[Toxoplasma gondii and necrotizing retinitis: a case report].

Toxoplasmic retinochoroiditis is an important opportunistic retinal infection in immunodeficiency and elderly patients. The diagnosis of toxoplasmic retinochoroiditis is based primarily on characteristic ocular findings, with supportive serological evidence. It may present as diffuse necrotizing retinitis instead of a focal lesion. We report the original case of a 74-year-old woman who presented with blurred vision in her left eye lasting 3 months. In her medical history, the patient described a tuberculous infection evolving for some months, as well as agranulocytosis treated with Rifadine. Fundus examination revealed diffuse necrotizing retinitis, mainly at the nasal quadrant, with marked vitreitis in the left eye. Clinical recognition of atypical presentations is critical for timely antiparasitic drug therapy. This case initially was misdiagnosed as acute retinal necrosis syndrome. The correct diagnosis was confirmed by response to polymerase chain reaction studies of an intraocular specimen and histopathological analysis. The extensive necrotizing retinitis was nonhemorrhagic but associated with retinal detachment. Significant visual loss accompanied the infection. Toxoplasmosis should be considered as a cause of diffuse necrotizing retinitis in elderly and immunosuppressive patients. Older patients may be more susceptible to severe ocular Toxoplasma infections because of age-related decline in cell-mediated immunity and chronic underlying diseases.