A client who complains of visual changes is being evaluated for glaucoma.
In preparing the client, how will the nurse educate the client about the name of the test that measures intraocular pressure?

Choice A rationale

Tonometry is the gold standard diagnostic procedure used to measure intraocular pressure by determining the resistance of the cornea to indentation or applanation. High intraocular pressure is a primary indicator of glaucoma, which can lead to optic nerve damage. This test specifically quantifies the fluid pressure inside the eye, helping clinicians monitor the effectiveness of treatments or the progression of the disease. It provides a numerical value that is critical for clinical decision making.

Choice B rationale

The Amsler grid is a diagnostic tool primarily used to detect vision problems resulting from damage to the macula or optic nerve, such as macular degeneration. It consists of a grid of horizontal and vertical lines used to monitor a central visual field. While useful for detecting metamorphopsia or central scotomas, it does not measure intraocular pressure. Therefore, it is not the correct test for the specific evaluation of pressure changes associated with glaucoma diagnosis.

Choice C rationale

The value 10-21 mm Hg represents the standard normal range for intraocular pressure in a healthy adult eye. Pressures exceeding 21 mm Hg are often suspicious for ocular hypertension or glaucoma. However, this numerical range is a measurement result or a physiological parameter rather than the name of a diagnostic test itself. The nurse must provide the name of the procedure, which is tonometry, rather than reciting the expected physiological reference values to the client.

Choice D rationale

Instilling a topical anesthetic into the eye is a procedural step often performed before contact tonometry to ensure patient comfort and prevent the blink reflex. While this is an important part of the preparation for certain types of pressure testing, it is a pharmacological intervention and not the name of the diagnostic test. Education should focus on the terminology of the procedure so the client understands what to expect during their clinical evaluation for visual changes.