ABSTRACT
PURPOSE: To quantify and describe practically a novel technique for donor tissue preparation in Descemet stripping endothelial keratoplasty to approach the superior visual outcomes of Descemet membrane endothelial keratoplasty. DESIGN: Experimental laboratory investigation. SETTING: Institutional. STUDY POPULATION: Eleven human donor corneas. INTERVENTION: Double-pass of microkeratome over donor corneas-first with a thicker cutting depth and subsequently with a thinner cutting depth. MAIN OUTCOME MEASURES: Donor tissue profiles and residual bed thicknesses. RESULTS: After the first pass of the microkeratome, the average cut thickness using the 250-µm cutting head was 342.5 ± 14.8 µm (range, 332 to 353 µm), that using the 300-µm head was 343.8 ± 39.2 µm (range, 315 to 411 µm), and that with the 350-µm head was 467.7 ± 50.1 µm (range, 419 to 519 µm). We used the 200-µm cutting head only once with a cut depth of 210 µm. For the second pass, when using the 110-µm head, the cutting depth averaged to 167.8 ± 28.8 µm (range, 133 to 203 µm). The 130-µm cutting head yielded a cut depth of 199.7 ± 24.4 µm (range, 180 to 227 µm). Two corneas were perforated during the second pass. The average final thickness of the residual bed was 121 ± 32.2 µm (range, 52 to 160 µm). CONCLUSIONS: Double-pass harvest for ultra-thin Descemet stripping automated endothelial keratoplasty could improve optical outcomes by obtaining donor Descemet stripping automated endothelial keratoplasty tissue with thinner residual beds. Further studies are needed with larger sample sizes to establish algorithms for appropriate cutting head thickness in each pass. Potential additional endothelial cell loss with the second pass of the microkeratome also should be evaluated.
