Abstract
Purpose: :
To evaluate the histologic changes of the full thickness cornea and posterior lamellar grafts after stripping endothelial keratoplasty (DSEK) surgeries.
Methods: :
Six full thickness corneas and 8 removed grafts were obtained from 14 DSEK patients. Sections form the tissues were stained with H&E and PAS. The posterior stroma and endothelium were analyzed by light microscopy. Immunohistochemical stains for anti-cytokeratins AE1,3 and MAK6 were performed in two cases to confirm the ingrowth epithelium. Electronic microscopic examination was also performed to evaluate the posterior stromal and endothelial changes in 2 cases.
Results: :
Microscopic examination showed the thickness of the anterior stoma ranged from 240.0 µm to 600.0 µm (mean 393.5±162.8 µm) in 6 patients who had penetrating keratoplasty(PK) after failed DSEK. The thickness of the graft ranged from 72.2 µm to 400.0 µm (mean 177.1±83.6 µm) in the center and 128.3 µm to 550.0 µm (mean 325.5±100.1 µm) peripherally in all 12 patients. The number of endothelial cells per high power field ranges from 0 to 13 cells. Pigmented cells were observed between the stromal bed and the DSEK graft in 3 cases. A sheet of stratified squamous epithelium was found on the posterior surface of the graft in 2 patients, epithelial markers were positive in these epithelial cells.
Conclusions: :
Dislocation of the graft, endothelial cells loss and epithelial implantation are common risk factors for the DSEK failure. The loss of the endothelial cells decreases the pump function and the thick graft allows less pump effect which causes the nonadhesion of the graft to the recipient’s stroma. Improved methods of graft may reduce the risk of repeated failure.
Keywords: refractive surgery: other technologies • pathology: human • wound healing