How Is Glaucoma Diagnosed?

Aug. 24, 2009— -- Question: How is glaucoma diagnosed?

Answer: When you visit the ophthalmologist, the first thing that the ophthalmologist will likely do is to take a very thorough history, including questions that pertain to the possibility of your having risk factors for glaucoma. In particular, family history or previous other members of your family having glaucoma is a very strong risk factor. However, many people -- in fact, the majority of people -- with glaucoma do not have a family history of glaucoma. Therefore, although it's an important risk factor, it doesn't mean that you don't have glaucoma.

After the thorough history, the doctor will likely do a very complete eye examination which includes a microscopic examination of the front of the eye as well as the back of the eye, including the optic nerve. There'll be a measurement of the intraocular pressure, the thickness of the cornea, which is the front window of the eye, and also a microscopic examination of the drainage angle of the eye called gonioscopy. A lot of times they'll also measure digitally the thickness of the nerve fiber layer, which is what comprises the optic nerve and the anatomic point of damage. Also, there will be a functional assessment of your visual field.

The visual field is a measurement of your peripheral vision -- the vision, in other words, that extends beyond what you see in the center part of your vision. Glaucoma typically affects the peripheral vision first, and that's why it's important to measure that.