Sir,

I would like to comment on the patient information leaflet (Appendix I) in Cataract Surgery Guidelines published by the Royal College of Ophthalmologists in February 2001.1 It states that patients given local anaesthesia during cataract surgery ‘will not be able to see what is happening, but will be aware of a bright light’. I believe this advice contradicts recent findings published in the literature.

 First, not all patients given local anaesthesia will be aware of a bright light. Studies by Talks et al2 and Scott et al3 showed that 25% and 22% of their series of patients respectively had no perception of light following a peribulbar injection. Other studies have documented that 15.7–20% of patients had no light perception in the operated eye during cataract surgery under retrobulbar anaesthesia.4,5 Even under topical anaesthesia, six out of 102 patients in one series lost light perception for a short interval during cataract surgery.6

Second, besides light perception, many patients are aware of a variety of visual sensations in the operated eye during cataract surgery under retrobulbar, peribulbar or topical anaesthesia.4,5,6,7,8,9,10 These visual sensations include perception of movements, flashes, one or more colours, surgical instruments, surgeon’s hand/fingers, surgeon and a change in light brightness. The proportion of patients who perceived these sensations in several clinical studies is summarised in Table 1.

Table 1 Intraoperative visual sensation during cataract surgery under local anaesthesia
Full size table

I am concerned that the advice that patients ‘will not be able to see what is happening, but will be aware of a bright light’ is neither complete nor accurate based on current evidence in the literature. Some patients may therefore become unduly anxious and frightened when they either experience additional visual sensations besides a bright light, or when they see only a dim light or have no light perception during the surgery. In fact, 15.4% of patients who were not informed of potential intraoperative visual sensations preoperatively in one series found their visual experience during phacoemulsification under topical anaesthesia frightening.9

Preoperative counselling about potential visual sensations that may be experienced during cataract surgery is conceivably more effective when the information given is complete and accurate. Preliminary findings from a multicentre randomised clinical trial show that patients who were given additional detailed counselling about potential intraoperative visual sensations were less likely to find their visual experience frightening than those who were not counselled.11