Effects of intravenous administration of dexmedetomidine on intraocular pressure and pupil size in clinically normal dogs.

Abstract

OBJECTIVE: To evaluate the effects of the intravenous administration of dexmedetomidine on the intraocular pressure (IOP) and pupil size (PS) in normal dogs. ANIMALS STUDIED: Forty-two animals with no ocular abnormalities were included in this study. PROCEDURE: Following initial readings (T(0)) of IOP and PS, the dogs received an intravenous injection of dexmedetomidine (5 μg/kg). Both measurements were repeated 10 min (T(10) ) and 20 min (T(20)) later. RESULTS: There were no significant differences in IOP measurements between T(0) and T(10), although a significant decrease was observed at T(20). A significant miosis was found in the first 10 min after sedation. At T(20), the PS slightly increased, resulting in no statistical differences with T(0) and T(10). CONCLUSION: Dexmedetomidine is an excellent option for surgery or diagnostic ocular procedures in dogs when a specific control of IOP is required. However, it must be used in combination with mydriatics in ophthalmic surgical or diagnostic procedures, which require complete dilation of the pupil.