Carotid endarterectomy restores decreased vision due to chronic ocular ischemia

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.

Ocular Ischemic Syndrome and the Role of Carotid Artery Revascularization

BACKGROUND

Ocular ischemic syndrome (OIS) is a rare presentation of atherosclerotic carotid artery stenosis that can result in permanent visual loss. This severely disabling syndrome remains under diagnosed and undertreated due to lack of awareness; especially since it requires expedited multidisciplinary care. The relevance of early diagnosis and treatment is increasing due to an increasing prevalence of cerebrovascular disease.

METHODS

The long-term visual and cerebrovascular outcomes following intervention for nonarteritic OIS, remain poorly described and were the objective of this concise review. We conducted a PubMed search to include all English language publications (cohort studies and case reports) between 2002 and 2023.

RESULTS

A total of 33 studies (479 patients) report the outcomes of treatment of OIS with carotid endarterectomy (CEA, 304 patients, 19 studies), and carotid artery stenting (CAS, 175 patients, 14 studies). Visual outcomes were improved or did not worsen in 447 patients (93.3%). No periprocedural stroke was reported. Worsening visual symptoms were rare (35 patients, 7.3%); they occurred in the immediate postoperative period secondary to ocular hypoperfusion (3 patients) and in the late postoperative period due to progression of systemic atherosclerotic disease. Symptomatic recurrence due to recurrent stenosis after CEA was reported in 1 patient (0.21%); this was managed successfully with CAS. None of these studies report the results of transcarotid artery revascularization, the long-term operative outcome or stroke rate.

CONCLUSIONS

OIS remains to be an underdiagnosed condition. Early diagnosis and prompt treatment are crucial in reversal or stabilization of OIS symptoms. An expedited multidisciplinary approach between vascular surgery and ophthalmology services is necessary to facilitate timely treatment and optimize outcome. If diagnosed early, both CEA and CAS have been associated with visual improvement and prevention of progressive visual loss.