title: Comparison of high order aberration after conventional and customized ablation in myopic LASIK in different eyes of the same patient.
abstract: OBJECTIVE
  To verify whether there exists any difference in higher order aberrations after undergoing myopic LASIK (laser in situ keratomileusis) with conventional ablation and customized ablation in different eyes of the same patient.
  
  
  METHODS
  This was a prospective randomized study of 54 myopic eyes (27 patients) that underwent LASIK using the Nidek EC-5000 excimer laser system (Nidek, Gamagori, Japan). Topography-guided customized aspheric treatment zone (CATz) was used in the first eye of the patient (study group) and the other eye of the same patient was operated on with conventional ablation (control group). Higher order aberrations [root-mean-square (RMS) in the 5-mm zone] of both groups were observed with the Nidek OPD-Scan aberrometer before and 3 months after LASIK. Preoperative mean refractive error was similar between two eyes of the same patient (t=-0.577, P>0.05).
  
  
  RESULTS
  Preoperatively, higher order aberrations (RMS in the 5-mm zone) in the CATz ablation and conventional groups were (0.3600+/-0.0341) microm and (0.2680+/-0.1421) microm, respectively. This difference was not statistically significant (t=1.292, P>0.05). Three months after LASIK, higher order aberrations (RMS in 5-mm zone) in the CATz ablation and conventional groups were (0.3627+/-0.1510) microm and (0.3991+/-0.1582) microm, respectively. No statistically significant difference was noted between pre- and postoperative higher order aberrations in the CATz group (t=-0.047, P>0.05). However, a statistically significant increase in higher order aberrations was observed after conventional ablation (t=-5.261, P<0.05). A statistically significant difference was noted in the increase of higher order aberrations after LASIK between groups (t=-2.050, P=0.045).
  
  
  CONCLUSIONS
  LASIK with conventional ablation and topography-guided CATz ablation resulted in the same BSCVA (best spectacle-corrected visual acuity) 3 month after LASIK. Higher order aberrations were increased, but the increase of higher order aberrations after customized ablation treatment was less than that after conventional ablation.
authors.affiliation: Department of Ophthalmology, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, China. duchixin@126.com
authors.forename: Chi-xin
authors.initials: CX
authors.lastname: Du
authors.forename: Ye
authors.initials: Y
authors.lastname: Shen
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D009216:Myopia / Q000601:surgery*; D011446:Prospective Studies; D014792:Visual Acuity