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The peripheral exfoliation band was scraped from seventeen lenses that were removed because of senile cataract. A suspension of the exfoliation substance, negatively stained with sodium silicotungstate, was studied and compared with the sectioned exfoliation material. It is concluded that the exfoliation substance probably consists of a collagen material, that perhaps comes from basement membranes.

The trabecular meshwork of three human eyes involved with the exfoliation syndrome were studied. The intraocular tension in the eyes represented successive stages. Exfoliation material was found in all three eyes: In Eye 1 (no glaucoma) only in intertrabecular spaces, in Eyes 2 and 3 also within trabecular beams and in the juxtacanalicular tissue. In addition, abnormal basement membranes were revealed. In Eye 3 (uncontrollable glaucoma), the disorganized trabecular meshwork contained increased amounts of connective tissue elements as well as small vessels. The concept is advanced that the accumulation of exfoliation material in the meshwork impedes aqueous outflow and thus is a pathogenetic factor of importance in glaucoma capsulare.

A light microscopic technique is described for identifying exfoliation material in the wall of iris vessels. Iris tissue from four cataractous eyes without and eight cataractous eyes with exfoliation syndrome was studied.

1. The walls of iris vessels in five human eyes were studied. 2. No fenestrae are present in capillary endothelium. 3. A several thousand A thick basement membrane is found in practically all vessels. The basement membrane is often multi-layered and its external limit irregular. 4. A distinct zone of thin collagen fibrils is present between the “inner” and “outer tube” in almost all vessels. 5. Membrane-bounded, moderately dense bodies about 0.3 μ in diameter are concentrated among the extracellular components of vessel walls. 6. Muscular tissue is scanty. 7. No elastic fibres are found.