Exophthalmos – Protruding eye – Bulging eyes
Exophthalmos is the medical term for a protrusion of the eyeball (a bulging eye). The condition can affect one or both eyes, which appear bulging. It is most often caused by an overactive thyroid (hyperthyroidism). Treatment usually focuses on balancing thyroid function. In cases of complications, anti-inflammatory injections or surgery may be necessary.
What is exophthalmos?
Exophthalmos refers to a protrusion of one or both eyes – The eye protrudes abnormally from the orbit.
The first cause is Graves' disease (hyperthyroidism).
It is most often benign and reversible with treatment of hyperthyroidism.
In cases of inflammatory complications, compression of the optic nerve or failure of the eye to close, medical or surgical treatment is indicated.
Diagnosis of exophthalmos
The diagnosis of exophthalmos is clinical and often presented directly by the patient. The clinical evaluation of exophthalmos by an ophthalmologist then includes:
An examination of eye movement.
An assessment of eyelid closure.
If necessary, a measurement of exophthalmos using the Hertel exophthalmometer.
An assessment of ocular surface inflammation using a slit lamp.
The causal assessment will then be carried out by a radiologist and in the laboratory;
Brain and facial MRI to measure exophthalmos and look for orbital involvement: hypertrophy of the extraocular muscles, orbital tumor,…
Blood test – Looking for hyperthyroidism
If you have hyperthyroidism, you will be referred to an endocrinologist to begin the appropriate treatment. The ophthalmologist will monitor the progression of the exophthalmos.
When to consult a doctor?
Consult an ophthalmologist if you notice that one or both of your eyes are protruding.
It is important to identify the cause, because if treatment is necessary, it is often more effective if undertaken as early as possible.
Symptoms
Exophthalmos is most often asymptomatic! However, some patients report experiencing:
A feeling of heaviness or eye discomfort.
Episodes of redness.
Episodes of diplopia (double vision).
Difficulty blinking.
Symptoms of eye irritation, redness, a gritty sensation.
A decrease in vision (rare).
Causes of exophthalmos
The primary cause of exophthalmos in developed countries is autoimmune hyperthyroidism, also known as Graves' disease.
Exophthalmos is found in ⅓ of patients with Graves' disease, to varying degrees of severity.
Antibodies secreted by the body attack the thyroid and send it abnormal stimulation signals.
The immune system also attacks the orbital fat and muscles through a cross-reaction, leading to inflammation, edema, and a protrusion of both eyeballs forward.
Exophthalmos can also have other causes, but these are generally less frequent:
Orbital trauma, specifically a fracture of the orbital floor.
Bleeding behind the globe – Rupture of orbital varices or carotid-cavernous fistula.
An infection of the orbital tissue – known as orbital cellulitis
Cancerous tumors.
Treating exophthalmos
The treatment for exophthalmos begins with addressing its underlying cause. In the case of dysthyroid exophthalmos, the indicated treatments are:
Antithyroid drugs – Medications to correct thyroid activity. They reduce the level of thyroid hormones in your blood. This doesn't necessarily improve eye problems, especially when starting treatment, but it can prevent them from worsening.
Anti-inflammatories – Intravenous corticosteroid injections to reduce orbital inflammation.
Orbital decompression – Surgery sometimes performed as an emergency in case of optic nerve compression, or as a scheduled procedure in case of eyelid malocclusion.
Comfort eye drops – Moisturizing and healing eye drops help reduce dryness and discomfort associated with blink abnormalities caused by the disease.
In other cases, treatment also varies depending on the cause. For example, radiotherapy, chemotherapy, and/or surgery may be recommended if the exophthalmos is caused by a tumor.
Complications of exophthalmos
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In cases of severe exophthalmos, the eyes no longer close when blinked voluntarily. Without eyelid closure, the cornea is constantly exposed, dry, and damaged.
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Patients may therefore develop an exposure ulcer, intense pain, and blurred vision. Without treatment, lasting effects may persist!
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Cases where the eyeball comes out of the orbit for a few minutes before coming back in are exceptional.