David Baxter PhD
Late Founder
Common Eye Disorders Explained: Cataracts, Glaucoma, AMD
Berkeley Wellness
February 22, 2018
Here are the basics about the four leading age-related eye disorders: cataracts, glaucoma, macular degeneration, and diabetic retinopathy.
Cataracts
What it is: A cataract is an opacification (cloudiness) of the eye’s normally clear crystalline lens. Cataracts can occur at any age (in fact, babies can be born with them), but they are most common later in life. In the U.S., about 70 percent of people over age 75 have cataracts. The three common types of cataracts are defined by where they occur in the lens: nuclear, cortical, or posterior subcapsular (in the rear of the lens capsule). Nuclear cataracts are the most common type; the incidence of nuclear cataracts increases with age and cigarette smoking. Cortical cataracts also become more common with age, and are related to lifetime exposure to ultraviolet rays from the sun. Posterior subcapsular cataracts are most likely to occur in younger people. They are often the result of prolonged use of corticosteroids (such as prednisone), inflammation, trauma, or diabetes.
Prevention: Because smoking contributes to the risk of cataracts, stopping the habit is a vital step in cataract prevention. Wearing UV-blocking sunglasses and a hat with a wide brim will help reduce eye exposure to UV radiation and may reduce the risk of cataracts. Researchers disagree about whether some drugs can reduce the risk of cataracts. Results from studies of medications such as aspirin, hormone replacement therapy, and statins have been contradictory. Other research, published in 2015 in Ophthalmology, found that high levels of physical activity were associated with a lower risk of cataracts later in life.
Signs and symptoms: When cataracts first appear, you may not notice changes in your vision. As they progress, however, your vision may become somewhat blurry, you may have trouble seeing at night or in low light, you may become sensitive to light, bright colors may look yellowed or faded, or you may come to need brighter light for reading.
Treatment: Surgery for cataracts involves removing all or part of the lens and replacing it with an intraocular lens implant (IOL). Cataract removal is the most frequently performed surgery in individuals over age 65 and is considered by many doctors to be the most effective surgical procedure in all of medicine. If the eye is normal except for the cataract, surgery will improve vision in more than 95 percent of cases.
Glaucoma
What it is: The second most common treatable cause of blindness in the U.S., glaucoma is a condition in which deterioration of the optic nerve leads to progressive loss of field of vision. There are two main forms: Open-angle glaucoma progresses slowly and produces no obvious symptoms until its late stages. This form of glaucoma is equally common in men and women and is responsible for about 90 percent of glaucoma cases. Angle-closure, or closed-angle, glaucoma occurs more often in people of Asian or Inuit descent; women are at greater risk than men, as are people who are farsighted.
Prevention: Eye drops that lower IOP have been shown to delay the development of open-angle glaucoma in people with elevated intraocular pressure (IOP) and no other signs of glaucoma. For closed-angle glaucoma, laser iridotomy, a procedure in which the laser makes a hole in the iris, can be preventive, although the decision to perform this treatment is complex.
Signs and symptoms: Open-angle glaucoma usually affects both eyes, although IOP levels and the extent of damage to the optic nerve often differ between eyes. Because of the way the optic nerve is structured, the first nerve fibers damaged are those used for peripheral vision. Individuals can have 20/20 vision when looking straight ahead but may have blind spots for images located outside the center of the visual field. Closed-angle glaucoma sometimes occurs as acute attacks that strike when IOP rises rapidly. Signs of an attack include severe pain in the eye, nausea and vomiting, blurred vision, and rainbow halos around lights. Chronic closed-angle glaucoma, like open-angle glaucoma, can cause damage without any noticeable symptoms.
Treatment: Most forms of glaucoma are chronic conditions that cannot be cured. However, open-angle glaucoma can often be treated safely and effectively with medication or surgery, but lifelong use of medication is almost always necessary. Acute angle-closure glaucoma is a medical emergency; if you experience symptoms, contact your ophthalmologist immediately or seek emergency treatment to prevent permanent damage or blindness.
Age-related macular degeneration
What it is: AMD is a condition that affects the macula—the central, most critical part of the retina for sharp vision. In the U.S., it is the leading cause of severe and irreversible loss of central vision in people over age 50. There are two types: The dry form (non-neovascular ) is more common and is caused by aging and thinning of the macula; the wet form (neovascular), which is more damaging, occurs when abnormal blood vessels start growing underneath the retina and leak fluid or blood that can blur or distort central vision.
Prevention: The AREDS and AREDS2 supplement formulas can help slow the progression of the condition in patients with intermediate AMD. The original AREDS formula is not recommended for smokers (or ex-smokers) because the beta carotene in it is associated with an increased risk of lung cancer in them. Some studies have linked UV exposure with AMD, so it makes sense to protect your eyes from the sun. Other suspected risk factors include obesity, high cholesterol levels, and coronary heart disease. Research also suggests that smokers with early AMD are more likely than their nonsmoking counterparts to progress to advanced AMD. For unknown reasons, the incidence of AMD has been declining dramatically in recent generations, so that the risk is nearly 90 percent lower for baby boomers than it was for their grandparents at the same ages, according to a study in JAMA Ophthalmology in December 2017.
Signs and symptoms: The early stages of AMD don’t usually cause symptoms. As the disease progresses, it can cause blurry vision with distance or reading, hazy vision, faded colors, or difficulty seeing when going from bright to dim light. AMD can be detected with a dilated eye exam, so it’s important that you have regular eye exams as you get older.
Treatment: The AREDS formulas can slow the progression of AMD. For wet macular degeneration, laser treatments can destroy the abnormal blood vessels, thus preventing the disease’s progression. For more advanced wet AMD, newer treatments involving injections of anti-VEGF (vascular endothelial growth factor) drugs into the affected eye can reduce the abnormal blood vessels.
Diabetic Retinopathy
If you have diabetes, there's one eye disease that should be on your radar screen: diabetic retinopathy, which can cause blood vessels in the retina to leak fluid or bleed, distorting vision in the process. The underlying reason: Chronically high blood sugar from poorly controlled diabetes can lead to damage to the tiny blood vessels in the retina, which can lead to vision loss and blindness in the worst-case scenario.
Diabetic retinopathy affects some 8 million Americans age 40 and older and is the most common eye complication of diabetes. More than 70 percent of people with type 2 disease will eventually develop some evidence of retinopathy—in most cases without experiencing any vision loss. However, diabetic retinopathy can cause blindness and is the most frequent cause of blindness in adults ages 20 to 74.
The good news is, if you have diabetes, the more tightly you control your blood sugar, the less likely you are to get diabetic retinopathy. You should also pay attention to your blood pressure, lipids, such as cholesterol and tryglycerides, and body weight, which may also be risk factors for diabetic retinopathy.
People with diabetes should make sure to schedule an annual visit to an ophthalmologist, because early detection and treatment of diabetic retinopathy can protect one's vision, according to the National Institutes of Health. Even so, 60 percent of people with diabetes in the United States skip annual eye exams, according to research from Wills Eye Hospital in Philadelphia. That's a shortsighted mistake, to say the least. People with diabetes should pay special attention to eye health in general.
Also see Protecting Your Aging Eyes.
Berkeley Wellness
February 22, 2018
Here are the basics about the four leading age-related eye disorders: cataracts, glaucoma, macular degeneration, and diabetic retinopathy.
Cataracts
What it is: A cataract is an opacification (cloudiness) of the eye’s normally clear crystalline lens. Cataracts can occur at any age (in fact, babies can be born with them), but they are most common later in life. In the U.S., about 70 percent of people over age 75 have cataracts. The three common types of cataracts are defined by where they occur in the lens: nuclear, cortical, or posterior subcapsular (in the rear of the lens capsule). Nuclear cataracts are the most common type; the incidence of nuclear cataracts increases with age and cigarette smoking. Cortical cataracts also become more common with age, and are related to lifetime exposure to ultraviolet rays from the sun. Posterior subcapsular cataracts are most likely to occur in younger people. They are often the result of prolonged use of corticosteroids (such as prednisone), inflammation, trauma, or diabetes.
Prevention: Because smoking contributes to the risk of cataracts, stopping the habit is a vital step in cataract prevention. Wearing UV-blocking sunglasses and a hat with a wide brim will help reduce eye exposure to UV radiation and may reduce the risk of cataracts. Researchers disagree about whether some drugs can reduce the risk of cataracts. Results from studies of medications such as aspirin, hormone replacement therapy, and statins have been contradictory. Other research, published in 2015 in Ophthalmology, found that high levels of physical activity were associated with a lower risk of cataracts later in life.
Signs and symptoms: When cataracts first appear, you may not notice changes in your vision. As they progress, however, your vision may become somewhat blurry, you may have trouble seeing at night or in low light, you may become sensitive to light, bright colors may look yellowed or faded, or you may come to need brighter light for reading.
Treatment: Surgery for cataracts involves removing all or part of the lens and replacing it with an intraocular lens implant (IOL). Cataract removal is the most frequently performed surgery in individuals over age 65 and is considered by many doctors to be the most effective surgical procedure in all of medicine. If the eye is normal except for the cataract, surgery will improve vision in more than 95 percent of cases.
Glaucoma
What it is: The second most common treatable cause of blindness in the U.S., glaucoma is a condition in which deterioration of the optic nerve leads to progressive loss of field of vision. There are two main forms: Open-angle glaucoma progresses slowly and produces no obvious symptoms until its late stages. This form of glaucoma is equally common in men and women and is responsible for about 90 percent of glaucoma cases. Angle-closure, or closed-angle, glaucoma occurs more often in people of Asian or Inuit descent; women are at greater risk than men, as are people who are farsighted.
Prevention: Eye drops that lower IOP have been shown to delay the development of open-angle glaucoma in people with elevated intraocular pressure (IOP) and no other signs of glaucoma. For closed-angle glaucoma, laser iridotomy, a procedure in which the laser makes a hole in the iris, can be preventive, although the decision to perform this treatment is complex.
Signs and symptoms: Open-angle glaucoma usually affects both eyes, although IOP levels and the extent of damage to the optic nerve often differ between eyes. Because of the way the optic nerve is structured, the first nerve fibers damaged are those used for peripheral vision. Individuals can have 20/20 vision when looking straight ahead but may have blind spots for images located outside the center of the visual field. Closed-angle glaucoma sometimes occurs as acute attacks that strike when IOP rises rapidly. Signs of an attack include severe pain in the eye, nausea and vomiting, blurred vision, and rainbow halos around lights. Chronic closed-angle glaucoma, like open-angle glaucoma, can cause damage without any noticeable symptoms.
Treatment: Most forms of glaucoma are chronic conditions that cannot be cured. However, open-angle glaucoma can often be treated safely and effectively with medication or surgery, but lifelong use of medication is almost always necessary. Acute angle-closure glaucoma is a medical emergency; if you experience symptoms, contact your ophthalmologist immediately or seek emergency treatment to prevent permanent damage or blindness.
Age-related macular degeneration
What it is: AMD is a condition that affects the macula—the central, most critical part of the retina for sharp vision. In the U.S., it is the leading cause of severe and irreversible loss of central vision in people over age 50. There are two types: The dry form (non-neovascular ) is more common and is caused by aging and thinning of the macula; the wet form (neovascular), which is more damaging, occurs when abnormal blood vessels start growing underneath the retina and leak fluid or blood that can blur or distort central vision.
Prevention: The AREDS and AREDS2 supplement formulas can help slow the progression of the condition in patients with intermediate AMD. The original AREDS formula is not recommended for smokers (or ex-smokers) because the beta carotene in it is associated with an increased risk of lung cancer in them. Some studies have linked UV exposure with AMD, so it makes sense to protect your eyes from the sun. Other suspected risk factors include obesity, high cholesterol levels, and coronary heart disease. Research also suggests that smokers with early AMD are more likely than their nonsmoking counterparts to progress to advanced AMD. For unknown reasons, the incidence of AMD has been declining dramatically in recent generations, so that the risk is nearly 90 percent lower for baby boomers than it was for their grandparents at the same ages, according to a study in JAMA Ophthalmology in December 2017.
Signs and symptoms: The early stages of AMD don’t usually cause symptoms. As the disease progresses, it can cause blurry vision with distance or reading, hazy vision, faded colors, or difficulty seeing when going from bright to dim light. AMD can be detected with a dilated eye exam, so it’s important that you have regular eye exams as you get older.
Treatment: The AREDS formulas can slow the progression of AMD. For wet macular degeneration, laser treatments can destroy the abnormal blood vessels, thus preventing the disease’s progression. For more advanced wet AMD, newer treatments involving injections of anti-VEGF (vascular endothelial growth factor) drugs into the affected eye can reduce the abnormal blood vessels.
Diabetic Retinopathy
If you have diabetes, there's one eye disease that should be on your radar screen: diabetic retinopathy, which can cause blood vessels in the retina to leak fluid or bleed, distorting vision in the process. The underlying reason: Chronically high blood sugar from poorly controlled diabetes can lead to damage to the tiny blood vessels in the retina, which can lead to vision loss and blindness in the worst-case scenario.
Diabetic retinopathy affects some 8 million Americans age 40 and older and is the most common eye complication of diabetes. More than 70 percent of people with type 2 disease will eventually develop some evidence of retinopathy—in most cases without experiencing any vision loss. However, diabetic retinopathy can cause blindness and is the most frequent cause of blindness in adults ages 20 to 74.
The good news is, if you have diabetes, the more tightly you control your blood sugar, the less likely you are to get diabetic retinopathy. You should also pay attention to your blood pressure, lipids, such as cholesterol and tryglycerides, and body weight, which may also be risk factors for diabetic retinopathy.
People with diabetes should make sure to schedule an annual visit to an ophthalmologist, because early detection and treatment of diabetic retinopathy can protect one's vision, according to the National Institutes of Health. Even so, 60 percent of people with diabetes in the United States skip annual eye exams, according to research from Wills Eye Hospital in Philadelphia. That's a shortsighted mistake, to say the least. People with diabetes should pay special attention to eye health in general.
Also see Protecting Your Aging Eyes.
