Vision Health Part 4: Glaucoma
"The best thing to do is get screened regularly, especially if you have a family history of glaucoma."
Dr. Keller Wortham, MD, is back for the final installment of his four-part series on vision health and the causes of vision loss. In the last three videos, we talked about the components of the eye and how it works, the number one cause of irreversible blindness (diabetic retinopathy) which affects the posterior segment of the eye, and the number one cause of reversible blindness (cataracts) that occurs in the anterior segment.
In today’s episode, we’ll talk about a form of irreversible blindness that affects both the anterior and posterior segment of the eye. This condition is so insidious that it’s sometimes known as the silent thief of sight, because you could be suffering from it and not even know it. Stay tuned to find out what it is, how to recognize it, and how to prevent it.
- 01:36: Glaucoma
- 03:53: Glaucoma Facts
- 05:46: Glaucoma Risk Factors
- 06:57: Causes of Glaucoma
- 11:23: How do You Know if You Have Glaucoma?
- 13:51: What Can You Do if You Have Glaucoma?
- 15:58: Prevention Methods
- 18:34: Wrap-Up
Glaucoma is another of the leading causes of irreversible blindness worldwide. It causes no pain, and happens very slowly. It can seem like a scary condition, but fortunately, it’s also a very manageable disease most of the time, if you take the proper steps and get diagnosed early, and it's quite easy to be screened for.
As we already mentioned, glaucoma is one of the leading causes of irreversible blindness worldwide, and affects millions of people in the U.S. every year. It is actually a group of diseases that cause damage to the optic nerve. In part one, we discussed the optic nerve, which is at the back of the eye, and carries light impulses from the retina to your brain. Since it is the main connection channel from your eye to your brain, the optic nerve is very crucial to sight. Glaucoma slowly destroys the optic nerve.
The word Glaucoma comes from the Greek term, "glaukos," which refers to a blue-green color that can happen in the eye if glaucoma reaches advanced stages.
Two Main Forms of Glaucoma
- Open Angle Glaucoma — this type is thought to involve a slow buildup of pressure in the anterior part of the eye.
- Closed Angle Glaucoma — this type happens rapidly and could cause redness and pain in the eye, and dilation of the pupil, pain in the eye. This form of glaucoma is a surgical emergency.
Glaucoma Risk Factors
Here are a few of the contributing factors that may indicate you should get screened for glaucoma.
- Family history — There is a hereditary risk to glaucoma. If your parents or grandparents had it, you should stay on top of your glaucoma screenings.
- Increased eye pressure is thought to be a risk factor for glaucoma. The two aren’t always associated, but sometimes they are. That’s why screening your eye pressure is important
- High blood pressure (hypertension)
- Ethnicity — Certain ethnic groups are at higher risk, especially, East Asians
Causes of Glaucoma
We already mentioned that Glaucoma is caused by the slow destruction of the optic nerve in the back of the eye, but there is some debate about what leads to that destruction. As we discussed above, there's an association of increased eye pressure — called intraocular pressure — with glaucoma. So, where does that increased eye pressure come from and why might it lead to glaucoma? In order to understand that, we need to understand a few other things.
We've been talking about the anterior segment of the eye, which is the area in the very front of the eye that involves the cornea, the iris, the pupil, and the lens. This anterior segment of the eye is bathed in a fluid called the aqueous humor, a watery substance that is actually made in the eye. The aqueous humor is made in a particular area called the ciliary body, where the muscles attach to the lens to help it bend to focus in different areas. So, it's making a fluid there, and that aqueous humor floats through the eye, through the pupil, and then needs to drain back out of the eye to circulate and bathe the eye. It drains through a special little system of canals and drains called the trabecular meshwork.
So, there’s a whole fluid system, where your eyes make this aqueous humor, it's circulating and bathing the eye, and then exiting through a drain. You can think of it like a sink. If something happens the water coming into the sink or the outflow through the drain, then, you can get a buildup of water in the sink. If the faucet is turned up too high for the drain to keep up, for example, the sink can overflow. Or, if a drain gets clogged, causing a slow exit of fluid, water builds up in the sink again, and it overflows.
But in the eye, there's no overflow. It's a closed system. So, if that little drain in the trabecular meshwork gets clogged, and that aqueous humor can't circulate back out, or if the ciliary body is making too much of it, then fluid starts to expand in this portion of the eye. In a closed system, that builds up eye pressure, and that increase in eye pressure can increase the risk of glaucoma.
There’s also some debate regarding exactly how all these things happening in the front part of the eye end up being damaging to the optic nerve, in the back of the eye. It’s believed that it has to do with a change in chemicals released in the eye as well as, probably, a reduction in blood flow to the optic nerve in the back.
The right angle between the cornea and the iris is where the trabecular meshwork is, and that angle is where the drains are. In people of East Asian descent, that angle can be narrower due to the configuration of the eye, which can mean that drains can get clogged more easily.
This can also be the case for the hereditary risk factor. Perhaps that angle is a little bit narrower or maybe the drains just don't work as well, with the end result that you're set up with a hereditary tendency to have increased eye pressure that can lead to glaucoma.
How do You Know if You Have Glaucoma?
The best thing to do is get screened regularly, especially if you have a family history of glaucoma. Go see your doctor and then possibly your ophthalmologist, so that they can check you for this condition. They’ll be looking for an increase in eye pressure, which can be very easily established by puffing a little puff of air on the surface of the eye and observing how much resilience it has. They can then calculate the pressure within the eye, and use that to determine if your risk is elevated.
Now, not everyone who has elevated eye pressure will end up with glaucoma and not all glaucoma is the result of elevated eye pressure. But there is a strong correlation, so it's a very good thing to have your eye pressure checked with an ophthalmologist or an optometrist.
The other thing your doctor can do is look at is through a funduscope — a dilated exam. The funduscope allows the doctor to look through the dilated pupil at back at the back of the eye and see what's happening with the optic nerve and optic disc. There's something called a cup-to-disc ratio, which is a fancy term for how big the little cup in your back of your optic nerve is, relative to the whole disc. As that ratio increases, you are at a higher risk for glaucoma. This may all seem a little confusing, but just be aware that those are two very easy things your doctor can check. It is not invasive at all to be screened for glaucoma and thus reduce your risk, or help you catch it early.
Remember, in the very beginning, glaucoma happens very slowly. They call it the silent thief of sight because when you start having glaucoma, you likely won’t notice. It may eventually start to reduce the peripheral vision, but by the time it's advanced enough for you to start noticing loss in your main visual fields, it's very far advanced. That vision loss is irreversible, so, go get screened.
What Can You Do if You Have Glaucoma?
Hopefully you caught it early, and if so, there are treatment options.
Next, you can start some treatment regimens, most of which involve eye drops. There are certain drops that help balance out the pressure in the eye, and help increase the drainage from the eye. Prostaglandin drops, for example, help speed up the drainage and get that fluid out, restoring the proper fluid balance.
There are also beta-blocking drops, which reduce the production of the fluid, with the same end goal of restoring fluid balance.
Another category is called alpha adrenergic drops, which help do both. They help reduce the inflow of fluid and simultaneously help speed up the drainage of fluid.
If drops and lifestyle changes aren’t enough, or if your doctor thinks the problem is more advanced, there are some surgical options. These usually involve laser surgeries — most of the time, what they're trying to do is open up the drains in that very specific part of your eye. They use lasers to help unclog the drains, or if they're too damaged or they won't open up, they can surgically insert artificial drains to help that fluid leave the eye. That way, you'll reduce the eye pressure and reduce your risk of glaucoma damage to the optic nerve.
The first step to preventing glaucoma is catching it early. So, get your screenings. If you're in your 40s, you should be having an eye exam at least every 5 to 10 years. If you're in your 50s, maybe you should be doing it every 2 to 4 years. As you get later in years, into your 60s, you should be doing it every one to two years.
It’s also important to know your family history, so that you know if you need to be more vigilant, and be aware of any risks associated with your ethnicity. If you come from an East Asian background with a higher incidence of glaucoma, again, you should be on higher alert and making sure that you're getting screened regularly.
As always, there are also some lifestyle things that everyone can do, including regular exercise and addressing any possible underlying conditions.
There are also some recommended foods to add to your diet to help with glaucoma. These are healthy things for the eyes, in general, and include:
- Dairy products, like cheese and milks. These products are fortified with very important vitamins like vitamin A and vitamin D, which can help with preventing vision loss and glaucoma.
- Green vegetables like kale, spinach, and other dark leafy greens can help improve vision.
- Brightly colored fruits and vegetables, like carrots, oranges, and peaches are very good foods for vision, and may help reduce the risk of blindness from glaucoma.
- If you, like many people, have a difficult time getting enough fruits and vegetables in your diet, find a good multivitamin. Get a trusted multivitamin that's plant-based and natural, like the Smarter Multivitamin. It’s designed to give you the amount of every mineral and vitamin that you need, without overdoing it. This is really important, since overdosing on certain vitamins and minerals can be toxic.
We know this glaucoma overview was pretty technical, but hopefully you'll walk away with a few tips that will help reduce your risk of developing this very serious condition and irreversible cause of blindness.