To investigate whether systemic lupus erythematosus (SLE) increases the risk of cataract development and to evaluate the impact of corticosteroid use and dosage on this risk.

Nationwide retrospective cohort study.

Using Taiwan’s National Health Insurance (NHI) database, which covers over 99.9% of the population.

The SLE cohort included 30 501 newly diagnosed adults from 2011 to 2020. For each patient with SLE, four individuals without SLE were selected from the NHI database using frequency matching by age (in 5 year intervals), gender and index year of diagnosis, resulting in a comparison cohort of 122 004 individuals.

The primary outcome was incident cataract. Secondary outcomes included risk stratification by age, sex, comorbidities and corticosteroid dose.

SLE patients had a higher incidence of cataracts than non-SLE individuals (adjusted HR (aHR) = 1.73, 95% CI 1.66 to 1.81). Stratified analyses showed elevated risks in women (aHR=1.74, 95% CI 1.66 to 1.83), men (aHR=1.68, 95% CI 1.52 to 1.86), and across age groups 20–49 years (aHR=2.32, 95% CI 2.11 to 2.56), 50–64 years (aHR=1.60, 95% CI 1.51 to 1.69), and ≥65 years (aHR=1.50, 95% CI 1.36 to 1.66). Analysis of corticosteroid exposure revealed that cumulative dose showed a trend towards increased risk at high exposure (adjusted OR (aOR) = 1.14, 95% CI 0.99 to 1.31), while average daily dose demonstrated a dose–response effect: 1–5 mg/day (aOR=1.31, 95% CI 1.13 to 1.52) and ≥5 mg/day (OR=2.48, 95% CI 2.16 to 2.86).

Adults with SLE have an increased risk of developing cataracts compared with matched controls, and higher average daily corticosteroid doses are associated with this risk. These findings highlight the need for careful monitoring of ocular complications in SLE patients.