Q: What first drew you to ophthalmology, epidemiology, and global health research?
A: I went to medical school in New York City, in northern Manhattan, where many of our patients came from the Dominican Republic. That exposure got me interested in immigrant health and the challenges faced by underserved populations. During my fourth year of medical school, I also did electives abroad in Africa, and those experiences were very formative. I saw disease at a scale and severity that was very different from what I had seen in New York, and that really made me want to help improve care in settings where even small changes could have a big impact.
Q: Where do you see the greatest opportunities for impact in reducing blindness in low-resource settings
A: Cataract remains the leading cause of blindness worldwide, so there is still a major opportunity to improve access to cataract surgery. The surgery itself is highly effective and well established, but many people still are not getting treated. There is also room to improve outreach strategies so more patients actually reach the eye hospital. In our work, we are interested in evaluating whether community health workers can help identify people who need surgery or other eye care more efficiently.
At the same time, we are studying diseases like glaucoma, macular degeneration, and diabetic retinopathy, which are less common than cataract but can cause irreversible vision loss if they are missed.
Q: Can you tell us about your current trial in Nepal?
A: In Nepal, we are conducting a cluster randomized trial that compares standard vision screening alone versus vision screening plus additional imaging for glaucoma, macular degeneration, and diabetic retinopathy using a technology called optical coherence tomography (OCT). Everyone in the study receives household vision screening using a smartphone-based app called Peak Acuity, which uses “tumbling Es” to test vision. If someone screens positive for reduced vision, they are referred in for further evaluation.
Half of the communities are then randomized to receive the additional OCT screening. The big question is whether the added complexity and cost of bringing OCT into the field actually identifies enough additional disease to justify the effort. It is a practical question, but an important one for real-world eye care delivery.
Q: Can you explain the WUHA trial and why water, sanitation, and hygiene are so central to trachoma control?
A: The WHO’s trachoma elimination strategy is called SAFE: Surgery, Antibiotics, Facial cleanliness, and environmental improvements. The antibiotic piece is straightforward because trachoma is caused by ocular chlamydia infection. Surgery is needed for advanced disease when scarring causes the eyelid to turn inward and the eyelashes to rub against the eye. Facial cleanliness and environmental improvements are more about preventing transmission. Clean faces are thought to reduce the infectious secretions that can spread disease, and better water and sanitation could reduce transmission through flies and other routes.
The WUHA trial was designed because, although there was observational evidence supporting water and sanitation improvements, there was not strong randomized evidence showing how much those components actually reduce trachoma. That mattered because these interventions are expensive, and programs need to know how to allocate limited resources. In the trial, we randomized communities and implemented a comprehensive intervention package in the WASH arm, including water points, hygiene promotion, wash stations, mirrors, and soap. What we found was that the overall chlamydia burden was similar in the intervention and control arms. That suggests antibiotics may have a larger impact than the WASH components alone when the primary goal is trachoma elimination.
Q: What did you learn from WUHA about the role of antibiotics?
A: In the trial, the communities had already received years of annual azithromycin before enrollment. We actually paused antibiotics for the first three years to see whether infection would return more slowly in the communities receiving the WASH intervention. It did return, but it returned similarly in both groups. When we restarted annual azithromycin, infection levels came back down again. So overall, the trial reinforced that antibiotics are effective, and it did not show a meaningful added effect from the WASH package in that setting.
Q: What are you most excited about next in this field?
A: I am starting research in the Navajo Nation in Arizona. The first step is to do a basic epidemiology study to identify the main causes of vision loss in that population. From there, the goal would be to design a randomized trial to address the biggest problem we find. It could be glaucoma, cataract, refractive error, or something else, but the point is to start with data and then build an intervention that is tailored to the community’s needs.
Q: What keeps you motivated in this work?
A: I think it is the opportunity to answer questions that can lead to broad, practical impact. Clinical trials and epidemiologic research can inform real decisions about how to deliver care, how to allocate resources, and how to prevent blindness in communities that need it most. That is incredibly motivating.
Jeremy Keenan, MD, MPH, is the H. Bruce Ostler Professor of Ophthalmology and the Director of International Programs at the Proctor Foundation. He is an epidemiologist and ophthalmologist with clinical specialties of cornea and uveitis. His research focuses on strategies to reduce the global burden of blindness, with an emphasis on developing countries.
