External dacryocystorhinostomy with and without silicone intubation.

摘要

Saiju and colleagues carried out a study to address the important issue of whether silicone intubation is necessary in external dacryocystorhinostomy (DCR) surgery. They concluded that DCR without silastic intubation is less expensive than DCR with silastic intubation in primary uncomplicated NLDO and has a similar success rate.There is no evidence that a prestudy sample size calculation was performed, and the numbers in the trial (100 patients enrolled in total) are far too low to detect any realistic clinical difference between the two arms of the study. Furthermore, no confidence intervals are given. It is particularly important for equivalence studies to be adequately powered; otherwise, one is bound to conclude that there is no significant difference when there is merely insufficient power to detect a difference.