Diseases affecting the optic nerve

The Optic nerve is affected by a variety of diseases -

Glaucoma 

Increase in eye pressure causes destruction of the delicate nerve fibers. This is seen as an increase in cupping of the optic nerve. The visual fields become constricted and blindness can result.

Figure Showing Optic Nerve In Glaucoma.

Optic neuritis

This means inflammation or swelling of the optic nerve. It can result from various causes and can occur with or without affecting other parts of the nervous system.

It occurs more commonly in young - middle aged females.

Symptoms -

Sudden loss/ diminished vision, inability to see colours. There may be associated pain. It can occur in one/ both eyes simultaneously or after intervals.

The eye needs a detailed exam.

A CTScan/ MRI may be needed.

Treatment consists of giving steroids as intravenous injections and monitoring the condition. A hospital admission may be needed.

Multiple sclerosis is the main condition to look out for in optic neuritis.

Systemic diseases like diabetes, hypertension, Giant cell Arteritis, Thyroid disease can affect the optic nerve. AION (anterior ischemic optic neuropathy) can be a cause of sudden loss of vision in elderly.

Optic nerve injury can occur in motor vehicular accidents. They can range from minor swelling to total tearing away of the nerve.

Optic nerve can be affected by tumors like meningioma, haemangioma etc.

The optic nerve can be affected due to birth anomalies like Coloboma.

Papilledema

This is the swelling of the optic nerve due to raised intracranial pressure, i.e. in association with swelling of the brain. Brain swelling can occur in 'Brain fever' or Meningitis, or any kind of Brain Injury. Since the Optic Nerve is connected to the brain, it gets swollen too. A simple Fundus Exam will help in diagnosis.

Optic Atrophy

Optic Atrophy means loss of function of the Optic nerve. The nerve becomes totally pale white. This may be the end result of many Optic nerve insults.

Optic Atrophy can occur due to:

Tobacco and Alcohol are the most important and avoidable causes.

Once the Optic nerve looses function it is permanent.