Degeneration of zonular fibrils in a case of exfoliation glaucoma

We examined ultrastructurally zonules of the lens obtained from a patient with exfoiliation glaucoma and lens dislocation. There was a great accumulation of exfoliation materials adjacent to and within degenerated zonules, and a gradual transition between zonular fibrils and exfoliation materials was observed. The initial change in the zonular fibrils was a loss of their regularity, next we could see fine granules deposited on degenerated zonular fibrils. A sparse and irregular deposition was found on the surface of the fibrils. Subsequently, the deposition became increased, and densely stained exfoliation materials, which were composed of a single degenerated zonular fibril and fine granules, were formed. Several fibrils accompanied by fine granules clustered together and became exfoliation materials of larger diameter. These observations suggest that degenarated zonular fibrils may develop into exfoliation materials.