Optic Nerve Disorders & Neuro-Ophthalmology

Optic Nerve Disorders and Neuro-OphthalmologyIschemic Optic Neuropathy

Ischemic optic neuropathy, a condition caused by restricted blood flow to the optic nerve, is the sudden loss of vision in one or sometimes both eyes. It primarily affects the elderly. There are two forms of ischemic optic neuropathy, caused by differing underlying conditions.

Non-arteritic ischemic optic neuropathy (NAION) is usually painless; it is caused by cardiovascular disease. If you have high cholesterol, high blood pressure, diabetes, or if you smoke, you are at higher risk of developing the condition. Unfortunately, there is no cure, and the central or peripheral (side) vision that you have lost cannot be restored. However, treating the underlying causes of your cardiovascular disease can help control non-arteritic ischemic optic neuropathy and prevent further vision loss.

Arteritic ischemic optic neuropathy (AION)
is a condition caused by inflammation of the arteries supplying blood to the optic nerve. This inflammation is known as giant cell arteritis (GCA) or temporal arteritis (TA), and its cause is unknown.  Giant cell arteritis rarely occurs in people below 50 years of age, and it typically begins at around age 70. Women are more likely to develop GCA than men, and Caucasians are affected at a much higher rate than people of other races. People of Scandinavian ancestry are at particular risk. If you have polymyalgia rheumatica, you have an increased risk of having GCA as well.


Giant Cell Arteritis (GCA) or Temporal Arteritis (TA)

Arteritic ischemic optic neuropathy (AION) is a condition caused by inflammation of the arteries supplying blood to the optic nerve. This inflammation is known as giant cell arteritis (GCA) or temporal arteritis (TA), and its cause is unknown.  Giant cell arteritis rarely occurs in people below 50 years of age, and it typically begins at around age 70. Women are more likely to develop GCA than men, and Caucasians are affected at a much higher rate than people of other races. People of Scandinavian ancestry are at particular risk. If you have polymyalgia rheumatica, you have an increased risk of having GCA as well.

Signs to look for include:

  • flu-like symptoms including headache, fatigue, and fever;
  • blurred vision;
  • double vision;
  • scalp tenderness (painful hair brushing);
  • jaw pain (painful chewing);
  • stiffness or pain in the neck, hip, or arms; and
  • unexplained weight loss.

When treated quickly with high doses of corticosteroids (anti-inflammatory medications) there is a good chance your symptoms will be improved and your vision loss may not be permanent.  Diagnosis after vision loss has occurred, however, portends a worse prognosis and places both eyes at risk for permanent vision loss.  A definitive diagnosis can only be made with a biopsy. For this reason, Dr. Haas may begin treatment before a biopsy confirms your diagnosis. You may need to take corticosteroids for as long as a few years, though at lower dosage levels if this diagnosis is made.

Major side effects of corticosteroids include:

  • osteoporosis;
  • high blood pressure;
  • muscle weakness;
  • major blood sugar fluctuations; and
  • cataracts.

You should discuss the complications of corticosteroid medications and alternative treatment options with Dr. Haas.

Ischemic Optic Neuropathy:    


Optic Neuritis

Optic neuritis is a condition characterized by inflammation of the optic nerve. This nerve is the pathway that carries impulses from the retina in the back of the eye to the brain and enables the brain to interpret the impulses as images. If the nerves are damaged, vision is greatly affected.

This condition may affect one or both eyes, and symptoms may appear slowly or over a few days. Some of these symptoms include blurred or dim vision, abnormal color vision, or pain in the back of the eye socket or when moving the eyes. These symptoms may get worse with heat or exhaustion. If you are experiencing any of these symptoms, see Dr. Haas for an eye examination right away. If optic neuritis goes untreated, symptoms will get worse.

The causes of optic neuritis are known to be associated with various diseases such as mumps, influenza, measles, multiple sclerosis, Leber's optic neuropathy (a rare eye condition), or vascular occlusions. However, in many cases, optic neuritis occurs with no known cause.

Steroid drugs are used to treat optic neuritis. In most patients, vision will significantly improve or return to normal with treatment. However, those with a pre-existing condition like multiple sclerosis may not recover their normal vision.


Pseudotumor Cerebri

Pseudotumor cerebri (PTC) is a condition in which the pressure from the cerebral spinal fluid inside your head is elevated. This can cause problems such as headaches, blurred vision, or loss of vision. The condition is known as pseudotumor cerebri because symptoms can mimic those of an intracranial tumor.

The cerebral spinal fluid (CSF) is a clear fluid that bathes the brain and spinal cord. In cases of PTC, this fluid is blocked from flowing back from the head as it should, leading to high CSF pressure inside the head. The pressure swells the optic disc at the back of the eye, which can damage (sometimes permanently) the optic nerve and cause vision loss. It can also damage the nerves that control eye movement, resulting in double vision.

The causes of PTC are not certain, but they may include the following:

  • hormonal influences, in young women;
  • antibiotics;
  • steroids; and
  • high doses of vitamin A.

The most common symptoms of PTC are headache and visual loss. The headache can be located anywhere, but is usually in the back of the head. It may wake you in the middle of the night, and it may worsen with bending or stooping. Other symptoms include:

  • dimming, blurring, or graying of vision;
  • difficulty seeing to the side;
  • brief visual disturbances;
  • double vision;
  • rushing or ringing noise in the ears; and
  • nausea and vomiting.

Dr. Haas will give you a complete eye examination. It may also be necessary for you to have an MRI scan and spinal tap to assure accurate diagnosis and to rule out other CSF abnormalities. The information learned during the eye exam will allow Dr. Haas to appropriately determine what, if any additional diagnostic tests are needed.
If your symptoms are mild, no treatment other than careful monitoring may be necessary. If you require treatment, certain glaucoma medications and diuretics can help lower CSF pressure. Weight loss (10% or more) is an effective treatment in overweight patients. Pressure can also be lowered by draining CSF through repeated spinal taps or a surgical intervention.

If your vision continues to deteriorate after you have begun treatment, surgical techniques may be required to protect the optic nerve from any further damage