Visual perception during phacoemulsification cataract surgery under subtenons anaesthesia

The aim of this study was to record the subjective visual experience of patients during phacoemulsification and intraocular lens implantation under subtenons anaesthesia.

Prospective, nonrandomised, cohort, postoperative questionnaire based study. Patients selected underwent routine phacoemulsification and intraocular lens implantation under regional subtenons anaesthesia. chi(2) and Fisher's exact tests (two-tail) were used to evaluate the data.

A total of 104 patients were selected, 38 (36.5%) were male and 66 (63.5%) were female. The mean age of patients was 74.0+/-8.8 years. In all, 87.5% saw light during the operation with 9.6% finding this painful. Photophobia was highest among younger patients (P=0.002). Coloured lights were seen by 56.7% and 13.5% found the visual experience frightening. Frightening visual experiences were significantly associated with the perception of colour (P=0.005) and photophobia (P=0.003). A volume of anaesthetic greater than 4 m was associated with a significant reduction in anxiety as a result of the visual experience (P=0.003). None of the other visual phenomena recorded were associated with a frightening visual experience.

Patients undergoing regional anaesthesia experience a wide variety of visual sensations during cataract surgery. Perception of colour and volumes of anaesthetic less than 4 m appear to be associated with the visual experience being more frightening. Detailed preoperative counselling is mandatory. It should include comprehensive information about visual perception during the procedure relieving the patients from unnecessary distress.