Iris mammillations: significance and associations

Iris mammillations are rarely described, distinctive villiform protuberances that can cover the iris. In the majority of reported cases they are unilateral and sporadic, and are seen in association with oculodermal melanosis. In past literature and current clinical practice they are frequently confused with the iris nodules seen in neurofibromatosis type 1. Their clinical significance is not established, although it has been suggested that iris mammillations may be an external sign of ocular hypertension or intraocular malignancy. We report a series of 9 patients between the ages of 3 and 28 years with iris mammillations. The mammillations appear as regularly spaced, deep brown, smooth, conical elevations on the iris, of uniform height or increasing in height as the pupil margin is approached. They often overlie a naevus or an exceptionally deeply pigmented iris, such as that seen in melanosis oculi. One case had an associated ciliary body mass. They tend to occur in more highly pigmented ethnic groups and can be dominantly inherited. Iris mammillations may occur in association with systemic conditions including phakomatosis pigmentovascularis type IIb and neurofibromatosis type 1 when they may even coexist with iris hamartomas.