In this article, we will tell you:
The optic nerve is a bundle of nerve fibers that carries image information from the retina to the brain, like electricity through wires. Nerve fibers, just like wires, have a protective sheath. They are covered with myelin, which ensures the rapid passage of nerve impulses and protects the nerve from damage.
A condition in which the optic nerve is partially or completely damaged is called optic nerve atrophy – the connection between the brain and the eyeball is broken. This leads to a decrease or complete loss of vision in one or both eyes.
What signs and symptoms can signal optic nerve atrophy?
- Visual acuity has decreased, it has become cloudy, blurry, cannot be corrected with glasses or contact lenses;
- The field of vision has narrowed (peripheral vision has disappeared);
- Eye movements cause discomfort;
- The presence of dark spots before the eyes;
- Pain in the eye area;
- Problems with the perception of colors – patients may see red, green, blue shades worse, complain that the colors have become duller, faded, the image contrast has decreased);
- Anisocoria is a violation of the reaction of one or both pupils to light.
You must have heard that nerve cells do not regenerate. Doctors and scientists say that this is a myth, but if you ignore atrophy of the optic nerve, you can bring the pathological process to an irreversible stage. If you notice similar manifestations in yourself or your family and friends, we recommend that you contact an ophthalmologist and neurologist as soon as possible to start treatment.
Causes of the disease
Optic nerve atrophy can develop:
- Due to an ophthalmic disease (for example, glaucoma);
- After a stroke, when there is a blockage of the vessels of the fundus or necrosis of the tissues responsible for visual function;
- Due to traumatic brain injury;
- With intraorbital neoplasms (glioma, glioblastoma or neurofibromatosis );
- Due to poisoning with toxic substances (poisons or surrogate alcohol);
- As a complication after a viral or infectious lesion of the brain, nervous or vascular systems (syphilis, encephalitis, meningitis and even influenza);
- In violation of the myelination of nerves in the process of intrauterine development.
According to the origin of the pathology, the following types of optic nerve atrophy are distinguished:
- Primary atrophy of the optic nerve, that is, one that has a hereditary (genetic) factor and develops as an independent disease;
- Secondary atrophy of the optic nerve is when a violation of nerve fibers is provoked by the influence of a concomitant disease.
According to the course of the disease, doctors distinguish:
- Stationary atrophy. When the disease progresses slowly, that is, the process of fiber damage and visual impairment remains approximately at the same level for a long time;
- progressive atrophy. A sharp abrupt decrease in vision, a complete loss of visual function can occur in just months.
According to the severity of the pathology can be:
- partial atrophy. The lesion affects only a small part of the nerve, vision has fallen and black spots appear on the image that a person sees;
- Complete. Irreversible blindness caused by the death of the entire structure of nerve fibers.
Diagnosis and treatment
An unambiguous conclusion about the presence of signs of atrophy of the optic nerve can only be made by a doctor after an ophthalmological examination and additional examinations.
First of all, the ophthalmologist or neurologist finds out if the patient has concomitant diseases, asks about what medications he takes on an ongoing basis, whether he comes into contact with chemicals. During a visual examination, the doctor makes sure that the patient does not have exophthalmos and performs standard procedures:
- Visometry – checking visual acuity according to the table;
- Computer refractometry to assess refractive errors;
- Skiascopy (or shadow test) to determine the refraction of the eye;
- Examination of the fundus;
- Test for eye mobility in different directions;
- Perimetry – assessment of changes in peripheral vision;
- Ocular tonometry – measurement of intraocular pressure (IOP);
- Direct ophthalmoscopy.
The examination may also include an electrophysiological method (registration of visual evoked potentials, VEP), which allows using special stimuli to assess the performance of the organ of vision and makes it possible to understand how the brain perceives and reacts to images. The patient looks at the monitor in special glasses, to which flashes and images are fed, on the screen he sees multi-colored cells – a reversal pattern. VEP is usually included in the complex of diagnostic procedures not only for suspected disorders of the visual analyzer, but also for multiple sclerosis and other neurological pathologies.
Which doctor to see?
In addition, the ophthalmologist will likely refer a patient with symptoms of optic nerve atrophy to a neurologist who will recommend x-rays and an MRI (magnetic resonance imaging). In case of detection of neoplasms or with increased intracranial pressure (hypertension), consultation with an oncologist or neurosurgeon is required. In cases where the disease is of an autoimmune nature, for example, caused by systemic vasculitis, a rheumatologist is involved in the treatment.
Methods of treatment
Since most often optic nerve atrophy is secondary, that is, it is not an independent disease, but only a consequence of other disorders in the body, treatment begins with the elimination of the root cause.
Of course, the preservation of visual function is in the first place. Based on this goal, doctors resort to non-specific conservative methods of treatment. Intravenous injections of glucocorticosteroids (GCS), as well as infusions of glucose, calcium chloride and intramuscular administration of diuretics (diuretic drugs) help to remove inflammatory infiltration and edema.
Since the ability of nerve cells to recover is very low, at the initial stage of the development of pathology, treatment can only stop the progression of atrophy, but complete recovery is still impossible. In cases where damage to the optic nerve is caused by serious vascular (atherosclerosis, hypertension), traumatic or toxic effects, the prognosis is extremely unfavorable – therapy may be powerless.
In the absence of contraindications – chronic or infectious diseases in the acute phase, inflammatory processes, diabetes and blood clotting disorders – surgical treatment is possible to eliminate the problem. Revascularization of the posterior eye and optic nerve in atrophy is an intervention aimed at restoring blood vessels. In most cases, revascularization allows you to expand the field of vision and stabilize visual function.
There are many techniques for this operation, in each individual case, the ophthalmic surgeon individually chooses the most appropriate method, based on the history, cause and severity of the disease. This is a minimally invasive operation that takes place on an outpatient basis under local anesthesia and takes no more than 20 minutes.
In the postoperative period, to prevent complications, patients are prescribed antibacterial eye drops. Within 30-45 days, compliance with recommendations will be required, including: limiting visual load and physical activity.
Forecast and prevention
What are the complications of optic nerve atrophy?
If optic nerve atrophy is not diagnosed in time and action is not taken, blindness may develop. In order to prevent this, it is important to treat ophthalmic, neurological, rheumatological, endocrine (hormonal) and infectious diseases in a timely manner.