Ocular Ischemic Syndrome
What is Ocular Ischemic Syndrome?
Ocular ischemic syndrome (OIS) is a rare condition characterized by abnormal growth of blood vessels in the eye causing visual loss and pain.
What are the Causes of Ocular Ischemic Syndrome?
It occurs due to ocular hypo perfusion (condition where the blood supply to tissues are restricted, resulting in lack of oxygen and glucose required for metabolism, also called ischemia). OIS is a severe form of chronic ischemia affecting both anterior (front, one-third portion of the eye) and posterior (back, two-third portion of the eye) segments and also the orbital structures of the eye. OIS occurs due to carotid artery stenosis i.e., when the blood vessels that supply blood to the eye become narrowed (>90%). Atherosclerosis (thickening of artery walls due to accumulation of calcium and cholesterol) is a major cause of OIS. The other causes of OIS are giant cell arteritis, fibrovascular dysplasia, Takayasu arteritis, Behcet’s disease and dissecting aneurysm of carotid artery.
Who is Most Likely to Develop Ocular Ischemic Syndrome?
OIS is more commonly seen in males than in females and occurs in the age group of 50-80 years.
What are the Consequences of Not Treating Ocular Ischemic Syndrome?
The untreated condition of ocular ischemic syndrome can lead to visual loss.
What are the Symptoms?
The common symptoms of OIS include vision loss and eye pain. Other clinical manifestations include uveitis (inflammation of uvea), neovascularization, asymmetric cataract, sluggish reaction to light, corneal oedema, dilated retinal veins, cherry-red spot, narrowed retinal arteries, orbital pain, cotton-wool spots, vitreous haemorrhage, etc.
How is Ocular Ischemic Syndrome Diagnosed?
OIS can be diagnosed by carotid artery ultrasound, Doppler imaging and fundus fluorescein angiogram. The differential diagnosis includes diabetic retinopathy and advanced central retinal vein occlusion.
What are the Treatment Options For Ocular Ischemic Syndrome?
The management of OIS involves treatment advice from specialist doctors like an ophthalmologist, a neurologist and a vascular surgeon. A consultation with a cardiologist may also be necessary in some cases. The treatment can be localized to the eye or systemic to address the narrowed carotid arteries. Local treatment includes medications, surgery or laser treatments to the eye. The systemic treatments include medications and surgical treatment to open up the carotid arteries. Early diagnosis is very essential with respect to treatment and survival due to the risk of stroke from carotid artery narrowing.