Conversion to deep anterior lamellar keratoplasty (DALK): learning curve with big-bubble technique.

BACKGROUND AND OBJECTIVE: To report the perioperative complications and clinical outcomes of 50 deep anterior lamellar keratoplasty (DALK) cases. PATIENTS AND METHODS: Fifty eyes of 50 patients with pathologies involving the corneal stroma and sparing the Descemet's membrane and endothelium were included consecutively in this prospective, noncomparative interventional case series study. DALK was performed using the big-bubble technique. RESULTS: The most frequent indication for DALK surgery was keratoconus (26 eyes), followed by corneal dystrophy (10 eyes) and superficial corneal scar (14 eyes). The average follow-up period was 12.0 ± 3.9 months. DALK was completed in 41 cases (82%). A big bubble was achieved successfully in 37 cases (74%). Descemet's membrane perforations occurred in 14 (28%) eyes, 8 of which were macroperforation and necessitated conversion to penetrating keratoplasty. Complications tended to decrease throughout the study. Postoperative best-corrected visual acuity of 0.5 or better was present in 30 of 41 (73.2%) eyes that underwent DALK. There was no episode of graft rejection. CONCLUSION: DALK big-bubble technique may be a valuable procedure during transition from penetrating keratoplasty to anterior lamellar keratoplasty. It provided acceptable visual and refractive outcome even during the learning period in a variety of corneal lesions.