Pachymetry
Warsaw · Krakow · Vienna · Zurich
Pachymetry is an examination of corneal thickness, or more precisely, a measurement of the corneal thickness at its center, performed non-invasively using a Scheimpflug camera or OCT, or invasively using an ultrasound probe.
Pachymetry in Corneal Diagnostics
Pachymetry is an examination of corneal thickness, or more precisely, a measurement of the corneal thickness at its center, performed non-invasively using a Scheimpflug camera or OCT, or invasively using an ultrasound probe. Pupil dilation is not required for the examination. Corneal thickness assessment is a mandatory examination for patients with glaucoma and ocular hypertension, and it is also performed before surgical procedures, including laser treatments, on the cornea, as well as in the diagnosis of keratoconus and other corneal diseases.
What influences the result of intraocular pressure measurement?
The examination has a fundamental impact on the assessment of intraocular pressure values, as it helps determine whether the measured intraocular pressure is overestimated or underestimated due to the presence of a thicker or thinner cornea.
Types of Pachymetry and Interpretation of Results
It has been shown that patients with corneas thicker than average may have higher pressure, which, however, may not be a cause for concern. Conversely, patients with thin corneas often have underestimated intraocular pressure – the pressure values are artificially lowered.
Contact pachymetry is performed using ultrasonic pachymeters. The examination requires contact between the device’s tip and the patient’s cornea. It is painless because the cornea is anesthetized beforehand with drops. During the examination, several measurements of the central corneal thickness are taken. The results are averaged, allowing for the reading and application of an appropriate correction to the intraocular pressure value.
Non-contact pachymetry is performed as part of corneal tomography using an ultrasound device. In this case, there is no contact between the device and the cornea, which reduces the risk of infection and discomfort. The advantage of this method is that it provides a thickness profile of the entire cornea, allowing for more precise diagnosis of various corneal conditions – in contrast to contact pachymetry, which measures corneal thickness only at one selected point.
NOTE: The results of examinations performed by both methods cannot be used interchangeably. Differences may occur between them due to the application of corrections calculated for a specific measurement method.
The most important thing is to choose the right method for your vision defect. During initial consultations, we will propose the appropriate laser correction technique.
