The protruding or bulging of one or both eyeballs is called bulging eyes. It is also known scientifically as proptosis or exophthalmos. Such patients tend to blink less and it may even appear as if they are always staring.
What Causes Bulging Eyes?
The most common reason behind bulging eyes is abnormal functioning of the thyroid gland causing eye disease. This thyroid eye disease is also known as Grave’s disease, Grave’s ophthalmology or Grave’s orbitopathy. This is an autoimmune condition where the body’s immune system attacks the healthy tissues around the eye resulting in the eyeball pushing forward and appearing to bulge. Such patients also complain of additional eye symptoms such as redness, dryness, itching, pain, sensitivity to light and double vision.
The majority of the patients with thyroid eye disease suffer from hyperthyroidism (overactive thyroid gland). There have been few cases where this condition was found in patients suffering from hypothyroidism (underactive thyroid gland) and in rare cases, it was found in people having a healthy thyroid function.
Apart from thyroid eye disease, bulging eyes can also afflict you if you suffered from an eye injury or experienced hyphema (bleeding in eyes), if you developed any serious eye infections or if there is presence of any cancerous tumors in your eyes.
How is a Bulging Eye Diagnosed?
If a patient suspects that one or both of their eyes are bulging, then they need to consult an ophthalmologist. The ophthalmologist will ask them about their optical symptoms including how long these symptoms have been present and if there has been any change in severity of the symptoms. In general, if symptoms have developed over a few days it is likely bulging eyes is a result of surgery, injury, infection or inflammation. Symptoms that have gradually developed and worsened over a few years are likely attributed to thyroid eye disease.
The ophthalmologist will than conduct a physical examination of the patient’s eyes using a slit lamp (a diagnostic instrument that allows the eye to be viewed under magnification) to evaluate the agility of eye movements. Slow eye movements are generally associated with thyroid eye disease. Then, the ophthalmologist will use an exophthalmometer (a diagnostic instrument to measure your eye size) to measure the extent of bulging. If there is any abnormality noted during these examinations, the patient will be recommended to undergo a computerized tomography (CT) scan or magnetic resonance imaging (MRI) scan to further examine eye sockets. The ophthalmologist will also order a blood test to check if there is any abnormality in thyroid function. Based on a combination of these results, the ophthalmologist will determine if the patient has bulging eyes or if further examination needs to be carried out to reach a diagnosis.
Is Bulging Eyes Disease Inherited?
In general, people are at a risk of inheriting a condition from their parents or someone in their family if that condition has a genetic link. Conditions with a strong genetic link are generally inherited while non-genetic disease are never inherited. Exophthalamus is a condition that is not related to genetics and cannot be passed down or inherited in the family.
However, Grave’s disease (the major underlying cause) is an autoimmune disease and there are genetic factors that may predispose you to this condition that may eventually lead you to develop bulging eyes. In addition, there are reports of rare cases where newborn babies have inherited a genetic abnormality that caused the vessels supplying blood to the eyes to become distorted or they had an abnormality in their eye sockets causing them to be very shallow. Such infants have gone on to develop bulging eyes because of the pre-existing genetic abnormality in their eyes. In such cases, treatment usually involves surgery to correct the base abnormality to correct vision and prevent further damage to the eyes.
- American Academy of Ophthalmology. (2021). Proptosis (Bulging Eyes). https://www.aao.org/eye-health/diseases/proptosis-bulging-eyes
- American Thyroid Association. (2021). Graves’ Disease. https://www.thyroid.org/graves-disease/
- Cleveland Clinic. (2021). Hyperthyroidism. https://my.clevelandclinic.org/health/diseases/8541-hyperthyroidism