The hypoplasia can be unilateral or bilateral.
Features of an affected eye:
(1) The optic nerve head is small (one third to half of normal) and usually gray.
(2) There is a pigmented ring around the disc ("double ring sign").
(3) Blood vessels arising from the disc show tortuosity or an abnormal origin.
Additional findings:
(4) The affected eye may be small or normal in size.
(5) Visual acuity may range from normal to total blindness.
(6) Rarely there may be a familial pattern of inheritance.
(7) Unilateral cases may show a difference in the optic foramina on skull X-rays.
(8) Patients may have an anomaly involving midline structures (congenital hypopituitarism, sept-optic nerve dysplasia, others)
