Effect of intravenous administration of romifidine on intraocular pressure in clinically normal horses

OBJECTIVE: To evaluate the effect of intravenous administration of romifidine on the intraocular pressure (IOP) in horses. ANIMALS STUDIED: Twenty‐four horses with no ocular abnormalities. PROCEDURE: Horses were randomly assigned into two equal groups (treatment and control). All horses in the treatment group received an intravenous (IV) injection of romifidine (40 μg/kg). The horses in the control group were administrated an intravenous injection of 0.9% saline (0.4 mL/100 kg). In both groups, the IOP values were measured immediately (T₀) pre‐administration and at 5 (T₅), 15 (T₁₅), 30 (T₃₀), 45 (T₄₅), 60 (T₆₀), 90 (T₉₀), and 120 (T₁₂₀) min after drug administration. RESULTS: The pre‐treatment values (T₀) of IOP for right and left eyes were 24.25 ± 3.5 and 25.16 ± 3.4 mmHg, respectively. A significant decrease in IOP values was observed in both right and left eyes of the horses in treatment group at T₅, T₁₅, T₃₀, T₄₅, T₆₀, and T₉₀ in comparison with the baseline values (P < 0.05). The lowest level of IOP in romifidine‐treated groups was recorded at T₄₅ for the right and left eyes (10.25 ± 2.3 and 11.25 ± 3.5 mmHg, respectively). CONCLUSION: Romifidine significantly decreased IOP in clinically normal horses and may be used safely for surgery or diagnostic ocular procedures in horses when specific control of IOP is required.