[Behavior of intraocular pressure in anesthesia with isoflurane in comparison with propofol/alfentanil]

To investigate the influence of isoflurane anaesthesia versus total intravenous anaesthesia with propofol/alfentanil on intraocular pressure (IOP).

40 patients undergoing ophthalmic surgery were randomly allocated to two study groups. In group 1 (n = 20), anaesthesia was induced with thiopentone 4 mg/kg and alfentanil 15 micrograms/kg. Maintenance of anaesthesia was achieved with isoflurane 0.5-0.8 Vol.% and 70% nitrous oxide in oxygen. Patients in group 2 (n = 20) received propofol 1.5 mg/kg, which was followed by a continuous infusion of 6 mg/kg/h. In addition, alfentanil 15 micrograms/kg was administered, followed by a continuous infusion of 15 micrograms/kg/h. In both groups, endotracheal intubation was facilitated by succinylcholine 1 mg/kg, and further muscle relaxation was achieved with vecuronium 0.07 mg/kg. Measurements of IOP using an applanation tonometer were taken in each patient at 10 different time points.

In both groups, there was a significant decrease in IOP after induction of anaesthesia. No significant differences in IOP occurred between groups, with patients in group 2 showing a trend towards lower IOP values.

We conclude from our results that both anaesthetic techniques can be administered if increases in IOP have to be avoided.