Blindness from bad bones.

Progressive visual loss is the most common neurologic finding in osteopetrosis. Several mechanisms may explain this phenomenon, including compression of the optic nerves caused by bony overgrowth of the optic canals and retinal degeneration. We report a child with osteopetrosis and progressive visual loss, even though patent optic canals were demonstrated by computed tomography and digital holography. This patient's visual loss was caused by increased intracranial pressure secondary, to obstruction of cerebral venous outflow at the jugular foramen. This case points to the importance of a full evaluation of the skull base foramina in the diagnostic workup of visual loss in patients with osteopetrosis.