[Abnormalities of the optic papilla in (peri)orbital encephaloceles--a contribution to the common pathogenesis of these abnormalities].

Eleven patients (6 female, 5 male) with unilateral (6) or bilateral (5) (peri)orbital encephaloceles (nasofrontal in 4 cases, naso-orbital in 3, spheno-orbital in 4), were ophthalmologically examined. All had normal anterior segments, but ipsilateral or bilateral anomalies of the optic nerve head such as coloboma, pits, morning glory syndrome, dysplasia, tilted disk syndrome, hypoplasia, or a persistent hyaloid artery. In regard to the pathogenesis of (peri)orbital encephaloceles associated with optic disk malformations a common clefting defect in the neuroectodermal and neurocristal midline structures of the head is postulated, taking place in the fourth to sixth week of development.