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6 Reducing pseudophakic ametropia to drive improved refractive IOL outcomes This, in summary, said Dr. Schallhorn, is a procedure that is easy to perform and used to treat low refractive errors. In fact, Dr. Schallhorn has no set minimum limit of refractive error to treat. "It depends on the discussion with the patient," he said. "I personally don't have any lower limits on who I'm going to treat." Even with small refractive errors, including those less than 0.5 D, the procedure achieves significant improvement in sphere and cylinder with good refractive predictability while improv- ing UDVA. "It's up to the patient, the patient's needs, whether I think I can improve the unaided vision and whether the expected improvement is worth the risk of the proce- dure itself," he added. "Fortunately, the procedure is very safe, producing no mean change in BCVA [best corrected visual acuity] in this study." Performing PRK The first thing surgeons should always do when it comes to performing PRK, said Karl G. Stonecipher, MD, director of laser and refractive surgery, Laser Eye Centers, Greensboro, N.C., is tell their patients the difference between PRK and LASIK. This is particularly important in the immediate postoperative course. Patients may come in having heard about the quick recovery of friends who have had LASIK; in con- trast, PRK produces more postoperative discomfort and irritation. Knowing this, Dr. Stonecipher pre- scribes all his patients pain medication and sleeping pills. He does not require that his patients take the medication, but the pills can help them through the postoperative discomfort. Perhaps most important is to have a regimen. "You have to stick with what you do," he said. "That affects your nomogram and your outcomes." For myopic or myopic astigmatic patients, Dr. Stonecipher performs transepithelial PRK. He programs the laser to perform a 60- to 68-micron photothera- peutic keratectomy (PTK)—60 microns if the patient has had no previous surgery, 68 microns if the patient has had previous surgery—with a diameter of 6.5 mm, transition zone of 0.5 mm, spherical adjust- ment of 0.66 D—basically lasing away the surface "until the fluorescence is gone." "There's a little bit of an art to it but it's not that hard," he said. Once the epithelium has been re- moved, Dr. Stonecipher waits for a minute with air flowing across the surface to dry it. He then performs a no-touch technique and uses the laser to treat the refractive error with a standard PRK of 6.0 mm. He applies 12 seconds of mitomycin-C (MMC) if indicated, as in all enhancements. He irrigates with frozen balanced salt solution and applies all his topical medication at the end. A transepithelial approach is not pos- sible with mixed astigmatism, hyperopia or hyperopic astigmatism—"Our lasers don't go out that far in terms of PTK," said Dr. Stonecipher. Instead, he performs alcohol epithelium removal, applying 20% alcohol Improvement in spherical equivalent after performing PRK in multifocal patients Improvement in UCVA after performing PRK in multifocal patients

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