Treating Equine Eye Irritation

Horses with equine recurrent uveitis (ERU) show swelling of the eye, irritation, and eventual blindness. Treatment used to involve medicating the eye with cyclosporine up to four times a day, a difficult schedule for many owners to meet. An implant was developed several years ago that would automatically dispense medication directly into the eye.

A recent study looked at the response of 151 horses that had used the implant for one to seven years. Almost 80% of studied horses still had sight compared to 50% expected to maintain sight with owner-administered medications over the same period of time. The rate of blindness increased in horses whose implants had been in place 48 months or longer, indicating the medication had run out by that time. Therefore, replacement of the implants at 36 months is recommended. However, some horses continued to do well even after this time, suggesting that three or four years of constant treatment had a persistent positive effect on the condition.