[Histological and ultrastructural analysis of the Descemet's membrane after descemetorhexis in DMEK surgery].

BACKGROUND In order to obtain an optimal visual outcome in the isolated transplantation of Descemet's membrane (DM) with the endothelial cell layer, a regular interface between the receiver cornea and the graft is important for the prognosis. The purpose of this histological and ultrastructural study was to investigate how precise the descemetorhexis works using the Sinskey hook and whether the precision of DM removal depends on the clinical and pathological diagnosis of the underlying corneal endothelial disease. PATIENTS AND METHODS 22 DM specimens of 22 patients obtained after descemetorhexis in DMEK using a Sinskey hook were examined using histological analyses and transmission electron microscopy for the presence of residual stroma, thickness of the DM, endothelial cell count, and presence of guttae. 17 patients had a Fuchs corneal dystrophy, 5 pseudophakic bullous keratopathy. RESULTS Light and electron microscopy showed no evidence of adherent stroma in all 22 specimes after descemetorhexis independent of the different underlying endothelial pathological abnormalities. The mean total thickness of the DM was 20.58 ± 4.23 µm in patients with Fuchs endothelial dystrophy and 21.31 ± 5.41 µm in patients with bullous keratopathy. There was no significant difference between both pathological abnormalities. The anterior banded layer measured a mean of 3.04 ± 0.40 µm and 3.25 ± 0.22 µm thick; the posterior non-banded layer 17. 63 ± 4.07 µm and 17.60 ± 5.0 µm thick in each case of Fuchs corneal dystrophy and pseudophakic bullous keratopathy. There was no significant difference between the two diseases. CONCLUSIONS Descemetorhexis allows a selective removal of the DM without adherent stroma in different underlying endothelial pathological abnormalities and in different variability of disease expression.