Study: Corneal Transplants Safe and Effective in Horses

According to a retrospective study involving 206 horses, corneal transplants can successfully restore vision in horses with a variety of eye problems including melting ulcers, iris prolapsed, stromal abscesses, and in horses that were not responsive to medical management. The overall success rate was 88.5%.

Corneal transplants can be performed using corneas harvested from donor horses which are then frozen until time of surgery. Transplantation results in both a functional and cosmetic repair of the damaged eye.

"At the University of Florida Veterinary Medical Center, we have used three different techniques for corneal transplants between 1993 and 2007," explained Professor Dennis Brooks, DVM, PhD, Dipl. ACVO. "The purpose of this study was to review our data to determine the visual outcome in horses treated via these three different surgeries."

A full thickness penetrating keratoplasty (PK) procedure was performed in 86 horses, a posterior lamellar keratoplasty (PLK) was performed in 54 horses, and 66 horses were treated using the deep lamellar endothelial keratoplasty (DLEK) procedure.

A positive outcome with the horses having vision in the operated eye was obtained in 77.9%, 98.1%, and 89.4%of horses for the PK, PLK, and DLEK procedures, respectively.

"The most worrisome and troublesome post-operative complication in corneal transplant patients is rejection of the corneal graft," said Brooks.

Graft rejection is often seen in human patients in infected eyes or if a disturbance of the immune system exists. In horses, both of these conditions are typical which places them at high risk for graft rejection.

"Despite the fact that graft rejection still occurs too frequently for our liking, corneal transplants still result in a good outcome and we have saved many eyes that would otherwise have been lost," concluded Brooks.

The study, "Corneal transplantation for inflammatory keratopathies in the horse: visual outcomes in 206 cases (1993-2007)" was published in 2008 in the volume 11, number 2 edition of the journal Veterinary Ophthalmology.

About the Author

Stacey Oke, DVM, MSc

Stacey Oke, MSc, DVM, is a practicing veterinarian and freelance medical writer and editor. She is interested in both large and small animals, as well as complementary and alternative medicine. Since 2005, she's worked as a research consultant for nutritional supplement companies, assisted physicians and veterinarians in publishing research articles and textbooks, and written for a number of educational magazines and websites.

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