By Prem Subramanian, M.D., Ph.D. (University of Colorado)
What are orbital vascular malformations?
They are a group of diseases affecting the eye and its surrounding structures originating from abnormalities in vascular structures in the orbital region (arteries, veins or lymph vessels)
How common are those malformations?
Depending on the disease, most of them are uncommon and some are extremely rare, but they should not be missed because of vision and life threatening risks that they may carry.
What are the types of Orbital Vascular malformations?
Orbital vascular anomalies can be classified into vascular tumors or vascular malformations. Vascular malformations are further categorized into three different groups: Those with high blood flow that usually involve the arteries, those with low blood flow affecting the veins or lymphatics and those with mixed flow including arteriovenous fistulas.
Capillary hemangioma is one of the more common vascular malformation that affects infants, arteriovenous malformations (AVM) are congenital abnormalities that are usually rare and caused by the failure of the differentiation of vascular networks. Wyburn –Mason Syndrome is a type of congenital AVM affecting the retina, brain and skin. Cavernous carotid fistula (CCF) is an acquired vision threatening condition where there is an abnormal connection between the cavernous sinus and a branch of the internal or external carotid artery. Ophthalmic artery aneurysms- or dilation of the walls of the ophthalmic artery- are extremely rare
Cavernous hemangiomas are the most common vascular malformations in adults; they present usually as a unilateral single benign slowly growing mass. Orbital Varices are thinning and dilation of venous walls, while lymphangiomas are rare entities caused by proliferation of lymphatic vessels forming cysts that can occasionally bleed.
When should I suspect Orbital Vascular Malformations?
Symptoms vary based on the underlying problem.
Capillary Hemangioma: Red strawberry like lesion over the face if superficial, blue lesion if deep, proptosis (bulging of the eye)
AVM: proptosis, pain, pulsating eye, double vision, loss of vison
Carotid cavernous fistula: pulsation of the eyes, proptosis, redness, swelling, dilated and tortuous conjunctival vessels, decreased visual acuity, double vision, limitation of eye movement,
Cavernous malformations: progressive painless proptosis (most common), lid swelling, double vison, palpable lump
Orbital varices: Proptosis and dilation of vessels due to engorgement of the veins. Symptoms are exacerbated with coughing, straining and bending. Bleeding can occur.
Lymphangiomas: Sudden painful bulging of the eye (due to bleeding or chocolate cyst), dilated discolorated lymphatic vessels over the eyelid or conjunctiva.
Why do you need to see an orbital specialist?
Although most orbital vascular malformations are benign, they may lead to deleterious consequences. They can cause decreased vision if they block the visual axis that might be permanent especially in children less than eight years of age. They might bleed and/or compress on the eye and jeopardize vascular supply to the eye. They might cause an increase in intraocular pressure and secondary glaucoma. They can cause restriction in eye movement and double vision.
Furthermore, although rare, the above mentioned symptoms might be a manifestation of a vascular tumor, and in such cases missing the disease can be life threatening.