title: Three-year clinical outcome after penetrating keratoplasty for keratoconus with the guided trephine system.
abstract: OBJECTIVE
  To determine the long-term clinical outcome after keratoplasty with the guided trephine system in keratoconus eyes.
  
  
  METHODS
  In a prospective study, all consecutive cases of penetrating keratoplasty had trephination performed with the guided trephine system, with which both donor and recipient cornea are trephined from the epithelial side with a same-sized blade. For wound closure, a double running antitorque suture technique with 10-0 nylon was used. Uncorrected and best-corrected Snellen visual acuity, subjective refraction, and astigmatism by keratometry were evaluated after final suture removal, 2 and 3 years postoperatively.
  
  
  RESULTS
  In the 31 patients (31 eyes) enrolled, mean best-corrected visual acuity improved from 0.72 +/- 0.16 (20/30) after final suture removal to 0.88 +/- 0.15 (20/25) 3 years postoperatively (P < .001). The mean spherical equivalent increased from -0.86 +/- 2.10 diopters after final suture removal to -2.35 +/- 2.65 diopters 3 years postoperatively (P < .001). Mean keratometric astigmatism decreased from 4.68 +/- 1.76 diopters after final suture removal to 3.57 +/- 1.37 diopters 3 years postoperatively (P = .001). Furthermore, an increase in mean keratometric levels with time (P = .01) was observed and associated with myopic shift (r(s) = -.46, P = .008).
  
  
  CONCLUSIONS
  With the guided trephine system, we attained favorable visual results, with prolonged improvement of visual acuity during the entire follow-up period. Our data show low and decreasing degrees of corneal astigmatism over time. During the follow-up period, a myopic shift was found after final suture removal. Nevertheless, this technique of performing same-sized grafts reduces postoperative residual myopia.
authors.affiliation: Department of Ophthalmology, University of Vienna, Vienna Medical School, Austria. irene.ruhswurm@akh-wien.ac.at
authors.forename: I
authors.initials: I
authors.lastname: Ruhswurm
authors.forename: U
authors.initials: U
authors.lastname: Scholz
authors.forename: T
authors.initials: T
authors.lastname: Pfleger
authors.forename: M
authors.initials: M
authors.lastname: Zehetmayer
authors.forename: G
authors.initials: G
authors.lastname: Hanselmayer
authors.forename: C
authors.initials: C
authors.lastname: Skorpik
mesh_terms: D000328:Adult; D003315:Cornea / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007640:Keratoconus / Q000601:surgery*; D015948:Keratoplasty, Penetrating / Q000295:instrumentation* / Q000379:methods; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000517:prevention & control; D011446:Prospective Studies; D012029:Refraction, Ocular; D012030:Refractive Errors / Q000503:physiopathology / Q000517:prevention & control; D013536:Suture Techniques; D016896:Treatment Outcome; D014792:Visual Acuity