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Brown Syndrome is a rare eye disorder characterized by defects in eye movements. This disorder may be present at birth (congenital) or may occur as the result of another underlying disorder (acquired). Muscles control the movements of the eyes. Some of these muscles turn the eyeball up and down, move the eyeball from side to side, or enable the eyeball to rotate slightly in its socket. The superior oblique tendon sheath of the superior oblique muscle surrounds the eyeball. The symptoms of Brown Syndrome are caused by abnormalities of this tendon sheath including shortening, thickening, or inflammation. This results in the inability to move the affected eye upward.
People with Brown Syndrome have limited eye movement in the affected eye. The ability to move the eyeball toward the center (adduction), or outward from the center (abduction), may be restricted or absent. One eye may appear to be out of alignment with the unaffected eye, especially when looking upward. The symptoms of Brown Syndrome may also include a droopy eyelid (ptosis), widening of the eye (palpebral fissure) when looking upward, crossing of the eyes (strabismus), and/or a backward head tilt. A downward appearance (hypotropia) is usually present in the affected eye when the individual is looking straight ahead (primary position) or in an upward direction. One eye is usually affected, but both eyes (bilateral) may be affected in approximately 10 percent of people with Brown Syndrome.
The exact cause of most cases of Congenital Brown Syndrome is not known. The symptoms of congenital Brown Syndrome may occur due to shortening of the tendon sheath of the superior oblique muscle or thickening of the sheath that restricts its movement. However, acquired Brown Syndrome may be the result of trauma, surgery, and/or inflammation due to another underlying disorder such as Lupus or Rheumatoid Arthritis.
There are several reports in the medical literature of a few rare cases of Brown Syndrome which may be inherited as an autosomal dominant genetic trait. Human traits, including the classic genetic diseases, are the product of the interaction of two genes, one received from the father and one from the mother. In dominant disorders, a single copy of the disease gene (received from either the mother or father) will be expressed "dominating" the other normal gene and resulting in the appearance of the disease. The risk of transmitting the disorder from affected parent to offspring is 50 percent for each pregnancy regardless of the sex of the resulting child.
Brown Syndrome is a rare eye disorder that affects slightly more females than males. The symptoms of the congenital form of the disease are usually present at birth. The acquired form may occur at any age.
Symptoms of the following disorder can be similar to those of Brown Syndrome. Comparisons may be useful for a differential diagnosis:
Duane Syndrome is a rare inherited eye disorder that is present at birth (congenital) and most commonly affects males. It is characterized by limited horizontal movement of the affected eye. Generally only one eye is affected. The ability to move the eye away from the center (abduction) is reduced or absent. Movement of the eye toward the center (adduction) is also limited, and there may be weakness in focusing (convergence). Attempted eye movements result in retraction of the eyeball. An abnormally small eye (microphthalmus), an unusually small cornea (microcornea), and an irregularly shaped cornea (keratoconus) may also occur. (For more information on this disorder, choose "Duane" as your search term in the Rare Disease Database.)
Some people with congenital Brown Syndrome may not require treatment. Alignment of the eyes may improve with age, especially in those children whose eyes are normally aligned when looking straight ahead. Other individuals with Brown Syndrome may require surgery to correct the alignment of the eyes. During surgery part of the tendon which connects the superior oblique muscle may be removed (sheathectomy with inferior oblique tuck). The results of surgery are usually excellent, but the condition may recur.
If Brown Syndrome is acquired because of another inflammatory disorder such as Lupus or Rheumatoid Arthritis, treatment of the underlying disorder may help to resolve the symptoms of Brown Syndrome.
Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government website.
For information about clinical trials being conducted at the National Institutes of Health (NIH) in Bethesda, MD, contact the NIH Patient Recruitment Office:
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Report last updated: 2008/03/23 00:00:00 GMT+0