Carotid revascularization and circle of Willis in ocular ischemic syndrome: association with neovascular glaucoma and visual prognosis

Background Ocular ischemic syndrome (OIS) and subsequent neovascular glaucoma (NVG) lead to irreversible visual impairment. This study aimed to investigate the association of carotid artery revascularization and the collateral circulation types via the circle of Willis (CoW) with NVG and visual prognosis in patients with OIS. Methods This retrospective cohort study included 22 patients with OIS, with a median follow-up of 12 months. The collateral circulation patterns via the CoW were classified into five types. The association of the carotid artery revascularization, collateral circulation types via the CoW, and morphological characteristics of the CoW with the presence of NVG and visual outcomes was assessed. Results The median time interval from baseline to visual decline during follow-ups in patients with carotid artery revascularization was longer than that in patients without carotid artery revascularization (13 months vs 9.5 months, P=0.041). Lacking collateral inflow via the CoW to the hemisphere ipsilateral to OIS was associated with NVG (odds ratio (OR), 11.000; P=0.022). The diameters of the C6 and C7 segments of the internal carotid artery, the A1 segment of the anterior cerebral artery, and the ophthalmic artery in OIS eyes were smaller than those in the contralateral eyes. Conclusion Early carotid artery revascularization should be considered in patients with OIS, with or without NVG, as it may contribute to an improved visual prognosis. Patients without collateral inflow via the CoW to the hemisphere ipsilateral to OIS may have a higher risk of NVG.