Neuro-ophthalmic complications of raised intracranial pressure, hydrocephalus, and shunt malfunction

The unique anatomic location of the visual sensory pathway and all the ocul ar motor nerves in the brain has made the ophthalmic system vulnerable to i ncreased intracranial pressure. Neuro-ophthalmic complications caused by in creased intracranial pressure range from loss of visual acuity, visual fiel d defects, abnormal pupillary function, and optic disc swelling or atrophy to eye movement abnormalities, including diplopia with extraocular motility disturbances and dorsal midbrain syndrome. Although ophthalmic involvement is well known to occur with increased intracranial pressure, it is not wid ely appreciated how frequently it is the major clue or sometimes the only r eliable clue to the diagnosis of elevated intracranial pressure, thus makin g the visual evaluation relevant to management of raised intracranial press ure. Ophthalmic signs caused by increased intracranial pressure can necessi tate emergent neurosurgical intervention sometimes even before the radioima ging signs become evident. Furthermore, the detection of ophthalmological s igns of raised intracranial pressure not only can facilitate an early diagn osis but also can guide the treatment of visual impairment caused by elevat ed intracranial pressure to preserve vision. This article reviews the commo n neuro-ophthalmic signs of increased intracranial pressure as a result of various processes, including venous thrombosis, tumors, hydrocephalus, and consequences of shunt malfunction.