Pachymetry

Pachymetry is a simple, painless test that measures the thickness of your cornea — the clear window at the front of the eye. Corneal thickness is an important measurement because it can influence eye pressure readings. A thin cornea may indicate a higher risk for glaucoma, while corneal thickness measurements are essential for surgical planning.

There are two main types of pachymetry: ultrasonic and optical. Ultrasonic pachymetry uses a small probe that gently touches the surface of the eye after numbing drops are applied. The probe emits sound waves that bounce off the back of the cornea, and the device calculates thickness based on how long the sound takes to return. Optical pachymetry uses light instead of sound and does not require any contact with the eye. Both methods are quick, taking only seconds per eye, and are completely painless.

Pachymetry is especially important in glaucoma diagnosis and management. Eye pressure is measured by how much force is needed to flatten a small area of the cornea. If your cornea is thinner than average, eye pressure may read lower than it actually is, potentially masking glaucoma. Conversely, a thicker cornea may give falsely high readings. Knowing your corneal thickness allows your doctor to interpret eye pressure measurements more accurately and assess your true risk for glaucoma.

At International Eye Hospital, pachymetry is performed as part of our comprehensive glaucoma evaluations and pre-surgical screenings, ensuring accurate diagnoses and safe treatment recommendations.