Comparison of deep lamellar keratoplasty and penetrating keratoplasty in patients with keratoconus.

OBJECTIVE To compare the therapeutic outcomes after deep lamellar keratoplasty (DLK) and penetrating keratoplasty (PK) in patients with keratoconus. DESIGN Retrospective case-control study. PARTICIPANTS We reviewed the clinical notes of 47 patients diagnosed clinically with keratoconus who had received DLK (26 eyes of 25 patients) or PK (25 eyes of 22 patients) at Moorfields Eye Hospital or the Royal Shrewsbury Hospital between 1994 and 2001. The patients in the 2 groups were matched for severity of their keratoconus by preoperative visual acuity. METHODS Deep lamellar keratoplasty was performed with the Melles technique in 7 eyes and the technique described by Sugita and Kondo in 19 eyes. Penetrating keratoplasty was performed with a standard technique using a Hessburg-Barron trephine. A single continuous 16-bite 10-0 nylon suture was placed and adjusted in both groups. MAIN OUTCOME MEASURES Best-corrected visual acuity (BCVA), refractive results, surgical techniques for DLK, and complication rates were analyzed. RESULTS The 25 patients with keratoconus who underwent DLK had a mean age of 32.6 years and a median follow-up of 28 months. The mean age of the 22 patients who underwent PK for keratoconus was 34 years. This group was followed up for a median time of 55 months. The median final BCVA of patients in the DLK group was 6/9 and in the PK group 6/6 (no statistical significance). The median result for the final spherical equivalent power in both groups was mild myopia, although the DLK group had more myopia, and the median astigmatism was less than 5.00 diopters cylinder for both groups. Complication rates were similar for DLK and PK, although the nature of the complications varied. CONCLUSIONS Penetrating keratoplasty is no longer an automatic choice for the surgical treatment for keratoconus; DLK seems to be a safe alternative. Best-corrected visual acuity, refractive results, and complication rates are similar after DLK and PK. Deep lamellar keratoplasty is more technically challenging but allows the risk of endothelial rejection to be avoided and may reduce the risk of late endothelial failure.