Exophthalmos is defined in Dorland's Medical Dictionary as an "abnormal protrusion of the eyeball; also labeled as proptosis." Proptosis in the same reference is defined as exophthalmos.

Henderson reserves the use of the word exophthalmos for those cases of proptosis secondary to endocrinological dysfunction.[1] Therefore, this dictum will be followed, and non–endocrine-mediated globe protrusion will be referred to as proptosis and exophthalmos will be reserved for protrusion secondary to endocrinopathies.

Bilateral exophthalmos and upper lid retraction secondary to Graves disease.

PathophysiologyThe etiological basis of proptosis can be inflammatory, vascular, or infectious. In adults, thyroid orbitopathy is the most common cause of unilateral and bilateral exophthalmos. Other causes include such neoplasms as cavernous hemangiomas, lymphangiomas, lymphomas, Wegener granulomatosis, and orbital cellulitis.

In children, unilateral proptosis is often due to an orbital cellulitis–type picture, and, in bilateral cases, neuroblastoma and leukemia are more likely.

For instance, lymphangiomas, by their histologic nature, can increase in size during viral illnesses and result in an increase in orbital volume. A ruptured lymph hemangioma can enlarge due to its rupture and sequestering of heme, which pathologically is described as a chocolate cyst. Orbital varices can result in proptosis with increased venous pressure in the orbit as seen with a Valsalva maneuver or change in postural position.

The etiology of the thyroid-related orbitopathy is an autoimmune-mediated inflammatory process of the orbital tissues, predominantly affecting the fat and the extraocular muscles. Lymphocytes, plasma, and mast cells are the cellular constituents in this process. The deposition of glycosaminoglycans and the influx of water increase the orbital contents. Obstruction of the superior ophthalmic vein with resultant diminished venous outflow also contributes to the orbital engorgement.

Nunery has segregated patients with thyroid-related orbitopathy into type I and type II.[2] Those with type I do not have restrictive myopathy, whereas those with type II do. Type I was believed to be caused by a profundity of hyaluronic acid manufactured by the orbital fibroblasts, stimulating lipoid hyperplasia and edema. Patients with type II experience restrictive myopathy and have diplopia within 20° of fixation.

Orbital emphysema can be a significant cause of proptosis and requires emergency treatment.

No matter what the etiology may be, globular protrusion is secondary to the increase in volume within the fixed bony orbital confines. Since the orbit is widest at its anterior aspect, the orbital contents are displaced anteriorly, resulting in proptosis and exophthalmos.

EpidemiologyMortality/Morbidity

Proptosis due to any cause can compromise visual function and the integrity of the eye.

A proptotic eye not adequately protected by the lids, as with lagophthalmos, can develop exposure punctuate keratopathy. Such disruption of the finely orchestrated homeostatic mechanism to protect the eye will result in corneal compromise, epithelial death, ulceration, and possible corneal perforation in severe cases. At a minimum, the disruption of the tear film layer and incomplete moisturizing of the eye will adversely affect vision and ocular comfort.

Proptosis secondary to a space-occupying process can result in a compressive optic neuropathy. Impeded optic nerve blood flow results in irreversible neuronal death and diminished optic nerve function. Such manifestations as depression of visual and color acuities, pupillary dysfunction, and constriction of visual field can occur.

Proptotic compressive effects are remedied initially by forward protrusion of the eye, thereby reducing the compressive effect within the orbit. However, the eye can extend only so far, and severe stretching can adversely affect the eye and compromise the optic nerve.

Race In adult Caucasian males, the average distance of globe protrusion is 21 mm, and, in adult

African American males, it is 23 mm. Females also show racial variation. A difference of more than 2 mm between the 2 eyes of any

given patient is considered abnormal.

Sex

Thyroid orbitopathy has a female preponderance with a female-to-male ratio of 5:1.

Age

Proptosis occurs in both adults and children at any age. Thyroid orbitopathy and the resultant exophthalmos show a predilection for females aged 30-50 years.

HistoryA meticulous history of the patient's ocular and systemic systems is key in establishing a diagnosis.

The ophthalmic history should address the duration and the rate of onset of the proptosis. The patient should be queried about pain, change in visual acuity or refraction, diplopia,

and decreased fields of vision. Transient visual loss or blackout periods may signify optic nerve compromise and may call for rapid intervention.

Complaints of foreign body sensation or dry gritty eyes are symptoms that may indicate corneal decompensation.

In performing a thorough medical history and a review of systems, the ophthalmologist should consider orbital involvement secondary to systemic pathology.

Past trauma and family history also may aid in the diagnosis.

PhysicalEvaluation of the patient with exophthalmos begins with a thorough ophthalmic and medical history. When concomitant sinus disease or an intranasal source is suspected, a speculum or endoscopic intranasal examination is warranted. Special emphasis on the duration and rate of progression of the patient's signs and symptoms is essential. Pain, diplopia, pulsation, change in effect or size with position or Valsalva maneuver, and disturbance of visual acuity are symptoms that should be explored.

A complete ophthalmic examination is paramount. Periorbital changes can be noted easily on gross examination in a well-illuminated examination room.

o Hypertelorism, exorbitism, eyeball protrusion (proptosis), eyelid lesions or edema, chemosis, and engorged conjunctival vessels are several periorbital signs.

o Blepharoptosis, lagophthalmos (incomplete lid closure), and interpalpebral fissure distance are additional signs to be considered during the examination.

Palpation of the anterior orbit can assess the level of tenderness, texture, and mobility of the mass.

o Tenderness may denote an inflammatory process or neural invasion by a neoplasm.

o Attention should be paid to regional lymph nodes.

o Tactile inspection of the globe may reveal pulsations secondary to arteriovenous communications or physiological intracranially pulsations transmitted through a bony defect of the orbit, such as an encephalocele.

Protrusion of the eye is an important clinical manifestation of orbital disease. In addition to proptosis, one should note the displacement of the eye in planes other than the anteroposterior dimension (eg, downward, lateral).

o Hertel exophthalmometry is a well-accepted tool to quantitate proptosis. The base is determined by the interlateral canthal space. The transection of the central cornea by the premarked millimeter ruler records the amount of anterior displacement of the globe. Its use requires intact lateral orbital rims. If the rim is not intact, a Luedde exophthalmometer can be used.

o Relative protrusion can be observed by simply standing behind a seated patient and gazing downward toward the chin from the forehead to assess the displacement of one globe as compared to the contralateral side.

Auscultation of the orbit may detect a high flow state in the orbit or intracranially. The bell is useful for this examination. If a high-flow lesion is suspected (eg, carotid cavernous fistula), arteriography should be sought to further qualify these lesions. It is important to have the contralateral eye remain fixated on a target while auscultating the orbit.

Decreased visual acuity, change of refraction, and pupillary abnormalities should be noted.

Extraocular motility dysfunction and diplopia should be carefully assessed and documented.

Forced duction testing may qualify the dysfunction as restrictive or neurogenic in nature. Intraocular pressure may be elevated, and slit lamp examination can discern chemosis and engorged or sentinel vessels.

Dilated funduscopic examination may reveal optic disc edema or pallor, retinal detachment, choroidal folds, vascular engorgement or shunt vessels, or indentation of the posterior pole.

CausesProptosis can be the result of a myriad of disease processes resulting from primary orbital pathology or systemic disease processes. The list below is not comprehensive but can help in forming a differential diagnosis. The list only consists of adult causes since a fair amount of overlap exists in the differential diagnosis of exophthalmos in adults and children.

Proptosis in adults o Infectious

Orbital cellulitis

Mucormycosis

Concurrent sinus disease

o Inflammatory

Orbital inflammatory syndrome (orbital pseudotumor, benign orbital inflammation)

Thyroidopathy

o Vasculitis

Wegener granulomatosis

Churg-Strauss syndrome

o Neoplastic

Lacrimal

Lymphoma

Leukemia

Meningioma

Glioma

Ossifying fibroma[3]

Metastatic (breast in women, lung and prostate in men, gastrointestinal, kidney)

o Orbital vascular disease

Orbital varix (venous malformation)

Orbital arteriovenous malformation (carotid-cavernous sinus fistula, arteriovenous malformation)

o Trauma

Traumatic or iatrogenic orbital hemorrhage

Orbital fractures

Facial fractures

o Pseudoproptosis (pseudoexophthalmos)

Buphthalmos

Contralateral enophthalmos

Ipsilateral lid retraction

Axial myopia

Contralateral blepharoptosis

Anophthalmos

Cellulitis, Orbital

Dacryoadenitis

Dermoid, Orbital

Duane Syndrome

Fistula, Carotid Cavernous

Glaucoma, Juvenile

Globe Retraction

Hemangioma, Cavernous

Horner Syndrome

Leukemias

Meningioma, Sphenoid Wing

Mucormycosis

Orbital Fracture, Apex

Orbital Fracture, Floor

Orbital Fracture, Medial Wall

Orbital Fracture, Zygomatic

Ptosis, Adult

Ptosis, Congenital

Thyroid Ophthalmopathy

Laboratory Studies Patients with thyroidopathy should undergo the appropriate thyroid function studies, even

though some patients are euthyroid at the time of presentation with exophthalmos. Approximately 80% of those with Graves disease manifest orbital signs within 18 months, supporting the need for ophthalmic evaluation.

Any patient suspected of having a neoplasm as the cause of the proptosis should undergo imaging studies (see Imaging Studies). The imaging results should direct further laboratory studies. For example, in a patient with proptosis due to lymphoma, hematologic studies, further body imaging, and a bone marrow biopsy may be indicated.

In patients with proptosis due to orbital cellulitis, complete blood counts, blood and nasal cultures, and sinus imaging studies may be warranted.

Imaging Studies

CT scan, first used in the 1970s, is the product of tissue density calculations. X-rays with different vectors are emitted, penetrating through target tissues with resulting radioabsorbencies. These differences in radioabsorbencies are assigned value-specific gray shades to create the 2-dimensional image. CT scan can produce detailed axial and coronal views of soft tissue and bony structures. Image windows from 1.0-3.0 mm in thickness allow for detailed evaluation of orbital masses. Contrast-enhanced images may be obtained and can help in identifying inflammatory processes, vascular tumors, and engorged vessels. Calcified lesions are discernible without the addition of contrast.

Magnetic resonance imaging (MRI) excites protons by applying a radio frequency with a strong magnetic field. Hydrogen nuclei emit signal intensities that are assigned specific gray tones to create an anatomical reproduction. Three-dimensional views can be gained directly, in any anatomical plane, offering excellent spatial resolution of orbital masses and soft-tissue enhancement. MRI may provide excellent soft-tissue resolution, but CT scan is superior for gleaning details about orbital bony structures.

Ocular ultrasonography can be used to visualize anterior and middle orbital lesions. Sound waves of 5-15 MHz breech orbital tissues that reflect echogenic energy captured by an oscilloscope. A-scan ultrasonography allows for a 1-dimensional description of echoes, while B-scan ultrasonography provides a 2-dimensional image. C-scan ultrasonography affords coronal views, and D-scan ultrasonography creates 3-dimensional orbital views. With the advent of CT scan, C- and D-scan ultrasonography remains unpopular. Doppler ultrasonography may be used to evaluate orbital vasculature and blood flow.

Medical CareMedical care for patients with exophthalmos is directed at reversing the problem and minimizing ocular complications.

ConsultationsOnce the etiology of exophthalmos or proptosis is established, the appropriate specialists should partake in the patient's care.

Medication SummaryThe goals of pharmacotherapy are to reduce morbidity and to prevent complications.

Ocular lubricantsClass Summary

Keep adequate moisture in eye and prevent dryness.

View full drug information

Artificial tears (Celluvisc, Murine, Refresh, Tears Naturale)

Contains equivalent of 0.9% NaCl and maintains ocular tonicity. Acts to stabilize and thicken precorneal tear film and prolongs tear film breakup time, which occurs with dry eye states.

urther Outpatient Care Patients should be monitored in intervals tailored to the degree of exophthalmos and

complications arising from this ocular malady. Measurement of exophthalmos, visual and color acuities, pupillary function, extraocular motilities, and visual fields should be obtained. In addition, any corneal breakdown should be assessed and remedied.

Adult Dosing & UsesRelief of Dry Eyes & Eye Irritation Associated with Deficient Tear Production

Instill 1-2 gtt into eye(s) TID/QID PRN; less frequency for some products

Patients with dry eyes may use drops as frequently as needed

Ocular ointments are helpful at bedtime

Additional Information

Many formulations available & many manufactures are going to preservative free formulations to avoid ocular irritation, especially in frequent users

Some preparations have prolonged contact time and require less often dosing (CelluviscR)

Adverse EffectsFrequency Not Defined

Blurred vision

Eye pain

Headache

Itching/stinging

Redness in and around the eyes

Skin rash

Contraindications

Hypersensitivity to ingredients

PharmacologyPregnancy: no problems reported

No kinetic info reported

Mechanism of Action

Relieves dryness and irritation

Exophthalmos  Author: Michael Mercandetti, MD, MBA, FACS; Chief Editor: Hampton Roy Sr, MD

http://emedicine.medscape.com/article/1218575-overview

What Is Exophthalmos? What Causes Exophthalmos?Editor's ChoiceMain Category: Eye Health / BlindnessArticle Date: 05 Nov 2009 - 0:00 PDT

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Exophthalmos, or exophthalmia, is a protruding eyeball anteriorly out of the orbit (eye socket). The Greek word ophthalmos means "eye" and the Greek word ex means "out". Exophthalmos can be either bilateral (both eyes bulge out) or unilateral (just one eye bulges out). Doctors use an exophthalmometer to measure the degree of exophthalmos.

Depending on the severity of the exophthalmos, if it is left untreated the eye lids may fail to close during sleep, resulting in corneal dryness and eventual damage. People with exophthalmos also risk developing superior limbic keratoconjunctivitis, where the area above the cornea becomes inflamed because of the friction that occurs when the patient blinks. Some patients may experience compression of the optic nerve or ophthalmic artery, which can eventually affect the patient's eyesight, leading to blindness.

Exophthalmos is not a condition, but rather a sign of a condition, usually caused by something wrong with the thyroid gland.

According to Medilexicon's medical dictionary, exophthalmos is "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)."

What are the signs and symptoms of exophthalmos?A symptom is something the patient feels and reports, while a sign is something other people, such as the doctor notice. For example, pain may be a symptoms while a rash may be a sign.

The most noticeable sign of exophthalmos are bulging or protruding eyeballs (either one or both). If the patient has Graves' disease, a thyroid condition, the bulging develops because the tissues in the eyeballs swell, and the number of cells in the eye increases - resulting in larger eyes which push forward from their orbits (sockets). The human eye sockets are rigid and cannot expand to accommodate the larger eyeball. As the eyeball protrudes the eyelid is forced apart, giving the patient a staring expression with a higher-than normal proportion of the whites of the eyes exposed.

Graves' disease is the most common cause of bulging eyeballs. Signs and symptoms of Graves' disease include:

Pain in the eyes Dry eyes

Eye irritation

Sensitivity to light (photophobia)

Lacrimation - eye secretions and shedding of tears

Diplopia - double vision caused by the weakening of the eye muscles

Progressive blindness, if the optic nerve is compressed

Difficulty in moving eyes - as the eye muscles weaken the patient may find it harder to move the eyes. In some cases the eyes may turn inwards (amblyopia).

The following non-ocular signs and symptoms are also possible with Graves' disease: Irregular heartbeats (arrhythmia, palpitations) Anxiety

Raised appetite

Sleeping problems (insomnia)

What are the causes of exophthalmos?

Graves' disease, an autoimmune disease that causes hyperthyroidism (thyroid gland produces too much thyroid hormone) is the most common cause of exophthalmos. Thyroid problems generally are common causes.

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The thyroid gland - the thyroid gland is in the neck, below the Adam's apple. It produces hormones which help to regulate growth and the rate of chemical reactions (metabolism) by which the body uses energy. The thyroid gland produces thyroxine and triiodothyronine.

Thyroid eye disease - also known as TO (thyroid orbitopathy), is a condition in which the soft tissues and muscles surrounding the eyes become swollen and inflamed. This condition is closely linked to hyperthyroidism (overactive thyroid gland), and sometimes hypothyroidism (underactive thyroid gland).

Exophthalmos does not necessarily occur during the onset of hyperthyroidism or hypothyroidism. The eyes may start bulging long after a thyroid problem starts; and even before.

Autoimmune diseases - healthy people's immune systems attack pathogens; organisms and substances that are bad for us, such as some bacteria, viruses, parasites, cancer cells and fungi. If the person's immune system starts attacking good tissue they have an autoimmune disease - the immune system is attacking parts of the person's body that are needed for good health. Graves' disease is an example of an autoimmune disease. Experts are not sure why autoimmune diseases, such as Graves' disease occur.

If the patient's immune system attacks the thyroid gland it often reacts by producing more hormones than normal. The excess thyroid hormone, as well as the autoimmune antibodies may attack the muscles and soft tissue surrounding the eyes, causing:

Dry eyes (often described as gritty eyes) Redness

Puffy eyes

Inflammation and swelling

Problems with eyesight

Exophthalmos (bulging or protruding eyes)

Inherited diseases - some diseases which may affect the eyes are inherited, the patient has acquired the faulty genes from their parents or grandparents. Graves' disease is an example of a hereditary disease.

Proptosis (eyeball protrusion, one eye) - the presence of something in the eye-socket can cause proptosis, such as:

A cancerous tumor Mucocoele (mucus-filled cyst)

A blood clot

Trauma (eye injury)

Sinus infection

Anybody who notices that one or both eyes are starting to bulge should see their doctor immediately.

How is exophthalmos diagnosed?In most cases the protrusion or bulging of the eyeballs from the sockets, with much more of the whites of the eyes exposed, is enough for the doctor to diagnose exophthalmos fairly easily. However, as mentioned earlier, exophthalmos is a sign of some disease or condition, and is not a disease in itself. Therefore, if a GP (general practitioner, primary care physician) suspects exophthalmos the patient will probably be referred to an eye specialist - an ophthalmologist. The ophthalmologist will most likely order further tests before confirming a diagnosis.

The following tests may be ordered:

A blood test - this will probably be a thyroid function test to see whether the thyroid gland is healthy.

Exophthalmometer - this instrument measures the degree of eyeball protrusion as well as determining how well the patient can move their eyes. Patients with exophthalmos will be able to look upwards without moving their eyebrows.

Imaging scans - in order to examine the orbit (socket) the doctor may order a CT (computerized tomography) scan or an MRI (magnetic resonance imaging) scan. A scan may also detect a tumor, or any abnormalities in or around the eyes.

What are the treatment options for exophthalmos?As exophthalmos tends to be a progressive disease - symptoms get worse over time - the ophthalmologist will wish to monitor the patient regularly. Treatment depends on several factors, including the cause, as well as the patient's age and general health.

Thyroid problems - the doctor will treat whatever is causing the thyroid problem so that thyroid hormone levels are brought back to normal. Usually, effective thyroid treatment results in the restoration of normal vision and the appearance of the eyes.

If the patient has Graves' disease thyroid treatment might make no difference to the appearance of the eyes. On occasions the affected vision and appearance of the eyes cannot be improved.

It is important to see your doctor as soon as you notice any bulging of the eyes. Treatment is much more effective if it can begin early.

Surgery - if there is a problem with the connection between the arteries and veins in the eyes the patient may have to undergo surgery. In severe cases the bony floors of the eye sockets may have to be surgically removed (surgical orbital decompression). The procedure allows excess material to move down into the extra space in the antrum (maxillary sinus) by the surgical intervention.

Eye drops - if the patient suffers from dry eyes, eye drops will help keep the eyeballs moist - it is important to keep the cornea lubricated.

Eyeshades - eyeshades may be required if the patient suffers from photophobia (oversensitivity to light).

Corticosteroids - for patients whose eyes are especially painful or swollen (inflamed), the doctor may prescribe corticosteroids. Corticosteroids are effective in reducing swelling and inflammation.

A tumor - most likely the doctor will talk to the patient about removing the tumor surgically, as well as using chemotherapy, radiotherapy (radiation therapy), or a combination.

What are the possible complications of exophthalmos?In severe cases patients may not be able to close their eyes properly, especially when they are asleep. This can cause the cornea to dry out and become damaged. If the cornea dries out too much there is a much higher risk of infection or ulcers, which can damage vision.

People with exophthalmos or proptosis are more susceptible to developing conjunctivitis.

Written by Christian Nordqvist Copyright: Medical News Today Not to be reproduced without permission of Medical News Today

http://www.medicalnewstoday.com/articles/169869.php