ABSTRACT
Hypertelorism refers to an interocular distance above the 95th percentile. Causes of hypertelorism include mechanical causes such as premature fusion of the skull bones or a cleft. Genetic syndromes such as craniofrontonasal dysplasia, Apert syndrome, and Crouzon syndrome can have hypertelorism as part of their features. Mild hypertelorism can also be present as an isolated finding with no clinical consequences. The inner and outer interocular distances are not routinely measured during second-trimester ultrasound. However, in the presence of other fetal anomalies, especially facial clefts, abnormal skull shape, micrognathia, and brain defects, a detailed study of the face can contribute to the diagnosis of an underlying condition. Surgical correction of hypertelorism is nowadays available but the outcome is mostly dictated by the underlying condition.
