Intraoperative cauterization of the cornea can reduce postkeratoplasty refractive error in patients with keratoconus

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.