title: Refractive outcome following radial keratotomy and combined radial and astigmatic keratotomy.
abstract: OBJECTIVE
  To determine whether the visual and refractive outcomes of combined astigmatic and radial keratotomy (AK/RK) procedures was different from that following RK for the correction of naturally occurring compound myopic astigmatism and spherical myopia.
  
  
  METHODS
  Private professional practice, San Diego, California, USA.
  
  
  METHODS
  The computer database of all incisional procedures performed by one surgeon over 10 years was reviewed to compare the visual acuity outcome of AK/RK and RK procedures. Enhancement procedures were excluded. Only data from the last office visits were analyzed to establish the relationship between visual acuity and type of keratotomy procedure performed. A multiple regression model was constructed, which included covariates of age, postoperative keratometric cylinder, and postoperative refraction.
  
  
  RESULTS
  After controlling for covariates, the AK/RK population had significantly lower postoperative uncorrected visual acuity levels than the RK population (P < .03) after one operation (prior to enhancement surgery).
  
  
  CONCLUSIONS
  Using the nomograms for myopia correction for unenhanced RK cases, combined AK and RK procedures appeared to reduce the expected visual results. Surgeons may consider modifying surgical nomograms to account for the expected spherical undercorrection that can occur when myopia and astigmatism are corrected simultaneously.
authors.affiliation: Ophthalmology Research Laboratory, National Vision Research Institute, San Diego, California, USA.
authors.forename: G W
authors.initials: GW
authors.lastname: Flanagan
authors.forename: P S
authors.initials: PS
authors.lastname: Binder
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000503:physiopathology / Q000601:surgery*; D003315:Cornea / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D007646:Keratotomy, Radial; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D012029:Refraction, Ocular; D014792:Visual Acuity / Q000502:physiology*