METHODS FOR DIAGNOSING AGE-RELATED MACULAR DEGENERATION. AMSLER TEST

09.07.2019

Age-related macular degeneration (AMD) is a chronic progressive disease. It is characterized by damage to the central zone of the fundus – the macula, or yellow spot.

Age-related macular degeneration is a bilateral disorder of the retina. In about 60% of cases, both eyes are affected, however, the retina is affected and the lesion progresses actively in one eye As a rule, the patient does not immediately notice vision problems, since at the initial stage, the better seeing eye takes on all the visual load.

Age-related macular degeneration can be diagnosed early. For people with risk factors (age 55-80 years, gender (women get the disease twice as often), smoking, heredity, cardiovascular diseases), examination by an ophthalmologist 1-2 times a year should be considered as normal. Diagnosis of AMD is based on data from anamnesis and special examination.

The primary complaints of a patient with AMD are:

· The appearance of dark spots in the central vision (scotomas);

· Loss of letters when reading;

· Blurred images;

· Distortion of objects (metamorphopsia);

· Deterioration in colour perception;

· Weakening of vision in the dark and in low light.

Some signs of AMD may appear before the actual moment of deterioration of vision, but only a substantive examination of the eye will help to identify them in time.

Ophthalmic examination methods include:

· examination of visual acuity;

· visocontrastometry (examination of visual functions);

· refractometry;

· examination of the central visual field;

· ophthalmoscopy (checking visual acuity, fundus condition);

· A and B-scanning (with insufficiently transparent optical media of the eyes, with subretinal hemorrhage).

For differential and clarifying diagnostics, the patient can be sent to highly specialized diagnostic centers, where a complex of clarifying diagnostic techniques is carried out:

· visocontrastometry;

· computerized microperimetry (examination of the visual field);

· fundus microperimetry;

· colour photography of the fundus;

· optical coherence tomography (OCT), a study that scans individual layers of the retina;

· fluorescence antiography (FAG) (with the help of intravenous fluorescein injection, it determines changes in the structure of the retinal vessels);

· electrophysiological studies (EPI)

The simplest way to determine the presence of AMD is the Amsler test. Amsler lattice or grid.

Amsler grid is a sheet of paper where a square is drawn on a black or white background, lined into 400 small squares. In the center of the grid there is a black dot on which the subject focuses his/her gaze. All grid lines are parallel and even, and the angles are straight. For the convenience of the procedure, the patient can print out the Amsler test.

Conditions for the Amsler test:

1. Conduct the test only when you are healthy and do not feel tired. It should be borne in mind that factors such as chronic stress, alcohol and certain medications may affect the test result;

2. If you constantly wear glasses or contact lenses, check their cleanliness and transparency, and only then put them on;

3. The room where the test is carried out should have good lighting (it is better if it’s natural);

4. During the study, do not squint your eyes or tilt your head. In addition, you cannot move your gaze from the central point of the chart;

5. You need to start the study with the eye that sees best.

How to test your vision with the Amsler grid:

1. Sit comfortably in a chair;

2. Position the Amsler grid so that the distance between it and your eyes is approximately 25-30 cm;

3. Put on lenses or glasses if you wear them;

4. Cover one eye with a sheet of opaque paper. Never press your hand over your eye, as this can give a false positive result;

5. With your other eye, look at the dark dot in the center of the grid and focus on it for 3-5 seconds;

6. Now slowly approach the grid, without taking your eyes off the central black dot, until the distance to the chart is approximately 20 cm;

7. Analyze the picture in front of your eyes: is there any distortion of lines and angles? Are all squares of the same and regular shape? Are there any places in the chart that seem vague or hazy to you ?;

8. Then repeat the same steps for the second eye.

How to evaluate the result:

If you saw a perfectly clear image, in which all the lines run parallel, the squares are the same, and the angles are straight, then you have normal vision and there are no signs of macular dystrophy. If the image is distorted, then it is necessary to urgently visit the ophthalmologist’s office.

Due to the fact that the Amsler test does not take much time and money, it is convenient and easy to use, we strongly recommend that patients with AMD regularly use it at home.

Early detection and treatment of AMD to stop visual impairment can preserve patients’ quality of life and independence.

This publication has been prepared with the support of the Presidential Grants Fund

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