Ocular toxoplasmosis in the immunocompromised patient

Ocular toxoplasmosis is a common infectious eye disease caused by the ubiquitous parasite, Toxoplasma gondii, and the leading cause of posterior uveitis in most populations worldwide. For the growing number of individuals living with some form of immunocompromise, T. gondii often represents an aggressive ocular pathogen. To demonstrate how an impaired immune system may impact the course and outcomes of ocular toxoplasmosis, the clinical descriptions of 276 immunocompromised patients, published across 109 reports in the medical literature, were compiled, and relevant epidemiological and immunological studies were summarised. The diverse phenotypes of ocular toxoplasmosis associated with congenital or acquired immunodeficiency or immunosuppression are described; diagnostic methods and their interpretation are outlined; and management approaches that may limit infectious ocular and systemic complications are highlighted. The visual outcome of ocular toxoplasmosis is often poor in immunocompromised individuals. Atypical presentations occur frequently in this patient group, and in over one-half of those whose clinical information has been reported, the diagnosis was initially missed. By synthesising the published literature, this review offers a perspective that may support improved outcomes of ocular toxoplasmosis in people living with systemic immunocompromise.