The Eyes Have It at NC State

One problem guaranteed to make horse owners cringe is an equine eye problem. But whether your horse has a corneal ulcer, eye injury from a bucket handle, tumor, or what have you, the veterinary ophthalmology department at North Carolina State University (NC State) stands ready to help.

Led by Professor Brian Gilger, DVM, MS, Dipl. ACVO, Chief of the Ophthalmology Service, the ophthalmology department evaluates and treats eye disorders in food animals, small animals, large animals, and even zoo animals. There are currently three ophthalmologists on staff, but that number is expected to grow to five. And the growth of the department doesn't stop there; plans are in the works for two new facilities to house the small and large animal ophthalmology departments. That's a pretty strong start for a department that was established only five years ago.

The facilities don't seem to be limiting factors even today; NCSU boasts a high-powered magnetic resonance imaging unit (1.5 tesla, compared to 0.3T in many standing MRI units) that is capable of imaging a horse's head as well as his legs. It has to be used on anesthetized horses, and it's one of only two veterinary MRI units in the United States with this level of power (the other is in Washington State University). For eye patients, it's used to help evaluate damage to the orbit (eye socket). And there are plenty of stalls--large and small (for goats and Miniature Horses)--to house eye patients.

Equine Eye Patients

Horses comprise about one-third of the ophthalmology cases at NCSU with about 500 cases--and 200 surgeries--per year, but equines account for more than 50% of the clinicians' time, says Gilger. While his oddest case was a cataract surgery in a male chimpanzee named Hondo from the North Carolina Zoo (which was quite successful), and the most intimidating cases are the grizzly bears he evaluates at the zoo, he notes that draft horses make the toughest eye patients in some ways.

"The horses that are 18 hands and 2,000 pounds are probably the most difficult cases to manage, because none of the equipment is big enough," Gilger comments. "On these horses, the head is probably 400 pounds. The number of people it takes to move these horses (when they're anesthetized) is a big factor; it takes 10 people to get the horse through the MRI. People don't always understand that--everyone in the barn has to participate."

However, he is quick to add that the draft's gentle temperament makes these horses wonderful to work with despite the physical challenges. That's a good thing, since he says heavy horses are quite popular and becoming more so in North Carolina as riding horses, and he sees a lot of them at NC State.

In equine ophthalmology patients as a whole, Gilger says corneal ulcers and infectious keratitis are the most common problems he sees, followed by equine recurrent uveitis (also called periodic ophthalmia or moon blindness).

Some eye problems are more preventable than others. Gilger recommendations horse owners minimize the risk of eye trauma and infection by using a fly mask, and feeding hay on the ground, not from nets, bags, or elevated mangers ("They're horrible about causing eye trauma," he warns).

Research Updates

Equine recurrent uveitis is said to be the most common cause of blindness in horses, and it is a major focus of research at NC State's Comparative Ophthalmology Research Laboratory.

"We have developed a drug delivery device (a micro-implant) for treating uveitis, and we're in the process of getting it FDA-approved right now," reports Gilger. "If that gets FDA-approved, it will be a wonderful thing for horses with uveitis."

The implant, which delivers a constant amount of cyclosporine (an immunosuppressive agent) within the eye, is made at NCSU and currently is being distributed free of charge to ophthalmologists who request one.

The implant device is patented by the National Eye Institute of the National Institute of Health, which funded the development of the system. Once the implant is FDA-approved, it will be manufactured by a pharmaceutical company for commercial sale.

"We're also looking at other mechanisms that cause uveitis, because too many people think it's just leptospirosis that causes moon blindness when in fact it's only one of many things that can cause it," Gilger reports. He is also looking at other mechanisms of treating this common disease.

Take-Home Message

North Carolina State University's veterinary ophthalmology department boasts a solid roster of specialists and good facilities, and the people there care for horses from Maryland to South Carolina. With the growth in staff and facilities that are planned, owners can expect even more groundbreaking clinical and research work in ophthalmology from NC State.

Additional Resources

NCSU Equine Ophthalmology Service  

NCSU Comparative Ophthalmology Research Laboratory  

NCSU information on Equine Recurrent Uveitis

About the Author

Christy M. West

Christy West has a BS in Equine Science from the University of Kentucky, and an MS in Agricultural Journalism from the University of Wisconsin-Madison.

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