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 Brief
- What it is: measurement of corneal thickness at its center and periphery – non-invasively (tomography, Scheimpflug camera) or with an ultrasound probe
- Why it’s done: determines if and by which method a refractive error can be safely corrected with a laser (how much tissue can be removed), corrects intraocular pressure measurement in glaucoma, monitors keratoconus
- Norms: average central thickness is approximately 520–560 micrometers; a thinner cornea does not rule out the procedure but changes the choice of method
- How it’s performed: a few dozen seconds, without pupil dilation, painlessly
- Price: At SwissLaser, we perform it as part of a comprehensive qualification examination (400 PLN, approximately 90 minutes, Warsaw and Krakow), which includes a complete set of measurements needed before the procedure.
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 step is to choose the appropriate method for your vision defect. During the initial consultation, we will propose the suitable laser correction technique.
Frequently Asked Questions
How much does pachymetry cost?
At SwissLaser, we perform pachymetry as part of a comprehensive qualification examination for 400 PLN, along with corneal topography, OCT, and biometry – in Warsaw and Krakow.
What is the normal corneal thickness?
On average, 520–560 micrometers in the center. A cornea below approximately 500 micrometers requires more careful planning of the laser procedure – we often choose a tissue-sparing method then, such as Trans-PRK, or an ICL phakic lens.
Is pachymetry painful?
No. Non-contact measurement takes a few dozen seconds; the ultrasound variant only requires anesthetic drops and a gentle touch with the probe.
Why is pachymetry important in glaucoma?
Corneal thickness affects the result of intraocular pressure measurement: a thick cornea overestimates, a thin one underestimates the reading. Without pachymetry, pressure can be misinterpreted.
Does a thin cornea rule out laser correction?
Not always. The relationship between thickness and the extent of the defect, as well as corneal regularity in topography, is decisive. With a thin but normal cornea, a surface method is often possible; with a very thin one – a phakic ICL lens.
All examinations are performed in Warsaw (ul. Kolejowa 1) and Krakow (ul. Kluczborska 15/U3). Diagnostic overview: eye examinations; what happens next: qualification for the procedure.
