Optic nerve decompression in benign intracranial hypertension.

Fourteen patients with benign intracranial hypertension who failed to respond to medical treatment, were treated with optic nerve decompression to prevent the sequelae of chronic unrelieved papilloedema. The mechanism by which optic nerve decompression protects the optic nerve is uncertain. These patients were reviewed to evaluate the efficacy of the procedure in the treatment of benign intracranial hypertension and to assess its mechanism of action. Preoperatively all patients had papilloedema, 11 patients had visual obscurations and 6 patients had evidence of visual failure. Postoperatively, visual obscurations and papilloedema resolved in all patients, and 5 of 6 patients had no further deterioration of visual function. Six patients had symptoms of raised intracranial pressure preoperatively and in 3 the symptoms resolved after surgery. Three patients had unilateral optic nerve decompression and papilloedema resolved in both eyes. In 1 patient intracranial pressure monitoring revealed raised pressure preoperatively with no significant change in the first 24 hours after surgery. We conclude that optic nerve decompression is effective in the treatment of benign intracranial hypertension, has its effect locally, and in some patients may lower the intracranial pressure.