Blindness Following Carotid Artery Stenting Due to Ocular Hyperperfusion - Report and Review of Literature

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.

Preoperative Ocular Symptoms Predict Acute Glaucoma After Carotid Revascularization: An Analysis of Combined Single-Center Data and a Systematic Review

BACKGROUND

Acute glaucoma is a potential complication of carotid revascularization procedures such as endarterectomy or stenting. Although preoperative ocular hypoperfusion may predispose patients to postoperative glaucoma, the details of this complication have not been clarified.

METHODS

We retrospectively reviewed the medical records of consecutive patients who underwent carotid revascularization at our institution from January 2019 to December 2022. These patients were divided into glaucoma and nonglaucoma groups. Given the rarity of the event, a systematic literature review was performed to additionally include data from patients who developed acute glaucoma after carotid revascularization. Multivariate logistic regression was performed to identify the risk factors for acute glaucoma.

RESULTS

Thirty-five cases, including 2 from our institution, were included in the glaucoma group, and 130 were included in the nonglaucoma group. Most cases (79%) occurred within five days postoperatively. Multivariate analysis revealed that preoperative ocular symptoms were significantly associated with the development of postoperative glaucoma (odds ratio, 361.06; 95% confidence interval, 34.09-3824.27; P < 0.001). Preoperative neovascularization at the iris or anterior chamber angle, indicating severe ocular hypoperfusion, was found in 84% of patients with glaucoma. Permanent visual loss occurred in 41% of patients. The incidence of postoperative glaucoma at our institution was 1.5% (2/132). The positive predictive value of preoperative ocular symptoms for postoperative glaucoma was 0.25 (95% confidence interval, 0.18-0.32).

CONCLUSIONS

This study was the first to clarify the risk factors and characteristics of acute glaucoma after carotid revascularization.

Ocular signs of carotid stenosis in ipsi- and contralateral eyes before and after carotid endarterectomy: a prospective study

PURPOSE

We describe hypoperfusion-related and embolic ocular signs of carotid stenosis (CS) before and six months after carotid endarterectomy (CEA) in a CS population.

METHODS

We enrolled prospectively 70 CEA patients (81% male, mean age 69) and 41 non-medicated control subjects (76%, 68), from March 2015 to December 2018, assessing intraocular pressure (IOP), best-corrected visual acuity (BCVA) in logMAR units and performing a bio-microscopy examination.

RESULTS

Main index symptoms included amaurosis fugax (Afx) (29, 41%) and hemispheric TIA (17, 24%), and 17 (24%) were asymptomatic. Of the 70, 17 patients (24%, 95% CI 16-36) showed ocular signs of CS. Of four embolic (Hollenhorst plaques) findings, one small macular plaque disappeared postoperatively. Four had hypoperfusion, that is ocular ischaemic syndrome (OIS), requiring panretinal photocoagulation: one for multiple mid-peripheral haemorrhages, two for iris neovascularization and one for neovascular glaucoma (NVG); only the NVG proved irreversible. Nine (de novo in three) showed mild OIS, that is only few mid-peripheral haemorrhages, ranging pre- /postoperatively in ipsilateral eyes from one to eleven (median two)/ one to two (median one), and in contralateral eyes from three to nine (median five)/ one to six (median three). Pre- and postoperative median BCVA was 0 or better, and mean IOP was normal, except in the NVG patient. Temporary visual impairment from 0 to 0.3 occurred in one eye soon after CEA due to ocular hyperperfusion causing macular oedema.

CONCLUSIONS

Ocular signs of CS are common in CEA patients, ranging from few mid-peripheral haemorrhages to irreversible NVG. Clinicians should be aware of these signs in detecting CS.