A prospective randomised study of local versus general anaesthesia for cataract surgery.

One hundred and sixty-nine patients (aged 65-98 years) were randomised to receive either local or general anaesthesia for cataract surgery. Cognitive function was assessed using a battery of psychometric tests performed pre-operatively, and at 24 h, 2 weeks and 3 months postoperatively. Oxygen saturation, blood pressure and heart rate were monitored and the results recorded throughout the anaesthetic and immediate recovery period. In the general anaesthetic group, 19% of patients experienced at least one episode of oxygen desaturation during the procedure compared with none in the local anaesthetic group. Pulse rate and blood pressure were stable in the local anaesthetic group compared with the general anaesthetic group where marked fluctuations were noted; 61% of patients in the general anaesthetic group experienced falls in systolic blood pressure greater than 30% of the pre-induction value. No evidence of long-term postoperative cognitive dysfunction was detected and there was no significant difference between the performances of the two groups.