Original article
Comparison of Outcomes of Lamellar Keratoplasty and Penetrating Keratoplasty in Keratoconus

https://doi.org/10.1016/j.ajo.2009.05.028Get rights and content

Purpose

To compare outcomes after penetrating keratoplasty (PK) and two techniques of deep anterior lamellar keratoplasty (DALK) in patients with keratoconus.

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.

Section snippets

Methods

A comparative cohort study was performed in which clinical data were retrieved from computerized database of the prospective Singapore Corneal Transplant Study.1 A total of 168 keratoconus patients underwent corneal grafts between January 1991 and December 2006 at the Singapore National Eye Centre. A cut-off at December 2006 allowed for a minimum follow-up of 6 months, leaving 164 patients. Of these 164 patients, 21 patients who had incomplete follow-up and 18 cases of automated lamellar

Patient Data

One hundred and twenty-five corneal grafts comprising 100 PK, 11 DALKm, and 14 DALKa procedures were included in the study. There were more patients of Indian ethnic origin (39.8%) than other ethnic groups. This deviates from the ethnic ratio in Singapore, although statistical significance was not achieved (P = .16). There was a preponderance of males (P = .44). Fifty-five percent of grafts were to the right eye and 45% of grafts were to the left eye. The mean follow-up period with standard

Discussion

Recent studies have shown that the Anwar technique for DALK achieved better postoperative results in terms of improved VA and reduced complications than PK and older forms of DALK techniques, for example, manual DALK.11, 12, 13, 14, 15, 16 Our study shows that DALKa, that is, the modified Anwar technique, performed as well as PK with respect to postoperative mean BSCVA, best BSCVA achieved, and percentage of cases achieving good postoperative BSCVA. In addition, our DALKa cases attained higher

Dr Daphne Han received her MBBS degree from The University of Melbourne, Australia and completed her medical internship in England. She completed her Ophthalmology residency at the Singapore National Eye Centre, where she is currently an Associate Consultant in Cataract and Refractive Surgery.

References (20)

There are more references available in the full text version of this article.

Cited by (219)

View all citing articles on Scopus

Dr Daphne Han received her MBBS degree from The University of Melbourne, Australia and completed her medical internship in England. She completed her Ophthalmology residency at the Singapore National Eye Centre, where she is currently an Associate Consultant in Cataract and Refractive Surgery.

See accompanying Editorial on page 629.

View full text