CCT (Central Corneal Thickness)

A Simple Measurement That Tells Us a Lot About Your Eyes

The thickness of your cornea — the clear dome at the front of your eye — plays a surprisingly important role in understanding your risk of glaucoma and planning certain types of eye surgery. CCT, or Central Corneal Thickness measurement, is a quick, painless test that gives your doctor critical information about your eye health that cannot be obtained any other way.

What Is Central Corneal Thickness?

Central Corneal Thickness refers to the measurement of how thick the central part of your cornea is — typically measured in micrometres. The average cornea is around 540 to 560 micrometres thick, but there is natural variation between individuals. This variation matters enormously in clinical practice because a thicker or thinner cornea affects how we interpret your eye pressure reading and how we plan refractive or glaucoma surgery.

Why Is CCT Important?

• A thinner cornea can make eye pressure readings appear falsely low — masking dangerous pressure levels
• A thicker cornea can make pressure readings appear falsely high — leading to unnecessary treatment
• CCT is essential for accurate glaucoma assessment and management
• It is a required measurement before LASIK and other refractive surgery procedures
• It helps identify conditions like Keratoconus — where the cornea thins and bulges abnormally

What Happens During the Test?

Step 1 — Numbing Drops

A single drop of local anaesthetic is applied to the eye. This numbs the surface completely so you feel nothing during the measurement.

Step 2 — The Measurement

A small, thin probe called a pachymeter is placed very gently against the centre of the cornea for just a fraction of a second. The ultrasound waves it emits measure the thickness of the cornea with extraordinary precision.

Step 3 — Instant Result

The thickness reading appears immediately. The measurement is taken several times per eye to ensure consistency, and the whole test takes only two to three minutes in total.

Is It Uncomfortable?

Not at all. With the numbing drops in place, you will feel nothing during the measurement. Some patients notice a very brief, mild sensation when the probe touches the eye — but this passes almost immediately and causes no lasting discomfort.

Why Patients Trust RGC Eye Hospital

• CCT is performed as part of every comprehensive glaucoma and refractive assessment
• Results are interpreted in context with your full clinical picture — not in isolation
• Accurate, well-calibrated pachymetry equipment for consistent and reliable readings
• Our specialists explain what your results mean in plain, clear language