Flap complication rate for two microkeratomes.

To the Editor: The article “Lower Intraoperative Flap Complication Rate with the Hansatome Microkeratome Compared to the Automated Corneal Shaper” (Walker MB, Wilson SE. J Refract Surg 2000;16:79-82) concludes that the Hansatome is less likely to have intraoperative flap complications than the Automated Corneal Shaper (ACS). This may be true but the methods used in the study do not allow this conclusion to be made. The authors performed 130 cases with the ACS (only counting 90) and then performed 598 cases with the Hansatome. This study is in no way random and is invalidated by not taking the learning curve into consideration. Essentially every study with lamellar corneal surgery identifies that a learning curve with the microkeratome is a major factor in the rate of intraoperative complications. The authors make a short comment that they “do not believe that the learning curve is attribuatable to the difference in complication rates...in this study” but they give no explanation why they believe this. Do they feel their surgical skills make them immune to this factor? If the authors want to truly show a lower complication rate with the Hansatome they need to perform several hundered cases, alternating each eye with the ACS and the Hansatome, and then compare the rates of intraoperative complications. I would think with this additional experience they would have a much lower rate of complications with the ACS compared to their reported study. By failing in the methodology the authors show only that lamellar corneal surgery has a learning curve with the microkeratome. Michael Campion, MD Mesa, Arizona