Donor corneal endothelial striae.

Excessive traction during excision of donor corneoscleral buttons can result in damage or death to corneal endothelial cells. This damage manifests as multiple peripheral and, less commonly, central striae or stretch marks that correspond to linear opacities at the level of the endothelium. The striae consist of parallel lines of degenerate endothelium, each line three to eight cells wide, and stain readily with trypan blue, which is indicative of cell damage or death. Light and electron microscopy demonstrates cell membrane lysis with abrupt demarcation between abnormal and normal endothelial cells. The number of these striae correlates with the degree of traction or stretch applied during corneoscleral excision. Careful slit-lamp biomicroscopy of corneoscleral buttons discloses endothelial striae in approximately 5% of specimens. Careful excisions of corneoscleral buttons are necessary to decrease the incidence and severity of endothelial striae.