|Title||Ocular Ischemic Syndrome Secondary to Carotid Stenosis Resulting from Radiotherapy|
|Author, Co-Author||Tina Zheng, Lee Vien, David Yang|
Ocular ischemic syndrome (OIS) is a rare condition caused by ocular hypoperfusion. It usually results from 90% or greater stenosis of the common carotid artery or internal carotid artery (ICA). Although the majority of carotid stenosis cases stem from atherosclerosis, it can rarely result from radiotherapy for head and neck malignancies. OIS can present with anterior and posterior segment findings. Diagnosis is confirmed with carotid ultrasonography. Symptoms may include sudden or gradual vision loss, ocular or periorbital pain, or transient vision loss. OIS is treated with surgical opening of the occluded artery.
A 69-year old Caucasian male presented for a comprehensive eye exam with no complaints. His exam was remarkable for mid-peripheral dot and blot hemorrhages in all quadrants in the left eye only. A carotid ultrasound was ordered and revealed complete occlusion of the left ICA and no stenosis of the right ICA. The occlusion of the left ICA was attributed to his history of extensive repeated radiotherapy of the left head and neck for squamous cell carcinoma, leading to arterial fibrosis. At follow up exams, the patient developed neovascularization of the iris (NVI) and panretinal photocoagulation was performed. He continued to show regressed NVI and scattered mid-peripheral hemorrhages OS without additional ocular sequelae at all follow-up visits.
OIS secondary to carotid occlusion from radiation therapy is rare. Radiotherapy for head and neck malignancy has been thought to cause arterial endothelial cell damage, resulting in endothelial thickening, proliferation of fibrous tissue, and eventual stenosis. These patients should be managed closely for the development of carotid stenosis and stroke. Asymptomatic patients without history of stroke or transient ischemic attack may be monitored without surgical intervention.
|Affiliation of Co-Authors||Veterans Affairs Palo Alto Health Care System, Veterans Affairs Palo Alto Health Care System|