title: Surgically induced astigmatism after 23-gauge transconjunctival sutureless vitrectomy.
abstract: OBJECTIVE
  To evaluate surgically induced astigmatism (SIA) after 23-gauge transconjunctival sutureless vitrectomy (23GTSV).
  
  
  METHODS
  We studied 56 patients (56 eyes) who underwent 23GTSV between January 2006 and December 2007 and who underwent preoperative and 1- and 3-4-months postoperative corneal topography. Fifteen of the 56 patients underwent combined 23GTSV and cataract surgery. SIA was evaluated with Naeser's polar method using the simulated keratometric values obtained with corneal topography. Preoperative and postoperative KP and DeltaKP values were compared in the 23GTSV only group and the combined 23GTSV and cataract surgery group.
  
  
  RESULTS
  There were no significant serial changes between the preoperative and postoperative Sim K astigmatism or KP values in the 23GTSV only group. In the 23GTSV only group, the DeltaKP (90) was negative (-0.10+/-0.78) at 1 month postoperatively, but it became positive (0.13+/-0.85) at 3-4 months postoperatively. The DeltaKP (135) showed serially decreasing negative values, -0.02+/-0.80 at 1 month postoperatively and -0.08+/-0.60 at 3-4 months postoperatively. In the combined cataract surgery group, the 1- and 3-4-month postoperative DeltaKP (135) values were -0.64+/-0.50 and -0.71+/-0.48, respectively, which represented a significant decrease compared with the 23GTSV only group (P<0.001, Mann-Whitney U-test). Although statistically insignificant, the DeltaKP (135) value was more negative in the sclerotomy-sutured group (n=6) than the sclerotomy non-sutured group (n=35) at 1 month postoperatively (-0.67+/-1.19 vs 0.09+/-0.67, P=0.110, Mann-Whitney U-test).
  
  
  CONCLUSIONS
  The 23GTSV does not induce significant SIA in the early postoperative period.
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Y-K
authors.initials: YK
authors.lastname: Kim
authors.forename: J Y
authors.initials: JY
authors.lastname: Hyon
authors.forename: S J
authors.initials: SJ
authors.lastname: Woo
authors.forename: K H
authors.initials: KH
authors.lastname: Park
authors.forename: Y S
authors.initials: YS
authors.lastname: Yu
authors.forename: H
authors.initials: H
authors.lastname: Chung
mesh_terms: D000368:Aged; D001251:Astigmatism / Q000209:etiology* / Q000503:physiopathology; D019781:Corneal Topography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D012189:Retrospective Studies; D013536:Suture Techniques; D014792:Visual Acuity; D014821:Vitrectomy / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods