Sir,

We welcome the fact that our paper has stimulated debate on pain relief in laser therapy and that we have received responses from Stanga and Muqit,1 and YiJun Hu.2 It became apparent during our 2006 survey of ophthalmic units across the United Kingdom that a small number of units had started using Pascal laser photocoagulation, and we reported that the respondents considered that this was improving the situation with regard to pain and compliance during the procedure. These comments were anecdotal and were reported in the paper. We noted in the conclusion that the results should be viewed with caution because of the nature of the surveys and that newer lasers were being introduced at the time of the survey.

In terms of analgesia, we reported that 9% of units routinely use sub-tenons anaesthesia. We stated that there may be a case to support the use of sub-tenons based on the laser being used at the time, but suggested caution because of the potential side effects that Stanga et al allude to in their letter and also that new lasers that may cause less pain were emerging.

YiJun Hu makes an excellent point about pain assessment. As this was a survey of practitioners, we only have their viewpoint and we did not therefore attempt to offer any results from the patient's perspective. What was clear from many responses was that the responders often considered that their own patients were not in pain but that they knew colleagues for whom pain was an issue when they performed this therapy, which seems to suggest that different practitioners do identify pain differently.

Regarding the ‘strength of burns per session’ identified by Stanga and Muqit as requiring clarification, this was a term proposed during our questionnaire pilot. It was apparent that laser ‘settings’ were variable and that therapists identified different aspects of ‘strength’, such as ‘intensity’ and ‘fluence’, mentioned by Stanga and Muqit. The decision to go with ‘strength’ was taken to try to cover all of these aspects and also to assist with questionnaire brevity, that is, to have one question to cover them all. Few respondents had difficulty with this term, but a small number of them clarified their understanding of the term in their response.