Ketamine anesthesia and intraocular pressure

We studied the influence of intramuscular ketamine-narcosis on the intraocular pressure of rabbits. Tonography and indirect arterial pressure measurements were performed 5 to 10 minutes after the administration of the agent. The systolic arterial pressure did not change significantly, whereas the intraocular pressure significantly increased. The intraocular pressure increase was 7% on the average with a maximal increase of 20%. In more than half of the cases the arterial and intraocular pressures changed in the opposite directions which speaks for the role of other factors in enhancing these pressure alterations.