AUTOMATED LAMELLAR KERATOMILEUSIS IN-SITU FOR MYOPIA

BACKGROUND: Keratomileusis in situ, particularly automated lamellar ke ratoplasty, is a commonly performed technique of keratomileusis in the United States. METHODS: A single center consecutive series of 152 eye s undergoing keratomileusis in situ for myopia was analyzed. Spherical equivalent refractions were compared before and after surgery. The st andard nomogram supplied with the automatic corneal shaper (Chiron Vis ion Corp, Irvine, Calif) was used. The mean of preoperative myopia tre ated was -9.30 +/- 3.10 diopters (D) (range, -5.12 to -22.75 D). RESUL TS: Of the 144 eyes with 1 month follow up, 30 (21%) were within 0.50 D of the planned correction at 1 month, 54 (38%) were within 1.00 D, a nd 97 (67%) were within 2.00 D. At 6 or more months follow up, 51 of 6 8 eyes (75%) achieved uncorrected visual acuity of 20/40 or better and 13 of 68 (19%) 20/20 or better when eyes with macular degeneration an d amblyopia were removed. Forty-six of 78 eyes (59%) with 6 months or greater follow up required retreatment procedures to correct residual myopia or astigmatism Multiple regression analysis explained 40% of th e variation between attempted correction and postoperative results. An overall 5% shift of refraction in the myopic direction occurred betwe en 1 and 6 months. Of the 110 eyes with both 1- and 3-month examinatio ns, the spherical equivalent refraction changed between these time int ervals by 1.00 D or more in 54 (49%) eyes; and 11 (31%) eyes changed b y 1.00 D or more between the 3- and g-month examinations. Although 6% of eyes lost 2 or more lines of spectacle-corrected visual acuity, 11% gained 2 or more lines. CONCLUSION: Myopic keratomileusis in situ usi ng the automated lamellar keratoplasty technique appears to be a safe and most effective procedure to reduce moderate to high myopia. Howeve r, the predictability of the procedure needs improvement.