Single versus double pass technique for preparation of ultrathin Descemet's stripping automated endothelial keratoplasty tissues from donated whole eyes.

Abstract

This study was conducted to analyze the preoperative thickness profile and endothelial rating of ultrathin Descemet's stripping automated endothelial keratoplasty (UT-DSAEK) tissues prepared with a single versus double microkeratome pass from donated whole eyes and corresponding eye bank postoperative results. Microkeratome-assisted UT-DSAEK tissues were prepared from freshly donated whole eyes with single-pass (SP) and double-pass (DP) technique in the Central Eye Bank of Iran. Preoperative thickness profiles and endothelial cell densities of UT-DSAEK tissues were obtained from optical coherence tomography and specular microscopy, respectively, and compared between groups. Corneal perforation rates during the eye bank preparation and postoperative reports of transplanted UT-DSAEK tissues were also compared. Over a 15-month period, 342 UT-DSAEK tissues were prepared: 248 via SP and 94 with DP technique. Mean donor corneal central thickness was 610 ± 58µm with SP and 790 ± 100µm with DP technique. Mean central thickness of UT-DSAEK tissues was not statistically different between the groups (84.8 ± 11.0µm with SP and 85.1 ± 10.5µm with DP technique, P = 0.857). Mean increase of UT-DSAEK thickness from central to pericentral and peripheral cornea was not significantly different with both techniques. Mean differences between thicknesses of 2 pericentral locations and between those of 2 peripheral locations were not statistically different in the study groups. Corneal perforation of 1.6 and 1.1% occurred in SP and DP groups, respectively. Failed graft was reported 6months postoperatively in 4 (1.6%) cases with SP and in 1 (1.1%) case with DP technique. Preoperative thickness profiles of UT-DSAEK tissues prepared from donated whole eyes via SP technique were not significantly different from those prepared with DP, showing a symmetric increase of thickness towards peripheral locations.