Disparities in Hydroxychloroquine-Induced Retinal Toxicity: A Retrospective Analysis

Background: Hydroxychloroquine (HCQ) is widely prescribed for systemic lupus erythematous (SLE). It is associated with dose- and duration-dependent retinal toxicity. Limited data are available regarding the intersection of race, socioeconomic status, and retinal toxicity risk. This study aimed to characterize patients who developed HCQ-induced retinal toxicity, with a focus on identifying demographic disparities via retrospective chart review. Methods: We conducted a retrospective chart review of adult patients at the University of North Carolina (UNC) with SLE who initiated HCQ between January 2008 and April 2020 and subsequently developed retinal toxicity, defined by abnormal findings on visual field testing, spectral-domain optical coherence tomography (SD-OCT), or fundus examination. Demographic, socioeconomic, and clinical data were extracted from the electronic health record. Socioeconomic status was approximated by ZIP code–linked median household income and insurance status. Data were analyzed descriptively and compared to national data. Results: Ten patients met inclusion criteria. Median age at HCQ initiation was 49 years (range 31-70 yo); 100% were female. Of these, 60% were Black, 20% Hispanic, and 20% White. When compared to national cohort of patients with SLE treated with HCQ (Black ~42%, White ~31–46%, Hispanic ~10–20%), Black patients were significantly overrepresented (p < 0.05, chi-square). ZIP code analysis showed that most patients (7/10) resided in areas with a median household income below $50,000, indicating a potential strong socioeconomic disparity. Conclusion: This study reveals a potential correlation between racial and socioeconomic disparities in the development of HCQ-induced retinal toxicity. Although SLE is more common in black patients, low-income and Black patients were disproportionately affected by HCQ-induced retinal toxicity, independent of dose and duration. However, the overlap between race and income in this cohort suggests a potential confounding relationship that warrants further investigation. Larger, multi-center studies are needed to disentangle these associations and identify whether race, socioeconomic status, or their intersection confers greater risk. Comparative analyses will be essential to guide more equitable screening and treatment strategies.