Currently, the most accurate and common method of accurate diagnosis of pathology of the optic nerve is computer perimetry. For its implementation, an electronic computer perimeter is used. The device is a spherical perimeter combined with a computer. The study program and the parameters of light objects are set by a medical professional or are set automatically, depending on the need.
After the end of each examination session, the computer displays the results in the form of a summary chart, which the ophthalmologist will have to decipher. The result looks like a three-dimensional chart on which the boundaries of the field of view are indicated by numbers. After drawing on such a map (which in ophthalmology is also called the “visual hill”), you can see where the patient’s visual field boundary ends.
Indications for computer perimetry:
- presence of diseases of the optic nerve
- retinal dystrophy
- a brain tumor
- head injuries
- circulatory disorders
THE VALUE OF COMPUTER PERIMETRY IN GLAUCOMA
- Allows you to detect changes associated with glaucoma at the earliest stages;
- It helps to assess the boundaries of the visual field, which often narrow as a result of increased intraocular pressure;
- Due to its high sensitivity, it reveals even small defects in the central field of view, which may still not manifest themselves in determining visual acuity;
- Allows you to save the results in computer memory or in hard copy and compare them with subsequent tests, watching the dynamics.
DESCRIPTION OF THE METHOD
- You will be asked to sit on a chair in front of the device.
- Before the examination, one eye will be closed with a bandage.
- The device has a chin rest and forehead rest, so that you can comfortably fit and fix your head in a position that is optimal for the examination.
- Inside the hemisphere there is a special mark on which it will be necessary to fix the look.
- The study is performed with good vision correction, therefore, if you are not wearing glasses or contact lenses, a special frame is usually provided in the perimeter for installing corrective glasses with the necessary diopters. With light degrees of myopia, hyperopia and astigmatism, correction is not required.
- The health worker will enter your data and install the desired program. Always follow his recommendations (you may be asked not to blink for a few seconds, etc.).
- During testing, you will be required to press a button on a special remote control as soon as you notice a light object. Depending on the type and purpose of the study, objects may move or remain motionless.
- The duration of computer perimetry will also depend on the selected program (from 8 to 15 minutes).
- If during the study you noticed that the lighting inside the device becomes brighter, it dims, do not worry. Continue to perform the test - this is due to the peculiarities of the visual system and the operation of the instrument.
- While checking the visual fields, you cannot turn your head and take your eyes off the point of gaze fixation you specified - all this will reduce the reliability of the study.