Ocular tonometry is a diagnostic test used very frequently in ophthalmology. It allows to measure the pressure levels inside the eye, that is, the so-called intraocular pressure (IOP).
Intraocular pressure is the pressure exerted by fluids from within the eye against the walls of the eye. It is a determining parameter that allows diagnosing serious pathologies such as glaucoma. This is very relevant, since if it is not treated it leads to blindness.
Ocular tonometry is a simple and safe test. However, there are different modalities and ways of doing it. In this article we explain everything you need to know.
What is an ocular tonometry?
Ocular tonometry, as we have pointed out in the introduction, is a test performed by ophthalmologists. It consists of measuring intraocular pressure. It is done indirectly, using an instrument called a tonometer .
Intraocular pressure is the pressure exerted by the fluids present within the eyeball against its walls. These liquids are the vitreous humor and the aqueous humor. The eyeball is a firm structure that cannot be overstretched.
Hence, when the amount of liquid inside increases, the pressure increases. It is considered normal when the measurement is between ten and twenty millimeters of mercury. This is explained in an article by the American Academy of Ophthalmology .
If the pressure rises above this figure, we speak of hypertension of the eye . This can damage the cells of the optic nerve. Ocular tonometry is considered the most useful test for the diagnosis of glaucoma.
However, there are factors that may condition the outcome of the study. Therefore, it is not considered a definitive test, but an estimate. One of the elements that affects the procedure is the thickness of the cornea; the thicker it is, the higher the pressure figures are likely to be.