Pseudoexfoliative material and oxytalan fibers.

Pseudoexfoliative material (PSX) was found to show oxytalan staining like the ocular zonular fibers. These two fibrous proteins also shared positive reactions for disulfide and sulhydryl groups and for acidic mucosubstances, both of which have been suggested as reactive groups in the oxytalan staining reaction. The deep striated zone in the pre-equatorial lens capsule and the lens capsular inclusions shared most of these reactions, indicating that they contain some similar components. PSX material showed histochemical differences from the zonule, including evidence of less PAS-positive glycoprotein and more acidic mucosubstance. Variations in staining within the PSX excrescences indicated that they are a composite of more than one substance. PSX material appears to be a product of local basement membrane-secreting cells, representing an abnormal polymerization of glycoconjugates similar to those in elastic microfibrils.