When the Eyes Go Dark: Transient Cortical Blindness After Primary Percutaneous Coronary Intervention

Transient cortical blindness is a rare neurological complication associated with iodinated contrast media used during coronary angiography and percutaneous coronary intervention (PCI). Although uncommon, its sudden onset may mimic acute stroke, creating diagnostic uncertainty and significant anxiety. We report the case of a 49-year-old woman with a three-year history of type 2 diabetes mellitus who presented with prolonged retrosternal chest pain. ECG revealed ST-segment elevation in the inferior leads, consistent with inferoposterior ST-elevation myocardial infarction. Coronary angiography demonstrated an occlusion of the proximal right coronary artery, and successful primary PCI was performed with restoration of thrombolysis in myocardial infarction 3 flow. Near the end of the procedure, the patient developed acute bilateral blindness, preceded by visual fog, despite stable vital signs and the absence of focal neurological deficits. An urgent brain CT and subsequent MRI with angiographic sequences, performed four hours after symptom onset, were unremarkable. Supportive management with intravenous hydration was initiated, and the patient experienced complete visual recovery within 24 hours. The clinical presentation, normal neuroimaging, and rapid resolution were consistent with contrast-induced cortical blindness, a phenomenon attributed to transient blood-brain barrier disruption and direct neurotoxic effects of contrast agents on the occipital cortex. Although self-limited, recognizing this rare complication is crucial to distinguish it from ischemic stroke or posterior reversible encephalopathy syndrome and to prevent unnecessary interventions. Contrast-induced cortical blindness remains a reversible but impactful complication of PCI, and early recognition, exclusion of alternative diagnoses, supportive care, and patient reassurance are essential for optimal management.