Causative factors
The causative factors of exophthalmos are divided into following categories: Inflammatory, vascular, neoplastic, and traumatic causes. Inflammatory causes are orbital cellulitis, diseases of thyroid gland, etc. Vascular causes may be local or systemic. Systemic vascular causes are Wegener’s granulomatosis, Churg-Strauss syndrome, etc. Local vascular factors are local vascular malformations and fistulas. Neoplastic factors may be local or metastatic. Neoplasm of lacrimal gland, meningioma, glioma, and metastasis from breast cancer in women and lung and renal carcinoma may cause exophthalmos. Traumatic factors that may lead to exophthalmos are orbital hemorrhage, orbital fracture, facial fracture, etc.
Dysfunction of the thyroid gland is the commonest cause of exophthalmos. The condition is referred to as hyperthyroidism, an overactive thyroid gland. It commonly occurs due to Graves’ disease. It is an autoimmune disorder where the immune system attacks the healthy muscles and fatty tissue around the eye and the eyes become inflamed and swollen.
Signs and symptoms
Signs and symptoms of exophthalmos vary according to the underlying cause of exophthalmos. Following are the signs and symptoms of exophthalmos: Redness and pain, dry eye, photophobia (sensitivity to light), double vision, etc. In severe cases of exophthalmos, patient may not close the eyes completely.
Complications
If the eyes become dry, it may lead to corneal ulceration. Exophthalmos increases the risk of optic nerve compression. It may damage the vision permanently. So treatment of exophthalmos should be started as early as possible.
Diagnosis
Meticulous history of the disease is the key to diagnosis. Doctor asks in details about the ophthalmic history of the patients. Questions are asked about duration and onset of exophthalmos, change in vision, redness, and other symptoms of eye; double vision, etc.
Next, the doctor examines the patient. Complete ophthalmological examination is carried out. Field of vision, visual acuity, etc., are tested and any abnormality is carefully noted. Palpation of the orbit is done to assess tenderness, nature, and mobility of the mass. Pupil is dilated to examine the optic disc and retina. Once the clinical examination is over, the patient is asked for laboratory and imaging studies. Thyroid function test is required to identify any disease of thyroid gland. Other laboratory tests may be done to identify any systemic illness. Imaging studies like x-rays and CT scan may be done to evaluate the orbital mass, surrounding soft tissue, and bony structures. USG and Doppler studies may be beneficial in this aspect.
Treatment
If exophthalmos is due to thyroid dysfunction, following treatment is undertaken :
- Medications are prescribed to correct the level of thyroid hormones in blood.
- Corticosteroid may be required to control inflammation.
- Corrective surgery may be undertaken to improve appearance of the patient.
If exophthalmos is caused by any other underlying pathology, it is treated accordingly. Treatment of the underlying cause is essential followed by any corrective surgery, if required. If exophthalmos is identified and treated early, then visual acuity is usually preserved without any permanent damage to the eyes.
