---
title: Tonometry
description: "Tonometry measures intraocular pressure IOP, a key risk factor for glaucoma. Several techniques exist, each with advantages and limitations. ## Types of tonometry Common methods include: - Goldmann applanation tonometry, the gold standard in clinics - Non-contact \"air puff\" tonometry…"
url: "https://bluefinvision.com/knowledge-base/topics/diagnostics-testing/tonometry/"
updated: "2025-12-17"
category: "Diagnostics & Testing"
---

# Tonometry

Tonometry measures intraocular pressure IOP, a key risk factor for glaucoma. Several techniques exist, each with advantages and limitations.

## Types of tonometry

Common methods include:

- Goldmann applanation tonometry, the gold standard in clinics
- Non-contact "air puff" tonometry often used in screening
- Handheld devices such as iCare rebound tonometers for children or bedside use
- Indentation methods like Schiotz tonometry in limited settings

## Interpreting results

IOP values must be considered in context.

- Normal range is roughly 10-21 mmHg, but damage can occur outside this range
- Corneal thickness and biomechanics influence readings
- Serial measurements help detect fluctuation or progression
- Tonometry is always combined with optic nerve and field assessment for glaucoma diagnosis