Long-term outcome after implantation of a suprachoroidal cyclosporine drug delivery device in horses with recurrent uveitis.

OBJECTIVE

To determine the long-term efficacy, complications, and duration of effect of a cyclosporine (CsA) suprachoroidal implant (CSI) in horses with equine recurrent uveitis (ERU).

METHODS

Horses with ERU were treated with a 6-mm diameter, 25 mg, reservoir matrix CsA implant in the deep sclera adjacent to the suprachoroidal space. Horses with follow-up >1 year were examined for frequency of uveitis episodes, complications, and vision at last recheck.

RESULTS

Data from 151 eyes of 133 horses from the USA and Europe that had CsA devices implanted for ERU were reviewed. Follow-up time ranged from 13 to 85 months after surgery, with a mean and median follow-up time of 28.9 and 26.3 months, respectively. Overall, at last follow-up 78.8% of eyes were considered visual and the overall mean frequency of uveitis episodes after CSI was 0.09 ± SD 0.08 episodes per month. The most common complications leading to vision loss at last follow-up were persistent uveitis episodes (54%), glaucoma (22%), mature cataracts (16%), and retinal detachment (6%). Persistent uveitis episodes tended to be the highest cause of vision loss in horses with <24 months and >48 months of follow-up.

CONCLUSIONS

This study demonstrated the long-term maintenance of vision of horses with ERU implanted with a CSI. The increased vision loss related to uveitis episode of inflammation in eyes after the likely depletion of CsA from the CSI suggests that a repeat CSI may be required at or before 48 months after surgery.