The effects of propofol-sevoflurane, midazolam-sevoflurane, and medetomidine-ketamine-sevoflurane anesthetic combinations on tear production measured by the schirmer tear test I (STT I) in healthy rabbits

Abstract

The maintenance of corneal and normal eye function is necessary for the ocular health and integrity. Tear plays an important role in defense mechanism and nutrition of eye. The Schirmer tear tests (STT I, II) are widely used in ophthalmic examination to evaluate tear production as an aid to diagnose eye diseases. The aim of this study was to compare the different effect of anesthetic combinations and their action period on tear production in healthy rabbits. Forty healthy New Zealand female rabbits (mean weight 2.34 +/- 0.67 kg), four months old, were used as materials. The animals were divided into four groups as propofol + sevoflurane (PS), midazolam + sevoflurane (MS), medetomidine + ketamine + sevoflurane (MKS), and control (C) groups, and each group contained 10 rabbits. The TP (tear production) was measured from left eyes before injectable anesthesia (0. min), during sevoflurane anesthesia at 5th, 10th, 15th, 20th, 25th and 30th min, and post anesthesia (after extubation) at 10th, 20th, 30th, 60th, 120th min and 24 h after in the study groups. In group C, at the same time intervals TP were also measured. In all groups statistical differences were recorded in different times of during and post anesthesia time periods. In post anesthetic time intervals the lowest TP values were detected in PS group. The new surgical techniques on eye surgery can require long general anesthesia periods. Extending of general anesthesia duration bring along risk factors such as perioperative dry eye syndrome. Perioperative dry eye syndrome (PDES) is the most common ophthalmologic complication of the general anesthesia. As a result of this study, PS anesthetic combination decreased the TP more than MS and MKS anesthetic combination during anesthesia. Although the present study put forward shows these results in rabbits, PS, MS and MKS anesthetic combinations may show different effects on TP.