The ocular ischemic syndrome is a rare condition that threatens vision. It is linked to severe carotid artery occlusive disease (occlusion or stenosis) leading to reduced or lack of blood supply to the eye called chronic hypo-perfusion. Ischemia will result in severe eyeball pain and symptoms of vision impairment.
Lack of or complete vision loss also referred to as amaurosis fugax, is a predominant symptom that may be mild to moderate. On the other hand, the pain could indicate a possible stroke. It is extremely urgent to rule out carotid artery obstruction to prevent cardiac arrest.
Who is more likely to develop the disease?
Ocular ischemia is twice more common in males than females. It is typically found in patients age 50 to 80 years. A study hasn’t identified any racial predilection because the disease still needs further research. While the incidence of OIS is estimated at 7.5 cases per million individuals per year, we need to consider that many patients could be misdiagnosed with a different disease like diabetic retinopathy or retinal vein occlusions.
What are the types of OIS?
- Common carotid terminology/artery – blockage of major blood vessels in the neck supplying blood to the face and brain
- Carotid artery occlusion – a buildup of fatty substances and cholesterol deposits in the artery, increasing the risk of a stroke
- Retinal arterial occlusion – painless loss of a portion or the entire field of vision due to embolism of the retinal artery
- Takayasu’s arteritis – chronic inflammation of the large blood vessels that distribute blood from the heart; a disease that is most common in women of Asian descent
- Internal carotid artery – divides to form the anterior cerebral artery and middle cerebral artery; an important pathway supplying the brain
- Giant cell arteritis – disease of the blood vessels that occurs in adults mostly over the age of 50
- Anterior segment ischemic syndrome – a severe disease of the internal carotid artery
What are the common causes of the condition?
In general, 90 percent of ischemic diseases of eyes is associated with vision loss. Most common reason for this is hypo-perfusion secondary to occlusion of the carotid artery. Most often we can observe occlusion in common carotid artery, which may result in stroke if not given immediate treatment. Ocular and retinal arterial bleeding is often found with a history of diabetes and hypertension. When hemorrhage and hypo-perfusion happen, fibers and retinal cells may develop lasting damage.
What kinds of test are used to diagnose OIS?
- Sedimentary Rate: Temporal Arteritis
- Increase White Blood Cell Count: Infection
- Ultrasound: Detects carotid artery stenosis and thrombosis
- Blood Sugar: Diagnoses level of sugar in diabetic patients
- Visual Field Testing and Visual Acuity: Changes in retina and fundus of the eyeball
- EEG, Cat Scan and MRI: Diagnose stroke
- EKG and Echocardiography: Spotted cardiac diseases
Pinpointing the cause of OIS is a major component of treatment. The priority of the vascular doctor is to try to get to the underlying cause, which is mainly carotid occlusive disease. Practitioners are advised to carefully assess both ocular and systemic findings before making a differential diagnosis.