ONE-YEAR RESULTS OF A PROSPECTIVE MULTICENTER STUDY OF THE CASEBEER SYSTEM OF REFRACTIVE KERATOTOMY

Purpose: To evaluate the clinical results, predictability, stability, safety, and the patient satisfaction after refractive keratotomy for t he correction of myopia and astigmatism using a defined protocol (the Casebeer system). Methods: The authors enrolled 324 patients (615 eyes ) in a prospective study conducted by 18 surgeons, All procedures were performed using ultrasonic pachymetry with the diamond knife blade se t at a length of 100% of the temporal paracentral corneal thickness re ading and four to eight centripental (Russian style) incisions with or without fixation of the globe, Straight transverse incisions were don e for astigmatism in 222 (36%) eyes. One to eight repeated operations (enhancements) were done on 241 (39%) eyes. Results: Mean baseline cyc loplegic refraction was -3.68 +/- 1.59 diopters (D) (range, -0.88 to - 8.25 D). One-year data were available for 546 eyes (89%). At 1 year, m ean spherical equivalent cycloplegic refraction was -0.27 +/- 0.78 D ( range, -3.13 to +3.00 D). There were 373 (68%) eyes with a refraction of +/-0.50 D, and 483 eyes (89%) within +/-1.00 D of emmetropia. Ten e yes (2%) were overcorrected by more than 1.00 D. Mean baseline refract ive cylinder was 1.01 +/- 0.75 D (range, 0-5.75 D); at 1 year, the mea n cylinder was 0.40 +/- 0.55 D (range, 0-2.50 D). Uncorrected visual a cuity was 20/20 or better in 297 (54%) eyes and 20/40 or better in 93% , Six eyes (1%) lost two to three lines of spectacle-corrected visual acuity; the worst visual acuity was 20/30. Of patients responding to a standardized questionnaire, 320 (77%) wore no spectacles for distance or near vision; there was a significant increase in glare and fluctua tion of vision from baseline; and 247 (90%) were very satisfied with t he outcome, Conclusions: Refractive keratotomy using radial incisions with or without transverse incisions and following the Casebeer system effectively reduces and often eliminates myopia and astigmatism with a high degree of safety, Enhancement surgery was required in 39% of ey es, Glare and fluctuation of vision increased postoperatively but were rated mild, and patient satisfaction was high.