Objectives: To verify the presence of age-related changes in the human iris and to determine whether such changes could be related to the pathogenesis of the exfoliation syndrome.
Design: Ultrastructural examination of the posterior surface of the normal iris in 9 enucleated eyes.
Patients or other participants: Eyes of persons aged 1 day, 3 months, and 3, 9, 27, 52, 59, 59, and 65 years.
Main outcome measure: The presence of aging changes in the iris.
Results: Aging changes included duplication of the basal lamina of posterior iris pigment epithelial cells, formation of atrophic invaginations in the posterior cell membranes containing interlacing basal lamina, formation (or deposition) of microfibrils 11 to 13 nm in diameter, with a banding periodicity of 12 to 16 nm, deposition of electron-dense material in relation to the basal lamina and/or microfibrils, and the presence of some fine granular material overlying the basal lamina.
Conclusion: These changes have been consistently described before in association with exfoliation material, which suggests the possibility that exfoliation is an eventual aging process.