Glaucoma is a group of progressive diseases that can damage your eye’s optic nerve and cause vision loss, even blindness. There are many theories, but the exact cause of glaucoma is unknown. It is most often related to a build-up of pressure inside your eye. When this pressure, called intraocular pressure, or IOP, remains high over time, it begins to harm optic nerve fibers.

IOP increases when the fluid inside your eye, called aqueous humor, which normally flows out of your eye through a mesh-like drainage channel called the trabecular meshwork, gets blocked and cannot leave the eye. As a result, the fluid builds up and IOP increases. In some case, however, glaucoma can occur in people who have normal IOP.

Another theory suggests that glaucoma is caused by an inadequate amount of blood flow to the optic nerve.

About 3 million Americans have glaucoma. It’s expensive and damaging to vision. It costs the US economy $286 billion every year in direct costs and productivity loses, and it’s the leading cause of irreversible blindness in the world.

There are two main types of glaucoma: open-angle glaucoma and angle-closure glaucoma.

Open angle glaucoma is the most common type, affecting approximately 95 percent of patients. In this type of glaucoma, fluid does not drain properly due to changes in and along the drainage passageway. There are typically no early symptoms of open-angle glaucoma, so you can have it for years and not know it. It is often called “the silent thief of sight.”

With angle-closure glaucoma, your eye doesn’t drain like it’s supposed to because the drain space, or angle, which is located between your iris and cornea, becomes too narrow and can become blocked. This can occur suddenly, which is called acute angle-closure glaucoma, or over time, called chronic angle-closure glaucoma.

Anyone can develop glaucoma, but there are certain factors that increase your risk for developing it. You are more likely to get it if you are over age 40, have a family history of glaucoma, have diabetes, take certain steroid medications such as prednisone, have had an injury to your eyes, have high eye pressure, or are nearsighted or farsighted. There are other risk factors as well.

Glaucoma-related damage to the optic nerve generally starts with a loss of nerve tissue in a specific pattern called cupping. This is when the center of the optic disc, called the cup, becomes larger, leaving less room for the remaining optic nerve fibers. It’s common for you to experience blurry spots in your peripheral, or side, vision when this occurs. This is often the first symptom of glaucoma.

As your glaucoma progresses, it may begin to affect your central vision, which is needed to see details and for activities such as driving and reading. Advanced glaucoma can lead to permanent blurred or dimmed vision or even to blindness.

Your eye doctor may use several painless tests to diagnose glaucoma in addition to a dilated eye exam and visual field test. Tonometry measures eye pressure; gonioscopy examines the drainage area of the eye, and optical coherence tomography (OCT) creates a three-dimensional image of the optic nerve and retina to evaluate the degree of cupping and ocular damage.

Glaucoma is treated using medications, laser therapy, and surgery. Medications, which may include eye drops or pills, lower eye pressure by reducing the amount of aqueous humor produced in the eye. They also help increase the outflow of fluid from the eye..

A laser procedure called trabeculoplasty opens clogs in the trabecular meshwork so fluid can drain out of the eye. Laser iridotomy, which is used for angle-closure glaucoma, creates a tiny opening in the iris to allow the drainage angle to open.

During a glaucoma surgery called trabeculectomy, the doctor creates a new channel in your eye to allow the fluid to drain, which eases IOP. Another surgical procedure your doctor may choose involves implanting a tube to help drain fluid from your eye.

Glaucoma treatment cannot restore vision you may have already lost, but it can help prevent any further vision loss.

Because glaucoma has no early symptoms, people at high risk should see their eye doctor for a dilated eye exam and visual field test at least every one to two years or as directed by their doctor. Don’t let glaucoma steal your sight. See your eye doctor today!

Diabetes increases the risk for multiple health problems, from cardiovascular disease to kidney damage to skin conditions. Another common – and often preventable – problem linked to diabetes is vision loss. November is Diabetes Eye Disease Month, a time to spotlight the most common eye disorders associated with diabetes and focus on ways to decrease your risk.

According to the Centers for Disease Control and Prevention’s “National Diabetes Statistics Report 2020,” which analyzed health data through 2018, 34.2 million Americans – just over 1 in 10 – have diabetes. In addition, 88 million American adults – approximately 1 in 3 – have prediabetes. Further, 7.3 million adults over 18 were unaware or did not report having diabetes.

Over time, diabetes can damage your eyes and cause poor vision, even blindness. It can lead to
diabetic eye disease, a group of eye problems that includes diabetic retinopathy, diabetic macular edema, cataracts and glaucoma.

The retina is the inner lining of the back of the eye. It senses light entering the eye and turns it into signals that your brain translates into images. Consistently high blood glucose levels associated with diabetes damages the small blood vessels in the eye, which can harm the retina and cause a disease called diabetic retinopathy.

In the early stage of diabetic retinopathy, called nonproliferative diabetic retinopathy, damaged blood vessels can weaken, swell, or leak into the retina. In the more serious stage, called proliferative diabetic retinopathy, some blood vessels close off and new blood vessels grow on the surface of the retina. These blood vessels are abnormal and can cause serious vision problems.

Diabetic macular edema involves fluid build-up on the center part of the retina, called the macula, which is responsible for the detailed, straight-ahead vision necessary for reading, driving and seeing faces. The built-up fluid makes the macula swell, blurring vision and destroying this sharp vision. Diabetic macular edema, which can cause permanent vision loss, typically develops in people who already have other signs of diabetic retinopathy.

The eye’s lens is a clear structure that sits behind the iris (the colored part of the eye) and helps focus light onto the retina. Natural lenses tend to become cloudy from protein deposits as people age. Cloudy lenses are called cataracts. People with diabetes are twice as likely to develop cataracts at a younger age than people without diabetes. That’s because, it is believed, high glucose levels cause protein deposits to build up on the lens.

Glaucoma is a group of diseases that cause damage to your eye’s optic nerve, which can lead to permanent vision loss. Glaucoma occurs when pressure builds up in your eyes. This pressure pinches the blood vessels that carry blood to the retina and optic nerve, causing gradual vision loss. Having diabetes doubles your chances of getting glaucoma.

With open-angle glaucoma, the most common type, pressure builds up inside your eye when fluid can’t drain effectively through the normal drainage channel, called the trabecular meshwork. This type of glaucoma can be treated with medication and eye drops that lower eye pressure, speed up drainage, and reduce the amount of fluid your eyes make

People with diabetes are at risk for a condition called neovascular glaucoma, in which new blood vessels form on the eye’s iris. These blood vessels block the normal flow of fluid and raise eye pressure. Treatment for neovascular glaucoma may include use of a laser to reduce the number of blood vessels or anti-neovascular endothelial growth factor (anti-VEGF) injections to halt the growth of new blood vessels.

There are other eye conditions associated with diabetes including branch retinal vein occlusion (BRVO) and central retinal vein occlusion (CRVO). Arteries and veins are blood vessels that carry blood throughout the body. There is one main artery and one main vein supplying the retina.

When this vein becomes blocked, blood and fluid spills out into the retina and the macula can swell, which affects your sharp central vision. Over time, if blood circulation remains cut off, nerve cells in your eye can die and more vision can be lost.

When branches of the retinal vein become blocked, the resulting condition is called branch retinal vein occlusion (BRVO). When the main retinal vein becomes blocked, it is called a central retinal vein occlusion (CRVO).

Here’s the good news: You can help prevent all of these diabetes-related eye disorders by taking steps to manage your diabetes. To do that, you must control your blood glucose, blood pressure and cholesterol levels. Take good care of yourself through healthy eating, exercising regularly and taking medications as prescribed.

In addition, if you smoke, quit. There are many resources online and in the community to help you quit smoking. And don’t forget to get a complete, dilated eye exam once a year, so your eye care professional can detect early signs of diabetic eye disease. Be eye smart: Take steps to protect your vision.

Do you worry about your vision? Many of us do. Vision loss is a common condition in the United States. It’s estimated that 25 million Americans are blind or visually impaired. One in 28 Americans ages 40 and older have low vision. Since low vision is so prevalent, I thought we ought to learn more about it.

First of all, let’s define low vision. It’s a significant visual impairment that can’t be corrected by any type of prescription lenses, or by medication or surgery. Low vision can make it difficult to perform your daily activities, as well as to read, use a computer, drive and watch TV. This can make you feel cut off from the world around you.

Low vision can also affect your mobility. It can interfere with your ability to get around independently. When mobility and communication are hampered, it can lead to feelings of anxiety and depression, and quality of life can be negatively affected in some people.

Eye disorders and injuries to the eye are the primary causes of low vision. These include diseases like macular degeneration, glaucoma and diabetic retinopathy, and genetic conditions like retinitis pigmentosa, as well as conditions like cataracts and traumatic brain injury, including head injuries, brain tumors and stroke.

There are a few common types of low vision. The first is the loss of central vision in which there’s a blur or blind spot in the middle of your vision, but your peripheral, or side, vision remains intact. This can occur with macular degeneration because the macula is responsible for central vision.

Low Vision Chart

• 20/30 to 20/60, this is considered mild vision loss, or near-normal vision.

• 20/70 to 20/160, this is considered moderate visual impairment, or moderate low vision.

• 20/200 to 20/400, this is considered severe visual impairment, or severe low vision.

• 20/500 to 20/1,000, this is considered profound visual impairment, or profound low vision.

• less than 20/1,000, this is considered near-total visual impairment, or near-total blindness.

• no light perception, this is considered total visual impairment, or total blindness.

 

Other types of low vision include loss of peripheral vision. With this, you won’t be able to distinguish anything at one or both sides, or anything directly above and/or below eye level. Loss of peripheral vision can happen with glaucoma and stroke. With blurred vision, both your near and far vision is out of focus. Cataracts can cause this.

There’s also a condition called generalized haze, when it seems like there’s a film covering everything you look at. Extreme light sensitivity is another common type of low vision. This is when regular amounts of light feel overwhelming. With night blindness, another type, you cannot see outside at night or in dimly-lit places indoors. Various eye disorders can cause these conditions.

Anyone can be affected by low vision, but it’s more common as we get older. That’s true, in part, because conditions that often cause low vision, such as macular degeneration and glaucoma, most commonly develop as people age.

Low vision is more frequently seen in people over age 45 and even more frequently seen in people over age 75. In fact, one in six adults over age 45 has low vision, and one in four adults over 75 has it.

The best way to catch and control the diseases and conditions that lead to low vision is by having regular eye exams by an eye care specialist. But if you notice any changes in your vision, contact your eye doctor right away.

Your eye doctor will perform a complete eye exam to diagnose low vision, including tests designed to check your vision and look for eye diseases. Your doctor will test your eyes for visual acuity or how well you see. He or she may use different instruments and lights when testing your vision.

If your eye doctor diagnoses low vision, he or she may refer you to a low vision specialist. A low vision specialist will help you learn new ways to use your remaining vision, modify your home and teach you how to use devices to aid your vision. Visual rehabilitation is part of this process.

Visual rehabilitation begins by recognizing the challenges of vision loss and making adjustments to maximize what vision you have left. It’s a process of learning how to do tasks, such as reading and writing, in news ways.

For example, if you have a blind spot, you may be asked to imagine the object you want to see is in the center of a large clock. You’ll be told to move your eyes along the clock numbers and note when you see the object most clearly. The doctor will tell you to use the same viewing direction when you look at other objects to see them as clearly as possible.

There are also many low vision aids that can help you see when doing your everyday activities. These includes a variety of optical magnifiers, including those that attach to your glasses, those that are handheld and those that stand on their own hands-free.

Telescopes can help you see things that are far away. They can be handheld or attached to your glasses. Non-optical aids that are available include everyday devices that talk. Some examples are watches, timers and blood sugar monitors that have an audio component.

There are also electronic devices such as video magnifies in portable and desktop formats. These devices combine a camera and a screen to make objects, like printed pages, forms and pictures, look larger.

Also helpful to those with low vision are audio books and electronic books that allow you to increase word size and contrast. The latest technology in smartphones, tablets and computers can read aloud or magnify what’s on the screen.

Low vision may be preventable in people with diabetes if they maintain healthy blood glucose levels. The best way to prevent the progression of low vision is by getting your eyes examined regularly so your doctor can catch and manage the eye disorders that can contribute to low vision. Do your eyes a favor, keep an eye on them!

Millions of Americans are being robbed of their vision, and many of them don’t even know it.

They have glaucoma, often called “the silent thief of sight” because it can cause irreparable harm before the patient notices any vision loss, which can’t be reversed. The disease is the leading cause of blindness in the United States and can occur at any age, although it’s more common among older adults.

January was National Glaucoma Awareness Month, so now is a great time to become familiar with the condition, what causes it and what can be done to treat it.

Glaucoma is actually a group of diseases that damage the optic nerve, a bundle of more than a million nerve fibers carrying information from the retina to the brain. The retina, the light-sensitive tissue at the back of each eye, is vital to good vision.

The two main types of glaucoma are open-angle and angle-closure, which refers to the drainage angle where the iris (the colored part of the eye) meets the cornea (the outer covering). Open-angle is the most common type of glaucoma, accounting for at least 90 percent of the cases.

Both forms of the disease are caused by increased pressure inside the eye resulting from impaired drainage of the clear fluid flowing in and out of the eye to nourish nearby tissues. The fluid can build up when the eye’s drainage canals become clogged over time (open-angle glaucoma) or are blocked completely (angle-closure).

Open-angle glaucoma is a slow-developing, lifelong condition, and symptoms and damage aren’t noticed in its early stages. As the disease progresses, patients may develop patchy blind spots or tunnel vision.

Angle-closure glaucoma can cause eye pressure to increase within hours, demands immediate medical attention and can result from other conditions, such as cataracts or tumors. Symptoms may include severe headache, eye pain, redness, nausea and vomiting, blurred vision and halos appearing around lights.

Not everyone whose eye pressure increases will develop glaucoma because some people can tolerate higher levels than others. A comprehensive exam can determine what level of eye pressure is normal for each patient.

Also, there’s a form of glaucoma called low-tension or normal-tension that can develop without increased eye pressure.

Immediate treatment for early-stage, open-angle glaucoma can delay the disease from worsening, which is why early diagnosis is so important. Drops or pills can help lower eye pressure, either by causing the eye to produce less fluid or by helping it drain.

An outpatient laser procedure can open the drainage holes in the eye, allowing the fluid to drain better. Another option is conventional surgery that involves making an incision into the eye’s drainage system to create new channels for a more normal flow of fluid. Shunts or stents also can be implanted in the eye to increase the flow.

Consult an eye care professional for more information on diagnosing and treating glaucoma.