What Is Retrobulbar Hemorrhage?
Retrobulbar hemorrhage is bleeding within the bony orbital cavity, behind the eyeball. Retrobulbar hemorrhage is a rare but sight-threatening condition that needs prompt medical intervention. Symptoms of retrobulbar hemorrhage include severe pain, inability to open the eyes, and vision loss. If untreated, retrobulbar hemorrhage can damage the optic nerve and blood vessels in the retina and lead to blindness. Common causes of retrobulbar hemorrhage are traumatic injury to the orbit and orbital surgery. Depending on the severity of the retrobulbar hemorrhage, surgery may be required.
- Retrobulbar hemorrhage is a condition in which blood accumulates in the orbital cavity, the space behind the eyeball.
- Retrobulbar hemorrhage is usually caused by a blunt force injury to the eye, but may also be a consequence of orbital surgery.
- Depending on the severity of the retrobulbar hemorrhage, surgery may be required.
Understanding Retrobulbar Hemorrhage
The eyeball, also called the globe of the eye, is contained in a bony structure called the orbit. The orbit is a deep depression in the skull that stores the eyeball. It is an empty cavity that is also known as the eye socket. The retrobulbar space is in the orbit, behind the eyeball. The orbital compartment is made up of four walls, which are formed by the cranial bones. The walls of the orbit are the roof, the floor, the lateral wall (close to the ear), and the medial wall (close to the nose). If the walls of the orbit are damaged or broken, blood can seep into the retrobulbar space. This pooling of blood is called a retrobulbar hemorrhage. A retrobulbar hemorrhage can cause many problems such as elevated eye pressure and decreased blood supply to the eye.
Bleeding in the retrobulbar space usually occurs due to blunt force trauma, such as being punched in the eye. Blunt force injury causes the orbital walls to fracture or break. When the orbital walls fracture, blood can seep in through the cracks and enter the retrobulbar space. The accumulation of blood in the retrobulbar space pushes on the eyeball and increases the eye pressure. The acute rise of orbital pressure is called orbital compartment syndrome, and it is an ophthalmic emergency that requires urgent treatment to avoid complete vision loss. When the orbital pressure becomes high, it stretches and damages the optic nerve. The central retinal artery, which supplies blood to the retina, also becomes compressed when the orbital pressure is high. The compression of the central retinal artery causes a central retinal artery occlusion, and the retina becomes devoid of blood supply. Lack of blood supply (ischemia) can injure most of the retinal cells within 90 minutes of the artery compression. Thus, people who have blunt trauma to the eye with suspected orbital compartment syndrome and retrobulbar hemorrhage should visit the emergency room or ophthalmologist immediately to have the best chances of visual recovery.
Most commonly, retrobulbar hemorrhage occurs due to traumatic injuries, especially orbital floor fractures. However, it can be associated with recent eye surgery. It may also be associated with conditions that affect the blood supply to the eyes such as arteriovenous malformations, orbital varicosities, or lymphangiomas.
High blood pressure and the use of anticoagulant medications such as NSAIDs, warfarin, or aspirin increase the risk of retrobulbar hemorrhage and compartment syndrome. Blood clotting disorders also increase the risk.
The diagnosis for the condition is mainly clinical and involves the ophthalmologist doing a detailed examination of the external and internal structures of the eye. Radiological imaging, such as a CT scan or MRI are also helpful.
Symptoms of a retrobulbar hemorrhage are:
- Rapid vision loss
- Sudden, intense pain inside or behind the eye
- Difficulty opening the eye
- Eyelid swelling
- The appearance of bulging eyes
- Double vision
Signs the doctor may see during their clinical examination include:
- Proptosis: The accumulation of blood in the space behind the eyeball displaces the eye forward, which can make the eyes appear bulging or popping out of the skull.
- Decreased visual acuity
- Afferent pupillary defect: improper pupillary response to light
- Restricted eye muscle movement
- Eyelid bruising
- High intraocular pressure
- Optic nerve and retinal pallor
Treatment depends on the extent of the retrobulbar hemorrhage and associated symptoms and exam findings. Small hemorrhage with good visual acuity and exam may be observed. However, if a patient has hemorrhage with orbital compartment syndrome, emergent surgery is needed. The orbital pressure can be decreased through a surgical procedure called canthotomy and cantholysis. During this surgery, the lateral part of the lower eyelid is cut with scissors. The goal of canthotomy and cantholysis is to cut the tendon attachments that hold up the eyeball. When the eyelid tendon is cut, the eyelid can move forward, and the increased space will decrease the orbital pressure behind the eye.