Episcleral cyclosporine A implants for the management of unilateral keratoconjunctivitis sicca in an 8‐year‐old mare

Abstract

An 8-year-old mare was presented for investigation of a 1-month history of blepharospasm, eyelid swelling, corneal edema, and ocular discharge of the right eye (OD). Ophthalmic examination confirmed mucopurulent ocular discharge, conjunctival hyperemia, and a dry, dull appearance to the cornea OD. Schirmer tear test results confirmed an absence of tear production OD (0 mm/min) consistent with keratoconjunctivitis sicca. Treatment with topical 0.2% cyclosporine A resulted in an improvement in clinical signs. An episcleral cyclosporine A implant was placed under standing sedation 5 days after initial presentation. Re-examination 9 days post-operatively confirmed that the mare's tear production in the right eye had improved and no further clinical signs had been observed. Topical medications were gradually discontinued. Re-examinations performed up to 12 months postsurgery showed no recurrence of clinical signs and no adverse effects of the implant. To our knowledge, this is the first report of the use of a cyclosporine A implant in the management of KCS in a horse and highlights its potential as an effective, alternative therapy in the management of KCS in horses.

Development of a Sustained-Release Voriconazole-Containing Thermogel for Subconjunctival Injection in Horses

“…It was selected due to its proven safety, ease of injectable administration through a minimally traumatic 30-gauge needle, and sustained-release characteristics when combined with small molecular weight, lipophilic drugs. 30,47,48 As a biodegradable substance, PLGA-PEG-PLGA demonstrates advantages over current alternate sustained-release devices available for treatment of keratopathies, such as cyclosporine-containing silicone-based matrix implants, 38,[49][50][51] as it is broken down by endogenous enzymes and therefore does not require surgical removal when it ceases releasing the loaded medication. The mode of breakdown of bioactive polymers varies greatly; for example, a PLGA and poly(d,l-lactide-co-caprolactone) microfilm surgically implanted in the SCS of rabbits was found to degrade via a combination of surface erosion and mass degradation.…”

Management of Sjogren’s Dry Eye Disease—Advances in Ocular Drug Delivery Offering a New Hope

“…Mackenzie et al treated an 8-year-old mare with a 1-month history of KCS using a cyclosporine implant and topical cyclosporine. The mare showed improved tear-production and absence of clinical signs 9 days post-op [ 65 ]. Therefore, subconjunctival and episcleral implants could provide routes of investigations for future management of KCS.…”