Pachymetry

Pachymetry is the process of measuring the thickness of the cornea. It can be done using contact methods, such as ultrasound and confocal microscopy, or noncontact methods such as optical biometry, Optical Coherence Tomography and online Optical Coherence Pachymetry (OCP). Pachymetry is essential prior to a LASIK procedure for ensuring sufficient corneal thickness to prevent abnormal bulging of the cornea, a side effect known as ectasia.

The instrument used for this purpose is known as a pachymeter. With the use of Corneal Waveform (CWF) we can capture an ultra-high definition echogram of the cornea. Pachymetry using the corneal waveform process allows us to more accurately measure the corneal thickness, verify the reliability of the measurements that were obtained, superimpose corneal waveforms to monitor changes in a patient's cornea over time, and measure structures within the cornea such as micro bubbles created during femto-second laser flap cuts.

Pachymetry is also considered an important test in the early detection of glaucoma. In 2002, the five-year report of the Ocular Hypertension Study (OHTS) was released. The study reported that corneal thickness as measured by corneal pachymetry was an accurate predictor of glaucoma development when combined with standard measurements of intraocular pressure. As a result of this study and others that followed, corneal pachymetry is now widely used by both glaucoma researchers and glaucoma specialists to better diagnose and detect early cases. Newer generation pachymeters have the ability to adjust the intraocular pressure that is measured according to the corneal thickness.