Comparison of outcomes of lamellar keratoplasty and penetrating keratoplasty in keratoconus.

PURPOSE To compare outcomes after penetrating keratoplasty (PK) and two techniques of deep anterior lamellar keratoplasty (DALK) in patients with keratoconus. DESIGN Retrospective cohort study. METHODS One hundred and twenty-five corneal transplantations comprising 100 PK and 25 DALK procedures for keratoconus at the Singapore National Eye Centre from April 1992 through December 2006 were included. DALK was performed with the modified Anwar technique (descemetic or DALKa group) in 14 eyes and manual lamellar keratoplasty (predescemetic or DALKm group) was performed in 11 eyes. RESULTS At 12 months, the DALKa and PK groups achieved a logarithm of the minimum angle of resolution mean best spectacle-corrected visual acuity (BSCVA) of 0.15 and 0.27, respectively (P = .26), whereas the mean BSCVA of the DALKm group was 0.41 compared with the PK group (P = .12). Significance level was achieved between the DALKa and DALKm groups (P = .013). There was no significant difference in the mean spherical equivalent (P = .72) and astigmatism (P = .88) between the PK and DALK groups. The DALK group had a significantly lower incidence of complications compared with PK cases, including allograft rejection and glaucoma. Graft survival rate of both the PK and DALKa groups was 100%, whereas that of the DALKm group was 73% at 3 years after surgery (P = .000 between PK and DALKm groups). CONCLUSIONS Visual acuity outcomes of the DALKa technique are comparable with those of PK for keratoconus, whereas DALK surgery results in fewer postoperative complications than PK. DALKa is emerging as a preferred choice among the lamellar techniques for better optical outcome. Further studies are required to provide long-term analysis of these results.