Fourier series harmonic analysis of corneal topography following suture removal after penetrating keratoplasty

Cornea. 2002 Apr;21(3):256-9. doi: 10.1097/00003226-200204000-00004.


Purpose: To evaluate quantitatively the influence of suture removal after penetrating keratoplasty on corneal refraction including irregular astigmatism.

Methods: Subjects were 42 eyes of 39 patients with clear corneal grafts who underwent suture removal after penetrating keratoplasty. Videokeratography data taken before and after suture removal were decomposed using Fourier harmonic analysis into spherical power, regular astigmatism, and irregular astigmatism (asymmetry and higher order irregularity).

Results: On average, spherical power significantly increased after suture removal (p < 0.0001, paired t test), and regular astigmatism did not change significantly (p = 0.247). Suture removal significantly decreased asymmetry (p < 0.0001) and higher order irregularity (p < 0.0001).

Conclusions: Suture removal after penetrating keratoplasty induces myopic shift and reduction in irregular astigmatism of the cornea.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Astigmatism / etiology*
  • Astigmatism / physiopathology
  • Cornea / pathology*
  • Cornea / physiopathology
  • Corneal Topography*
  • Female
  • Fourier Analysis*
  • Humans
  • Keratoplasty, Penetrating*
  • Male
  • Middle Aged
  • Refraction, Ocular / physiology
  • Retrospective Studies
  • Suture Techniques / adverse effects*