Comments on 23-gauge versus 20-gauge system for pars plana vitrectomy.

摘要

We read with interest the paper by Wimpissinger et al, comparing the sutureless 23-gauge (23GA) system with a standard 20-gauge (20GA) system for pars plana vitrectomy, in a randomised clinical trial. We aim to highlight a few issues in the design, methodology and analysis.The authors have analysed postoperative pain and conjunctival injection as primary outcome measures. The effort by the assessor to elicit a response on the degree of pain is likely to be biased if they are not masked, as in this study. In assessment, the authors have used descriptive terms like no pain, mild, moderate and severe pain.