Brown’s Syndrome is mechanical that is caused by an altered curve of the superior oblique muscle that moves through a ring of tissue that surrounds it. This prevents the lower eye from raising the eye inward.
Brown’s Syndrome can be congenital or acquired in adulthood. It may be constant or intermittent. In 90% of cases, only one eye is affected, more often, the right one. Examination of passive motility is highly positive for a mechanical obstacle.
The exact cause of Brown’s Syndrome is unknown but it is clear that there is an abnormality of the superior oblique muscle or its tendon sheath that includes a reduced elasticity of the muscle, a short tendon, thick or inelastic sheaths, fibrous adherence between the tendon and trochlea, etc.
Video Transcription: Brown’s Syndrome is a mechanical problem due to an alteration of the superior oblique muscle and the trochlea, that would be a ring through which the tendon slides. The muscle that we are talking about is what allows us to raise the eye up and toward the nose. An alteration of these structures consequently causes an abnormal sliding of the eye. Often, patients with Brown’s Syndrome have their eyes straight in the primary/neutral position and looking down, then the problem shows as they look upwards, especially in the gaze position where the superior oblique muscle enters into action.
It is a relatively rare syndrome and affects both adults and children because it can be congenital or acquired. For children, it often improves over time. Cases that require surgery are when the eyes are out of alignment when looking straight ahead, has double vision, or if the head position is very abnormal.
Acquired Brown’s Syndrome is rare but may be caused by surgery to extraocular muscles, eyelid trauma, or inflammatory diseases (rheumatoid arthritis, lupus erythematosus, etc.). The eyes are usually straight when facing front or bottom.
The pathognomonic sign is the reduced ability of an eye to elevate in adduction, that is to look up and down and with the elevation in the normal abduction. Patients with Brown’s Syndrome will occasionally hold their chin up or turn their head to avoid looking in the direction that causes their eyes to misalign.
Sometimes the restricted movement can unlock suddenly and the patient will notice a “click” that can be painful. Since this syndrome has a tendency to gradually diminish over time, it is better to be attentive in cases where there are concerns with the neck and the risk of losing binocular vision is strong. Surgery will have to be done: a wide recession of the superior oblique muscle.
The acquired form from inflammatory processes (sinusitis, rheumatoid arthritis, Wegener Granulomatosis) is treated with subcutaneous injections of steroids at the regions of the trochlea. Treatment varies according to severity. Simple observation and strict controls can be sufficient in mild cases.
In younger children, visual acuity and binocular vision should be monitored frequently. Surgical treatment is indicated in cases of eye misalignment when looking straight ahead, double vision, pronounced abnormal head position or recent binocular vision loss. Sometimes you may need more than one surgery to correct Brown’s Syndrome.