Intraocular pressures after ketamine and sevoflurane in children with glaucoma undergoing examination under anaesthesia

AIM: For accurate intraocular pressure (IOP) measurement in very young children examination under anaesthesia (EUA) may be necessary. Most anaesthetic agents used for EUA have some effect on IOP. We compared IOPs in children after ketamine and sevoflurane anaesthesia. METHODS: Consecutive patients with definite or suspected glaucoma, uncooperative for reliable IOP measurement in clinic and requiring EUA, were included in this study. IOPs were measured after intramuscular injection (5 mg/kg) or intravenous injection (2 mg/kg) of ketamine using a Perkins applanation tonometer. Three measurements were taken from each eye. The IOPs were rechecked after sevoflurane, given for maintenance anaesthesia. Mean IOPs were used for analysis. Paired t test was used to assess the differences in IOPs for the whole group and one-way ANOVA for the three subgroups (ketamine IOP <20, 20-30, >30 mmHg). RESULTS: The records of eight patients (16 eyes) were available for review. The mean age was 55.42 (SD 25, range 26-89) months. Seventy data-points from both eyes (35 EUAs) were used for the analysis. The mean IOP after sevoflurane (17 (SD 10) mmHg) was statistically lower than after ketamine (24.4 (SD 12.7) mmHg, p<0.001). The percentage difference was 28.5 (SD 20.8; 95% CI 23.5 to 33.4)). The difference between the subgroups was not statistically significant (p = 0.192). CONCLUSION: Sevoflurane lowers the IOP significantly compared with the IOP measured after ketamine. This difference is independent of the IOP level. It may be important to use ketamine as the induction anaesthetic agent when accurate IOP measurement is necessary during EUA for children.