Case Report: Chloroquine Induced Keratopathy – Toxicity from Systemic Use

The application of chloroquine has been expanded over time from the treatment of malaria to a variety of connective tissue, inflammatory, and dermatologic disorders. More recently, chloroquine and its derivative, hydroxychloroquine, have been investigated for its possible application against SARS-CoV-2 due to their antiviral properties. We present a case of a patient receiving chloroquine as adjuvant therapy for glioblastoma multiforme who developed significant keratopathy and review this overlooked entity in view of the resurgence of this enduring medication. A 48-year-old woman with a history of Marfan syndrome presented with a five-day history of pain and discomfort in her right eye. She had a history of glioblastoma multiforme that had been treated with surgical resection, radiation, and chemotherapy and was currently undergoing adjuvant treatment with chloroquine and cimetidine. Her exam was notable for decreased visual acuity, bilateral epithelial erosions, multiple subepithelial white dots in a whorl-like distribution, and decreased corneal sensation. These corneal changes reversed following cessation of chloroquine. While chloroquine related retinopathy is reported frequently in the literature, the corneal changes related to chloroquine have been less frequently discussed. With the resurgence of interest in using chloroquine and hydroxychloroquine as therapy for SARS-CoV-2 due to their promising in-vitro activity against the virus [1, 2], corneal toxicity is an important side effect to identify and monitor.