Surgeon's choice of laser or blade for corneal flap plays role in visual outcome of procedure
New scientific data being presented at this year's ASCRS meeting reveals the key to a better-than-20/20 outcome in LASIK surgery may depend on whether your doctor uses a blade or a laser to create the corneal flap in the first step of the procedure.
"It turns out that the flap that we make in LASIK is not an innocent bystander," says Roger F. Steinert, M.D., 2005 ASCRS president, professor of ophthalmology, professor of biomedical engineering, director of cornea, refractive and cataract surgery, and vice chair of clinical ophthalmology at University of California, Irvine.
"We now have data validating something we suspected for the past year but hadn't firmly proven, which is that the rate of achieving high levels of vision is better with the IntraLase laser than with the conventional metal microkeratome. On theoretical grounds we knew flap creation with IntraLase would be safer, and its performance bore that out. But we didn't anticipate seeing a difference in actual vision. Multiple studies now show higher rates of 20/20, higher rates of better than 20/20, and that Custom treatments show better results as well."
LASIK has always been a two-step process. In the first step, the surgeon makes a thin flap and folds it back for the second step, where an excimer laser is used to ablate corneal tissue for vision correction.
Until now, advancements like Custom LASIK and Wavefront have focused on improving the second step (precision of tissue ablation). But new research shows the importance of the first step on visual outcomes. The discovery was made when surgeons began using a new laser, instead of the hand-held microkeratome blade, to create the corneal flap. Doctors found that in addition to fewer complications, more patients achieved vision better than 20/20 -- up to 20/15 and even 20/12.5 -- when the IntraLase laser was used in the first step. When the microkeratome was used to make the corneal flap, surgeons found a greater incidence of high and low spots and irregular hydration on the corneal surface, factors that can compromise the tissue ablation, and with it the visual outcome. Multiple clinical studies show the IntraLase laser provides for better vision by creating an optimal corneal surface under the flap, allowing for more precise vision correction.
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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