Bilateral Acquired Brown's Syndrome

A 27 year old female with a history of Sjogren's syndrome reported a 2 year history of a vertical binocular diplopia with looking up-and-to-the right. She has also noticed an audible "click" when positioning her eyes in this direction. As depicted in the video, when attempting to look up-and-to-the-right, the left eye has moderate deficiency of supraduction; likewise, when attempting to look up-and-to-the-left, the right eye has mild deficiency of supraduction. On ocular alignment testing (Maddox Rod), there was no ocular misalignment in primary gaze, right gaze, or left gaze; however, in up-and-to-the-right gaze there was a right hyperdeviation of 25 prism diopters, and in up-and-to-the-left gaze there was a left hyperdeviation of 3 prism diopters. The patient was symptomatic with diplopia in up-and-to-the right-gaze, but not any other direction of gaze (including no diplopia in primary gaze). An MRI of the brain was negative. This patient has bilateral Brown's syndrome, which in her case was believed to be acquired, likely on an autoimmune basis related to inflammation of the bilateral trochlear region and associated with her Sjogren's syndrome. Brown's syndrome can be congenital or acquired, but is usually congenital. It is typically unilateral, though bilateral Brown's syndrome is occasionally encountered. Brown's syndrome is characterized by limitation of the ability to elevate the eye when it is in an adducted position, with normal (or near normal) elevation from a primary or abducted position. It is caused by mechanical "tethering" of the superior oblique muscle tendon sheath, which is unable to lengthen, causing limitation of elevation of the adducted eye (simulating an inferior oblique palsy). Ocular alignment in primary gaze is typically normal, though ipsilateral hypotropia can sometimes be seen (particularly in severe cases of Brown's syndrome). Patients may experience an audible click or pop, or experience discomfort or strain in the eye on attempted upgaze. The acquired form typically occurs when the superior oblique tendon/trochlea complex is affected by inflammation (such as in rheumatoid arthritis, or systemic lupus erythematosus), infection (ex. orbital infection or paranasal sinusitis), trauma, or surgery involving the superior eyelid or superonasal orbit. The presented case demonstrates an infrequent but recognized cause of Brown's syndrome.