[Bilateral idiopathic orbital myositis]

Orbital myositis is an idiopathic inflammation of the extraoccular muscles. It is often included under the broad description of orbital pseudotumor. It is commonly a unilateral affection.

We report one case of bilateral orbital myositis in a 45-year-old woman. The first symptoms were diplopia and acute bilateral orbital pain exacerbated by eye movements. Physical examination especially neurological was normal. Serum creatine kinase and biological thyroid function were normal. CT scan found a bilateral enlargement of rectus oculi medialis and lateralis. Clinical improvement was obtained a few days after oral corticosteroid treatment with remission of all signs.

Orbital myositis is a rare entity. 90-95p.cent of cases are unilateral. Bilateral forms are exceptional and in this case require search for specific etiologies particularly thyroid ophthalmopathy. There is controversy concerning treatment options but corticosteroids are still the most common first choice therapy with good outcome.