Reduced number of hemidesmosomes in the corneal epithelium of diabetics with proliferative vitreoretinopathy.

Morphometry on transmission electron micrographs of the hemidesmosomal width was related to the length of the basal plasmalemma in corneal epithelium biopsy specimens. The basal plasmalemma length occupied by hemidesmosomes showed a mean fraction of 0.227 in eight patients undergoing cataract extraction or vitrectomy for diabetic proliferative vitreoretinopathy. In seven non-diabetic control patients of comparable age and sex undergoing cataract or pterygium surgery, 0.412 of the basal plasmalemma was covered by hemidesmosomes. A reduction in hemidesmosomes (P less than 0.001) may contribute to a weakness in the adhesion of diabetic corneal epithelium to the underlying stroma.