In vivo confocal microscopy features of endothelial rejection after penetrating keratoplasty

Abstract

Objective To demonstrate the features and the outcomes after treatment of endothelial rejection in human corneal allograft rejection by in vivo confocal microscopy. Methods Sixteen patients with endothelium rejection ofallogratt after penetrating keratoplasty were examined by confocal microscopy, to analyze the quantity and morphological changes of corneal epithelial cells, stroma cells, endothelium cells and immune cells before treatment and 3-7days and 1 month after treatment. Results Among the 16 patients, typically endothelial rejection line were seen in 8 cases, another 8 cases' keratic precipitates was diffusely scattered.Confocal microscope images revealed that the endothelial rejection lines were formed by cellular aggregate of small inflammatory cells and damaged larger endothelial cells with pyknotic highly reflective nuclei. With the progression of endothelial endothelia line, epithelium cells were large in size and lose distinct boundaries, numerous Langerhans cells (LCs) were seen in the basement epithelial cell region, keratocytes were altered in appearance with increased visibility of the cytoplasm, damaged endothelial cells decreased in number, increased in size with loss of normal polygonal shape and sticked by highly reflective immune cells which scattered or gathered. In the severely edematous area, the endothelial cells were not visualized with confocal microscopy.After 3 or 7 days of treatment, 12 cases were cured. Confocal microscopy examination revealed that the density of LCs reduced gradually and normal keratocytes were detected, the endothelial cells restored to hexagon structure and the density of immune cells decreased. Endothelial cells of 4 cases still were not visualized with confocai microscopy because of the degeneration fibrosis of deep stromal layer. LCs in the basement epithelial cell region still could be found after I month of treatment, and their endothelial cells appeared elongated or rounded with loss of their normal cell junctions. Conclusions In vivo confocal microscopy can provide us with detailed histopathology proofs and appear dynamically the transformation after treatment of endothelial rejection at cell level. It plays an important role in improving the diagnostic level and directing anti-rejection medication in our clinical practicing works. Key words: Confocal microscopy; Corneal transplantation; Endothelial rejection