Single Pass Technique Using 400μm versus 350μm Microkeratome Head for Preparation of Donor Endothelial Keratoplasty Lenticules from Fresh Whole Eyes

To compare single pass technique for preparation of donor endothelial keratoplasty lenticules from fresh whole eyes using 400 mm versus 350 mm microkeratome head in three different time intervals.
Precut corneas were prepared for Descemet stripping automated endothelial keratoplasty according to the standard protocol of the Central Eye Bank of Iran and by using either 400 μm or 350 μm microkeratome heads. The preparation was performed in three different time intervals: less than 30 seconds, 30-50 seconds, and more than 50 seconds. Expected thickness of endothelial keratoplasty lenticules (full thickness of central cornea minus the size of microkeratome head) was measured by ultrasound pachymetry. Final thickness of endothelial keratoplasty lenticules and depth of cut were measured by Visante-Optical Coherence Tomography. ANOVA and Bonferroni tests were used to analyze the results considering the size of microkeratome head and duration of the lenticule preparation.
The study enrolled 316 precut corneas that were prepared between October 2015 and December 2015. Mean depth of cut using the 350 μm microkeratome was not significantly different among 3 time intervals (P= 0.405); however, the depth of cut with the 400 μm microkeratome was significantly different among the different time interval groups and was significantly increased with pass time lasting more than 50 sec (P=0.014).
Single slow pass technique using 400 μm microkeratome head is an effective method for preparation of thin donor endothelial keratoplasty lenticules from fresh whole globes.