Brown's syndrome

Overview

Brown’s syndrome, also known as superior oblique tendon sheath syndrome, is a rare eye movement disorder characterized by restricted elevation of the eye when it is turned inward (adduction). This condition affects the superior oblique muscle and its tendon, which normally helps the eye move in various directions. In Brown’s syndrome, mechanical restriction — not nerve or muscle weakness — limits the movement, leading to strabismus (misalignment of the eyes), diplopia (double vision), and abnormal head posture. The condition may be congenital or acquired and can affect one or both eyes.

Causes

Brown’s syndrome can be classified based on its origin:

• Congenital Brown’s syndrome:

  • Present at birth

  • Due to abnormal development of the superior oblique tendon or its sheath

  • Often stable over time, though spontaneous improvement may occur

• Acquired Brown’s syndrome:

  • Resulting from trauma, surgery, or inflammation

  • Causes include sinusitis, rheumatoid arthritis, orbital trauma, or scarring near the trochlea (pulley system of the tendon)

Symptoms

The most characteristic symptom of Brown’s syndrome is restricted upward eye movement in adduction. Other common signs and symptoms include:

• Limited elevation of the affected eye during inward gaze

• Downward deviation (hypotropia) of the affected eye

• Diplopia (double vision), especially when looking upward and inward

• Abnormal head posture – such as head tilt or chin elevation to compensate for restricted movement and prevent double vision

• Absence of globe retraction – differentiating it from other mechanical restriction syndromes

• Normal eye appearance at rest – misalignment may only be noticeable during certain movements

Diagnosis

Diagnosis of Brown’s syndrome is based on clinical examination and eye movement testing. Diagnostic steps include:

• Ocular motility testing – to observe movement restriction, especially on attempted up-and-in gaze

• Forced duction test – performed by an eye specialist to confirm mechanical restriction of the superior oblique tendon

• Cover-uncover and prism tests – to detect and quantify strabismus or misalignment

• Imaging (CT or MRI) – may be used in acquired cases to identify inflammation, trauma, or mass lesions near the trochlear area

• Inflammatory markers – if autoimmune causes (e.g., rheumatoid arthritis) are suspected

Treatment

Treatment for Brown’s syndrome depends on the severity of symptoms and whether the condition is congenital or acquired. Options include:

• Observation:

  • Mild or asymptomatic cases may not require treatment

  • Congenital cases often remain stable or improve spontaneously

• Medical therapy:

  • Anti-inflammatory medications or corticosteroids for acquired cases linked to inflammation

• Surgical treatment:

  • Reserved for significant motility restriction, abnormal head posture, or persistent diplopia

  • Procedures may include superior oblique tendon lengthening or tenotomy

  • Risk of overcorrection (leading to superior oblique palsy) should be carefully considered

• Prism glasses:

  • May be prescribed to manage double vision in select cases

Prognosis

The prognosis for Brown’s syndrome is generally good, especially in congenital cases, many of which remain stable or improve without intervention. Acquired cases may resolve with treatment of the underlying cause. When surgery is needed, most patients experience improved eye alignment and symptom relief, although complications like overcorrection or recurrence can occur. Long-term follow-up by an ophthalmologist is important for monitoring progression and managing any residual symptoms.