Eyeworld

54 methods. "I have not tried the ReLEx or SMILE femtosecond meth- ods of refractive surgery," Dr. Chan said. "I have considered incorporat- ing the femtosecond laser platform into my practice, but the inferior accuracy of the laser and the unan- swered questions as to how en- hancements would be performed are the main issues I am concerned about." Dr. Wang also expressed similar concerns. The femtosecond laser is less accurate, so there appears to be a risk of increased higher-order aberra- tions (HOAs) post-op, he said. Furthermore, the procedure does not lend itself to enhance- ments, he said. The most logical way to enhance this procedure would be to perform a PRK, but doing so would require a second laser, and thus it would negate the financial benefit of a single-laser platform. "In SMILE, in which a full-flap ablation is not performed, enhance- ment would present more of a chal- lenge as there is no flap to lift," Dr. Tan said. "In theory, one could per- form surface ablation, but to date we have not needed to perform en- hancement in our pseudoSMILE cases." In FLEx or pseudoSMILE cases, where a full-flap laser incision is per- formed, enhancement can be per- formed, similar to conventional LASIK, in which the flap is relifted and retreatment with an excimer laser can be performed in the usual manner, Dr. Tan said. A potential LASIK partner With these considerations, especially the sacrificing of the excimer laser's accuracy, Dr. Wang said he think the single-laser platform could become a supplement to LASIK to help treat about 5% of the population, chiefly those patients with thin corneas who pose a keratoconus risk. "I would recommend not to jump into it," Dr. Wang said. "Sur- geons should wait to see the long- term results. For now, it is best to stick with the tried-and-true, two- laser platform." Dr. Chan offered a similar as- sessment, noting patients with pre- vious herpetic eye keratitis could benefit. Currently, he avoids using an excimer laser on these patients because of the risk of reactivating the condition, although this is a very small subpopulation of his pa- tients. "I think the femtosecond ap- proach may induce less biomechani- cal change than flap LASIK," Dr. Chan said. "If proven, this could benefit the approximately 25% of my patients who have surface abla- tion instead of LASIK because of sus- pect corneas." EW Editors' note: Dr. Tan and his col- leagues receive research funds from Carl Zeiss Meditec in a collaborative research program at Singapore Eye Research Institute; otherwise, he does not have any financial interests related to his comments. Drs. Chan and Wang do not have any financial interests related to their comments. Contact information Chan: 1300-065-766, colin.chan@vgaustralia.com Tan: +85 6227 7255, snecdt@pacific.net.sg Wang: 615-321-8881, drwang@wangvisioninstitute.com EW REFRACTIVE SURGERY 54 September 2011 Femtosecond continued from page 53 EyeWorld factoid Post-LASIK enhancements are necessary in about 10% of all cases Source: Kellogg Eye Center, University of Michigan

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