Comparison of Astigmatic Keratotomy Results in Deep Anterior Lamellar Keratoplasty and Penetrating Keratoplasty in Keratoconus

PURPOSE: To compare astigmatic keratotomy (AK) outcomes in high astigmatism after deep anterior lamellar keratoplasty (DALK) and after penetrating keratoplasty (PK) in keratoconus patients. DESIGN: Prospective, comparative, interventional case series. METHODS: This study comprised 20 eyes that underwent DALK and 24 eyes that underwent PK. After suture removal, all eyes had more than 5 diopters (D) of astigmatism and underwent standard manual 1-pair, 90-degree, and 90% corneal thickness AK incisions. The main outcome measures included preoperative and postoperative manifest refraction, uncorrected visual acuity, best spectacle-corrected visual acuity, surgically induced astigmatism, Orbscan II (Bausch & Lomb) corneal topography results, keratometric astigmatism, and complications. RESULTS: All eyes completed 6 months of follow-up. The overcorrection rate was 35% and 41.6% in the DALK and PK groups, respectively (P = .75). At 6 months after AK, logarithm of the minimal angle of resolution uncorrected visual acuity improved from 0.88 +/- 0.20 to 0.54 +/- 0.26 and from 1.0 +/- 0.34 to 0.53 +/- 0.26 in the DALK and PK groups, respectively (P = .01 to P < .01). Best spectacle-corrected visual acuity improved from 0.16 +/- 0.09 to 0.13 +/- 0.08 and from 0.16 +/- 0.12 to 0.11 +/- 0.08 in the DALK and PK groups, respectively (P = .13 to P =.01). The mean refractive cylinder was decreased 2.74 +/- 1.44 D in the DALK group and 3.18 +/- 2.96 D in the PK group (P = .35). Surgically induced astigmatism was 6.10 +/- 3.27 D in the DALK group and 7.15 +/- 2.98 D in the PK group (P = .36). CONCLUSIONS: The manual AK for the treatment of postkeratoplasty astigmatism after DALK and PK in keratoconus patients is a safe and effective surgical procedure, allowing similar refractive cylinder reduction and improvement in uncorrected visual acuity and best spectacle-corrected visual acuity. (Am J Ophthalmol 2011;151:637-643. (C) 2011 by Elsevier Inc. All rights reserved.)