Intraoperative cauterization of the cornea can reduce postkeratoplasty refractive error in patients with keratoconus
Historical images
Presented in part at the Annual Meeting of the American Academy of Ophthalmology, San Francisco, California, October 1997.
Received 26 October 1997; accepted 4 February 1998.
Abstract
Objective
This study aimed to evaluate the effect of intraoperative corneal cauterization on the postkeratoplasty refraction of patients with keratoconus.
Design
A randomized clinical trial.
Participants
Thirty eyes of 29 patients with keratoconus undergoing standard penetrating keratoplasty by the same surgeon were evaluated (MB).
Intervention
Standard penetrating keratoplasty included the use of an 8.0-mm donor button sutured into a 7.5-mm recipient bed by means of two running 10-0 nylon sutures with 16 bites each. Before trephination of the recipient bed, superficial cauterization causing tissue shrinkage was applied to a 6-mm central area of the cornea of only 15 eyes (group A). The remaining 15 eyes (group B) did not undergo intraoperative cauterization. Before surgery, 6 months, and 13 months after surgery, a complete ophthalmologic examination was performed on each patient, including uncorrected and best-corrected visual acuity, refraction, keratometry, computerized corneal topography, as well as A-scan contact ultrasonography.
Main outcome measures
Postkeratoplasty refractive error was measured.
Results
Both 6 months (sutures still in place) and 13 months (suture removal performed in all patients) after surgery, the average spherical equivalent was significantly less myopic in the patients undergoing cauterization. At 6 months, it was +1.72 diopters (D) ± 1.13 D in group A and −3.16 D ± 2.84 D in group B; at 13 months, it was +0.09 D 1.52 D in group A and −3.89 D ± 3.01 D in group B. The average keratometric astigmatism also was significantly lower in group A than in group B both at 6 (2.5 D ± 1.6 D vs. 4.1 D ± 2.3 D) and 13 months (2.7 D ± 1.5 D vs. 4.4 D ± 2.4 D) after surgery.
Conclusion
Cauterization of the central cornea improves the postkeratoplasty refractive results of patients with keratoconus.
ABSTRACT