Glaucoma is a disease that damages the eye’s optic nerve. It usually happens when fluid builds up in the front part of the eye. That extra fluid increases the pressure in the eye, damaging the optic nerve. Glaucoma is a leading cause of blindness for people over 60 years old. But blindness from glaucoma can often be prevented with early treatment.
Several large studies have shown that eye pressure is a major risk factor for optic nerve damage. In the front of the eye is a space called the anterior chamber. A clear fluid flows continuously in and out of the chamber and nourishes nearby tissues. The fluid leaves the chamber at the open angle where the cornea and iris meet. When the fluid reaches the angle, it flows through a spongy meshwork, like a drain, and leaves the eye.
In open-angle glaucoma, even though the drainage angle is “open”, the fluid passes too slowly through the meshwork drain. Since the fluid builds up, the pressure inside the eye rises to a level that may damage the optic nerve. When the optic nerve is damaged from increased pressure, open-angle glaucoma-and vision loss—may result. That’s why controlling pressure inside the eye is important.
Another risk factor for optic nerve damage relates to blood pressure. Thus, it is important to also make sure that your blood pressure is at a proper level for the body.
There are two major types of glaucoma.
Primary open-angle glaucoma
This is the most common type of glaucoma. It happens gradually, where the eye does not drain fluid as well as it should (like a clogged drain). As a result, eye pressure builds and starts to damage the optic nerve. This type of glaucoma is painless and causes no vision changes at first.
Some people can have optic nerves that are sensitive to normal eye pressure. This means their risk of getting glaucoma is higher than normal. Regular eye exams are important to find early signs of damage to their optic nerve.
This type happens when someone’s iris is very close to the drainage angle in their eye. The iris can end up blocking the drainage angle. You can think of it like a piece of paper sliding over a sink drain. When the drainage angle gets completely blocked, eye pressure rises very quickly. This is called an acute attack. It is a true eye emergency, and you should call your ophthalmologist right away or you might go blind.
Signs of an acute angle-closure glaucoma attack:
• Vision is suddenly blurry
• Severe eye pain
• See rainbow-colored rings or halos around lights
At first, open-angle glaucoma has no symptoms. It causes no pain. Vision stays normal. Glaucoma can develop in one or both eyes.
Without treatment, people with glaucoma will slowly lose their peripheral (side) vision. As glaucoma remains untreated, people may miss objects to the side and out of the corner of their eye. They seem to be looking through a tunnel. Over time, straight-ahead (central) vision may decrease until no vision remains.
Glaucoma is detected through a comprehensive dilated eye exam that includes the following:
Visual acuity test. This eye chart test measures how well you see at various distances.
Visual field test. This test measures your peripheral (side vision). It helps your eye care professional tell if you have lost peripheral vision, a sign of glaucoma.
Dilated eye exam. In this exam, drops are placed in your eyes to widen, or dilate, the pupils. Your eye care professional uses a special magnifying lens to examine your retina and optic nerve for signs of damage and other eye problems. After the exam, your close-up vision may remain blurred for several hours.
Tonometry is the measurement of pressure inside the eye by using an instrument called a tonometer. Numbing drops may be applied to your eye for this test. A tonometer measures pressure inside the eye to detect glaucoma.
Pachymetry is the measurement of the thickness of your cornea. Your eye care professional applies a numbing drop to your eye and uses an ultrasonic wave instrument to measure the thickness of your cornea.
There is no cure for glaucoma. Vision lost from the disease cannot be restored.
Immediate treatment for early-stage, open-angle glaucoma can delay progression of the disease. That’s why early diagnosis is very important.
Glaucoma treatments include medicines, laser trabeculoplasty, conventional surgery, or a combination of any of these. While these treatments may save remaining vision, they do not improve sight already lost from glaucoma.
Medicines. Medicines, in the form of eye drops or pills, are the most common early treatment for glaucoma. Taken regularly, these eye drops lower eye pressure. Some medicines cause the eye to make less fluid. Others lower pressure by helping fluid drain from the eye.
Before you begin glaucoma treatment, tell your eye care professional about other medicines and supplements that you are taking. Sometimes the drops can interfere with the way other medicines work.
Glaucoma medicines need to be taken regularly as directed by your eye care professional. Most people have no problems. However, some medicines can cause headaches or other side effects. For example, drops may cause stinging, burning, and redness in the eyes.
Many medicines are available to treat glaucoma. If you have problems with one medicine, tell your eye care professional. Treatment with a different dose or a new medicine may be possible.
Because glaucoma often has no symptoms, people may be tempted to stop taking, or may forget to take, their medicine. You need to use the drops or pills as long as they help control your eye pressure. Regular use is very important.
Laser trabeculoplasty. Laser trabeculoplasty helps fluid drain out of the eye. Laser trabeculoplasty is performed in the doctor’s office or eye clinic. A high-intensity beam of light is aimed through the lens and reflected onto the meshwork inside the eye. The laser makes several evenly spaced burns that stretch the drainage holes in the meshwork. This allows the fluid to drain better.
Studies show that laser surgery can be very good at reducing the pressure in some patients. However, its effects can wear off over time.
Conventional surgery. Conventional surgery makes a new opening for the fluid to leave the eye. Conventional surgery often is done after medicines and laser surgery have failed to control pressure.
Conventional surgery is performed on one eye at a time. Usually the operations are four to six weeks apart.
Conventional surgery is about 60 to 80 percent effective at lowering eye pressure. If the new drainage opening narrows, a second operation may be needed.
Age-related macular degeneration (AMD) is a common eye condition and a leading cause of vision loss among people age 50 and older. It causes damage to the macula, a small spot near the center of the retina and the part of the eye needed for sharp, central vision, which lets us see objects that are straight ahead.
In some people, AMD advances so slowly that vision loss does not occur for a long time. In others, the disease progresses faster and may lead to a loss of vision in one or both eyes. As AMD progresses, a blurred area near the center of vision is a common symptom. Over time, the blurred area may grow larger or you may develop blank spots in your central vision. Objects also may not appear to be as bright as they used to be.
AMD by itself does not lead to complete blindness, with no ability to see. However, the loss of central vision in AMD can interfere with simple everyday activities, such as the ability to see faces, drive, read, write, or do close work, such as cooking or fixing things around the house.
Age is a major risk factor for AMD. The disease is most likely to occur after age 60, but it can occur earlier. Other risk factors for AMD include:
Smoking. Research shows that smoking doubles the risk of AMD.
Race. AMD is more common among Caucasians than among African-Americans or Hispanics/Latinos.
Family history and Genetics. People with a family history of AMD are at higher risk. At last count, researchers had identified nearly 20 genes that can affect the risk of developing AMD. Many more genetic risk factors are suspected. Because AMD is influenced by so many genes plus environmental factors such as smoking and nutrition, there are currently no genetic tests that can diagnose AMD, or predict with certainty who will develop it.
The early and intermediate stages of AMD usually start without symptoms. Only a comprehensive dilated eye exam can detect AMD. The eye exam may include the following:
Visual acuity test. This eye chart measures how well you see at distances.
Dilated eye exam. The eye care professional places drops in the patient’s eyes to widen or dilate the pupils. This provides a better view of the back of the eye. Using a special magnifying lens,
Amsler grid. The eye care professional also may look at an Amsler grid. Changes in the central vision may cause the lines in the grid to disappear or appear wavy, a sign of AMD.
Fluorescein angiogram. In this test, which is performed by an ophthalmologist, a fluorescent dye is injected into the arm. Pictures are taken as the dye passes through the blood vessels in the eye. This makes it possible to see leaking blood vessels, which occur in a severe, rapidly progressive type of AMD. In rare cases, complications to the injection can arise, from nausea to more severe allergic reactions.
Optical coherence tomography. Optical coherence tomography (OCT) is a non-invasive imaging test. OCT uses light waves to take cross-section pictures of the patient’s retina.
There are three stages of AMD defined in part by the size and number of drusen under the retina. It is possible to have AMD in one eye only, or to have one eye with a later stage of AMD than the other.
Early AMD. Early AMD is diagnosed by the presence of medium-sized drusen, which are about the width of an average human hair. People with early AMD typically do not have vision loss.
Intermediate AMD. People with intermediate AMD typically have large drusen, pigment changes in the retina, or both. Again, these changes can only be detected during an eye exam. Intermediate AMD may cause some vision loss, but most people will not experience any symptoms.
Late AMD. In addition to drusen, people with late AMD have vision loss from damage to the macula. There are two types of late AMD:
In geographic atrophy (also called dry AMD), there is a gradual breakdown of the light-sensitive cells in the macula that convey visual information to the brain, and of the supporting tissue beneath the macula. These changes cause vision loss.
In neovascular AMD (also called wet AMD), abnormal blood vessels grow underneath the retina. (“Neovascular” literally means “new vessels.”) These vessels can leak fluid and blood, which may lead to swelling and damage of the macula. The damage may be rapid and severe, unlike the more gradual course of geographic atrophy. It is possible to have both geographic atrophy and neovascular AMD in the same eye, and either condition can appear first.
AMD has few symptoms in the early stages, so it is important to have your eyes examined regularly.
Currently, no treatment exists for early AMD, which in many people shows no symptoms or loss of vision. A comprehensive dilated eye exam should be performed at least once a year. The exam will help determine if the condition is advancing.
Intermediate and late AMD
Researchers at the National Eye Institute tested whether taking nutritional supplements could protect against AMD in the Age-Related Eye Disease Studies (AREDS and AREDS2). They found that daily intake of certain high-dose vitamins and minerals can slow progression of the disease in people who have intermediate AMD, and those who have late AMD in one eye.
The first AREDS trial showed that a combination of vitamin C, vitamin E, beta-carotene, zinc, and copper can reduce the risk of late AMD by 25 percent. The AREDS2 trial tested whether this formulation could be improved by adding lutein, zeaxanthin or omega-3 fatty acids. Omega-3 fatty acids are nutrients enriched in fish oils. Lutein, zeaxanthin and beta-carotene all belong to the same family of vitamins, and are abundant in green leafy vegetables.
The AREDS2 trial found that adding lutein and zeaxanthin or omega-three fatty acids to the original AREDS formulation (with beta-carotene) had no overall effect on the risk of late AMD. However, the trial also found that replacing beta-carotene with a 5-to-1 mixture of lutein and zeaxanthin may help further reduce the risk of late AMD. Moreover, while beta-carotene has been linked to an increased risk of lung cancer in current and former smokers, lutein and zeaxanthin appear to be safe regardless of smoking status.
Advanced neovascular AMD
Neovascular AMD typically results in severe vision loss. However, eye care professionals can try different therapies to stop further vision loss. The condition may progress even with treatment.
Injections: One option to slow the progression of neovascular AMD is to inject drugs into the eye. With neovascular AMD, abnormally high levels of vascular endothelial growth factor (VEGF) are secreted in your eyes. VEGF is a protein that promotes the growth of new abnormal blood vessels. Anti-VEGF injection therapy blocks this growth.
Photodynamic therapy: This technique involves laser treatment of select areas of the retina.
Laser surgery: Eye care professionals treat certain cases of neovascular AMD with laser surgery, though this is less common than other treatments. It involves aiming an intense “hot” laser at the abnormal blood vessels in patient’s eyes to destroy them. This laser is not the same one used in photodynamic therapy which may be referred to as a “cold” laser.
The retina converts the light rays into impulses that travel through the optic nerve to our brain, where they are interpreted as the images we see. A healthy, intact retina is key to clear vision.
The middle of our eye is filled with a clear gel called vitreous that is attached to the retina. Sometimes tiny clumps of gel or cells inside the vitreous will cast shadows on the retina, and the patient may sometimes see small dots, specks, strings or clouds moving in the field of the vision. These are called floaters.
Usually, the vitreous moves away from the retina without causing problems. But sometimes the vitreous pulls hard enough to tear the retina in one or more places. Fluid may pass through a retinal tear, lifting the retina off the back of the eye — much as wallpaper can peel off a wall. When the retina is pulled away from the back of the eye like this, it is called a retinal detachment.
The retina does not work when it is detached and vision becomes blurry. A retinal detachment is a very serious problem that almost always causes blindness unless it is treated with retinal surgery.
Symptoms of a retinal tear and a retinal detachment can include the following:
• A sudden increase in size and number of floaters, indicating a retinal tear may be occurring;
• A sudden appearance of flashes, which could be the first stage of a retinal tear or detachment;
• Having a shadow appear in the periphery (side) of the field of vision;
• Seeing a gray curtain moving across the field of vision;
• A sudden decrease in the vision.
A retinal tear or a detached retina is repaired with a surgical procedure.
Torn retina surgery
Most retinal tears need to be treated by sealing the retina to the back wall of the eye with laser surgery or cryotherapy (a freezing treatment). Both of these procedures create a scar that helps seal the retina to the back of the eye. This prevents fluid from traveling through the tear and under the retina, which usually prevents the retina from detaching.
Laser surgery (photocoagulation)
With laser surgery, the ophthalmologist uses a laser to make small burns around the retinal tear. The scarring that results seals the retina to the underlying tissue, helping to prevent a retinal detachment.
Freezing treatment (cryopexy)
The eye surgeon uses a special freezing probe to apply intense cold and freeze the retina around the retinal tear. The result is a scar that helps secure the retina to the eye wall.
Detached retina surgery
Almost all patients with retinal detachments must have surgery to place the retina back in its proper position. Otherwise, the retina will lose the ability to function, possibly permanently, and blindness can result. The method for fixing retinal detachment depends on the characteristics of the detachment. In each of the following methods, the ophthalmologist will locate the retinal tears and use laser surgery or cryotherapy to seal the tear.
This treatment involves placing a flexible band (scleral buckle) around the eye to counteract the force pulling the retina out of place. The ophthalmologist often drains the fluid under the detached retina, allowing the retina to settle back into its normal position against the back wall of the eye. This procedure is performed in an operating room.
In this procedure, a gas bubble is injected into the vitreous space inside the eye in combination with laser surgery or cryotherapy. The gas bubble pushes the retinal tear into place against the back wall of the eye. Sometimes this procedure can be done in the ophthalmologist’s office.
This surgery is commonly used to fix a retinal detachment and is performed in an operating room. The vitreous gel, which is pulling on the retina, is removed from the eye and usually replaced with a gas bubble.
A cataract is a clouding of the lens in the eye that affects vision. Most cataracts are related to aging. Cataracts are very common in older people. A cataract can occur in either or both eyes.
Age-related cataracts can affect the vision in two ways:
The lens consists mostly of water and protein. When the protein clumps up, it clouds the lens and reduces the light that reaches the retina. The clouding may become severe enough to cause blurred vision. Most age-related cataracts develop from protein clumpings. When a cataract is small, the cloudiness affects only a small part of the lens. You may not notice any changes in your vision. Cataracts tend to “grow” slowly, so vision gets worse gradually. Over time, the cloudy area in the lens may get larger, and the cataract may increase in size. Seeing may become more difficult. Your vision may get duller or blurrier. The clear lens slowly changes to a yellowish/brownish color, adding a brownish tint to vision.
The risk of cataract increases with age. Other risk factors for cataract include:
• Certain diseases (for example, diabetes).
• Personal behavior (smoking, alcohol use).
• The environment (prolonged exposure to ultraviolet sunlight).
• Cloudy or blurry vision.
• Colors seem faded.
• Headlights, lamps, or sunlight may appear too bright. A halo may appear around lights.
• Poor night vision.
• Double vision or multiple images in one eye. (This symptom may clear as the cataract gets larger.)
• Frequent prescription changes in your eyeglasses or contact lenses.
Different Types of Cataract
Secondary cataract. Cataracts can form after surgery for other eye problems, such as glaucoma. Cataracts also can develop in people who have other health problems, such as diabetes. Cataracts are sometimes linked to steroid use.
Traumatic cataract. Cataracts can develop after an eye injury, sometimes years later.
Congenital cataract. Some babies are born with cataracts or develop them in childhood, often in both eyes. These cataracts may be so small that they do not affect vision. If they do, the lenses may need to be removed.
Radiation cataract. Cataracts can develop after exposure to some types of radiation.
Slit-lamp exam. The ophthalmologist will examine the cornea, iris, lens and the other areas at the front of the eye. The special slit-lamp microscope makes it easier to spot abnormalities.
Retinal exam. Using the slit lamp, the doctor looks for signs of cataract. The ophthalmologist will also look for glaucoma, and examine the retina and optic nerve.
Refraction and visual acuity test. This test assesses the sharpness and clarity of the vision.
There is no way to prevent cataract development. Currently, the only way to treat cataracts is to surgically remove the natural lens in the eye. During cataract surgery, the cloudy natural lens is removed and replaced with a clear artificial lens. That lens is called an intraocular lens (IOL). Cataract removal surgery may be done in an outpatient surgery center or in a hospital.
Dry eye occurs when the quantity and/or quality of tears fails to keep the surface of the eye adequately lubricated. Experts estimate that dry eye affects millions of adults in the United States. The risk of developing dry eye increases with advancing age. Women have a higher prevalence of dry eye compared with men.
Tears are a complex mixture of fatty oils, water, mucus, and more than 1500 different proteins that keep the surface of the eye smooth and protected from the environment, irritants, and infectious pathogens.
Tears form in three layers:
An outer, oily (lipid) layer, produced by the Meibomian glands, keeps tears from evaporating too quickly and helps tears remain on the eye.
A middle (aqueous) layer contains the watery portion of tears as well as water-soluble proteins. This layer is produced by the main lacrimal gland and accessory lacrimal glands. It nourishes the cornea and the conjunctiva, the mucous membrane that covers the entire front of the eye and the inside of the eyelids.
An inner (mucin) layer, produced by goblet cells, binds water from the aqueous layer to ensure that the eye remains wet.
Dry eye causes a scratchy sensation or the feeling that something is in the eye. Other symptoms include stinging or burning, episodes of excess tearing that follow periods of dryness, discharge, pain, and redness in the eye. People with dry eye may also feel as if their eyelids are heavy and may experience blurred vision.
Dry eye can occur when basal tear production decreases, tear evaporation increases, or tear composition is imbalanced. Factors that can contribute to dry eye include the following:
• Medications including antihistamines, decongestants, antidepressants, birth control pills, hormone replacement therapy to relieve symptoms of menopause, and medications for anxiety, Parkinson’s disease, and high blood pressure have been associated with dry eye.
• Advancing age is a risk factor for declines in tear production. Dry eye is more common in people age 50 years or older.
• Rosacea (an inflammatory skin disease) and blepharitis (an inflammatory eyelid disease) can disrupt the function of the Meibomian glands.
• Autoimmune disorders such as Sjögren’s syndrome, lupus, scleroderma, and rheumatoid arthritis and other disorders such as diabetes, thyroid disorders, and Vitamin A deficiency are associated with dry eye.
• Women are more likely to develop dry eye. Hormonal changes during pregnancy and after menopause have been linked with dry eye. Women also have an increased risk for autoimmune disorders.
• Windy, smoky, or dry environments increase tear evaporation.
• Seasonal allergies can contribute to dry eye.
• Prolonged periods of screen time encourage insufficient blinking.
• Laser eye surgery may cause temporary dry eye symptoms.
Some treatments focus on reversing or managing a condition or factor that’s causing your dry eyes. Other treatments can improve the tear quality or stop the tears from quickly draining away from the eyes.
Treating the underlying cause of dry eyes
In some cases, treating an underlying health issue can help clear up the signs and symptoms of dry eyes. For instance, if a medication is causing the dry eyes, the doctor may recommend a different medication that doesn’t cause that side effect.
Prescription medications used to treat dry eyes include:
Drugs to reduce eyelid inflammation. Inflammation along the edge of your eyelids can keep oil glands from secreting oil into the tears. The doctor may recommend antibiotics to reduce inflammation. Antibiotics for dry eyes are usually taken by mouth, though some are used as eye drops or ointments.
Eye drops to control cornea inflammation. Inflammation on the surface of the eyes (cornea) may be controlled with prescription eye drops that contain the immune-suppressing medication cyclosporine (Restasis) or corticosteroids. Corticosteroids are not ideal for long-term use due to possible side effects.
Eye inserts that work like artificial tears. In case of moderate to severe dry eye symptoms and for patients that artificial tears don’t help, another option may be a tiny eye insert that looks like a clear grain of rice.
Tear-stimulating drugs. Drugs called cholinergics (pilocarpine, cevimeline) help increase tear production. These drugs are available as pills, gel or eye drops.
- American Academy of Ophthalmology. Glaucoma, 2015. Available at: https://www.aao.org/eye-health/diseases/glaucoma-symptoms
- National Eye Institute (NEI). Facts about glaucoma, 2015. Available at: https://nei.nih.gov/health/glaucoma/glaucoma_facts
- American Academy of Ophthalmology. Age-related macular degeneration, 2018. Available at: https://www.aao.org/eye-health/diseases/amd-macular-degeneration
- American Academy of Ophthalmology. Retinal Detachment: What Is Torn or Detached Retina; 2016. Available at: https://www.aao.org/eye-health/diseases/detached-torn-retina
- National Eye Institute (NEI). Facts about Cataract, 2015. Available at: https://nei.nih.gov/health/cataract/cataract_facts
- National Eye Institute (NEI). Facts about Dry Eye, 2017. Available at: https://nei.nih.gov/health/dryeye/dryeye
- Mayo Clinic. Dry eyes. Available at: https://www.mayoclinic.org/diseases-conditions/dry-eyes/diagnosis-treatment/drc-20371869