Ocular proptosis is the medical term for the forward bulging of one or both eyeballs from their natural position in the eye socket. This protrusion is not a disease, but a sign of an underlying medical condition causing pressure behind the eye. The condition can alter a person’s appearance and requires medical attention to address the root cause.
Causes of Eye Bulging
The most frequent cause of eye bulging is an autoimmune condition known as thyroid eye disease, or Graves’ ophthalmopathy. In this disorder, the immune system attacks the tissues and muscles behind the eyes, causing inflammation and swelling that displaces the eyeball. This is the leading cause of proptosis affecting both eyes.
Other conditions can also lead to eye bulging. Infections in the eye socket, such as orbital cellulitis, cause inflammation and swelling that results in proptosis. Tumors, whether noncancerous or cancerous, can physically push the eye forward from within the orbit. Traumatic facial injuries that cause bleeding or swelling inside the eye socket are another potential cause.
Recognizing the Signs and Symptoms
Beyond the visible protrusion, a common sign is a distinct staring appearance where more of the white part of the eye is visible. This occurs because the bulging prevents the eyelids from closing completely.
Symptoms that affect comfort and vision include a sensation of pressure or a gritty feeling. The eyes may become dry, irritated, and red, sometimes leading to excessive tearing due to increased surface exposure. In some cases, misalignment of the eyes can cause double vision, or swelling can make it difficult to move the eyes.
Medical Evaluation and Treatment
To determine the cause, a physician conducts a medical evaluation starting with a physical exam. This may include using a specialized ruler called an exophthalmometer to measure the eye’s protrusion. Blood tests are ordered to assess thyroid function, while imaging tests like a CT scan or MRI are used to view the structures behind the eye and identify abnormalities.
Treatment for proptosis is directed at the underlying medical issue. If thyroid eye disease is the cause, medications can regulate thyroid hormones and reduce inflammation. For bacterial infections like orbital cellulitis, antibiotics are the standard approach. When a tumor is responsible, surgery to remove the growth may be necessary, or a procedure called orbital decompression can create more space in the eye socket.
Outlook and Potential Complications
The long-term outlook depends on the specific cause and how quickly it is treated. When the underlying condition is managed effectively, the eye’s bulging can be reduced or resolved, and vision can be preserved. Early medical intervention is important for a positive outcome.
Failing to address proptosis can lead to complications. One risk is damage to the cornea, the eye’s protective outer layer. If the eyelids cannot close properly, the cornea can become overly dry, leading to ulcers and scarring. A more severe complication is compressive optic neuropathy, where pressure in the eye socket squeezes the optic nerve, potentially resulting in permanent vision loss if not treated.