Arteritic Ischemic Optic Neuropathy

Dr Ben Wild

Overview

Our vision comes from light waves stimulating retinal photoreceptors and these photoreceptors transferring their signals through a multitude of other cells to the ganglion nerve cells. These ganglion cells bunch together and form the optic nerve. The optic nerve then sends the signal to the occipital lobe in the brain where vision is interpreted and recognized.

An image of a healthy retina and optic nerve.

Arteritic ischemic optic neuropathy (AION) occurs due to an autoimmune condition called Giant Cell Arteritis (GCA) that causes inflammation in large and medium arteries within the body. This inflammation can lead to the decay of arteries such as the aorta around the heart, the temporal artery above the eye and ear, the ophthalmic artery inside the optic nerve, along with many others. AION usually occurs in the elderly with an average age around 70 years old and has an unknown connection to polymyalgia rheumatica, a secondary diagnosis 50% of the time.

An image showing a swollen optic nerve consistent with AION.

Signs and Symptoms

Signs

White swollen nerve.

Symptoms

AION	Double vision, sudden profound decreased vision in 1 eye then the other eye in 33% of cases within 1 week, amaurosis fugax (brief complete black out of vision), pain around the eye.
GCA	Scalp tenderness (combing hair), headache on the front/forehead of the affected side of the head, headache on the back of the head or around the ears, difficulty chewing or moving the jaw, weight loss, fever, sweats, general unwell feeling

Causes and Risk Factors

Causes

Autoimmune inflammation of medium and large arteries caused by GCA.

Risk Factors

Female gender, increased age, Caucasian decent, polymyalgia rheumatica, genetics.

Prevention and Treatment

Prevention

There are no known preventative measures.

Treatments

· Intravenous steroids.

· Antiplatelet therapy.

· Immunosuppression therapy with methotrexate.

Prognosis

Vision loss is usually permanent but prompt treatment may lead to partial recovery and may protect the fellow eye from losing vision.