He has published over 350 peer-reviewed articles, and his reports are the most cited in the ophthalmic literature over the last 30 years (Archives of Ophthalmology, 2007). His research has improved the early diagnosis of glaucoma and has developed instruments and techniques to identify glaucoma damage better. He has participated in pioneering studies of the epidemiology, morbidity and progression rate of glaucoma and other eye disease in American, African, Asian and Hispanic populations, serving as a consultant to the World Health Organization. In the laboratory, he has demonstrated successful gene therapy to protect retinal ganglion cells from experimental glaucoma and developed glaucoma models in monkeys, rats and mice.