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Exophthalmos (also called exophthalmia or proptosis) is a bulging of the eye anteriorly out of the orbit. Exophthalmos can be either bilateral (as is often seen in Graves' disease) or unilateral (as is often seen in an orbital tumor). Measurement of the degree of exophthalmos is performed using an exophthalmometer. Complete or partial dislocation from the orbit is also possible from trauma or swelling of surrounding tissue resulting from trauma.
If left untreated, exophthalmos can cause the eye lids to fail to close during sleep leading to corneal dryness and damage. Another possible complication would be a form of redness/irritation called "Superior limbic keratoconjunctivitis," where the area above the cornea becomes inflammed as a result of increased friction when blinking. The process that is causing the displacement of the eye may also compress the optic nerve or ophthalmic artery leading to blindness.
Exophthalmos vs. proptosis[edit | edit source]
Some sources define exophthalmos as a protrusion of the globe greater than 18 mm and proptosis as a protusion equal to or less than 18 mm. (Epstein et al., 2003). Others define exophthalmos as protrusion secondary to endocrine dysfunction and proptosis as any non-endocrine-mediated protrusion .
Causes[edit | edit source]
- Orbital cellulitis
- Meningioma, sphenoid wing
- Orbital fracture: apex, floor, medial wall, zygomatic
- Duane syndrome
- Carotid cavernous fistula
- Congenital glaucoma
- Eyelid ptosis: adult, congenital
- Hand-Schuller-Christian disease,
- Hemangioma, cavernous
- Thyroid ophthalmopathy (Graves' disease)
- High altitude cerebral edema (proptosis)
Exophthalmos in dogs[edit | edit source]
- Main article: Eye proptosis
Exophthalmos is commonly found in dogs. It is seen in brachycephalic (short nosed) dog breeds because of the shallow orbit. However, it can lead to keratitis secondary to exposure of the cornea. Exophthalmos is commonly seen in the Pug, Boston Terrier, Pekingese, and Shih Tzu.
See also[edit | edit source]
References[edit | edit source]
- Owen Epstein, David Perkin, John Cookson, David P de Bono (April 2003). Clinical examination, 3rd edition, St. Louis: Mosby.
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