Histopathology of the lens capsule in fibrillopathia epitheliocapsularis (FEC) or so-called senile exfoliation or pseudoexfoliation. An electron microscopic study.

Twenty lenses from cataractous eyes have been subjected to enzymatic breakdown by collagenase and alpha-chymotrypsin in order to remove part of the lens capsule and the zonular apparatus. Twelve of the lenses had clinical fibrillopathia epitheliocapsularis (FEC syndrome). In addition four FEC lenses and four ordinary cataractous lenses served as controls. A characteristic fibrillar substance was found in the FEC lenses located to circular epithelium-near areas varying in size from 10 micrometers to 150 micrometers. The circular areas were found in zona germinativa in front of the bow region and corresponded to the discoid plaques of the deep layer. The ultrastructure of the finely fibrillar material of the deep layer were indistinguishable from that of the surface material of the peripheral band and the central disc. A connection between the discoid plaques of deep layer and the peripheral granular band were demonstrated in the form of radial "cobble-stone" sectors seen in partially digested FEC capsules. An increased amount of age dependent spindleshaped formed bodies were also found in FEC lenses. The evidence presented points towards a lenticular origin of the Busacca-bushes in the peripheral ganular band of the lens capsule.