A 66-year-old man with diabetes and a family history of glaucoma presents with new onset vision difficulties. Which of the following tests is commonly used as part of a comprehensive glaucoma exam?

Choice A reason: Fluorescein angiography is primarily used to assess retinal and choroidal circulation, especially in conditions like diabetic retinopathy or macular degeneration. It is not a standard test for glaucoma evaluation. Choice B reason: Computed tomography (CT) is used for imaging the orbit or brain in cases of trauma or suspected tumors. It is not part of routine glaucoma screening or diagnosis. Choice C reason: A slit lamp is used to examine the anterior segment of the eye, including the cornea, iris, and lens. While it is part of a comprehensive eye exam, it does not measure intraocular pressure, which is critical for glaucoma diagnosis. Choice D reason: Tonometry measures intraocular pressure (IOP), which is a key diagnostic criterion for glaucoma. Elevated IOP is a major risk factor for optic nerve damage in glaucoma, making tonometry an essential component of the exam.