Letters: July 13

Given the recent adjudication by the Advertising Standards Authority (ASA) as reported in Optician on June 1 2007, I was surprised to read your article ‘The clinical performance of two daily disposable contact lenses’ in the July 6 issue detailing a study comparing the performance of 1-Day Acuvue with Focus Dailies with AquaComfort.

The ASA adjudication deemed that this study, sponsored by Johnson & Johnson, as well as three other studies submitted by Johnson & Johnson, were not sufficient to substantiate claims of superior comfort and from the information provided lacked scientific rigour.

In the above study, two separate groups of patients wore only one contact lens type, however no details of previous lens brand or wearing experience, occupation or lifestyle for each group of subjects have been presented. The ASA took advice from an independent expert in the field who expressed concern that this study was likely to produce questionnaire bias and that it would have been more appropriate to conduct a cross-over study where each patient wore both types of lenses.