What is the perimetry of the eye

The device of the human eye allows you to view objects at close and long distances, to see objects located on a straight line of focusing and away from it. Usually no one thinks, so that he can navigate in space. However, it is the possession of peripheral vision that gives us this opportunity. When the eye focuses on a particular object, it is called the central vision. But the ability to see and feel objects on the sides of the focus is usually called peripheral perception. The human eyes in the forces cover the sector approximately 180˚ in the horizontal plane and about 130˚ in the vertical plane. These characteristics are called visual fields.

The limitation of such fields can occur due to a variety of reasons: increased IOP, damage to the retina, intracranial injuries, vascular pathologies, However, in most cases the cause is still in the development of age-related glaucoma, caused by a gradual increase in IOP.

In the study of the pathological symptom, the most objective measure of the degree of progression of the disease becomes the perimetry method-the study of the visual fields.

When is the

The importance of peripheral perception of objects is enormous, although some may not think about their significance.After all, the central vision allows you to perceive only those objects that are in the zone of the focused visual beam, otherwise - to which the view falls. One can compare the presence of only the central vision with the examination of objects through the tubes.This vision will not allow you to navigate in space and avoid unpleasant surprises.

Sometimes there may be a local restriction. In the field of view there is an unclear spot when trying to examine objects in a certain direction. Such an ambiguity can be localized in the form of a fogging or black spot.

If you want to test your peripheral vision on your own, then spread your hands to the sides and move your fingers.If your eyes catch movement, then everything is fine. With limited perception it is worth to see the doctor.

What diseases say about the violation

The list of all possible causes of an alarming symptom includes various pathological conditions of the eyes or the whole organism:

• Retinal disinsertionappears as a result of severe short-sightedness, retinal dystrophy, eye trauma. In addition to falling out of the fields of vision, a distorted perception of lines and forms arises, and blurredness may appear;
• Increased pituitary glandis usually characterized by a limited vision in the outer (from the temple) sites;
• Glaucomagives the following effects: an impermeable or transparent "veil" from the side of the nose, glowing halos around the light sources, misting. Perhaps concentric narrowing of the fields, but before all the same, central vision deteriorates;
• Macular degeneration- pathology of the vascular system, resulting in the majority of cases suffering from central vision. The perception of the shape and size of the image may be impaired;
• Retinal dystrophy, most often, accompanied by a concentric narrowing of the visual fields while maintaining high indicators of the central perception of objects;
• Vascular sclerosisthe brain causes a disturbance in the nutrition of the optic nerve, which invariably leads to concentric constriction, a decrease in central vision, dizziness, and a partial loss of memory.

The narrowing of the fields of vision is evidence of the progression of serious eye diseases or the body as a whole. These disorders occur, most often due to age-related causes, which indicates the need and importance of preventive examinations for the elderly.

More rare causes of the onset of an anxiety symptom may be neurological pathologies, atherosclerotic changes, hypertension, diabetes, blood loss, poisoning nitrogen, hypoxia.

Types of violations

Almost always the diagnosis is established depending on the characteristics of the revealed pathological condition. To describe the loss of visual fields, as a rule, several defining terms are used:

• Concentric.The restriction of sight is observed from all sides from the central perception and can be either weakly expressed or close to a significant narrowing when a person looks as if through a pipe. Such a symptom is characteristic of lesions from the nervous system (neurosis, neurasthenia, etc.) ), as well as for eye diseases (glaucoma, optic nerve atrophy, etc.) );
• Local.Narrowing of perception occurs only in any particular area: in the outer or inner part, the upper or lower. At the same time, in the remaining areas, the field of vision is not detected;
• Scotoma.The appearance of spots in the field of view, the boundaries of which do not coincide with the boundaries of peripheral vision. Such spots can be of various shapes and colors, while their permeability can range from easy misting to the darkest color.

With the greatest degree of reliability, the perimeter method of the eye helps to establish the true cause of the limitation of the visual fields.

Possible complications

The narrowing of the fields of vision always indicates the development of severe pathological processes in the eyes associated with either the atrophy of the optic nerve or the impaired functionality of the retina.And that, and another phenomenon carries a potential threat of complete blindness. Therefore, any abnormalities identified in the field of vision studies should be diagnosed.And after this, it is urgent to begin treatment.

Diagnostics

To study the functionality of the visual fields, the following several methods are used:

• Touching the screen;
• Goldman's perimeter;
• Automated perimetry;
• Microperimeter.

However, the most common is the perimeter of the Ferster: a metal semicircular arc, painted black. On the outer surface there are fissions, which denote degrees. With the help of objects (glued to the black sticks of white paper circles) determine the nature of the fallout of the visual fields, both in the horizontal and in the vertical plane.

When using perimeters, two main research methods are used:

• Kinetic perimetry. The study is carried out by moving white or colored objects from the periphery to the center, while the doctor on a special scheme marks the limits of light perception in each sector. The survey uses projection or desktop perimeters;
• Static perimetry. It is carried out by means of changing the degree of illumination of the object. More often such research is spent on special devices. The patient looks at a certain point located in the perimeter, and presses the button when the illumination force makes this point visible to him. All indications are fixed automatically, and at the end of the procedure the doctor is given the result;
• The Donders Method. The research is conducted without involving instruments. The doctor sits opposite the patient and closes the left eye, and the patient - the right eye. The doctor begins to move his fingers, placed between the open eyes - his and the patient. If the object disappears from the field of view simultaneously, then this indicates the absence of pathology. In this case, the physician's field of vision is the control to detect abnormalities in the patient.

Medication Therapy

Conservative treatment is used in the treatment of glaucoma, atrophy of the optic nerve.In these cases, special drugs are used that can effectively reduce IOP and alleviate symptoms.

When diagnosing ciliated cattle due to the narrowing of the cerebral vessels, treatment with antispasmodics is indicated.

Surgical methods

Operative intervention is resorted to in the most serious cases, with the detection of extensive and severe lesions:

• Retinal disinsertion;
• Progressive throat;
• Cataract;
• Intraocular tumor.

Narrowing of the fields of vision is a very serious symptom, most often indicative of the development of severe eye pathology. Therefore, if there are even weak manifestations of a restriction in visual acuity or peripheral perception of objects, it is necessary to undergo an emergency examination.

Prevention

Most of the narrowing of the fields of vision is associated with two systems: the nervous and circulatory systems.Therefore, in addition to an ophthalmologist, it is worthwhile to constantly undergo a survey with a neurologist or neurologist. Particular attention to overall health should be given to people with high blood pressure or a tendency to increase it.

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conclusions

Any organ in the human body is inextricably linked to other organs and systems, so the health problems of the whole organism can be reflected in the eyes, and in the most unexpected way. And one of such symptoms is the narrowing of the fields of vision.

The method of perimetry allows to detect the beginning of changes in the functioning of the eyes at the earliest stages, and together with it to reveal the cause, most often - a serious disease. Thus, an early examination allows you to start treatment on time and provides the highest chance of success.

Also read about methods of diagnosing visual acuity through tables and visometry.