One-year outcome of bilateral randomised prospective clinical trial comparing photorefractive keratectomy (PRK) with mitomycin C (MMC) and laser in situ keratomileusis (LASIK).

摘要

We read with great interest the article by Wallau and Campos, who compared the 1-year outcome of photorefractive keratec-tomy (PRK) with mitomycin C (MMC) and laser in situ keratomileusis (LASIK) in a bilateral randomised prospective clinical trial. The authors concluded that Wavefront-guided PRK with 0.002% MMC is more effective than wavefront-guided LASIK for correction of moderate myopia, which is consistent with previous studies.We would like to make the following comments.The authors have conducted a bilateral randomised control trial; however, there is no mention of whether the postoperative evaluations were masked or not, as this could introduce an element of bias.The authors claim that there is a statistically significant difference in the uncor-rected visual acuity (UCVA) with a UCVA better than 20/12.5 in the PRK+MMC group versus the LASIK group, with 52% of the eyes in the former group achieving >20/12.5 UCVA as compared with 31% in the latter. However, it is not clear why the authors have selected 'supranormal' UCVA for the cut-off rather than normal vision (20/20). It would be useful to know how many in each group had a UCVA of 20/20.