RESUMEN

The aim of this report is to emphasize that corticosteroids should not be prescribed when the etiological factors remain unidentified. A 34-year-old male visited our ophthalmology clinic suffering from blurred vision. Behçet's disease had been diagnosed 5 years prior, and the patient was taking an oral immunosuppressant and a systemic corticosteroid. Vitreous cell count and foci of chorioretinitis (apparently confined to the ocular fundus) were evident. A vitreous sample was subjected to polymerase chain reaction, which resulted in the identification of and Mycobacterium tuberculosis. Treatment with a combination of four anti-tuberculosis drugs was commenced. During the follow-up, the vitritis disappeared, and the foci of active chorioretinitis improved. Systemic and Sub-Tenon corticosteroid treatment should not be prescribed until vitreous and anterior chamber fluid samples have been evaluated in patients with uveitis. Some microbes are not detected on routine examination.