Subretinal haemorrhage in idiopathic intracranial hypertension

Among the more frequently cited aetiologies are trauma, choroidal tumour, aneurysmal subarachnoid haemorrhage, and retinal vascular disease such as diabetic or hypertensive retinopathy. Acute increases in intracranial pressure induce a venous stasis retinopathy, which may result in intraocular bleeding. 4 Given that the mechanism of disc oedema in IIH is raised intracranial pressure, it would follow that retinal haemorrhages should be common in this disorder. Pre-existing communicating vessels between the retinal and choroidal circulations probably dilate in response to long standing papilloedema, creating optociliary shunt vessels of varying sizes. 5 Perhaps these shunts unload the increased venous pressure on the retinal circulation, reducing the incidence of large intraocular haemorrhages from venous stasis retinopathy.