Irvan Syndrome (idiopathic retinal vasculitis, aneurysms, and neuro-retinitis) is a disease that was initially described as "bilateral retinal vasculitis with multiple aneurysmal dilatations" in 1983. It is an inflammatory disease of the retina and retinal blood vessels. It corresponds to the combination of inflammation of the retinal arteries, arterial aneurysms (especially in the bifurcations where the angles are widened) and retinal edema. The vision can be threatened by neovascular proliferation and by the accumulation of lipid exudates in the macula. The lesions are bilateral and can spread across the entire fundus of the eye. No systemic damage occurs in most cases.