Diagnostic Dilemma and Therapeutic Challenges in Managing an Atypical Presentation of an Ocular Toxoplasmosis Patient With Myasthenia Gravis: Literature Review

Abstract

Purpose The aim of the study was to report a case of ocular toxoplasmosis (OT) in an immunocompromised patient with myasthenia gravis, the diagnostic dilemma, and therapeutic challenges in managing the patient. Method This is a case report with literature review. Articles reviewed were limited to publications in English, and there were no restrictions on date, age, ethnicity, or geographic locations of patients. In addition, a brief literature review of similar reported cases was conducted to discuss about the diagnostic dilemma and therapeutic challenges in managing our patient. Observation We report a case of an immunocompromised, 53-year-old man who presented with rapid deterioration of left eye vision for 2 weeks. The ophthalmological examination showed nongranulomatous panuveitis with dense vitritis and retinitis with the absence of adjacent pigmented scar. Diagnostic dilemma arose as the clinical picture mimicked several possible etiologies. He was initially treated clinically as viral retinitis but failed to show improvement with antiviral treatment. Because of recent history of left empyema, he was then treated as presumed endophthalmitis and received broad-spectrum antimicrobial and antifungal therapies. He was also given oral sulfamethoxazole and trimethoprim (Bactrim) because of suspicion on OT. Despite multiple drug therapy, he still did not improve clinically. A diagnostic pars plana vitrectomy was performed and the toxoplasma polymerase chain reaction was positive. Therapeutic challenges were apparent due to limited choice of antibiotics which can be used in patients with myasthenia gravis and possible resistance to Bactrim in this case. After 6 weeks of pyrimethamine and sulfadiazine, he was clinically stable with vision of 6/60 due to macular scarring. Conclusions The diagnosis of atypical OT is challenging and frequently misdiagnosed as viral retinitis or endophthalmitis, leading to delayed diagnosis and treatment. Clinicians should have a high index of suspicion whenever seeing an atypical manifestation of OT in immunocompromised patients. In addition, there is very limited published data looking into the clinical presentations, diagnostic methods, treatment modalities and outcomes, specifically in reported atypical OT case reports or series. Therefore, it warrants an in-depth review to help clinician have a better understanding about this disease.