ELECTRON MICROSCOPY OF WALL OF IRIS VESSELS IN EYES WITH AND WITHOUT EXFOLIATION SYNDROME (PSEUDOEXFOLIATION OF LENS CAPSULE)

An electron microscopic study was performed of the vessel wall of the iris in four eyes with cataracts without the exfoliation syndrome and in eight eyes with cataracts with the exfoliation syndrome. The following results were obtained: 1. Iridial vessels in cataractous eyes without exfoliation syndrome appeared like vessels of the normal iris. 2. Iridial vessels in cataractous eyes with exfoliation syndrome appeared different from normal: An abnormal extracellular material was found outside the endothelial cells. This material consisted of fibrillar and nonfibrillar components. The basement membrane was often thin and sometimes interrupted in the vessels with a great amount of abnormal extracellular material. The outer part of the connective tissue layer was always normal. It is concluded that the appearance of the abnormal extracellular material is associated with the exfoliation syndrome, and that the morphology of the fibrillar component of this material agrees with previous descriptions of exfoliation material. © 1969 Springer-Verlag.