Diplopia and ocular pain due to orbital myositis

Excerpt

A 19-year-old man presented to the emergency department because of sudden onset of diplopia and ocular pain. He reported a 1-week history of malaise and headache. He denied travels or rash. Physical examination revealed ptosis and limited and painful abduction of the right eye. Pupillary light reflexes and dilated fundus examination were normal. Complete blood count, biochemical profile, erythrocyte sedimentation rate, C-reactive protein, and thyroid function tests were within normal limits. Antinuclear antibodies, anti-neutrophil cytoplasmic antibodies (ANCA), anti-myeloperoxidase, and anti-proteinase 3 were negative. Fat suppression T1-weighted magnetic resonance imaging (MRI) showed right lateral rectus muscle enlargement with contrast enhancement, and tendinopathy (Fig. 1).

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