Vision becomes smaller

Introduction The reduction of visual acuity is a kind of perceptual comprehensive disorder. The optic nerve degeneration caused by various reasons loses the conduction function, resulting in blurred or even blindness. If you look at the object image is much smaller than the real thing.

Cause

1. Hemorrhagic shock caused by acute hemorrhage: the blood pressure is too low, so that the blood supply to the small blood vessels on the optic disc is insufficient, blood circulation disorder occurs, and infarction occurs, and local tissue is hypoxic.

2. Vascular diseases such as hypertension, arteriosclerosis, diabetes, and sputum arteritis: The blood vessel wall changes, the blood vessels are narrowed or occluded, and the small blood vessels of the optic disc are also changed, causing ischemia.

3. Severe anemia: Reduce blood oxygenation; increase blood viscosity, such as polycythemia, leukemia, etc. due to slow blood circulation, resulting in hypoxia of the optic disc.

4. Increased intraocular pressure in glaucoma: the small blood vessels of the optic disc are compressed, causing poor blood flow and insufficient blood supply.

5. Vasculitis: giant cell arteritis, nodular polyarteritis, systemic lupus erythematosus, Buergers disease, allergic vasculitis, post-viral vasculitis, post-immunization, syphilis, radiation necrosis.

6. Systemic vascular disease: hypertension, atherosclerosis, diabetes, migraine, arteritis, carotid artery obstructive disease.

7. Blood diseases: polycythemia vera, sickle cell disease, acute hypotension.

an examination

1, fundus examination:

The optic disc is mostly small, and the physiological depression is not obvious.

2, the macular area:

Usually not damaged, so central vision disorders are sometimes not very heavy.

3, fundus performance:

For mild optic disc edema, the border is more blurred, the optic disc can have localized color fade areas, there may be some localized flaming hemorrhage around the optic disc, retinal vascular changes are not very obvious, a few retinal arteries are slightly thin, in some monocular episodes The patient can also observe the contralateral eye, although the visual function is normal, but it may also manifest as optic disc edema, which may worsen after a long time, and the visual function declines.

4, after the optic disc edema subsided:

The border is still very clear, but a certain area of the optic disc may be slightly lighter or paler, sometimes manifesting as optic disc edema and optic atrophy in the other eye.

5, visual field defect:

It is quite special. If you carefully check the perimeter and central vision, you can often find its typical visual field changes.

Differential diagnosis

Differential diagnosis of visually impaired symptoms:

(1) temporal lobe epilepsy clinically common visual objects become larger, visual objects become smaller, and visual objects are deformed. This kind of perceptual change usually occurs in the onset of the disease, or it may be a precursor to an episode. The patient feels that the object being viewed becomes larger, sometimes smaller, sometimes farther away, and sometimes close, and more complex when there is a visual distortion. The above performance often affects the behavior of the patient.

(2) Schizophrenia can be disintegrated in reality, and it is a manifestation of the comprehensive barrier of spatial perception. The patient's feelings about the attributes of the outside world have not changed, but the impression of the external things is not vivid, not obvious, often unclear, such as barriers, illusory, lack of realism.

(3) Epidemic encephalitis B (epidemic encephalitis B) In its acute phase, high fever louvers above 40 °C, may have varying degrees of disturbance of consciousness or even coma, resulting in mental symptoms, which may appear larger, visually smaller Perceptual comprehensive obstacles such as visual distortion. As the disturbance of consciousness improves, the perception barrier can quickly disappear.

(4) Cocaine and alkaloid poisoning cause metabolic disorder of cortical sensory cells and conductive fibers in patients, and there are perceptual comprehensive obstacles such as visual distortion and enlarged objects.

The patient's subjective feeling can be diagnosed.

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