Enflurane, isoflurane and the eye

The intra-ocular pressure was monitored in ophthalmological patients in whom nitrous oxide/oxygen anaesthesia was supplemented with an inspired concentration of 1% enflurane (10 patients) or 0.7% isoflurane (10 patients). These concentrations are proportionate to 0.6 MAC in oxygen. Both agents caused a significant decrease in intra-ocular pressure, enflurane by a mean of 3.1 mmHg (0.4 kPa) and isoflurane by 2.1 mmHg (0.3 kPa). There was no significant difference between agents. Isoflurane offers an alternative to enflurane in surgery when intra-ocular pressure is of importance.