Hydroxychloroquine Dose and Risk for Incident Retinopathy : A Cohort Study.

Area of Science:

• Ophthalmology
• Rheumatology
• Pharmacovigilance

Background:

• Hydroxychloroquine is a common treatment for systemic lupus erythematosus and other inflammatory diseases.
• A significant long-term risk associated with hydroxychloroquine is vision-threatening retinopathy.
• Understanding this risk is crucial for patient safety and treatment management.

Purpose of the Study:

• To determine the long-term incidence of hydroxychloroquine retinopathy.
• To assess how average hydroxychloroquine dosage over the first five years predicts retinopathy risk.
• To provide data for evidence-based clinical guidelines.

Main Methods:

• A cohort study was conducted within a U.S. integrated health network.
• Included were patients aged 18+ receiving hydroxychloroquine for ≥5 years (2004-2020) with retinopathy screening.
• Hydroxychloroquine dose was tracked via pharmacy records; retinopathy was adjudicated using spectral domain optical coherence tomography.

Main Results:

• Among 3325 patients, 81 developed retinopathy (cumulative incidence 8.6% at 15 years); most cases were mild.
• At 15 years, retinopathy cumulative incidence was 21.6% for doses >6 mg/kg/day, 11.4% for 5-6 mg/kg/day, and 2.7% for ≤5 mg/kg/day.
• Risks for moderate-to-severe retinopathy at 15 years were 5.9%, 2.4%, and 1.1% for the respective dose groups.

Conclusions:

• The overall risk of hydroxychloroquine retinopathy after 15 years is 8.6%, with most cases being mild.
• Higher hydroxychloroquine doses are progressively associated with increased risk of incident retinopathy.
• Active surveillance and dose management are critical for preventing vision loss in patients on long-term hydroxychloroquine therapy.