Glaucoma is a group of eye conditions that cause damage to the optic nerve, which is vital for vision. The optic nerve sends the signal of vision from our eyes to our brain allowing us to see. Glaucoma leads to vision loss by affecting peripheral or side vision first, then moves in to affect central vision as the disease progresses. This damage is often caused by high eye pressure.
Glaucoma is usually a slowly progressive disease and mainly occurs in patients over 50 years old. That it is slowly progressing is often dangerous because it makes visual changes less noticeable. Changes inside vision are also difficult to detect without testing. Most patients will not notice vision changes until it is at the advanced stage. At that point, vision loss is no longer preventable. Unfortunately, vision loss from glaucoma is irreversible. Therefore, it is extremely important to catch the disease in early stages so that treatment can be initiated. If left untreated, glaucoma will cause blindness.
What are the symptoms of glaucoma?
Most of the time glaucoma is symptomless until advanced stages. In some cases, when eye pressure is very high, it can cause sudden blurry vision, eye pain, nausea, or frontal headaches. Other symptoms include tunnel vision, and patchy blind spots in the periphery. If you are experiencing the above symptoms, it is strongly advised to be seen immediately by one of our optometrists.
What causes Glaucoma?
Glaucoma is caused by damage to the optic nerve, which results in decreased sensitivity of points in your side vision then affects central vision in later stages. Usually this is due to increased eye pressure. High eye pressure is usually caused by build up of fluid that normally flows through the eye. This build up is due to insufficient drainage causing pressure in the eye increase. Mechanisms of how and why drainage decreases is largely unknown at this point.
Race is a risk factor as well. People of African, Hispanic, and Asian descent are at higher risk of developing glaucoma. Glaucoma most commonly occurs after the age of 50 though some types are present at birth or develop at younger ages. Many patients with glaucoma have a family member with the disease. Black, Hispanic, and Asians are at higher risk for developing glaucoma.
Types of Glaucoma
There are many types of glaucoma. Here we will cover the two most common types:
Primary open angle glaucoma - this is the most common form of the diseases. The drainage area remains open but the amount of drainage is still slowed. This causes pressure in the eye to gradually increase. This pressure damages the optic nerve. This type of glaucoma is usually slowly progressing and causes vision loss over time.
Angle closure glaucoma - this form occurs when the drainage area is very narrow, meaning there is not enough space for fluid to drain from the eye. As a result, fluid builds up the eye and pressure increases. Some people are born with narrow drainage structures, putting them at increased risk of angle-closure glaucoma. Vision loss from this type of glaucoma can be sudden or gradual. Signs of angle closure include eye pain, redness, sudden vision loss, and nausea. If these symptoms are felt, you should see an eye care professional immediately.
What testing is needed?
The first step in determining risk for glaucoma is through a comprehensive yearly exam at your optometrist. Dilation is recommended to thoroughly assess the health and appearance of the optic nerve. Based on the exam findings, our optometrist evaluates your risk for glaucoma. If risk is high, we recommended additional testing. The first test is a scan optic nerve which images the nerve to a microscopic level. This scan allows us to see if there are any areas of optic nerve damage. The second vital test maps out the visual field in detail. This is done to see if there are any points in the visual field that have lost sensitivity which is the first sign of glaucoma. Other tests include using a lens to inspect the drainage system for openness and checking the thickness of the front surface of the eye. If diagnosed with glaucoma or risk for glaucoma is high, testing will be repeated in a time frame recommended by the optometrist to track for progression.
How do you treat glaucoma?
Unfortunately vision loss from glaucoma is not reversible. However, regular check ups and treatment can help slow down the progression of vision loss. Glaucoma is treated by lowering eye pressure. This is usually done with prescription eye drops, but also with laser procedures, surgery, or a combination of these.
Why is follow up important:
If you are found to have glaucoma, or if you are at risk for developing glaucoma, it is extremely important to follow up with your optometrist regularly. Glaucoma causes vision loss if left untreated or if treated inconsistently. At each visit, your eye pressure will be checked to ensure that it is in the target range. If not in the target range or testing shows fast progression, treatment needs to be altered so that vision can be preserved.
If you are found to be suspicious for glaucoma it is crucial to follow up as recommended. The best chance at preserving vision long term is catching glaucoma early meaning progression will be slowed down from the start.