Neovascular glaucoma masked by cerebral hyperperfusion syndrome following carotid artery stent placement: illustrative case.

backgroundCarotid artery stent (CAS) placement and carotid endarterectomy can improve ocular ischemic syndrome (OIS). However, paradoxical visual deterioration due to neovascular glaucoma (NVG) may rarely occur after revascularization. The authors report a case of NVG developing after CAS placement, resulting in severe and irreversible vision loss. OBSERVATIONS: A 74-year-old man with severe right internal carotid artery stenosis and preoperative retinal ischemia underwent CAS placement. The stenosis was successfully resolved. On the day after the procedure, he developed a headache and was diagnosed with cerebral hyperperfusion syndrome, which stabilized with strict blood pressure control. Despite this, his headache persisted, accompanied by progressive visual deterioration. On postoperative day 10, ophthalmological evaluation confirmed NVG, and topical treatment was initiated. Nevertheless, the visual impairment remained irreversible. LESSONS: NVG following carotid revascularization has no established preventive strategies and often leads to profound vision loss. Neurosurgeons and neurointerventionalists should recognize this potential complication. The authors recommend conducting preoperative and postoperative ophthalmological assessments for high-risk patients, including those with OIS or a history of cataract surgery. https://thejns.org/doi/10.3171/CASE25746.