Diplopia Due to Orbital Myositis: Diagnosis with Magnetic Resonance Imaging

Orbital myositis is an orbital inflammation characterized by an acute onset, unilateral periorbital pain, and diplopia, often involving one or more of the extraocular muscles. Swelling of the eyelid and conjunctival injection are also usually present (1). Orbital myositis can be idiopathic or secondary to any systemic and localized inflammatory disorder. Viral upper respiratory tract infections and inflammatory intestinal diseases can also cause orbital myositis. The condition is very rare in the pediatric age group, especially among infants (2). Diagnosis can usually be made clinically based on the characteristics of pain and signs of inflammation. Imaging methods, particularly magnetic resonance imaging (MRI), are useful for differential diagnoses. The presence of a thickening of the affected muscle, uptake of contrast medium, and high signal intensity on T2-weighted images (WIs) suggests orbital myositis (3). Inflammation is usually unilateral and response to steroid treatment is very good (1). In this article, we report on the case of a 13-year-old girl who was diagnosed with idiopathic orbital myositis through MRI findings after being admitted to the hospital with double vision.