The hourglass facial deformity as a consequence of orbital irradiation for bilateral retinoblastoma.

We report a case illustrating characteristic facial deformities following irradiation during infancy for bilateral retinoblastoma. CT and MR imaging revealed distinctive features of the resulting "hourglass facial deformity": hypotelorism, enophthalmos, depressed temporal bones, atrophy of the temporalis muscles, and a depressed nasion. This case also displayed premature metopic craniosynostosis and frontal sinus aplasia; these may be additional hallmarks of this deformity.