The effects of propofol-sevoflurane, midazolam-sevoflurane and medetomidine-ketamine-sevoflurane anesthetic combinations on intraocular pressure in rabbits

Intraocular pressure (IOP) is dependent on equilibrium between the rate of formation and outflow humor aqueous in the eye. Determination of IOP is one of the most important points and a very useful parameter in ophthalmic surgery. The aim of this study was to compare the effects of propofol + sevoflurane, midazolam + sevoflurane, medetomidine + ketamine + sevoflurane anesthetic combinations on IOP, and to find out suitable anesthesia protocol in rabbits for ophthalmic surgery. For this purpose, a total of 40 healthy four months old New Zealand female rabbits (Mean weight 2.34±0.67 kg) were used as subjects. The animals were divided into four groups; propofol + sevoflurane (PS), midazolam + sevoflurane (MS), medetomidine + ketamine + sevoflurane (MKS), and control (C), each having 10 rabbits. The IOP was measured from the right eyes before injection of anesthetics (0. min), during sevoflurane anesthesia at 5th, 10th, 15th, 20th, 25th and 30th min, and post anesthesia at 10th, 20th, 30th, 60th, 120th min and 24 h in the study groups. In PS group; IOP values decreased during anesthesia between 5th and 25th min. In general, the measured IOP values of MS group were higher than 0th min, and the increases continued at 10th min in post anesthesia. The measured IOP values of MKS group during anesthesia were higher than other time points. As a result of this study PS anesthetic combination is an ideal anesthesia for ocular surgery in rabbits. The increase in IOP is undesirable in ocular surgery due to operative and postoperative complications. It was also concluded that investigating the effects of anesthetic combination on IOP should continue in more detailed researches including in different species.