Relentless Placoid Chorioretinitis: A Differential Diagnosis and Management Approach in a Challenging Case

This case study presents a 51-year-old male diagnosed with relentless placoid chorioretinitis (RPC), a rare condition within the spectrum of inflammatory chorioretinopathies, who experienced progressive vision loss following a COVID-19 infection. The patient's clinical presentation was accompanied by a similar episode, misdiagnosed and untreated, nine years earlier. During clinical evaluation, the patient exhibited overlapping features of acute posterior multifocal placoid pigment epitheliopathy (APMPPE), serpiginous choroiditis (SC), and RPC. Fundoscopic examination revealed bilateral chorioretinal involvement, including characteristic placoid lesions in the posterior pole resembling APMPPE, as well as serpentine, amoeboid-shaped peripheral lesions similar to SC. Optical coherence tomography (OCT), autofluorescence imaging, and angio-OCT demonstrated active inflammatory lesions, along with chronic atrophic changes, reflecting different stages of the disease. The article further discusses the differential diagnosis, considering inflammatory chorioretinopathies, systemic disease-related chorioretinopathies, and other conditions with a similar clinical course. This case study presents the recommended therapeutic strategy for RPC: triple immunomodulatory therapy (IMT) consisting of cyclosporine A, mycophenolate mofetil, and methylprednisolone, which resulted in clinical remission six months after therapy initiation in the reported patient. The article highlights the necessity of recognizing the chronic and progressive nature of RPC, as well as the need for aggressive immunosuppressive treatment rather than corticosteroid monotherapy.