exophthalmos


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Related to exophthalmos: Graves disease

Exophthalmos

 

Definition

When there is an increase in the volume of the tissue behind the eyes, the eyes will appear to bulge out of the face. The terms exophthalmos and proptosis apply. Proptosis can refer to any organ that is displaced forward, while exophthalmos refers just to the eyes.

Description

The eye socket (orbit) is made of bone and therefore will not yield to increased pressure within it. Only forward displacement of the eyeball (globe) will allow more room if tissue behind the eye is increasing.

Causes and symptoms

The most common cause of exophthalmos is Graves' disease, overactivity of the thyroid gland. The contents of the orbits swell due to inflammation, forcing the eyes forward. The inflammation affects primarily the muscles. This combination of muscle impairment and forward displacement reduces eye movement, causing double vision and crossed eyes (strabismus). The optic nerves can also be affected, reducing vision, and the clear membrane (conjunctiva) covering the white part of the eyes and lining the inside of the eyelids can swell. Finally, the eyes may protrude so far that the eyelids cannot close over them, leading to corneal damage.
Exophthalmos from Graves' disease is bilateral (occurring on both sides), but not necessarily symmetrical. In contrast, exophthalmos from orbital tumors or a blood clot in the brain happens on only one side.

Diagnosis

Exophthalmos is obvious when it is advanced enough to cause complications. When there is doubt in the early stages, a mechanical device called an exophthalmometer can measure the protrusion. Computed tomography scans (CT scans) are of great value in examining the bony components of the orbit. Magnetic resonance imaging (MRI) scanning is equally valuable for displaying the contents of the orbit, because it "sees through" the bone.

Treatment

If a tumor is growing behind the eye, it needs to be removed. If Graves' disease is the cause, it may subside with treatment of the overactive thyroid, but this is not guaranteed. Local care to the front of the eye to keep it moist is necessary if the eyelid cannot close.

Prognosis

Exophthalmos can be progressive. Its progress must be carefully followed, treating complications as they occur.

Prevention

Vision can usually be preserved with attentive treatment. There is currently no way to prevent any of the underlying conditions that lead to exophthalmos.

Resources

Books

Fauci, Anthony S., et al., editors. Harrison's Principles of Internal Medicine. New York: McGraw-Hill, 1997.

Key terms

Conjunctivae — The clear membranes that line the inside of the eyelids and cover the white part (sclera) of the eyeballs.
Cornea — The clear, dome-shaped part of the front of the eye, through which light first enters the eye. It is located in front of the colored part of the eye (iris).
Inflammation — The body's reaction to invasion by foreign matter, particularly infection. The result is swelling and redness from an increase in water and blood, and pain from the chemical activity of the reaction.
Strabismus — Any deviation of the eyes from a common direction. Commonly called a turned eye.
Thyroid — A gland in the neck overlying the windpipe that regulates the speed of metabolic processes by producing a hormone, thyroxin.

exophthalmos

 [ek″sof-thal´mos]
abnormal protrusion of the eye. adj., adj exophthal´mic. It results in a marked stare and is usually due to hyperthyroidism. Occasionally the condition is caused by an infection of the eye or a tumor behind the eye.
Exophthalmos and goiter in Graves' disease. From Frazier et al., 2000.

ex·oph·thal·mos

, exophthalmus (ek'sof-thal'mos),
Protrusion of one or both eyeballs; can be congenital and familial, or due to pathology, such as a retroorbital tumor (usually unilateral) or thyroid disease (usually bilateral).
Synonym(s): proptosis
[G. ex, out, + ophthalmos, eye]

exophthalmos

/ex·oph·thal·mos/ (-thal´mos) abnormal protrusion of the eye.exophthal´mic

exophthalmos

also

exophthalmus

(ĕk′səf-thăl′məs)
n.
Abnormal protrusion of the eyeball.

ex′oph·thal′mic adj.

exophthalmos

ex·oph·thal·mos

, exophthalmus (eks'of-thal'mos, -mŭs)
Protrusion of one or both eyeballs; can be congenital and familial, or due to pathology, such as a retroorbital tumor (usually unilateral) or thyroid disease (usually bilateral).
Synonym(s): proptosis.
[G. ex, out, + ophthalmos, eye]

exophthalmos

Protrusion of an eyeball. This forces the eyelids apart and causes a staring appearance. Exophthalmos is caused by an increase in the bulk of the contents of the bony eye socket (ORBIT) from any cause. The commonest cause is an immunological disorder associated with the thyroid gland, but exophthalmos, or proptosis, may be caused by tumour, bleeding or a mucous cyst from a sinus (MUCOCOELE).

exophthalmos

eyeball prominence due to orbital deposition of mucopolysaccharide; characteristic of hyperthyroidism or thyrotoxicosis

exophthalmos

Abnormal protrusion of the eyeball(s) from the orbit, caused by Graves' ophthalmopathy, endocrine malfunction, paralysis of the extraocular muscles, injury of the orbit, cavernous sinus thrombosis or a tumour behind the eye. The palpebral fissure is usually wider and a rim of sclera may be visible above and below the cornea (Fig. E7). Unilateral displacement is usually referred to as proptosis. See pathological diplopia; Graves' disease; elephantiasis oculi; enophthalmos; Apert's syndrome; Crouzon's syndrome.
Fig. E7 Severe bilateral exophthalmos and lid retraction in Graves disease. (From Kanski 2003, with permission of Butterworth-Heinemann)enlarge picture
Fig. E7 Severe bilateral exophthalmos and lid retraction in Graves' disease. (From Kanski 2003, with permission of Butterworth-Heinemann)

ex·oph·thal·mos

, exophthalmus (eks'of-thal'mos, -mŭs)
Protrusion of one or both eyeballs; can be congenital and familial, or due to pathology.
Synonym(s): proptosis.
[G. ex, out, + ophthalmos, eye]

exophthalmos (ek´softhal´mōs),

n an abnormal protrusion of the eyeball. It is characteristic of toxic (exophthalmic) goiter.

exophthalmos

abnormal protrusion of the eye.

congenital exophthalmos
seen in brachycephalic breeds with shallow orbits; see also euryblepharon.
inherited exophthalmos
exophthalmos with strabismus is inherited in cattle.
ophthalmoplegic exophthalmos
inability to move the eye because of exophthalmos.
pulsating exophthalmos
due to an arteriovenous fistula of the orbit.
References in periodicals archive ?
The final radiologic diagnosis was exophthalmos, which made a retrobulbar mass, caused by an abscess, granuloma, or neoplasia, the most likely cause of the disease.
Hydatid cyst: unusual cause of unilateral exophthalmos.
Exophthalmos is a common avian presentation, whereas buphthalmos is rarely reported.
3) Orbital tumors usually cause slowly progressive unilateral exophthalmos with variable displacement.
Examples of organ-specific autoimmune diseases include IDDM; Hashimoto's thyroiditis; pernicious anemia with chronic atrophic gastritis; primary adrenal gland atrophy (Addison's disease); MS; pemphigoid skin disorders; and Graves' disease, which is a multi-system disorder characterized by diffuse thyroid gland hyperplasia, myopathy, and exophthalmos.
The patient denied tremor and palpitations, had a normal-sized thyroid, had no exophthalmos, and had no history of thyroid disease before pregnancy, which is consistent with hyperemesis gravidarum rather than Graves disease.
Abstract: An African grey parrot (Psittacus erithacus) was presented with exophthalmos and a semisolid mass dorsomedial to the left eye that led to ventrotemporal deviation of the globe.
In addition to the mild right exophthalmos, physical examination revealed fullness over the right maxilla that extended to the temporal area.
Hepatitis from methimazole during adrenal steroid therapy for malignant exophthalmos.
The clinical picture is characterised by severe general malaise, exophthalmos, a motility deficit and considerable lid and conjunctival swelling.
Abstract: Squamous cell carcinoma of the infraorbital sinus was diagnosed in a 5-year-old Solomon Island eclectus parrot (Eclectus roratus solomonensis) that presented with exophthalmos of the right globe and an ulcerative mass of 2-months duration at the right commissure of the beak.
Less severe cases can be characterized by an asymmetric prominence of the face, nasal or sinus obstruction, exophthalmos, and epiphora.