Campimetry is an ophthalmological examination performed by the ophthalmologist to assess the quality of life. These patients are limited in their ability to perceive the central and peripheral visual field, and is mainly indicated for the diagnosis and follow-up of the treatment of glaucoma.
Campimetry, which is also known as visual field examination, can also be performed to identify changes in the visual field and retinal diseases, such as diabetic retinopathy, macular degeneration or edema, retinitis pigmentosa, tumors or retinosis, for example.
The campimetry exam can be carried out free of charge by the SUS, as long as it has a medical indication, but it is also carried out in private examination clinics, and the results must be analyzed by the ophthalmologist, who may also indicate the performance of other complementary examinations to evaluate the structures of the eyes, such as the OTC test or corneal topography, for example.
When is indicated
Campimetry is mainly indicated to diagnose and monitor the evolution and response to treatment of glaucoma , but it can also be used to diagnose and monitor other situations such as:
- Macular degeneration;
- macular edema;
- Retinitis pigmentosa;
- Changes in the optic nerve, such as papilledema and papillitis;
- Neurological problems such as stroke or brain tumors;
- Eye pain;
- Drug intoxication;
- Changes in the field of view.
In addition, perimetry should be performed when there is a diagnosis of hyperthyroidism, multiple sclerosis, diabetes, high blood pressure, or pituitary diseases, as it allows checking for changes in the visual field.
Types of perimetry
According to the way the test is performed, perimetry can be classified into three main types:
1. Computerized perimetry
Computerized perimetry, also called computerized perimetry, is performed using an electronic device, with no operator interference, and generally provides a more accurate diagnosis, and can be performed on one or both eyes.
2. Kinetic Campimetry
Kinetic perimetry uses equipment with a light source that is in motion, being displaced at different angles, which is perceived by the person.
3. Static perimetry
In static perimetry, the equipment with the light source remains stationary, without moving, emitting different light stimuli, and the person must click on a button on the device each time he identifies the luminosity.
4. Manual perimetry
Manual perimetry encompasses kinetic perimetry and static perimetry, as it is performed based on the commands of a trained professional.
In general, manual perimetry is indicated to identify problems in more peripheral vision and to assess people with great loss of visual acuity, the elderly, children or debilitated people who have difficulty following the device’s commands.
How is campimetry done?
Visual perimetry is performed with the person sitting down and with their face glued to the measuring device, called a perimeter, which emits points of light in different places and with different intensities in the patient’s field of vision.
During the test, a light at the back of the device is emitted so that the person keeps the vision focused on it. Thus, he will have to press a bell as he manages to identify the new points of light that appear, but without moving his eyes to the sides, finding the lights only with his peripheral vision.
The perimetry exam is simple and does not cause pain, lasting about 10 to 20 minutes, depending on the person’s collaboration. It is not necessary to prepare to perform this exam, it is only indicated that people who are being treated for glaucoma suspend the medication pilocarpine about 3 days before the exam, according to the doctor’s guidance.
Also, people who wear contact lenses do not need to remove them for the exam, but they should always remember to bring the last doctor’s prescription for the eyeglass prescription.