Picture a horse running across an open field, eyes on the horizon. Now picture that horse’s vision slowly spotting and fading, the horizon blurring, until ultimately, he can’t see anything at all.
That’s the tragedy that UF/IFAS microbiology, veterinary, and ophthalmological researchers are trying to prevent. One day, their work might even be relevant in human medicine.
A study published in Frontiers in Immunology looked at the safety and anti-inflammatory effects of a new eye drop they developed to treat equine recurrent autoimmune uveitis. Researchers from the University of Florida’s Institute of Food and Agricultural Sciences (UF/IFAS) microbiology and cell science department, UF College of Veterinary Medicine, and UF College of Medicine’s ophthalmology department worked together to see if they could restore and protect vision in horses with this condition.
What Is Uveitis?
Uveitis is a leading cause of blindness in horses and humans. It is responsible for about 10% of blindness and visual handicap cases in the U.S., which accounts for about 30,000 new cases of blindness each year, according to the Cleveland Clinic.
Uveitis is a serious condition where the uvea (the middle layer of the eye) is inflamed. The condition causes vision loss through two mechanisms: breakdown of the structures of the eye and blockage of light to the retina. If caught early, medicine can prevent uveitis from causing loss of eyesight. In more advanced cases, however, the damage is already done, said Lauren Stewart Stafford, a former UF/IFAS microbiology and cell science Ph.D. student who is now a post-doc at Case Western Reserve University.
Treatment for Uveitis
The way uveitis affects eyes–and the way the treatment works–is similar in horses and people, said Joesph Larkin, associate professor in the UF/IFAS microbiology and cell science department.
“It turns out that the place where the drug sits to have its effect in the eye is the same in people and in horses,” he said. “We think that if we’re able to prove its effect in horses, we’ll also be able to treat the disease in people. People go blind if they have this disease, so it definitely alters their quality of life permanently.”
Traditionally, steroids are the go-to treatment for uveitis, but they aren’t a viable long-term solution due to side effects, Larkin said. Since recurrent uveitis keeps coming back after treatment, a more sustainable long-term solution is needed.
With autoimmune uveitis, immune cells destroy the structures inside the eye, he said. To address this condition, the researchers developed drops containing a SOCS1-KIR mimetic peptide, which is a synthetic molecule that mimics a building block of a protein, used in many types of therapies. SOCS1-KIR molecules regulate chemical messaging between immune cells to reduce inflammatory activity and potentially improve cell communication.
Study Results
In a prior study by these researchers, the team demonstrated the treatment’s effectiveness in horses at UF’s College of Veterinary Medicine.
Larkin said several horses came into the study with a painful sensitivity to light and were either mostly or entirely blind. Several horses improved–they were in less pain and could see better than before.
“Once we reduced the inflammation, one horse was even able to see again,” he said.
Next Steps
This study demonstrated possible methods into how the treatment changed the horses’ immune response. The next step, Larkin said, would be to do a clinical trial with horses.
The study was funded by the Grayson-Jockey Club Research Foundation, a non-profit organization that focuses on funding equine veterinary research.
About UF/IFAS
The mission of the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) is to develop knowledge relevant to agricultural, human, and natural resources and to make that knowledge available to sustain and enhance the quality of human life. With more than a dozen research facilities, 67 county Extension offices, and award-winning students and faculty in the UF College of Agricultural and Life Sciences, UF/IFAS brings science-based solutions to the state’s agricultural and natural resources industries and all Florida residents.
Related Reading
- Disease Du Jour: Equine Recurrent Uveitis
- AAEP Health Coverage: Novel Drug (SOCS1-KIR) to Treat Uveitis in Horses
- Risk Factors for Equine Recurrent Uveitis
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