The fluid, which is located in the anterior chamber, in the posterior chamber, as well as in the vitreous body of the eyeball, exerts some pressure on the walls of the eye itself. In view of the fact that both chambers are non-insulated cavities, they communicate with each other through the pupil orifice, and from the vitreous body the posterior chamber is separated only by a very flexible zinc ligament. Therefore, if the pressure in these three cavities varies, then this difference quickly equalizes. All this allows us to consider the eye as a single cavity filled with intraocular fluid. The pressure that this fluid exerts on the walls of the eye is called intraocular, or eye strain, i.e. his ophthalmotonus.
Eye pressure, the norm of which is determined by the ratio between the capacity of the eyeball and the amount of its contents, may vary somewhat during the day, and this will not be a pathology. Blood pressure has a huge effect on the origin of such magnitude as eye pressure. The norm of arterial tone is 120/80 mm Hg. Art. This is due to the community of blood vessels that nourish the eye. However, there is no complete parallelism between blood pressure and ophthalmotonus in the sense that the higher the first value, the higher and the second, no. Eye pressure, the norm of which varies from 18 to 24 mm Hg. Art., largely independently. This is because the local blood pressure in the organs is regulated independently and not always in parallel in large vessels. The sinuous course of the adducting vessels and their very small caliber soften the pressure of the pulse wave in the eye. On the other hand, a small number of large venous trunks greatly facilitates the outflow of blood from the eye, preventing the formation of venous stasis in this structure. There is another factor that greatly reduces the pressure of blood pressure on the eye. This is the osmotic pressure of protein fractions of the blood.
As noted above, there are daily fluctuations that have eye pressure, the magnitude of such fluctuations do not exceed 3-5 mm RT. Art. Anything that goes beyond this range is defined as low or high eye pressure. And this is a pathological condition. The first change is called hypotension or hypotension, and the second - hypertension, glaucoma. Eye strain can be determined tentatively, using finger research, as well as using special devices, in particular a Maklakov tonometer. When measuring intraocular pressure with an eye tonometer, the eye should first be anesthetized, because the instrument will be placed directly on the cornea, which is the most sensitive part of not only the organ of vision, but also of the whole organism. For reliability, several samples are taken from one eye. To make the indicator shade, use special dyes based on solutions of silver (collargol) or other substances. To fix the data, the impression of the site left by the cornea of ββthe eye is applied to paper previously rubbed with cotton wool moistened with alcohol. The image must be allowed to dry well so as not to smear it. Then, the level of intraocular pressure is determined by special rulers. The narrower the area, the therefore, the ophthalmotonus is higher, and, conversely, the wider the area of ββthe print, the lower the eye pressure. At the present stage, there are more convenient methods for determining ophthalmotonus, for example, non-contact tonometry. However, the contact method is still very relevant and, most importantly, an effective way to measure eye strain.
If high levels of eye pressure are found, a detailed examination is carried out, which includes their daily monitoring. If elevated ophthalmotonus is constantly fixed, then glaucoma is diagnosed. It can lead to a gradual loss of vision. In order not to cause complete blindness, high eye pressure from the patient (only a specialist can determine how to treat it) requires an immediate, adequate response to the eye condition, composure and patience.