Comparison of Clinical Outcomes of Same-size Grafting between Deep Anterior Lamellar Keratoplasty and Penetrating Keratoplasty for Keratoconus

Purpose: To compare the clinical outcomes between deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PKP) with same-size grafts in patients with keratoconus. Methods: Medical records of 16 eyes from 15 patients treated from June 2005 through April 2011 were retrospectively reviewed. Patients with contact lens intolerance or who were poor candidates for contact lens fitting due to advanced cone underwent keratoplasty. The transplantations consisted of 11 DALK and 5 PKP with same-size grafting for keratoconus. Best-corrected visual acuity (BCVA), refractive error, corneal topographic profiling, and clinical course were compared between DALK and PKP groups. Results: The follow-up period was 30 ± 17 months in the DALK group and 45 ± 20 months in the PKP group(p = 0.145). At final follow-up, the DALK and PKP groups achieved a BCVA (logarithm of the minimum angle of resolution) of 0.34 and 0.52, respectively (p = 0.980). Postoperative refractive error and mean simulated keratometric index showed myopic astigmatism in both groups without any statistical difference. Corneal irregularity index measured at 5 mm in the DALK group was less than that of the PKP group at 1-year followup(p = 0.021); however, at final follow-up, there was no longer a statistically significant difference. Endothelial cell counts were lower in the PKP group than in the DALK group at final follow-up (p = 0.021). Conclusions: The optical outcomes of DALK with same-size grafts for keratoconus are comparable to those of PKP. Endothelial cell counts are more stable in DALK compared to PKP.