Microkeratome-assisted preparation of ultrathin grafts for descemet stripping automated endothelial keratoplasty.

PURPOSE To compare three microkeratome-assisted techniques for the preparation of ultrathin (UT) grafts for Descemet stripping automated endothelial keratoplasty. METHODS After dissection with a 300-μm microkeratome head in 40 donor tissues, a second cut was performed with a 130-μm head either after manual stromal hydration (group A, n = 10) or osmotic hydration at the eye bank (group B, n = 10) or with a 50- or 90-μm head, depending on residual bed thickness (group C, n = 10); no further dissection was performed in the control group (group D, n = 10). Corneal thickness and endothelial cell (EC) count were determined at all appropriate stages. Statistical analysis was performed using a Fisher exact test. RESULTS Final graft thicknesses in groups A (89.1 ± 34.1μm), B (84.1 ± 18.6 μm), and C (72.1 ± 10.1 μm) were significantly lower than in group D (201.9 ± 25.3 μm) (P < 0.001). EC loss did not differ significantly among the groups. Multiple areas of Descemet detachment were seen in 4 of 10 corneas of group A. CONCLUSIONS All methods proved equally efficient in producing UT grafts, but stromal hydration induced tissue structural changes. EC loss was unaffected by the additional manipulation required to prepare UT grafts.