Three-year clinical outcome after penetrating keratoplasty for keratoconus with the guided trephine system

Am J Ophthalmol. 1999 Jun;127(6):666-73. doi: 10.1016/s0002-9394(99)00036-7.


Purpose: 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).

Conclusion: 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.

MeSH terms

  • Adult
  • Cornea / surgery*
  • Female
  • Follow-Up Studies
  • Humans
  • Keratoconus / surgery*
  • Keratoplasty, Penetrating / instrumentation*
  • Keratoplasty, Penetrating / methods
  • Male
  • Middle Aged
  • Postoperative Complications / prevention & control
  • Prospective Studies
  • Refraction, Ocular
  • Refractive Errors / physiopathology
  • Refractive Errors / prevention & control
  • Suture Techniques
  • Treatment Outcome
  • Visual Acuity