Optic Nerve Neuropathy Explained

Optic Neuropathy is a problem associated with the optic nerves. This condition can affect people of all age groups. Optic nerves serve the function of connecting the eyes to the brain. Optic nerve has millions of axons originating from the retinal ganglion cells. These axons or nerve tracts carry visual information from retina to the optic chiasm.

There are many types of optic neuropathies. Some of these conditions are discussed below:

Glaucomatous Optic Neuropathy – Glaucoma of all types are characterized as optic neuropathy. It is a condition in which the optic nerves are damaged in a characteristic pattern leading to loss of visual field of an individual. If this condition is not treated in a timely manner, the loss can become permanent and may gradually advance to blindness in worst cases. The traditional explanation of optic nerve damage is related to the increased fluid pressure in the eyes. The condition may also develop because of elevated intra ocular pressure, vascular insufficiency or insufficient supply of blood and faulty auto-regulatory mechanism which may lead to death of ganglion cell and supportive tissues. Besides these factors, genetic causes and old age may also lead to glaucomatous optic neuropathy.

Inflammatory Optic Neuropathy – This condition arises from the inflammation of the optic nerves and may be caused by a number of reasons including an autoimmune condition such as multiple sclerosis or lupus, bacterial infection, vaccination, bee sting, cranial arteritis, diabetes, toxins and drugs. Individuals suffering from inflammatory optic neuropathy experience pain in their affected eye(s) which may aggravate on eye movements. The patient may also undergo changes in his / her color vision. Eventually, they may experience gradual loss of vision that may lead to a situation of no perception of light at all.

Compressive Optic Neuropathy – Compressive optic neuropathy is caused by the mechanical pressure on the optic nerves caused by tumors, lesions etc. Lesions may also be caused because of some infection or inflammation. The mechanical pressure on the nerve may result in swelling of the nerves and gradual loss of vision. Individuals suffering from this condition may have degradation in color vision that may later on be accompanied by an acute loss of the vision. Patients may sometimes also have the problem of double vision. Other symptoms of this condition include swelled and bulging eyes.

Ischemic Optic Neuropathy – This type of optic neuropathy is caused by insufficient supply of blood to the optic nerve resulting in the death of ganglion cell or supportive tissues. Based on the affected area and cause of reduced blood flow, Ischemic optic neuropathy is further classified into two types – anterior ischemic optic neuropathy and posterior ischemic optic neuropathy. The symptoms include sudden loss of vision with or without swelling in the optic nerves.

Infiltrative Optic Neuropathy – This kind of optic neuropathy is most commonly associated with sarcoidosis. Other causes include systematic infections, blood borne cancer, metastatic diseases and systematic autoimmune disorder like lupus erythematosus etc. In this type of neuropathy, blood flow is impeded in optic nerves because of infiltration caused by tumors, inflammation or infection. This lack of supply of blood may eventually result in the death of axons and neuropathy.

Traumatic Optic Neuropathy – This optic neuropathy is caused by a direct or indirect injury to the optic nerve. For example, direct injury may be caused by a bullet or forceps etc. whereas a blunt impact in accidents may cause an indirect injury. The results are similar and cause the blood supply to the optic nerve to be impeded. As a result, the ganglion cells and axons may die and the patient may suffer from loss of vision.

Based on other reasons causing the condition of optic neuropathy (hereditary, congenital, radiation, toxic etc.), there are some more classifications as well. However, the resulting symptoms may be more or less the same.

Diagnosis and Treatments

I order to treat this condition, the medical practitioner has to first ascertain the degree and cause of damage. A neuro-opthalmic examination is carried out on the patient to ascertain whether the causes of vision loss is optic neuropathic or retinopathic. The specific investigations may include visual field testing, contrast testing, electro physiological tests, optical coherence tomography etc.

Is it possible to reverse neuropathy of optic nerves? Well, damage to the optic nerves is often irreversible and cannot be treated in most cases. However, if the condition and causative factors are diagnosed in early phase, medicines may be prescribed to prevent further damage. Therefore, any kind of vision loss should be immediately reported to the doctor for timely neuropathy cure.

Prevention

Not all the causes of optic neuropathy can be treated or prevented. However, there are some precautions an individual can take to reduce the chances of being affected by optic neuropathy.

• You can prevent injuries to your face in order to remain safe from optic neuropathy. Injuries to face are most common during car accidents. So, you must use the seat belts to avoid this.
• Get your eyes checked at least once a year to eliminate any kind of possibility leading towards optic neuropathy. You must be especially cautious if you have a family history of optic problems or suffer from diabetes or blood pressure.
• Routine checkups are also important for old people. In addition, they must keep their blood pressures and blood sugar in control to avoid damage to optic nerves.