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.

Automated summary

The study found no significant increased risk of stroke associated with intravitreal ranibizumab injection in AMD patients within 60 days, but indicated a significantly increased risk of hemorrhagic stroke in subgroup analysis. Further research is recommended to explore underlying biological mechanisms and drug safety.