Capsular Block Syndrome after an Intravitreal Injection of Ranibizumab: A Case Report

Introduction: We present a case of capsular block syndrome that occurred after intravitreal injection of ranibizumab in a patient with age-related macular degeneration, which has not been reported in the literature. Case Presentation: A 78-year-old male presented with decreased visual acuity in the right eye. Slit-lamp examination findings were unremarkable; however, AMD was diagnosed based on fundus examination, fluorescein angiography, and optical coherence tomography (OCT). Subsequently, the patient was administered an intravitreal injection of ranibizumab. A slit-lamp examination revealed residual cortical material, numerous inflammatory cells, and posterior capsular distension 1 week after the injection. OCT showed an adhesion of the intraocular lens to the continuous curvilinear capsulorhexis site. The patient's vision improved following Nd:YAG laser posterior capsulotomy. Conclusion: Meticulous cortical removal is crucial during phacoemulsification to prevent capsular block syndrome. In patients with a history of cataract surgery, verifying the absence of residual cortical material before administering an intravitreal injection of ranibizumab is important.