Use of an intravitreal sustained-release cyclosporine delivery device for treatment of equine recurrent uveitis.

This research article is about using an intravitreal device that dispenses cyclosporine (a type of medicine) at a consistent rate to treat recurrent uveitis in horses, a chronic eye disease. The study found that the device successfully reduced the recurrence of uveitis episodes and maintained vision in most horses.

Background

• The research is centered on equine recurrent uveitis (ERU), which is a common, painful, and potentially blinding disease in horses.
• Cyclosporine A (CsA) is known to be effective in treating ERU, but its administration is challenging due to the frequency of dosage required and the potential side effects.
• The researchers were focusing on a new method of delivering CsA through a sustained-release device implanted into the horse’s eye.

Method

• 16 horses with frequent ERU episodes or with disease progression despite medication were selected for this study.
• To qualify, the horses needed to have adequate retinal function, lack severe cataract formation, and no vision-threatening complications such as retinal detachment or severe retinal degeneration.
• The CsA delivery devices, releasing 4 micrograms of CsA per day, were implanted into the vitreous of the horses’ eyes through a sclerotomy at the pars plana.
• Follow-up exams were conducted 1, 3, 6, and 12 months post-implantation, and then annually thereafter. During these, the horses’ ophthalmic changes, recurrent uveitis episodes, and vision status were scrutinized.

Results

• The rate of recurrent uveitis episodes dramatically decreased post-surgery, from 75 episodes/year to just 0.36 episodes/year.
• Only 3 horses out of the 16 developed recurrent uveitis after the surgery.
• Vision was detected in 14 out of 16 affected eyes at an average follow-up time of 13.8 months (from 6 to 24 months).

Conclusions

• The CsA sustained-release device implanted intravitreally shows promising results in long-term treatment of horses with ERU.
• The significant reduction in the recurrence of uveitis episodes and maintenance of vision in most horses indicates the device’s efficacy and potential as a therapeutic tool for this chronic disease.