Antibodies against Toxoplasma gondii positive in serum and aqueous humor to diagnose clinically suspected ocular toxoplasmosis: A case report

Introduction: Previously, diagnosis of ocular toxoplasmosis is based on clinical symptoms and Toxoplasma serology. Checking serological indicators often cannot reflect the real intraocular situation, and may even mislead clinicians to make wrong judgments. Patient concerns: A 38-year-old male patient visited our ophthalmology clinic with a chief complaint of decreased vision for about 5 days in his right eye. Diagnosis: Aqueous humor sample analysis found Toxoplasma DNA detectable, and Toxoplasma immunoglobulin G (IgG) and immunoglobulin M (IgM) to be positive. His serum Toxoplasma IgG was also positive (10.04 IU/mL; reference range: 0 to 7.2 IU/mL). Therefore, the final diagnose was ocular toxoplasmosis involving his right eye. Interventions: Oral prednisone 60 mg/day and azithromycin 0.25 g/day were started. Oral antibiotic treatment for toxoplasma was continued for 4 weeks, and prednisone followed by weekly stepwise tapering in steps of 10 mg/day. Outcomes: The BCVA and fundus of right eye remained stable after treatment at follow-up. Conclusions: This article reported a case of ocular Toxoplasma gondii infection diagnosis by serum and aqueous humor antibody tests. We provide some additional information on the T gondii infection diagnosis.