Diagnosing Glaucoma

    Published: 06-16-2009
    Views: 10,378
    Dr. Guy Eakin and Donald Zack, M.D., Ph.D., discuss the diagnosis of the glaucoma.

    Dr. Guy Eakin: Today I'm talking about glaucoma, the leading cause of irreversible vision loss and ultimately blindness. In this segment I'm going to talk about how glaucoma is diagnosed. If you are at high risk of developing glaucoma, your doctor will often perform several tests to determine whether or not the optic nerve has been damaged.

    During the eye examination, the doctor will check several readings and these will include a number of different things and often your eye doctor will want to take more than one readings so that they can determine what the pressure is at different times of the day. Since eye pressure can vary from day to day and even from hour to hour, these comparative readings are much more likely to give your doctor an accurate picture of your overall pressure.

    However, if the cornea or the clear covering of your eyes thin because of genetics or of prior surgeries, this pressure reading can be artificially low. LASIK, which is the surgical procedure intended to reduce a person's dependency on glasses, can cause the cornea to become thinner than normal.

    So if you have had LASIK or a similar procedure, be sure to inform your doctor.

    Dr. Donald Zack: So usually, when a patient comes to see a glaucoma doctor, one of the first things we'll do is do a functional test of the vision. We'll use a visual field test which is basically like a video game. It's a big bowl and the computable shine lights in different places in a patient's visual field. And then the patient's holding a little control a little button and whenever they see the light, they push the button and the machine will shine the light in different places and will also shine in different intensities.

    So it measures not only whether the patient could see the dot in a particular area, but how sensitive they are and this allows us to measure as I mentioned the visual field and that's very important, because in glaucoma vision loss usually is not the central high equity vision in the middle, but it's a side vision and we see the vision gets smaller and smaller.

    We'll also measure the patient's visual equity using a standard reading chart, like 20-20, 20-30, 20-40, we'll also use a lamp exam to measure these general mechanical and these general structures of the eye, then we'll use an appellation of the denominator to measure the eye pressure in the eye and then we'll dilate the eye and we'll look in back to look at the optic nerve and the optic nerve or the optic disc is basically like a cable that takes information from the eye to the brain and that's what ultimately gets damaged in glaucoma. We'll also use a special kind of lens to look at the side part of the eye called the angle and those are really most of tests that we generally do.

    Guy Eakin: All these tests are painless and noninvasive. To learn more about glaucoma, check out the other videos in this series, including how to treat glaucoma.