Antimicrobial Drug Prophylaxis for Recurrent Ocular Toxoplasmosis

Ocular toxoplasmosis is a relapsing infectious eye disease that carries an increasing risk of vision loss with each reactivation episode. Antimicrobial drug prophylaxis has been used to reduce the rate of recurrence. This review aims to summarize the current literature regarding expert clinician preferences, as well as the effectiveness and safety of prophylaxis. A literature search was conducted using the PubMed platform of the National Library of Medicine of the National Center for Biotechnology Information and relevant pre-specified search terms. Four professional surveys indicated that approximately three-quarters of experts gave antimicrobial drug prophylaxis for recurrent ocular toxoplasmosis, and that trimethoprim-sulfamethoxazole was the most popular approach. Clinical studies of prophylaxis varied in multiple parameters, including drug, dosing and duration, plus time of follow-up. Considering the four studies with at least 50 participants, the rate of recurrence of ocular toxoplasmosis within 5 years was up to 9.1% of patients taking prophylaxis, and treatment-limiting side effects occurred in up to 7.9% of patients. The available literature demonstrates that antimicrobial drug prophylaxis can reduce the recurrence rate of ocular toxoplasmosis; however, further research on drug dosing and duration of treatment is required to assist decision-making in clinical practice.