Hydroxychloroquine and chloroquine retinal safety concerns during COVID-19 outbreak

Purpose: The current coronavirus disease 2019 (COVID-19) has been declared by the World Health Organization a global pandemic. Chloroquine (CQ) and hydroxychloroquine (HCQ) have been largely adopted in the clinical setting for the management of SARS-CoV-2 infection; however, their known retinal toxicity has raised some safety concerns, especially considering the higher-dosage employed for COVID-19 patients as compared with their suggested posology for their usual indications, including systemic lupus erythematosus and other rheumatic diseases. In this review, we will discuss the optimal dosages recommended for COVID-19 patients when treated with HCQ and CQ. Methods: A comprehensive literature search was performed in PubMed, Cochrane library, Embase and Scopus, by using the following search terms: "chloroquine retinal toxicity" and "hydroxychloroquine retinal toxicity" alone or in combination with "coronavirus", "COVID-19", " SARS-CoV-2 infection " from inception to August 2020. Results: Although there is still no consistent evidence about HCQ/CQ retinal toxicity in patients with COVID-19, these possible drug-related retinal adverse events may represent a major safety concern. For this reason, appropriate screening strategies, including telemedicine, should be developed in the near future. Conclusion: A possible future clinical perspective for patients with COVID-19 treated with HCQ/CQ could reside in the multidisciplinary collaboration between ophthalmologists monitoring the risk of HCQ/CQ-related retinal toxicity and those physicians treating COVID-19 infection.