Globally, the World Health Organization reports at least 2.2 billion people have a vision impairment. Many of those affected live in low-income and middle-income countries (LMICs), but they also live in rural areas of the U.S. and North Carolina. Encouragingly, more than 90% of people with vision impairment have a preventable or treatable condition. Sustainable development goals set by the United Nations 2030 Agenda describe improving eye health as a practical and cost-effective way of unlocking human potential.
Emily Gower, PhD, is an ocular epidemiologist and member of the UNC Institute for Global Health and Infectious Diseases, working to improve vision at home and abroad. She’s led multiple clinical trials in Ethiopia and Tanzania, investigating different approaches to trichiasis surgery, a neglected tropical disease and leading infectious cause of blindness globally, caused by infection with the bacterium Chlamydia trachomatis. In the U.S., her work has focused on diabetic retinopathy which occurs when blood vessels in the back of the eye become weak and leak, causing swelling of the retina, and eventually, blindness. Most recently, in the U.S. and North Carolina, including her hometown of Kinston, she’s been studying vision impairment, and finding high rates of refractive error that can be easily solved with new prescription glasses.
“We know there’s a clear correlation between eye health and quality of life as people age, and most vision impairment is avoidable,” said Gower, professor at the Gillings School of Global Public Health. “We just need to be able to find the resources to provide what people need in these different global communities, so that we can prevent or overcome vision loss.”
Infectious Disease
In roughly 38 countries, Trachoma is responsible for the blindness or visual impairment of about 1.9 million people, and young children harbor the principal reservoir of infection. After years of repeated infection, the inside of the eyelid becomes severely scarred, turning inward and causing eyelashes to rub against the eyeball (trachomatous trichiasis), resulting in pain and light intolerance. Treatment involves a surgery to ease discomfort and improve sight. If left untreated, the disease can lead to blindness.
Global Innovations
In 2010, Dr. Gower developed the trachomatous trichiasis (TT) clamp, a tool to help surgeons identify where to make a cut that would return a person’s eyelashes to their original position. But the surgical procedure, typically performed by eye nurses with very basic medical training, saw a wide range of outcomes in a Tanzanian study. There was a clear gap between didactic and hands-on training. In response, Gower developed a portable low-cost surgical simulator for training, working with Jim Johnson, a professor of Applied Learning, at Wake Forest University.
Trainees began to practice on a silicone head, with removable eye sockets and disposable eyelid cartridges that mimic the layers of a human eyelid. Global outcomes improved dramatically, and it’s now the WHO standard for training new trichiasis surgeons around the world, currently being used in 25 countries.Then, Gower had an idea to develop a phone app that would give the public health community another tool to fight the disease. Known as the “TT Screener,” the smartphone-based app uses an algorithm to assess high-quality photos of eyelids and can detect trichiasis in 13 seconds with an estimated 92 percent rate of accuracy.
Most recently, Gower and her team have developed a new surgical procedure to improve outcomes for people who need repeat surgery.
“Individuals are at high risk of complications after their second surgery, because it’s so hard to do surgery on an eyelid that’s already had surgery. We’ve just completed a clinical trial comparing our new procedure with an existing one and we found that our new procedure reduced recurrence by about 50% for people with severe trichiasis before surgery.”
In the U.S. and North Carolina
Dr. Gower’s work shows the mutual benefits of global health research, applying what she’s learned about vision screenings in limited resource settings, from Africa to North Carolina, and vice versa. Dr. Gower is engaged in improving access to care in marginalized populations and analyzing large-claims databases to assess the utilization of eye-care services.
“Being from North Carolina I’ve really wanted to improve the lives of people living in rural communities, knowing how much poverty and lack of access to care there is.”
When an opportunity presented itself to add research questions to the Long-Life Study, a nationwide ancillary study to the Women’s Health Initiative (WHI), Dr. Gower proposed conducting distance vision assessments to look at the association between vision impairment and wellbeing. Funded by the National Eye Institute, Gower’s team started data collection in June 2023 and screened over 3,000 women aged 80+ in their homes.
Long Life Study and Findings
“This came about around the time our team was starting to use mobile phones to do vision collection in Africa. Over the past five years, we’ve conducted vision screening for about 8,000 women in Ethiopia, using phone-based data collection that reduces the need for the data collector to interpret vision screening data.”
Gower realized that if she could train people living in Africa with limited experience using a smartphone how to use an app for vision screening in <10 minutes, the same could be done in the U.S. Her team trained over 130 data collectors how to use the PEEK Acuity app to screen distance vision for individuals in the Long-Life Study.
The app works by presenting a capital E in one of four orientations. The participant having their vision screened points in the direction the E is pointing, and then the examiner swipes their phone in that direction. If the participant has answered correctly, the size of the letter goes down. If they got it wrong, it either stays that size to test it again or increases.
The Long-Life study is looking at how common vision impairment is in older adults, the causes for that vision loss, and the impact on social measures, psychosocial measures and physical health. Examiners across the U.S. were trained online to do home visits in all 50 states, which included vision assessments for distance, and for people who had vision worse than 20-40, a pinhole assessment, using a device with small holes that changes the angle of light coming into the eye. This allowed examiners to assess whether the vision loss is due to refractive error. If their vision loss was due to refractive error, their vision got much closer to 20/20.
Nearly 3,400 women have completed the exam, and just over 550 individuals needed pinhole testing. Among these, over 80% improved with pinhole. So far, Gower says the study shows that about 14% of this population has either uncorrected refractive error or under-corrected refractive error, and they would benefit from getting a new glasses prescription.
“We’ve just begun to look at associations between vision and well-being, but early assessments show the worse an individual’s vision is, the more likely they were to report reduced independence and worsening mental health. There are a lot of negative impacts with vision impairment reducing psychosocial, social and physical well-being thatwe will continue to look at the next couple years.
Eastern North Carolina
Last year, Grower was contacted by Prevent Blindness North Carolina to do a study in Eastern North Carolina looking at whether self-reported rates of vision loss were the same as measured vision loss in communities where the American Community Survey had reported vision loss above 3%.
“I’m from Kinston, in Lenoir County, and when I saw Lenoir was one of the counties that had the highest rates of vision loss in the state, I wanted to know more.”
Dr. Gower’s team used the same distance vision screening tool used for the WHI’s Long-Life Study, and her study idea was so well liked that Fayetteville was added. Working with community health centers in Lenoir and Cumberland Counties, the team linked up with food distribution groups, health fairs and other community groups. They were able to recruit participants at a variety of locations.
“Overall, within this population, about 92% had good vision in both eyes. That means that 8% of individuals had vision loss, even with their presenting correction. The study showed almost triple the amount of vision loss anticipated. Over half of those who had vision loss were concerned about running out of food, and a quarter of them had been unhoused within the past year.” This reflects the tremendous need for increased, affordable and accessible vision services in this area,
“Refractive error is a big problem in these communities with approximately 40% of individuals improving by at least three lines. This is the difference between being able to drive and not being able to drive.”
Providing individuals with affordable glasses could have a significant impact on their quality of life.
Gower is an active member of the Ethiopian Ministry of Health’s taskforce for managing post-operative trichiasis. She regularly provides guidance on best practices for managing post-operative trichiasis. Additionally, she serves as the lead organizer for the World Health Organization’s annual global scientific meeting on trachoma and has participated in multiple WHO global scientific meetings on trichiasis. She was also a finalist for the Reaching the Last Mile Global Game Changing Innovator award, for her team’s surgical simulator.