Sir,

A Sub-tenon block (STB) is the most preferred choice of anaesthesia in the United Kingdom for cataract surgery. STB offers good akinesia and anaesthesia with a relatively low complication rate.1, 2 Nonetheless, STB has potentially serious complications including severe chemosis, and increased ocular pressure.3 Since the late 90s, topical anaesthesia (TA) has been described as a safe alternative for injection anaesthesia in cataract surgery.4, 5

We studied patient satisfaction with topical and sub-tenon anaesthesia and the factors that may affect patient satisfaction in cataract surgery.

A written questionnaire was distributed to 56 patients within 30 min post-operatively. The modified Iowa Satisfaction with Anaesthesia Scale (ISAS) was used, where patients responded to five statements (eg, ‘I would want to have the same anaesthetic again’) by placing a mark along a six choice vertical response column (eg, ‘Disagree moderately’). In each statement, totally satisfied patient would score +3, a totally dissatisfied patient would score −3. The maximum and minimum score was 15 and −15, respectively. Additionally, patients were asked to score their level of pain on a Visual Analogue Scale (VAS) from 0–10, 0 being no pain and 10 being the worst pain experienced.

Analysis of the ISAS responses showed a mean score of 12.4 for the STB group (SD=3.75) and 11.1 for the TA group (SD=5.93), suggesting higher but not statistically significant (P=0.399) patient satisfaction in the STB group. However, significant differences were seen in patient satisfaction with reduced duration of the operation (P<0.002) and seniority of operating surgeon (P<0.004). Post-operative pain evaluation using VAS showed no statistical difference between STB and TA groups. There were two cases (3.4%) of excessive pain experienced in TA group, requiring conversion to injection anaesthesia. In STB group, one patient had severe chemosis, one patient with minimal akinesia interfering with the surgery, resulting in reinforcement of anaesthesia.

We have found that there is no significant difference in patient satisfaction between the two groups. Patient satisfaction is, however, affected by the duration of the operation and seniority of the surgeon, which suggests that more complicated cases are best performed by senior surgeons.