Risk of stroke associated with intravitreal ranibizumab injections in age-related macular degeneration: a nationwide case-crossover study.

Objective: To evaluate the risk of stroke associated with intravitreal ranibizumab in age-related macular degeneration (AMD).

Methods: A nationwide retrospective case-crossover study was performed using data from the Korean National Health Insurance Service (KNHIS) database, which included patients with exudative AMD in South Korea (n = 41,860). The index date was the date of hospitalization for stroke. We defined the case period as 60 days and four control periods before the index date. A pharmacy prescription database was searched for ranibizumab use during the case and control periods. We calculated adjusted odds ratios (ORs) and 95% confidence intervals (CIs) with a conditional logistic regression model.

Results: A total of 865 patients with AMD and incident stroke were included. Of all the patients, 12.02% had been treated during the preceding 60-day case period, compared with 9.25-10.29% during control periods. The adjusted OR of stroke associated with intravitreal ranibizumab during the case period was 1.285 (95% CI 0.979-1.686) (p = 0.07). In the subgroup analysis, the risk of hemorrhagic stroke had an OR of 2.252 (95% CI 1.068-4.749, p = 0.033). Further analyses based on patient gender, age, and different risk periods of 15 and 30 days yielded no increase in the risk of stroke associated with intravitreal ranibizumab.

Conclusions: This case-crossover analysis revealed no evidence of increased risk of hospitalization for stroke within 60 days of intravitreal ranibizumab injection in AMD patients. A secondary analysis indicated the possibility of an increased risk of hemorrhagic stroke, with borderline significance. Further research is needed regarding the underlying biological mechanisms and drug safety.