title: Pupil size and quality of vision after LASIK.
abstract: OBJECTIVE
  To evaluate factors related to the quality of vision after LASIK.
  
  
  METHODS
  Survey study.
  
  
  METHODS
  One hundred consecutive patients.
  
  
  METHODS
  LASIK with a 6.0-mm elliptical ablation pattern without transition zone to treat mild to moderate myopia or astigmatism (preoperative manifest spherical equivalent [MSE], -4.79 +/- 1.33 diopters [D]; range, -2.88 to -9.25 D). The second eye was treated 1 month after the first.
  
  
  METHODS
  Completed questionnaires assessing night vision problems (glare, haze, and halo symptoms) before surgery and at 1, 3, and 6 months after surgery in 97, 75, 81, and 66 subjects, respectively. Mesopic pupil size and preoperative and postoperative variables were analyzed with questionnaire data using an analysis of variance (ANOVA) and multivariate regression analysis.
  
  
  RESULTS
  Patients with large mesopic pupils had significantly more reports of glare, haze, and halo than did those with smaller pupils in the treated eye at 1 month after surgery (P=0.02, P=0.03, and P=0.02, respectively ANOVA) and of glare at 3 months (P=0.05). Significant predictors of symptoms at 6 months, identified through multivariate regression analysis, included preoperative MSE (for glare and haze), preoperative contrast acuity (glare), postoperative uncorrected visual acuity (UCVA; haze), and residual cylinder (haze). Together, these factors accounted for only 19% of the overall variability in glare and 37% of the variability in haze responses. No relationship between pupils and symptoms was noted at 6 months after surgery in either the ANOVA or regression analysis group.
  
  
  CONCLUSIONS
  Patients with large pupils had more quality of vision symptoms in the early postoperative period, but no correlation was observed 6 months after surgery. Factors related to long-term symptoms include the level of treatment (preoperative myopia), preoperative contrast acuity, postoperative UCVA, and residual cylinder. Most of the variability in visual quality could not be explained by preoperative or clinical outcome measures, including pupil size.
authors.affiliation: Department of Opthalmology, Naval Medical Center, San Diego, California 92134-5000, USA. sschallhorn@nmcsd.med.navy.mil
authors.forename: Steven C
authors.initials: SC
authors.lastname: Schallhorn
authors.forename: Sandor E
authors.initials: SE
authors.lastname: Kaupp
authors.forename: David J
authors.initials: DJ
authors.lastname: Tanzer
authors.forename: Jim
authors.initials: J
authors.lastname: Tidwell
authors.forename: John
authors.initials: J
authors.lastname: Laurent
authors.forename: Linda B
authors.initials: LB
authors.lastname: Bourque
mesh_terms: D000328:Adult; D000368:Aged; D001251:Astigmatism / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D019466:Glare; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D011680:Pupil / Q000502:physiology*; D011795:Surveys and Questionnaires; D014785:Vision, Ocular / Q000502:physiology*