Concentric narrowing of the field of view
Introduction
Introduction If there is a large defect directly to the edge of the visual field, the outer edge of the defect has no normal vision, that is, the field of view is reduced, and the uniform adduction in the visual field in each direction is the central isopter constriction. The narrowing of the visual field is divided into functional and organic. Since intact myelin is the basis for rapid treaty-based conduction of the electrical signals of the optic nerve, loss of myelin leads to a significant slowing of the visual electrical signaling of the optic nerve, leading to significant visual impairment. As the disease progresses, the myelin sheath gradually repairs and the visual acuity gradually returns to normal.
Cause
Cause
The cause is more complicated:
1, inflammatory demyelination: is a more common cause. The exact cause of inflammatory demyelinating neuritis is unknown. It is probably due to certain precursor factors such as respiratory or digestive tract virus infection, mental attack, vaccination, etc., causing the body's autoimmune response, producing autoantibodies to attack the optic nerve. Lost and become sick. Since intact myelin is the basis for rapid treaty-based conduction of the electrical signals of the optic nerve, loss of myelin leads to a significant slowing of the visual electrical signaling of the optic nerve, leading to significant visual impairment. As the disease progresses, the myelin sheath gradually repairs and the visual acuity gradually returns to normal. This process is similar to the pathophysiological process of multiple sclerosis in the nervous system sheath disease; optic neuritis is often the first symptom of MS, often accompanied by clinical or clinical lesions of white matter, and some patients eventually convert to multiple sclerosis.
2, infection: local and systemic infections can affect the optic nerve, leading to infectious optic neuritis.
1 Local infection: Intraocular, intraorbital inflammation, oral inflammation, middle ear and mastoiditis with intracranial infection, etc., can be directly caused by local spread of optic neuritis.
2 systemic infection: some infectious diseases can cause optic neuritis, such as: diphtheria (diphtheria), scarlet fever (streptococcus), pneumonia (pneumococcal, staphylococcus), dysentery (dysentery), typhoid fever (typhoid bacillus), tuberculosis (Mycobacterium tuberculosis), purulent meningitis, sepsis and other systemic bacterial infectious diseases, the pathogens can enter the bloodstream, grow and reproduce in the blood, release toxins, causing optic nerve inflammation. Viral diseases such as influenza, measles, mumps, herpes zoster, chickenpox, and other parasitic infections such as Lyme spirochete, Leptospira, Treponema pallidum, Toxoplasmosis, Toxoplasmosis, Coccidiosis, etc., all cause optic neuritis Report.
3, autoimmune diseases: such as systemic lupus erythematosus, Wegener granulomatosis, Behcet's disease, Sjogren's syndrome, sarcoidosis, etc. can cause non-specific inflammation of the optic nerve. In addition to the above reasons, about one-third to half of the clinical cases can not find the cause; some of the patients may be Leber hereditary optic nerve.
Examine
an examination
Related inspection
CT and optic nerve examination in the eye and temporal region
The onset is sharp. If the internal vision is highly degraded, and even the degree of no light perception can be caused, when the visual acuity is severely reduced, the pain symptoms disappear. The measurement field of view can also be diagnosed.
Diagnosis
Differential diagnosis
Differential diagnosis of visual field narrowing symptoms:
1, ischemic optic neuropathy
The vision is suddenly lost, there is no pain during eye movement, the optic disc swelling tends to be grayish white, and the visual field defect is most commonly divided. In the axis of ischemic optic neuropathy caused by giant cell arteritis, the patient is older than 50 years old, more common in 70 years old, erythrocyte sedimentation rate and C-reactive protein difference can help differential diagnosis; pulmonary arteritis (AION is more common in 40-60 years old, Most of the medical history can also lead to risk factors for atherosclerotic vascular disease, such as hypertension, hyperlipidemia, diabetes, and history of precipitated smoking.
2, Leber optic neuropathy
Men who often occur in teens or twenties, with or without family history. At a glance, the eyesight quickly became a city, and then another eye was in the summer to a few months. There may be capillary retraction along the optic disc, optic disc edema, followed by optic atrophy; mitochondrial DNA point mutation examination can help differential diagnosis, most of which show 178 point mutations, there may be 3460 and 14484 point mutations.
3. Toxic or metabolic optic neuropathy
Progressive painless bilateral vision loss, may be secondary to alcoholism, malnutrition, various toxins such as ethylamine, chloroquine, isoniazid, chlorpropamide, heavy metals, and anemia.
Other optic neuropathy, such as pre-exposed tumors that cause optic neuritis, should be noted for identification.
The onset is sharp. If the internal vision is highly degraded, and even the degree of no light perception can be caused, when the visual acuity is severely reduced, the pain symptoms disappear. The measurement field of view can also be diagnosed.
