World Sight Day (WSD) is an annual day of awareness, held the second Thursday of October, to focus global attention on blindness and vision impairment. WSD is coordinated by the International Agency for the Prevention of Blindness. This year’s theme is Hope in Sight.
What are some of the biggest impediments to healthy vision around the world? To find out, we spoke to Meraf Wolle, assistant professor of ophthalmology and a researcher at the Dana Center for Preventive Ophthalmology at the Johns Hopkins Wilmer Eye Institute. The Dana Center, founded by Alfred Sommer, is a leader in global and domestic research on blindness prevention, and the only World Health Organization collaborating center in the U.S.
More than a billion people can’t see well. For more than three out of four people with vision impairment, the condition could have been avoided. How can we improve these statistics?
The biggest reversible problem is unaddressed refractive error — that is, people who are nearsighted, farsighted or presbyopic, meaning that they need reading glasses. This may sound like an easy fix, but when you’re looking at resource-poor areas, it’s difficult for many reasons. For example, it’s difficult to get a proper refraction in those areas because there are no clinics with proper phoropters.
A second, related issue is getting people low-cost glasses. This issue is so important — particularly with regard to children, since it impacts their ability to learn. Here at Wilmer, Megan Collins has been doing a lot of work on school screening programs for refractive error in children, mostly in the States. Elsewhere, programs are working on delivering cost-effective ways to make an impact on a large scale. Aravind Eye Hospitals in India figured out a way to do remote refraction and make the glasses right there at a cost of around $3 per person.
What eye diseases contribute to impaired vision, and are we making progress to address them?
Cataract remains one of the leading causes of vision impairment worldwide, so having high quality, low cost cataract surgery is extremely important. At the Dana Center, a team including Al Sommer undertook a project to establish a model for training local surgeons to improve the quality and efficiency of cataract surgery in order to address the large number of cataract surgeries that need to be done. The hope is to then use this model to ultimately decrease the burden of visual impairment from cataract globally.
If diseases such as macular degeneration, glaucoma and diabetic retinopathy are not caught early, the damage that results is irreversible. These are diseases that need to be managed. In high income countries, we’ve made excellent headway in treating them, but they’re more difficult to treat in low- and middle-income countries due to a lack of robust health care systems.
For macular degeneration, the main treatment we have is the AREDS (Age-Related Eye Disease Studies) vitamins, a formula that can potentially slow the progression of the disease. We also have anti-VEGF (vascular endothelial growth factor) injections for wet macular degeneration that help prevent further vision loss and can sometimes reverse some amount of vision loss. We’re fortunate to have these treatments readily available here in the U.S. and in many high income countries. Unfortunately, they are often not available in low-income countries.
Glaucoma is an issue to tackle. Glaucoma treatment would require getting drops to patients in remote areas. Moreover, surgery is sometimes indicated for glaucoma with subsequent close follow-up required, and this is often not feasible in these areas.
Diabetic retinopathy is another leading cause of visual impairment. Although we’re able to treat this with lasers in clinic, these are not always readily available in certain areas. In addition, any eye-specific treatments need to be combined with working on the health of populations — on things like healthy eating, increased physical activity and systematic screening to prevent diabetes. Unfortunately, by the time many people seek care for diabetic eye disease, damage to the eye has already occurred.
Corneal opacity, which is often caused by trachoma, is a big contributor to visual impairment around the world and is my area of expertise. There are 44 countries in which trachoma remains endemic, most in sub-Saharan Africa, Asia, and a few pockets in Latin America. Sheila West and I are working with the WHO and global partners to help eliminate trachoma globally. That means eliminating the early active infection stage of the disease, which children get, and doing surgery for the trichiasis that develops in adults after multiple infections. This surgery for trichiasis prevents individuals from going blind from corneal opacities.
How has the coronavirus pandemic affected efforts to deal with these problems?
An important part of our work as public health ophthalmologists at the Dana Center, and as practicing ophthalmologists in general, involves assessing to see where the burden of visual impairment is, and researching how best to deliver eye care services to limit this burden or find new ways to tackle the various causes of visual impairment. During the coronavirus pandemic, the in-person assessments required as part of these efforts were halted. There are mass drug administration programs underway to try to prevent trachoma infection in children, and those also stopped. Elective surgeries around the world, including cataract surgeries, came to a halt. Now, everything that had been put on hold is restarting, and they’re trying to get through the backlog of not only surgeries but mass drug administrations to push elimination programs forward.
What makes you hopeful?
Even more so than five or 10 years ago, there is a big focus on some of these reversible causes of blindness, especially when it comes to refractive errors, cataract surgery — which has excellent outcomes — and trachoma. There’s a new energy both at the institutional level at Johns Hopkins and at partner organizations, including nongovernmental organizations. I think that will allow for a lot of collaboration.
The Dana Center has been at the forefront of figuring out how to approach these public health issues and how to make an impact globally.
Bonnielin Swenor is doing important work on age-related visual impairment, and Megan Collins on uncorrected refractive error. Pradeep Ramulu is working on how to improve functioning in older individuals with vision loss from glaucoma. Xiangrong Kong is working on clinical trials in inherited retinal diseases. Oliver Schein is leading efforts on how to improve the quality and safety of ophthalmic surgeries.
Sheila West and I have a trachoma project underway now that is a collaboration among Johns Hopkins and three other institutions. It spans three countries and two continents. It’s going to allow for more collaboration in our approach to trachoma research and allow us to find innovative approaches and solutions for the difficult questions surrounding trachoma elimination — issues that have plagued us for a long time.