Increased antero-grade flow, can result from vascular
malformations of the face and scalp.
Obstruction of distal venous drainage, as cavernous sinus
Ab-normal retro-grade flow, as carotid–cavernous fistula.
Increased intracranial pressure.
Most common cause of spontaneous orbital
Lesions result from congenital weakness in
post-capillary venous wall.
Have a large communication with the venous
system and distend during maneuvers that
increase venous pressure.
Have only a small
the venous system
and do not distend.
Patients with usually
manifest stress or
appearance, axial on
Or mild enlargement of
the involved veins.
pressure is required to
Varices may be
of Opth. veins.
Orbital mass of
At MR imaging:
Hypo- to hyper-
intense signal on T1.
Fed by ophthalmic artery branches.
Consist of multiple congenital micro-vascular
connections between arteries and veins.
Manifest with peri-orbital swelling, dilated
retinal veins, visible or palpable pulsations, an
audible bruit, glaucoma, and, visual field
Consists of unilateral
AVM of the visual
pathways and midbrain.
Facial vascular nevi or
Patients present with
optic atrophy and
Abnormal communication between the
cavernous sinus and one or more branches of
the internal or external carotid artery.
Causes direct trauma, surgery, dural sinus
thrombosis, or spontaneously.
Spontaneous with Ehlers-Danlos syndrome
and osteogenesis imperfecta.
Manifest with the
classic triad of pulsatile
and an auscultatory
Gradual decrease in
Palsy of cranial nerves
III, IV, V, and VI.
Intracanalicular ophthalmic artery aneurysms are
More common carotid-ophthalmic artery
Arise at origin of the ophthalmic artery.
May extend intra-cranially above the sella and
sometimes extend into or through optic canal.
Lesion withdiameter of 2–3 mm are usually
More than 3 mm may compress the artery or optic
nerve or rupture.