Equine Medical Services: Cyclosporine Implants

Cyclosporine is an immunosuppressant drug that is commonly used for treatment to prevent organ transplant rejection and for treatment of dry eyes in dogs. Cyclosporine is the ideal drug to prevent the recurrence of immune-mediated ocular inflammation like keratitis (IMMK). It suppresses the activity of the T-lymphocyte, which is the most common infiltrating cell in equine recurring uveitis (ERU) eyes.

However, cyclosporine eyedrops or ointment do not penetrate past the cornea and cannot get into the eye to treat the uveitis and oral cyclosporine would likely be too toxic and expensive to give a horse.

Studies performed at NC State have shown that reservoir devices placed into the eye can allow long-term (more than 4 years) release of low levels of cyclosporine. Studies have also shown that the implants are safe and effective in decreasing inflammation in the equine eye.

Clinical studies in horses with ERU have shown excellent control of the disease. However, this is an experimental device and not approved for use in horses by the FDA.

Is my horse a candidate for cyclosporine implants?

The best candidates for the implant are those with the following characteristics:

  • ERU is controllable with traditional medication, but the horse has frequent recurrences
  • The horse has good vision between episodes
  • The horse has minimal scarring in the eye and no cataract formation
  • There is no retinal degeneration and has good retinal function
  • The horse does not have other systemic illnesses (such as a high titer to leptospirosis)


Your veterinarian’s examination will help determine if your horse is a good candidate.

Who can do the surgery?

There are veterinary ophthalmologists in nearly all areas of the US who are or will be trained to perform the implant surgery.

Please call us at 919.513.6659 to determine the closest ophthalmologist in your area.

What are the success rates?

This is an experimental procedure, however, long-term results have shown that greater than 80% of horses have ERU controlled. Some horses have lost vision after implantation.

Helpful Resources

To order cyclosporine implants from the NC State Veterinary Hospital:

Please remember that cyclosporine implants may not be returned once they leave the NC State Veterinary Hospital, so please ensure that you are ordering the correct implants.

Implant orders are processed the next business day.

Order Implants Here

The Gilger Lab at NC State

We work on eye diseases and injuries, specifically equine eye health and occular drug development. Our group is different to a lot of scientific research labs because our research, teaching and outreach activities integrate across two complimentary, yet specialized, areas of expertise.

Learn More about our Lab

Support Us

Cyclosporine implants have been studied, tested, and manufactured at the Comparative Ophthalmology Research Laboratory at North Carolina State University College of Veterinary Medicine. A large amount of time and money has been spent to develop these devices specifically for the treatment of equine uveitis.

Please support our laboratory and our efforts in the treatment of equine uveitis by donating to the Equine Uveitis Research Fund in care of the North Carolina Veterinary Medical Foundation.

Donate now!