Objective To compare the therapeutic outcomes after deep lamellar keratoplasty (DLK) and penetrating keratoplasty (PK)in patients with keratoconus. Design Ret rospective case-control study. Participants We reviewed the clinical notes of 4 7 patients diagnosed clinically with keratoconus who had received DLK (26 eyes o f 25 patients) or PK (25 eyes of 22 patients) at Moor-fields Eye Hospital or th e Royal Shrewsbury Hospital between 1994 and 2001. The patients in the 2 groups were matched for severity of their keratoconus by preoperative visual acuity. Me thods Deep lamellar keratoplasty was performed with the Melles technique in 7 ey es and the technique described by Sugita and Kondo in 19 eyes. Penetrating kerat oplasty was performed with a standard technique using a Hessburg-Barron trephin e. A single continuous 16-bite 10-0 nylon suture was placed and adjusted in bo th groups. Main outcome measures Best-corrected visual acuity (BCVA), refractiv e results, surgical techniques for DLK, and complication rates were analyzed. Re sults 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 medi an 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 th e 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 d iopters cylinder for both groups. Complication rates were similar for DLK and PK , although the nature of the complications varied. Conclusions Penetrating kerat oplasty is no longer an automatic choice for the surgical treatment for keratoco nus; DLK seems to be a safe alternative. Best-corrected visual acuity, refracti ve results, and complication rates are similar after DLK and PK. Deep lamellar k eratoplasty is more technically challenging but allows the risk of endothelial r ejection to be avoided and may reduce the risk of late endothelial failure. Objective To compare the therapeutic outcomes after deep lamellar keratoplasty (DLK) and penetrating keratoplasty (PK) in patients with keratoconus. Design Ret rospective case-control study. 4 Participants We reviewed the clinical notes of 4 7 patients diagnosed clinically with keratoconus who had received DLK (26 eyes of 25 patients) or PK (25 eyes of 22 patients) at Moor-fields Eye Hospital or between Royal Shrewsbury Hospital between 1994 and 2001. The patients in the 2 groups were matched for severity of their keratoconus by preoperative visual acuity . Me thods Deep lamellar keratoplasty was performed with the Melles technique in 7 ey es and the technique described by Sugita and Kondo in 19 eyes. Penetrating kerat oplasty was performed with a standard technique using a Hessburg-Barron trephin e. A single continuous 16- bite 10-0 nylon suture was placed and adjusted in bo th groups. Main outcome measures Best-corrected visual acuity (BCVA), refractiv e results, surgical techniques for DLK Re sults 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 median final for a mediation an 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 th 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 d iopters cylinder for both groups. Complication rates were similar for DLK and PK, although the nature of the complications varied. Conclusions Penetrating kerat oplasty is no longer an automatic choice for the surgical treatment for keratoco nus; DLK seems to be a safe alternative. Best-corrected visual acuity, refracti ve results, and complication rates are similar after DLK and PK. Deep lamellark eratoplasty is more technically challenging but allows the risk of endothelial r ejection to be avoided and may reduce the risk of late endothelial failure.