Idiopathic intracranial hypertension presenting with gaze-evoked amaurosis

Abstract

Purpose: Gaze-evoked amaurosis is transient monocular visual loss induced by an eccentric position of gaze, most frequently associated with orbital mass lesions. To our knowledge, there has been no reported case of idiopathic intracranial hypertension as a cause of gaze-evoked amaurosis. We present the hypothesis that in an eccentric position of gaze, ischaemic compression of a tense dilated optic nerve sheath results in further elevation of intrasheath pressure compromising blood flow to the retina. Method: We describe a case of unilateral gaze-evoked amaurosis and headaches in a 46 year old man diagnosed with idiopathic intracranial hypertension. He did not respond to medical treatment and had optic nerve sheath decompressions. Result: Following surgery, this patient's visual function improved with resolution of his gaze-evoked amaurosis. Conclusion: Raised intracranial pressure associated with a tense dilated optic nerve sheath should be considered in the differential diagnosis of gaze-evoked amaurosis.