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Dorado, Puerto Rico-LASEK has certainly gained some proponents over the last couple of years. These surgeons claim that the procedure is less painful and offers quicker visual recovery than PRK and spares tissue and avoids flap complications associated with LASIK.
Others disagree, claiming LASEK is an extremely challenging procedure that may contribute to a high incidence of haze, according to Louis D. "Skip" Nichamin, MD. He spoke about LASEK and the epi-LASIK procedures during the Current Concepts in Ophthalmology meeting held here, sponsored by Johns Hopkins University School of Medicine and Ophthalmology Times.
LASEK, which is a hybrid procedure of LASIK and PRK, involves the manual creation of an epithelial flap using alcohol to loosen the epithelium. With this surface technique, one lifts only the epithelium and ablates Bowman's membrane, thus the biomechanics of the cornea remain stable, explained Dr. Nichamin, medical director of the Laurel Eye Clinic, Brookville, PA.
In 2002 in the Journal of Cataract and Refractive Surgery, Thomas V. Claringbold, MD, Clare, MI, published a study of more than 200 myopic eyes that he treated with LASEK and followed for 12 months. He concluded that LASEK for myopia was as good as or better than LASIK in terms of refractive and visual results. In fact, there was no loss of best spectacle-corrected visual acuity and no serious complications, Dr. Claringbold reported.
Discussing another viewpoint, Maria R. Chalita, MD, Cleveland, outlined the results of a retrospective study published in 2003 of one surgeon who performed 20 LASEK procedures. The experienced refractive surgeon found the creation of the epithelial flap to be challenging, contributing possibly to a high incidence of haze.
"If you look carefully at the literature, it shows almost a 50-50 split, for those in favor of LASEK and those who aren't," Dr. Nichamin noted. "So the jury is still out on LASEK, whether it is mostly a marketing tool or a real substantive improvement."
Epi-LASIK: an alternative Epi-LASIK may potentially be "the best of all of these worlds," noted Dr. Nichamin, who described the procedure using a unique microkeratome and noted its potential advantages.
Epi-LASIK is a novel approach for surface ablation, developed by Ioannis G. Pallikaris, MD, PhD, professor and chairman of the department of ophthalmology, University of Crete, Greece. It differs from LASEK by the mechanical separation of the epithelium using a subepithelial separating device, which does not require the use of alcohol. The Centurion SES Microkeratome (Norwood Abbey, Ltd.) produces a gutterless flap with a combination blade/cartridge component and a bar applanator, Dr. Nichamin said.
"This device is not cutting a flap but rather bluntly dissecting the epithelium off of Bowman's membrane," he said. "The leading edge is a blunt, plastic-like material that insinuates itself down against Bowman's membrane and brings up the complete epithelial flap."
The main advantage of this approach is the ability to preserve the architecture of the epithelium. Dr. Nichamin noted that histopathologic study shows no blebbing of the basal epithelial cells, and under magnification, the flap appears quite viable.
The microkeratome head, which is long and flat, is being modified currently to hinge upward, so the surgeon working on the left eye will not have to come over the nasal bridge, he said.
Dr. Nichamin, who has experience with the device in the laboratory, noted that the device is small and lightweight and when activated offers only a fraction of the vacuum compared with other microkeratomes.
In a video of the procedure, Dr. Nichamin pointed out how easily the blunt edge of the device found the proper plane to dissect. The epithelial flap was "gossamer thin" and could be manipulated with irrigation.