To understand glaucoma there are two key concepts about the eye we need to understand. The first being what is the optic nerve. The optic nerve is a cable of nerve fibers that carries the visual information from our eye to our brain. Second, we need to understand eye pressure. Our eye is constantly making fluid and draining it. If we make too much or do not drain it fast enough, the pressure inside the eye can build up. If that pressure is too high for an individual, it can create a shearing force on the optic nerve and slowly cause damage over time. This progressive damage to the nerve is glaucoma.

Will I notice if I have glaucoma?

            Usually no! High eye pressure has to be incredibly high in order for someone to be symptomatic. That is why it is important to have it checked at annual comprehensive eye exams. Additionally, the initial vision loss from glaucoma is slow and far in the periphery in areas that are very difficult to perceive.

What causes the eye pressure to be elevated?

            A high eye pressure can vary from person to person depending on the makeup of your eye. Most commonly, in what is called primary open angle glaucoma (POAG), the drainage system is open, but the drain is clogged on a microscopic level. There are secondary conditions that can cause elevated pressure as well. These include history of inflammation in the eye, trauma, steroid use, and conditions that release particles inside the eye. Lastly, some people have naturally smaller eyes and are predisposed to their drainage system having a very small opening. These individuals are at risk for acute or sudden severe spikes in their eye pressure.

How do we treat glaucoma?

            We lower the eye pressure. This is usually done with a daily eye drop prescribed by your eye doctor. Alternatively, eye pressure can be lowered with an outpatient laser procedure. These methods are both great options. They work by either opening the drainage system in the eye or decreasing the amount of fluid the eye produces. In severe cases, more elaborate surgical procedures may need to be performed by a specialist.

What can I expect at my visit to test for glaucoma?

            At your annual exam, you can expect your eye doctor to measure your eye pressure and take a thorough look at your optic nerve. If they see anything of concern, they may recommend a follow up visit for additional testing. These extra tests include precise imaging and measurement scans of your optic nerve and retina, a side vision test, visualization of your drainage system, measurements of your cornea, and re-checking your eye pressure. These initial tests usually serve as a baseline to compare to for future changes. Glaucoma is a progressive disease, so multiple measurements spaced out over many months may be necessary to definitively diagnose glaucoma.

Author: Dr. Elizabeth Stern-Green