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Anterior ischaemic optic neuropathy or infarction of the optic nerve head is a condition that is much less well known than cardiac infarction, but about which one needs to be informed because it can dramatically affect vision and it is extremely important to recognise the early signs early in order to manage this emergency.

Infarction of the optic nerve head

Anterior ischaemic optic neuropathy is an acute and painless condition in which optic nerve cells, as a result of a lack of blood supply, die, exactly as in the case of myocardial infarction, but in this case it occurs in the visual pathways.

The interruption of blood flow can lead to permanent damage and may result in sudden loss of vision.

Classification and Causes

Anterior ischaemic optic neuropathy can be classified into two forms:

1. Non-arteritic
2. Arteritics

Causes of the non-arteritic form

The non-arteritic form is caused by an atherosclerotic-based occlusion associated with local or general risk factors.

Local factors include a particular conformation of the optic nerve head (e.g. an optic disc with too many blood vessels) in combination with general risk factors, which include:

• myocardial infarction
• hypertension
• diabetes mellitus
• smoke
• high cholesterol and hyperhomocystenemia
• obesity
• poor exercise

Non-arteritic optic neuritis usually affects the other eye by the age of 5 years in 25-50% of cases.

Causes of the arteritic form

Arteritic optic neuritis is part of a generalised disease, Horton's Arteritis, in which the cause of the occlusion is inflammatory. It can also occur in the course of other diseases, such as rheumatoid arthritis and SLE (Systemic Lupus Erythematosus).

It may affect one eye or both.

Symptoms to Recognise

Symptoms of ischaemic optic neuropathy are often sudden and can include partial or complete loss of vision in one eye. Some people experience a dark shadow or blurred vision.

Early recognition of these signs is crucial. Prompt treatment can improve the chances of recovering sight.

Diagnosis

In order to diagnose ischaemic optic neuropathy, a thorough history must be taken, reconstructing the patient's medical history in detail, and a comprehensive ophthalmic examination, including:

1. Ophthalmoscopy: to view the ocular fundus.
2. Fluorescein angiography: to check the blood flow to the retina and optic nerve.
3. Optical coherence tomography: to get an image of the different retinal layers.

Timely examinations are essential to identify the extent of the damage and to develop an appropriate and effective treatment plan.

Treatment

Treatment is different for the two forms, arteritic and non-arteritic.

The non-arteritic formIn the acute phase, it can be treated with the administration of oral steroids, which serve to reduce oedema of the optic disc. Of considerable importance is blocking the progression of the damage in the eye already affected by ischaemic neuropathy and preventing its onset in the healthy eye. To this end, the use of antiplatelet agents and the control of cardiovascular risk factors such as systemic arterial hypertension, diabetes and dyslipidaemia are recommended.

The arteritic form is treated in the acute phase with steroid boluses intravenously and then orally, and scaled up in the maintenance, in the chronic form. Collaboration between ophthalmologist, internist and immunologist is important in the management of the patient.

Research is investigating possible neuroprotective strategies to prevent the onset of ischaemic optic neuritis. Several human clinical studies are underway and animal studies on the possibilities of optic nerve regeneration have also been initiated.

Impact on Daily Life

Visual loss resulting from ischaemic optic neuropathy can limit daily activities and it is essential to find ways to adapt to these new conditions.

Affected persons may experience difficulties in reading, driving and other activities. Accepting limitations is the first step to finding practical solutions.

Visual aids and assistive technologies can help improve quality of life by making everyday activities more manageable, such as:

• Electronic magnifiers for reading.
• Screen Reading Software for the computer.
• Adequate lighting for all domestic environments.

These aids can greatly improve independence and safety and allow a certain degree of independence to be maintained. An ophthalmologist can recommend the most suitable aids.

Ocular Prevention and Well-being

Taking care of your eyes can prevent many problems and healthy lifestyle habits can play an important role in reducing the risk of ischaemic optic neuritis

Some recommendations:

• Monitor blood pressure and cholesterol.
• Avoid smoking.
• Adopt a diet rich in fruit and vegetables.

In particular, some healthy habits contribute to ocular well-being.

• Regular eye rest while using digital devices.
• Eye protection from bright light.
• Adequate hydration to avoid dry eyes.

Regular Medical Visits

Regular medical check-ups are essential for monitoring eye health. Regular check-ups can detect problems early on.

• Comprehensive eye examinations at least every two years.
• Recognise unusual symptoms and report them to a specialist.

Early diagnosis is essential for effective treatment in the case of ischaemic optic neuritis.

Answers to Frequently Asked Questions

• Can one recover completely from visual loss? Timely treatment is crucial.
• What are the first signs to notice? Sudden loss or blurred vision should always be assessed immediately.

See also:

Risk of NAION and Semaglutide - Oculist Italiano

• Morrow MJ. Ischemic Optic Neuropathy. Continuum (Minneap Minn). 2019 Oct;25(5):1215-1235. doi: 10.1212/CON.0000000000000767. PMID: 31584535.
• Arnold AC, Levin LA. Treatment of ischemic optic neuropathy. Semin Ophthalmol. 2002 Mar;17(1):39-46. doi: 10.1076/soph.17.1.39.10292. PMID: 15513455.