Which tonometry method is more accurate?

Goldmann applanation tonometry (GAT) is the gold standard for IOP measurement. Non-contact tonometry (NCT) is useful for screening but has greater variability and tends to read higher than GAT.

Does corneal thickness affect IOP readings?

Yes — thicker corneas (>570 μm) tend to give falsely high IOP readings, while thinner corneas (<500 μm) give falsely low readings. Pachymetry-based correction is sometimes applied in glaucoma management.

Applanation vs Non-Contact Tonometry Comparison

Compares IOP measurements from Goldmann applanation tonometry (GAT, gold standard) versus non-contact tonometry (NCT/air puff). NCT readings are typically 1–3 mmHg higher than GAT. Adjusts NCT readings based on published correlation data to estimate GAT-equivalent IOP.

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Frequently Asked Questions

Which tonometry method is more accurate?

Does corneal thickness affect IOP readings?