Eyeworld

EW FEATURE 52 by Faith A. Hayden EyeWorld Staff Writer Surface ablation for the refractive surgeon Managing haze, pain, and scarring in PRK and LASEK I f recent surveys are any indica- tion, there's a back to the sur- face movement happening among refractive surgeons. According to the 2010 Practice Styles and Preferences of U.S. ASCRS Members report by David Leaming M.D., Palm Springs, Calif., 4.6% of those polled were not currently per- forming surface ablation but planned to start. Results were similar in 2009, with 3% and 4% prepping to take on PRK and LASEK, respec- tively. "When I talk to people and say I'm surface, 5 years ago the response was, 'Are you kidding? How do you deal with the pain and scarring?'" said Emil Chynn, M.D., founder, Park Avenue LASEK, New York. "Now when I say that, they say, 'I've been thinking of doing that in gen- eral, and I am doing that on select cases like the high prescriptions.'" It's true that surface ablation has some negatives such as slower visual recovery, occasional discomfort dur- ing healing, and haze with the po- tential of scarring. There's also less of a "wow factor" in comparison to LASIK; patients don't go to work the day after surface ablation. But PRK and LASEK enable surgeons to ex- pand their patient pool to those with a higher refractive error—such as the –22 Dr. Chynn recently treated—as well as patients with thin corneas, previous flap compli- cations, and corneal scars. There are also strategies to minimize—if not eradicate—pain, haze, and scarring. "There are things you can do be- fore surgery, in surgery, and right af- terward that make a big difference," said Daniel S. Durrie, M.D., clinical professor of ophthalmology, Univer- sity of Kansas, Overland Park. For instance, resolve any ble- pharitis, dry eye, red eye, or meibo- mian gland disease before surgery to avoid operating in a hostile environ- ment. Those patients are eligible for treatment, but only after they're on an established routine of cleaning their eyelids, using Restasis (cy- closporine, Allergan, Irvine, Calif.), and whatever else needed to create a healthy surgical setting. Dr. Chynn likes to pre-dose all patients with oral and topical steroids the morning of surgery in order to immunosuppress them and relies on mitomycin C intraopera- tively to avoid scarring. "If you don't use mitomycin, the patient is going to scar," he said. "We're using mitomycin based on laser time. If the patient is a myope, we're doing the same time as laser time. If the patient is a hyperope, we're doing the laser time divided by two. It reduces scarring to almost zero." Dr. Durrie has a different ap- proach to mitomycin usage and doesn't believe it should be used for everyone having surface ablation. "It's a toxic chemical that I don't want to use unless it's neces- sary," he said. He recommended using it for high myopic corrections above six diopters and in young patients under 30. "Younger patients are more likely to have haze, and people who have high corrections are more likely to have haze," Dr. Durrie said. "I also use it on anyone who has had previous surgery, like a corneal transplant, and those with very ac- tive corneas." For those patients, Dr. Durrie recommended using mitomycin at 0.2% for 12 seconds. He also believes surgeons are removing more epithe- lium than they need to and sug- gested reducing the size of the epithelial defect from 9 mm to 7.5 mm. "Using a 7.5 mm epithelial de- fect is one of those big things you can do," he said. "There are no prob- lems with it optically, and it's been February 2011 Challenging refractive cases October 2011 AT A GLANCE • Surface ablation gives surgeons a larger patient pool to treat • To avoid haze, make sure the epithelial defect closes as quickly as possible • If haze develops, it will clear up with a tapered steroid regimen. No other intervention is needed • If a patient scars, perform a transepithelial removal of the epithelium using a laser with PTK mode Successful LASEKs of primary granular corneal dystrophy Source: Emil Chynn, M.D. 52-67 Feature_EW October 2011-DL33_Layout 1 9/29/11 4:51 PM Page 52

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