Ultrastructural age-related changes on the posterior iris surface. A possible relationship to the pathogenesis of exfoliation.

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.