Toxoplasmic Chorioretinitis with Unilateral Disc Edema

A 53-year-old man had a history of high myopia and a seronegative spondyloarthropathy treated with immunosuppressive agents. He presented with mild, painless vision loss in his right eye. His examination showed findings of a right anterior optic neuropathy: visual acuity: 20/20 OD (right eye), 20/20 OS (left eye); pupils: new 1+ right relative afferent pupillary defect; optic disc edema OD. His initial work-up included a normal MRI brain/orbits with contrast, and negative or normal RPR, CBC, ESR, CRP, bartonella serology, anti-AQP4 and anti-MOG antibodies. Color photographs centered on the optic nerves show findings related to the patient's high myopia (tilted optic nerves with peripapillary atrophy bilaterally). The right optic nerve is edematous with peripapillary whitening. Humphrey visual fields (HVF, 24-2 SITA Fast) show a nasal step defect OS (related to the patient's tilted optic discs) and a new inferior arcuate visual field defect OD. OCT macula of the right eye shows vitreous opacities suggestive of vitritis in the right eye. Based on the presence of chorioretinal inflammation and vitritis, the patient was diagnosed with a posterior uveitis OD. Concern was for an infectious chorioretinitis. A vitreous sample returned positive for toxoplasmosis. The patient was treated with oral sulfamethoxazole / trimethoprim and oral prednisone. After initial worsening, the uveitis resolved and a chorioretinal scar appeared.