Ocular tuberculosis masquerading as atypical ocular toxoplasmosis

Abstract

Ocular tuberculosis is a great mimicker of various uveitis entities. We present a case of a 29-year-old male who came in with blurring of vision and floaters in the left eye. On examination, the left eye had anterior chamber cells and vitritis associated with retinitis. He had no other symptoms. The initial presentation was consistent with ocular toxoplasmosis, and he was started on oral sulfamethoxazole-trimethoprim and showed a good response to the treatment. However, work-up revealed negative toxoplasma antibody titers but a positive M. tuberculosis interferon-gamma release assay test and Mantoux test, making the diagnosis of ocular tuberculosis more likely. The patient was shifted to antituberculous therapy, which eventually resulted in the resolution of the inflammation with a recovery of the visual acuity. The diagnosis of ocular tuberculosis requires a detailed medical history as well as microbiologic and immunologic studies. A high index of suspicion by the treating ophthalmologist is necessary to reveal the diagnosis.

Keywords: masquerade syndrome; retinitis; toxoplasmosis; tuberculosis; uveitis.

Figure 1. Fundus photograph of the left eye showing foci of retinitis at the temporal aspect of the macula associated with exudates arranged in a macular star

Figure 2. Fluorescein angiogram showing blocked hypofluorescence from retinal edema adjacent to areas of retinal vasculitis

Figure 3. Optical coherence tomography scan through the lesion showing hyperreflectivity of the inner retinal layers with posterior shadowing, consistent with retinitis

Figure 4. Serial fundus photographs showing the response of ocular inflammation with the various treatment regimens started. The fundus at (A) baseline, (B) after 1 week of antitoxoplasmic therapy, (C) after 1 month of antituberculous therapy, and (D) after completion of antituberculous therapy