Postoperative graft thickness obtained with single-pass microkeratome-assisted ultrathin descemet stripping automated endothelial keratoplasty

Purpose: To evaluate the results of microkeratome-assisted ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) using a nomogram developed for the single-pass technique. Methods: A retrospective study of eyes operated between September 2014 and March 2015 at Villa Serena-Villa Igea Private Hospitals (Forlí, Italy) by a single surgeon (M.B.). Study eyes underwent UT-DSAEK performed using a linear microkeratomeassisted lamellar dissection with disposable heads of different sizes (Moria ALTK system; Moria SA) chosen according to a pachymetry- based nomogram developed at our department. The main outcome measure was the graft thickness as assessed by means of anterior segment optical coherence tomography, measured between 1 and 3 months postoperatively. Results: Forty-two eyes were included in this study. Mean followup time was 5.0 ± 1.8 months (range 1.2-6.9 months). No perforation or other complication occurred during graft preparation. Mean postoperative central thickness of donor grafts was 63 ± 29 mm. Thickness ranged between 23 and 177 μm, and the second thickest graft measured 116 μm. By 3 months postoperatively, 41/42 (97%) of the grafts were of thickness ≤130 μm and 38/42 (90%) of the grafts were of central thickness ≤100 μm. The mean nasal-totemporal absolute thickness difference at the graft's central 3-mm zone was 5 ± 7 μm at the last available measurement. Conclusions: The nomogram developed at our institution allowed reliable single-pass microkeratome-assisted dissection of donor tissue, creating consistently thin and symmetric grafts without loss of tissue. The results obtained compare favorably with those reported in the past for double-pass microkeratome-assisted dissection of UT-DSAEK.