title: Stereoacuity changes after laser in situ keratomileusis.
abstract: OBJECTIVE
  To study changes in near and distance stereoacuity after laser in situ keratomileusis (LASIK).
  
  
  METHODS
  A prospective interventional study was conducted at an apex tertiary care ophthalmology center in India. Near and distance stereoacuity was tested in 40 patients (80 eyes) who underwent LASIK for myopic correction and got unaided vision of 0.67 or better in each eye. Stereoacuity was tested with best spectacle correction before LASIK, and post-LASIK stereoacuity was tested with unaided eye near and distance Randot tests.
  
  
  RESULTS
  Forty patients (80 eyes) had a mean (±SD) pre-LASIK refractive error of -4.70 (±1.72) DS OD and -4.59 (±1.58) DS OS and a mean (±SD) anisometropia of 0.55 (±0.51) DS. The median pre-LASIK near stereoacuity was 70 arcsec and distance stereoacuity was 200 arcsec, both of which improved after LASIK to 30 and 60 arcsec, respectively (p < 0.001, both). Amount of refractive error was not associated with stereoacuity but anisometropia of greater than or equal to 1 diopter had significantly worse distance stereoacuity in both the pre-LASIK and post-LASIK period. The post-LASIK near stereoacuity and distance stereoacuity were strongly associated (r = 0.706, p < 0.001) unlike the change in stereoacuity.
  
  
  CONCLUSIONS
  Near and distance stereoacuity shows significant improvement after LASIK. Stereoacuity is associated with the degree of anisometropia but not the amount of refractive error corrected.
authors.affiliation: *MD Dr. Rajendra Prasad Center for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India (all authors).
authors.forename: Digvijay
authors.initials: D
authors.lastname: Singh
authors.forename: Rohit
authors.initials: R
authors.lastname: Saxena
authors.forename: Rajesh
authors.initials: R
authors.lastname: Sinha
authors.forename: Jeewan S
authors.initials: JS
authors.lastname: Titiyal
mesh_terms: D000293:Adolescent; D000328:Adult; D015858:Anisometropia / Q000503:physiopathology*; D003867:Depth Perception / Q000502:physiology*; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D011446:Prospective Studies; D015348:Vision, Binocular / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology*; D055815:Young Adult