Which diagnostic test is considered the "gold standard" for measuring intraocular pressure (IOP) in glaucoma?
A) Visual field testing
B) Ophthalmoscopy
C) Tonometry
D) Optical coherence tomography (OCT)
Explanation: Intraocular pressure (IOP) is an important parameter to evaluate in glaucoma, a condition characterized by increased pressure within the eye. Let's evaluate the options:
A) Visual field testing: Visual field testing is a diagnostic test used to assess peripheral vision. While it is valuable for detecting and monitoring visual field defects in glaucoma, it does not directly measure intraocular pressure. Therefore, it is not the correct answer.
B) Ophthalmoscopy: Ophthalmoscopy involves examining the structures at the back of the eye, including the optic nerve, blood vessels, and retina. While it is essential for evaluating the optic nerve damage associated with glaucoma, it does not provide a direct measurement of intraocular pressure. Hence, it is not the correct answer.
C) Tonometry: This is the correct answer. Tonometry is the gold standard diagnostic test for measuring intraocular pressure in glaucoma. It involves using a specialized instrument to gently flatten the cornea and measure the resistance, providing an accurate measurement of intraocular pressure.
D) Optical coherence tomography (OCT): OCT is a non-invasive imaging technique that provides high-resolution cross-sectional images of the retina and optic nerve. While OCT is valuable for assessing structural changes in the eye, it does not directly measure intraocular pressure. Therefore, it is not the correct answer.