[A case of pulmonary tuberculosis associated with orbital myositis]

Ocular tuberculosis is rare. We report a case of orbital myositis suspected to be infected with tuberculosis. In January 2008, a 34-year-old man experienced discomfort in the right eye. In May 2008, this patient developed right exophthalmos, diplopia, and pain in the right eye, and he was diagnosed with idiopathic orbital myositis. The patient underwent 2 courses of steroid pulse therapy; after which, the dosage of steroids was reduced. The steroid treatment reduced the eye pain, but his diplopia and exophthalmos persisted. By November of the same year, his general malaise had increased, and chest X-ray radiography and computed tomography were performed on 3rd December. On the basis of the imaging results, we suspected active pulmonary tuberculosis of the right upper lobe. The smear made by using the sample obtained after bronchial brushing was negative for acid-fast bacilli, but a Mycobacterium tuberculosis nucleic acid amplification test of the post-bronchoscopic sputum yielded positive results. Therefore, the patient was diagnosed with pulmonary tuberculosis. After the 2HREZ/7HR regimen of treatment, the extent of the tuberculosis lesions of the lung was reduced and the exophthalmos and eye pain were alleviated. Orbital myositis is inflammation of the extraocular muscles and can be either idiopathic, without a known etiology, or secondary to conditions such as tuberculosis, sarcoidosis, or hyperthyroidism. Our patient was not definitively diagnosed with tuberculosis of the eye. A definitive diagnosis of tuberculosis of the eye would require detection of granulomatous lesions in the eye or isolation of Mycobacterium tuberculosis by puncturing the eye muscles; however, our findings suggested the possibility that it was secondary to tuberculosis. We think that a careful examination of the chest should be performed for patients with ocular abnormalities.