Long-term results of deep anterior lamellar keratoplasty in patients with keratoconus

Purpose Long-term endothelial cell density changes and visual and refractive outcomes after descemetic (d) and predescemetic (pd) deep anterior lamellar keratoplasty (DALK) using the big-bubble technique in eyes with keratoconus. Methods Retrospective, consecutive, non-comparative, case series analysis of 95 eyes that have undergone DALK for keratoconus using the big-bubble technique with at least 1 year of follow-up. Big-bubble was achieved in 74 (77.9%) eyes (dDALK), whereas 21 (22.1%) eyes underwent manual lamellar dissection (pdDALK) because of failed big-bubble. Results Descemet ruptures occurred in 13 of 95 cases (13.7%). Five ruptures (5.3%) were converted to penetrating keratoplasty. Mean length of follow-up was 5.3 years (range, 1-8 years). Postoperative best spectacle-corrected visual acuity was significantly better in dDALK group than in pdDALK group at years 1 and 2. But, at the final examinations, there was no significant difference between the study groups (0.25 ± 0.22 logarithm of the minimum angle of resolution in dDALK group and 0.33 ± 0.15 logarithm of the minimum angle of resolution in pdDALK group; p = 0.12). The 2 groups were comparable regarding astigmatism and spherical equivalent refractive error throughout the follow-up period. Mean endothelial cell loss was 22.5 ± 17.9% at last follow-up with most of the loss occurring in the first year (8.7% ± 5.6%). Stromal graft rejection episodes occurred in 3 eyes (3.2%), which resolved with appropriate therapy. Conclusion DALK using the big-bubble technique is effective in patients with keratoconus. In DALK, manual lamellar dissection is a reasonable alternative when big-bubble separation of the Descemet membrane is not achieved.