Laser in situ keratomileus using the LaserSight 200 laser: Results of 950 consecutive cases

Purpose: To examine the refractive outcome in 950 consecutive eyes having l aser in situ keratomileusis (LASIK) by 1 surgeon with experience in keratom ileusis, Setting: Outpatient excimer laser surgical facility. Methods: This study comprised 950 consecutive eyes of 475 patients having L ASIK as a primary procedure with a LaserSight 200 excimer laser (8.51 softw are). A nasal hinged flap and a Chiron microkeratome were used. Preoperativ e cycloplegic refraction was done only in patients younger than 25 years an d in all hyperopic cases, Subjective preoperative and postoperative manifes t refractions were done after autorefractometry in all cases. In cases of h yperopia, the software was modified by adding 30% to the refractive error. Enhancement results are not included. Results: Of the 950 eyes, 893 (94.00%) were myopic and 57 (6.00%), hyperopi c, in the low myopia group (1.00 to 3.99 D) of 223 eyes (24.97%), mean sphe rical equivalents (SEs) were -2.90 D +/- 0.56 (SD) preoperatively, -0.46 +/ - 0.6 D 3 months postoperatively, and -0.41 +/- 0.5 D 6 months postoperativ ely. In the moderate myopia group (4.00 to 5.99 D) of 205 eyes (22.96%), re spective mean SES were -4.90 +/- 0.7 D, -0.90 D +/- 0.9 D, and -0.67 +/- 0. 7 D. In the high myopia group (6.00 to 9.99) of 266 eyes (25.30%), the resp ective-means were -7.70 +/- 1.3 D, -0.76 +/- 0.99 D, and -0.60 +/- 0.8 D. I n the extreme myopia group (10.21 to 30.00) of 199 eyes (22.28%), the respe ctive means were -13.30 +/- 2.9 D, -1.30 +/- 1.4 D, and -1.13 +/- 1.3 D, Fo r the entire myopic group, the mean astigmatism was +1.55 +/- 1.38 P, +1.09 +/- 0.92 D, and +0.87 +/- 0.79 D, respectively, The low hyperopia group (1 .00 to 2.99 D) of 39 eyes (68.42%) had a mean preoperative SE of +1.80 +/- 0.59 D and mean postoperative SEs of +1.00 +/- 0.76 D at 3 months and +1.16 +/- 0.52 D at 6 months. The respective means in the moderate hyperopia gro up (3.00 to 6.00) of 18 eyes (31.57%) were +4.62 +/- 1.19 D, +3.71 +/- 1.12 D, and +4.00 +/- 1.07 D. Conclusions: Laser in situ keratomileus for myopia using the LaserSight 200 excimer laser was stable with time and safe for the correction of differen t degrees of myopia. In the hyperopic group, marked regression occurred in a large percentage of patients. Thus, we will not perform LASIK for hyperop ia until the software improves.