1 Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California.
2 Mitchel and Shannon Wong Eye Institute, Dell Medical School at the University of Texas at Austin, Austin, Texas.
3 Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California. Electronic address: ETsui@mednet.ucla.edu.