Tonometry

Tonometry is the procedure used to measure the pressure inside your eye, known as intraocular pressure (IOP). This test is a critical part of any comprehensive eye examination because elevated eye pressure is the most significant risk factor for glaucoma — a leading cause of irreversible blindness worldwide. Regular tonometry allows early detection of pressure changes, enabling timely intervention before optic nerve damage and vision loss occur.

There are several methods for measuring eye pressure. The Goldmann applanation tonometry is considered the gold standard and involves using a small probe to gently flatten a tiny area of the cornea after numbing eye drops are applied. Non-contact tonometry (air puff) uses a brief puff of air to flatten the cornea without touching the eye — this method is commonly used for screening because it requires no eye drops. At International Eye Hospital, we also use advanced iCare tonometry, which uses a tiny disposable probe to gently touch the cornea without the need for numbing drops, making it especially comfortable for patients.

Normal eye pressure typically ranges between 10 and 21 mmHg (millimeters of mercury). However, glaucoma can develop even within this range, and some people may have higher pressure without developing glaucoma. This is why tonometry is always combined with other tests such as optic nerve examination, visual field testing, and OCT imaging for a comprehensive glaucoma assessment.

Tonometry is recommended for all adults during routine eye exams, but it is especially important if you have risk factors for glaucoma, including being over 60 years old, having a family history of glaucoma, being of African or Hispanic descent, having diabetes or high blood pressure, or having had a previous eye injury.

At International Eye Hospital, we perform accurate tonometry as part of every comprehensive eye examination, using the most appropriate method for each patient's comfort and clinical needs.