Pachymetry can be used to measure the corneal thickness of the human eye. The examination can be carried out without contact or using an attached ultrasound probe. Pachymetry is used to plan eye surgery, but also for the early detection and assessment of various corneal diseases.
Here you will find further information and selected pachymetry specialists.
Pachymetry is an ophthalmic diagnostic procedure for measuring the thickness of the cornea of the eye. As part of the outer skin of the eye, the cornea forms the front, translucent protective layer of the eye. It is, so to speak, the "windshield of the eye".
If various diseases are suspected, such as
this examination technique is essential. In addition, the thickness of the cornea has a significant effect on the results of other eye measurement procedures. This also includes the determination of intraocular pressure.
Precise knowledge of the corneal thickness is also important in the run-up to various surgical procedures. Pachymetry is therefore an extremely important diagnostic tool.
Pachymetry can be used for various purposes. It is usually only necessary to measure corneal thickness once in the course of treatment. It may be indicated again if
One of the functions of the cornea is to refract incoming light through its curvature. If the thickness or curvature of the cornea changes, the refraction of light is different. This in turn influences visual acuity.
Pachymetry allows the corneal thickness to be measured precisely. This allows conclusions to be drawn about existing diseases. If treatment is initiated at an early stage, some diseases can be stopped in time.
The pressure in the eye, i.e. the intraocular pressure, gives the eye its evenly curved shape. This is essential for the eye to function correctly. Abnormal intraocular pressure can lead to diseases and visual impairment. One dreaded condition is glaucoma, chronic optic nerve damage due to increased intraocular pressure.
Intraocular pressure can be determined by exerting a defined external counter-pressure on the eye. However, the effects of external pressure on the eye are influenced by the thickness of the cornea. The results of the intraocular pressure measurement vary depending on the thickness of the cornea.
On average, the cornea has a thickness of 550 µm = 0.550 mm in the center. However, the cornea can also be significantly thicker and therefore less flexible. The measurement of intraocular pressure would then falsely result in a higher intraocular pressure.
For this reason, the thickness of the cornea must first be measured precisely using pachymetry. Once this value is known, the pressure measurement on the eye can be corrected upwards or downwards if necessary.
A minimum corneal thickness is required for various eye operations to improve vision. The refractive power of the cornea can be adjusted using laser treatment, thereby correcting defective vision.
During laser treatment, corneal tissue is removed. It is therefore essential to measure the thickness of the cornea beforehand using pachymetry. This is the only way to recommend or advise against laser treatment. The mechanical stability of the cornea must still be ensured after the operation.
A certain corneal thickness is also essential for the treatment of keratoconus using cross-linking. In this procedure, the cornea is cross-linked in order to stabilize the thinned cornea. However, this procedure is only possible with a minimum corneal thickness of 400 µm. Otherwise, a corneal transplant, e.g. in the form of a deep anterior lamellar keratoplasty (DALK), may be necessary.
Other corneal surgery procedures also require a certain corneal thickness. Or they require precise knowledge of the thickness and condition of the cornea for planning purposes.
Pachymetry is painless and provides results accurate to a few micrometers.
The measurement can be carried out optically without contact using a so-called optical coherence pachymeter. Otherwise, an ultrasound examination is used. A small ultrasound probe is then placed on the cornea.
Sometimes a complete thickness profile over the entire cornea may be necessary. This results in a kind of "thickness map". This can be done optically without contact using Scheimpflug imageswith the so-called Pentacam, for example.
Risks and side effects of the procedure are not known.
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Pachymetry is available to all patients in Germany as an optional diagnostic procedure. However, statutory health insurance companies only cover the full cost of this examination in very rare cases. However, the costs are considered affordable.
Private health insurance companies are more likely to cover the costs. Patients should always enquire in advance with their insurance company about the assumption or sharing of costs.
Nevertheless, it is often worth having a pachymetry performed. If glaucoma is suspected, the diagnosis can be refined by precisely measuring the intraocular pressure. This allows countermeasures to be initiated at an early stage.
For this reason, pachymetry is now an integral part of many diagnostic procedures or intervention planning.
Pachymetry performed by an ophthalmologist © bigguns | AdobeStock
The ophthalmologist can decide on further treatment options once all the examination results are available.
Pachymetry is often performed as part of other diagnostic procedures. In their entirety, they aim to either rule out or detect various eye diseases.
Accordingly, pachymetry is an important (auxiliary) procedure for diagnosis and thus, if necessary, for prevention, but also for the preparation of surgical interventions on the eye.
