Hereditary congenital external ophthalmoplegia.

Several members of a large pedigree suffering from hereditary congenital external ophthalmoplegia, an autosomal hereditary disorder of ocular movements, were examined and surgically treated. From nystagmographic findings it was concluded that the main cause of this disorder is of supranuclear origin. Specimen of the inferior oblique muscle revealed no abnormalities or showed decrease of type I muscle fibers.