There are several eye exams to assess eye health and quality of vision. One of them is campimetry, also known as perimetry. It consists of a measurement of the visual field, that is, the part of space that an eye is able to see by keeping its gaze on a fixed point.
A simple exam that is not painful
The exploration of the visual field is carried out in a monocular way. Thus, the measurement of each eye is performed separately. In its realization, the patient needs to look at a reference point located on the field meter screen. In this way, the center of the visual field coincides with the fixation point and with the center of the macula. Campimetry
Visual field measurement is performed in degrees and with two possible variants: central and peripheral visual field. The first varies in each patient and usually decreases over time. The second surpasses the central 30 degrees and requires more time to analyze it.
Currently, this type of study is carried out using computerized technology . Thus, through light stimuli, one can detect a person’s ability to see .
This exam requires the patient to be in a room with the light off. Then, the patient rests his chin on the device and looks at the colored dots that appear on the screen. As the dots of light appear, it is necessary to press a button to indicate what has been seen. Campimetry
Once the data is obtained , the campimetry provides general information on the state of the patient’s visual field. The main data collected are as follows:
1) the visual field index quantifies the percentage of the patient’s field relative to age-matched individuals with normal parameters (parameters range from 100% in a normal field to 0% in the case of a blind person);
2) the mean deviation represents the mean height of the “hill of vision” and shows the depression or elevation of the global visual field in relation to normal parameters;
3) the standard deviation model shows the surface irregularities of the patient’s “hill of vision” in relation to normal patients.
With this exam it is possible to detect glaucoma
The study of the visual field is normally carried out in cases in which the existence of glaucoma in the patient is suspected, since campimetry detects the scotomas associated with this ocular pathology. This exam is also performed to assess the visual cortex, the optical pathway or even possible neurological damage. Campimetry