What is tonometry used to measure?

Tonometry is a diagnostic test specifically used to measure intraocular pressure (IOP) in the eye. This measurement is critical in the assessment of glaucoma, a condition characterized by increased pressure within the eye, which can lead to optic nerve damage and vision loss if not detected and treated timely.

During a tonometry test, various methods can be employed to measure the pressure inside the eye, such as non-contact (air puff) tonometry or applanation tonometry, where a small probe flattens a part of the cornea to gauge pressure. Understanding intraocular pressure levels helps healthcare providers determine whether a patient is at risk for glaucoma or if they already have the condition, guiding appropriate management options.

In contrast, the other choices refer to different aspects of eye health. Corneal thickness is evaluated through pachymetry. Lens position assessment may involve imaging techniques or physical examination to determine if there is lens displacement. Visual acuity testing measures the clarity or sharpness of vision, typically using letter charts. Each of these factors plays a role in overall ocular health but is not assessed through tonometry.