title: [Clinical studies on Q-factor guided LASIK for the correction of myopic astigmatism].
abstract: OBJECTIVE
  To compare the results of the Q-factor guided LASIK with the conventional LASIK for the correction of myopic astigmatism.
  
  
  METHODS
  Forty-three eyes underwent Q-factor guided LASIK and 41 eyes were received conventional LASIK. The patients were followed up for more than 3 months . Examinations included refraction, distance and near vision, noncontact tonometer, topography (provide Q value), aberrometer, ultrasonic pachymetry, contrast sensitivity function.
  
  
  RESULTS
  At 3 months, 97.67% of Q-factor guided LASIK eyes attained UNCVA 1.0 or better and 97.56% eyes in the control group. The mean postoperative SE for Q-factor guided LASIK group was (-0.19 +/- 0.20) diopters (D) at 3 months and (- 0.17 +/- 0.17) diopters (D) in conventional LASIK group. The postoperative Q value of Q-factor guided LASIK was (0.50 +/- 0.28) and (0.82 +/- 0.40) in the conventional LASIK group, significant difference was noted between two groups. Both Q-factor guided LASIK and conventional LASIK significantly increased spherical aberration, the mean RMS of postoperative spherical aberration were (-0.265 +/- 0.156) microm, (-0.487 +/- 0.159) microm respectively, significant difference were noted between two groups at 3 months . Contrast sensitivity was reduced at 1 week and restored at 1 month postoperatively in Q-factor guided LASIK, while in conventional LASIK it was reduced at 1 week, 1 month and restored at 3 months. Corneal topography revealed in Q-factor guided LASIK the diameter of effective optical zone (EOZ) was (5.74 +/- 0.22) mm. However postoperative EOZ of conventional LASIK was (5.34 +/- 0.29) mm in control group.
  
  
  CONCLUSIONS
  Q-factor guided LASIK is effective, safe and predictable for correction of myopic astigmatism. The postoperative visual quality of Q-factor guided LASIK is better than that of conventional LASIK due to its superiority for correction of spherical aberration.
authors.affiliation: State Key Laboratory of Ophthalmology & Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China.
authors.forename: Guo-Fu
authors.initials: GF
authors.lastname: Huang
authors.forename: Bin
authors.initials: B
authors.lastname: Yang
authors.forename: Zheng
authors.initials: Z
authors.lastname: Wang
authors.forename: Xiao-Xiao
authors.initials: XX
authors.lastname: Zhang
authors.forename: Ping
authors.initials: P
authors.lastname: Qiu
authors.forename: Sheng
authors.initials: S
authors.lastname: Zhou
mesh_terms: D000293:Adolescent; D000328:Adult; D001251:Astigmatism / Q000601:surgery*; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D008297:Male; D009216:Myopia / Q000601:surgery*; D016896:Treatment Outcome; D055815:Young Adult