deep anterior lamellar keratoplasty versus penetrating keratoplasty for keratoconus

purpose: to compare the outcomes of deep anterior lamellar keratoplasty (dalk) using the big-bubble technique with that of penetrating keratoplasty (pk) in patients with keratoconus. methods: this double-blind clinical trial included patients with moderate to advanced keratoconus and poor spectacle-corrected visual acuity or contact lens intolerance. refractive errors, best corrected visual acuity (bcva), contrast sensitivity function (csf) and higher order aberrations (hoas) were compared between the study groups. results: forty-two eyes underwent dalk while 35 eyes received pk. mean patient age was 26.91±7.9 versus 30.89±10.3 years in the dalk and pk groups, respectively (p=0.06). mean follow-up period was 19.0±7.9 months in the dalk and 24.6±3.5 months in the pk group (p=0.32). mean postoperative spherical equivalent refractive error was -3.23±3.4 d in the dalk group versus -2.22±4.6 d in the pk group (p=0.28) and mean postoperative bcva was 0.18±0.08 logmar and 0.15±0.10 logmar, respectively (p=0.12). there was no significant difference between the study groups in terms of csf, total aberrations and hoas. conclusions: dalk may be considered as an effective alternative to pk in patients with keratoconus.