Comparison of Three Different Techniques of Corneal Transplantation for Keratoconus

PURPOSE: To compare the visual outcomes following deep anterior lamellar keratoplasty (DALK), penetrating keratoplasty (PK), and manual top,hat PK (TH-PK) in subjects undergoing corneal transplantation for keratoconus (KC). DESIGN: A retrospective comparative case series. METHODS: SETTINGS: Cornea clinic at the Toronto Western Hospital. STUDY POPULATION: Fifty patients who underwent corneal transplantation for KC: 17 eyes underwent DALK, 20 eyes underwent traditional PK, and 13 had TH-PK. MAIN OUTCOME MEASURES: Preoperative and postoperative uncorrected and best spectacle-corrected visual acuity (UCVA, BSCVA), high order aberrations (HOA), complication rate, and endothelial cell counts. RESULTS: The median BSCVA at 12 months follow,up was 20/40 in the DALK eyes and 20/30 in the traditional PK and TH-PK eyes. The mean final spherical equivalent power in the three groups was less than -1 diopter (D). The median astigmatism was less than 3.5 D in the three groups. Complication rates were similar for three groups, although the DALK group tended toward more complications. Although DALK and TH-PK procedure results in significantly shorter time to suture removal (P < .01), they caused increased levels of HOAs (P = .02). Endothelial cell counts at 12 months were significantly higher in DALK and TH-PK eyes when compared to the traditional PK eyes (P < .001). CONCLUSIONS: DALK, PK, and TH-PK provide comparable visual outcomes in keratoconus patients. Although DALK and TH-PK induce more HOA, they speed up the time to suture removal and provide higher endothelial cell density at one year of follow-up. (Am J Ophthalmol 2008;146:905-912. (C) 2008 by Elsevier Inc. All rights reserved.)