Subconjunctivally implanted micro-osmotic pumps for continuous ocular treatment in horses

Objective-To evaluate the feasibility of using a subconjunctivally implante d micro-osmotic pump for continuous delivery of medication to the eyes of h orses-during a 7-day period. Animals-4 healthy adult horses; Procedure-With horses restrained in a standing position, micro-osmotic pump s were implanted subconjunctivally in each eye for 7 days. The treatment ey e received an atropine-loaded micro-osmotic pump (100 mu l of 1.5% atropine ); and the contralateral eye received a sterile saline-loaded pump (100 mu l of 0.9% NaCl) as a control treatment. Pupil size was measured at 12-hour intervals until values returned to baseline. Results-The micro-osmotic pumps were tolerated and did not migrate or becom e dislodged. During the 7-day treatment period, pupils were significantly l arger in the eyes implanted with atropine-loaded pumps. compared with salin e-implanted control eyes. Conclusions and Clinical Relevance-Micro-osmotic pumps;were implanted and r emoved easily from standing horses and were not associated with corn; plica tions during the 7-day treatment period. Therefore, subconjunctivally impla nted micro-osmotic pumps can potentially be used when treating ophthalmic d isease in horses.