments of Epidemiology and Anesthesiology, Columbia University Mailman School of Public Health and College of Physicians and Surgeons, New York, NY. Katherine M. Keyes is with the Center for Injury Epidemiology and Prevention, Columbia University, and the Department of Epidemiology, Columbia University Mailman School of Public Health. Xiwen Huang is with the Doheny Eye Institute, Los Angeles, CA.