title: Vector analysis of corneal and refractive astigmatism changes following toric pseudophakic and toric phakic IOL implantation.
abstract: OBJECTIVE
  To determine the efficacy of the astigmatism correction following toric intraocular lens (IOL) and toric phakic IOL (pIOL) implantation in eyes with no previous ocular surgery and in postkeratoplasty (PKP) eyes. In addition, changes in corneal astigmatism were determined.
  
  
  METHODS
  Astigmatism was analyzed in 35 eyes with an AcrySof toric IOL, 35 eyes with an Artiflex toric pIOL, 50 eyes with an Artisan toric pIOL, and 40 PKP eyes with an Artisan toric pIOL. Refractive astigmatism was analyzed by using Alpins method. Surgically induced corneal astigmatism (SICA) was determined following a superior 2.2-mm, 3.4-mm, or 5.4-mm incision. Follow-up was 12 months.
  
  
  RESULTS
  Following toric IOL implantation, the index of success was 0.14 and overall residual astigmatism, 0.37 diopter (D). Following toric pIOL implantation, the index of success was 0.32 (Artiflex) and 0.18 (Artisan), and overall residual astigmatism was approximately 0.60 D. In PKP eyes, Artisan pIOLs resulted in an index of success of 0.28 and overall residual astigmatism of 1.56 D. The SICA, following 2.2-mm, 3.4-mm, 5.4-mm (normal eyes), and 5.4-mm (PKP eyes) incisions, was -0.25 ± 0.42 D (P = 0.108), -0.31 ± 0.43 D (P < 0.001), -0.48 ± 0.55 D (P < 0.001), and -0.49 ± 1.48 D (P = 0.035), respectively.
  
  
  CONCLUSIONS
  Toric IOLs and pIOLs provide an effective astigmatism correction. Incorporating the SICA into the toric IOL power calculation may further increase their effectiveness. Therefore, incorporation of 0 D, -0.30 D, or -0.50 D of SICA for a 2.2-, 3.4-, or 5.4-mm superior incision, respectively, is recommended.
authors.affiliation: University Eye Clinic Maastricht, Maastricht University Medical Centre, The Netherlands. nienke.visser@mumc.nl
authors.forename: Nienke
authors.initials: N
authors.lastname: Visser
authors.forename: Tos T J M
authors.initials: TT
authors.lastname: Berendschot
authors.forename: Noël J C
authors.initials: NJ
authors.lastname: Bauer
authors.forename: Rudy M M A
authors.initials: RM
authors.lastname: Nuijts
mesh_terms: D000328:Adult; D000368:Aged; D000867:Anterior Chamber / Q000601:surgery*; D001251:Astigmatism / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D002387:Cataract Extraction / Q000009:adverse effects*; D003315:Cornea / Q000473:pathology* / Q000601:surgery; D003316:Corneal Diseases / Q000601:surgery; D016039:Corneal Transplantation / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007910:Lenses, Intraocular; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D019591:Pseudophakia / Q000503:physiopathology*; D012029:Refraction, Ocular; D012189:Retrospective Studies; D016896:Treatment Outcome