Longitudinal Follow-Up of Peripapillary Kyrieleis Plaques in a Case with Unilateral Intermediate Uveitis Related to Ocular Toxoplasmosis without a Focus of Retinochoroiditis

Purpose: To describe an atypical presentation of ocular toxoplasmosis, characterized by dense vitritis and circumferential peripapillary Kyrieleis plaques. Method: Case report. Results: A 49-year-old healthy man presented with right visual deterioration. He had previously received a short course oral corticosteroid treatment without systemic evaluation. On examination, dense vitritis and peripapillary, near-360 degrees Kyrieleis plaques without any focus of chorioretinitis were noted. Fluorescein angiography showed diffuse posterior pole masking from vitritis and mild late optic disc hyperfluorescence without peripheral vascular leakage. Infectious screening showed positive Toxoplasma gondii (IgG) and negative IgM. A diagnosis of ocular toxoplasmosis-related unilateral intermediate uveitis was established. Oral trimethoprim/sulfamethoxazole and azithromycin were initiated, resulting in improved visual acuity and reduced vitritis within three weeks. Five months later, new visual decline due to macular edema was treated with oral methylprednisolone and trimethoprim/sulfamethoxazole, leading to resolution. Over 10 months, Kyrieleis plaques decreased but did not fully disappear. Conclusion: Ocular toxoplasmosis can manifest atypically without a focus of retinochoroiditis. Kyrieleis plaques should prompt consideration of infectious causes before corticosteroid therapy.