Deep Anterior Lamellar Keratoplasty (DALK)

Abstract

To review the visual outcome and complications of deep anterior lamellar keratoplasty (DALK), using Melles technique. All patients undergoing DALK between December 1999 and March 2005 were routinely entered into a longitudinal study. DALK was attempted in 80 eyes of 68 consecutive patients. Descemet membrane perforation occurred in 11 eyes, of which 7 required conversion to penetrating keratoplasty. The visual and refractive outcome of these eyes is presented separately. The mean follow-up was 21.2 months. Best-corrected visual acuities (BCVAs), refraction, graft clarity, and complications were recorded at each visit and analyzed. The mean patient age was 34.2 years. Keratoconus was the main indication for surgery (58 eyes), followed by herpes simplex keratitis (6 eyes), corneal stromal dystrophy (5 eyes), stem cell failure with scarring (2 eyes), corneal dermoid (1 eye), and corneal opacity (1 eye). The mean central corneal thickness changed from 0.42 +/- 0.07 mm preoperatively to 0.62 +/- 0.06 mm postoperatively. At latest follow-up, BCVA of 6/6 or better was present in 24.7%, 6/9 or better in 69.9%, and 6/12 or better in 84.9% of the eyes. The mean postoperative refractive cylinder was 3.31 +/- 2.59 D, and the mean spherical equivalent was -2.54 +/- 3.61 D; 52.2% of the eyes had a refractive cylinder less than +/-3 D and 49.3% of the eyes had a spherical equivalent less than +/-3 D. Rejection episodes occurred in 9.6% of the eyes but were successfully reversed in all eyes. Graft failure occurred in 1 eye with severe stem cell deficiency. This is the largest series of DALK cases using the Melles technique in a variety of corneal lesions. Our results confirm the usefulness and safety of this procedure in conditions with no endothelial involvement. Graft rejection remains a significant complication but is associated with good recovery because the endothelium is spared.