Prospective evaluation of clinical outcomes between pre-cut corneal grafts prepared using a manual or automated technique: with one-year follow-up

Purpose: Posterior lamellar corneal surgery is considered the standard of care for irreversible endothelial cell dysfunction. Pre-cut grafts can be prepared either manually (Descemet stripping endothelial keratoplasty; DSEK) or mechanically (Descemet stripping automated endothelial keratoplasty; DSAEK). We performed a head-to-head clinical comparison between DSEK and DSAEK grafts. Methods: All DSEK and DSAEK procedures performed by two corneal specialists at the University Medical Center Utrecht from 1 January 2016 through 31 October 2016 were prospectively included. Pre-cut grafts were delivered by two eye banks, which either exclusively prepared the DSEK or DSAEK grafts. Preoperative and postoperative measurements were obtained, and all surgical events and adverse events were recorded. Results: A total of 21 DSEK and 53 DSAEK procedures were included for analysis; the two groups were similar at baseline, with the exception of graft endothelial cell density, which was 2531 ± 67 versus 2748 ± 148 cells/mm ² , respectively (p < 0.001). At the one-year follow-up visit, corrected distance visual acuity and endothelial cell loss were similar between the groups. Mean pachymetry was significantly lower in the DSEK group (521 ± 39 versus 588 ± 59 μm; p < 0.001), whereas the rebubbling rate was significantly higher in the DSEK group (47.6% versus 18.9%; p = 0.001). Finally, three grafts in the DSEK group experienced failure compared to one graft in the DSAEK group (14% versus 1.9%, respectively). Conclusion: Manually dissected and microkeratome-dissected grafts performed similarly with respect to vision and endothelial cell loss assessed one year after surgery. The higher incidence of graft failure among manually dissected (i.e. DSEK) grafts may be attributable to reduced relative thickness compared to DSAEK grafts and/or the resulting differences in tissue handling and the surgeon's learning curve.