Brown Syndrome

Dr Ben Wild

Overview

Eye movements are controlled by 6 extra-ocular muscles. The superior rectus pulls the eye upwards, the inferior rectus pulls the eye downwards, the lateral rectus pulls the eye outwards and the medial rectus pulls the eye inwards. The superior oblique muscle connects to the eye after passing through a pulley called the trochlea and is mainly responsible for rotating the eye inwards and pushing the eye downwards. The inferior oblique follows a similar path as the superior oblique, except underneath the eye and does not travel through a pulley system.

Frontal view of an eye with the extra-ocular muscles. The black square shows the trochlear tendon that holds the superior oblique muscle (shown behind the superior rectus muscle).

Brown syndrome refers to a restriction of the superior oblique muscle usually due to tightness around the trochlea. It is almost always congenital (born this way) but can be acquired in cases of trauma or inflammation secondary to auto-immune diseases like rheumatoid arthritis.

A person with Brown syndrome, while looking up and inwards with the affected eye, may experience double vision because that eye cannot look upwards while the other eye can. Other notables include tenderness/pain, and possibly a clicking noise when trying to look up and inwards.

Signs and Symptoms

Signs

Limited elevation of the eye in up and in gaze, clicking sound on up gaze, normal elevation when looking up and outwards. Rarely, you may notice one eye is pointed downwards in straight ahead gaze and is compensated for by raising of the chin.

Symptoms

Usually no symptoms, sometimes patients may notice double vision and pain/tenderness in up and inwards gaze.

Causes and Risk Factors

Causes

Congenital malformation, trauma to the trochlea or inflammation of the trochlea.

Risk Factors

Scleritis, pansinusitis, autoimmune conditions such as rheumatoid arthritis.

Prevention and Treatment

Prevention

There are no known preventative measures.

Treatments

· No treatment required in most cases.

· Surgery to lengthen the trochlea if it is causing double vision or affecting head posture.

· Treat inflammation.

Prognosis

Brown syndrome does not usually cause much discomfort or affect vision. It does not lead to further damage to vision or the eye. In certain cases where the patient has double vision or needs to hold their head a certain way to maintain single vision, surgery can restore proper function and is well tolerated.