title: The intrastromal corneal ring in penetrating keratoplasty-long-term results of a prospective randomized study.
abstract: OBJECTIVE
  Postoperative astigmatism after penetrating keratoplasty is a major problem in corneal transplantation. The purpose of this prospective randomized study was to evaluate the efficacy and safety of an intrastromal corneal ring after penetrating keratoplasty.
  
  
  METHODS
  Twenty patients were included, 10 of whom received an intracorneal ring (group 1) and 10 who did not (group 2, control group). Astigmatism in Orbscan corneal topography, occurrence of immune reactions, and occurrence of side effects were this study's main outcome criteria.
  
  
  RESULTS
  Mean follow-up time was 27.6 ± 5.3 months. Mean astigmatism (Orbscan) was 4.4 diopters in group 1 and 4.4 diopters in group 2 (P = 0.695). Spontaneous suture rupture occurred in 5 patients with corneal ring but in none of those in the control group. We observed 3 immune reactions in 3 patients with corneal ring, whereas group 2 experienced no rejection (P < 0.05). Endothelial cell loss was 15.1% in the group with the ring and 8.7% in the control group. That difference was not statistically significant (P = 0.146).
  
  
  CONCLUSIONS
  The use of the intrastromal corneal ring after penetrating keratoplasty caused no reduction in postoperative astigmatism. However, its use was statistically significantly associated with adverse events.
authors: University Eye Hospital, Albert-Ludwigs-University Freiburg, Freiburg, Germany. florian.birnbaum@uniklinik-freiburg.de
authors: Florian
authors: F
authors: Birnbaum
authors: Johannes
authors: J
authors: Schwartzkopff
authors: Daniel
authors: D
authors: Böhringer
authors: Thomas
authors: T
authors: Reinhard
mesh_terms: D001251:Astigmatism / Q000517:prevention & control*; D003319:Corneal Stroma / Q000601:surgery*; D019781:Corneal Topography; D005500:Follow-Up Studies; D005642:Fuchs' Endothelial Dystrophy / Q000601:surgery*; D006801:Humans; D007640:Keratoconus / Q000601:surgery*; D015948:Keratoplasty, Penetrating; D011183:Postoperative Complications; D011446:Prospective Studies; D019736:Prostheses and Implants; D019919:Prosthesis Implantation; D014025:Titanium; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology; D014800:Vitallium
chemical_list: D014800:Vitallium; D014025:Titanium