Tag Archives: eye health

Saving Sight

Eyesight fades a little bit with age. It’s a natural process, one that is an ordinary result of the eye getting older. What is not normal is gradually losing the ability to see things in the center of the visual field, having difficulty adapting to low light levels, not being able to read normally because the words are blurred, or having difficulty making out enough detail on other people’s faces to recognize them.

That is a condition called age-related macular degeneration the most common cause of blindness in developed nations. Macular degeneration runs in families and is more common among smokers and obese people. A healthy diet is recommended to avoid the condition, and studies suggest cholesterol-fighting drugs can help prevent the condition or stop its progress.

Although it’s called age-related macular degeneration and most commonly affects people over age 65, researchers have recently found that the processes within the eye that lead to the condition begin earlier, with some patients starting to show symptoms in their 40s in eye exams. Regular eye exams are an important part of fighting the condition—the degeneration can be slowed or stopped, but lost eyesight cannot be restored. The symptoms of the disease are not always noticeable early on, but there are some signs an eye doctor would be able to spot.

While the cause of macular degeneration isn’t entirely clear, research has found that one culprit might be deposits of minerals forming in the eye. The condition has long been understood to involve fat-and-protein deposits in the retina starving the cells of the center of the eye of needed nutrients. The latest study found the source of these deposits. The scientists discovered that calcium phosphate from the bones and teeth act as seeds, places fat and proteins cluster around to form these blockages. Armed with this information, doctors may be able to diagnose the condition before it really gets underway by looking for calcium phosphate in the eyes.

A different study found that an anti-inflammatory drug called sulindac can help protect the eyes from damage. The researchers determined that the drug helps prevent a type of damage to the cells called oxidative stress, which is behind many signs of aging.

Infectious Conjunctivitis

The inner surface of the eyelid consists of a thin membrane called the conjunctiva. It is one of the places tears are produced, though not to the same extent as in the tear ducts; these tears serve as a lubricant to reduce friction between the eye and eyelid. This layer also helps protect the eye from dust and microorganisms. Despite its usefulness, the conjunctiva is almost never noticed by people until an infection or an allergic reaction causes the inflammation that results in the redness, itching, burning, and sensitivity to light characteristic of conjunctivitis, or pinkeye.

Conjunctivitis can be caused by a viral or bacterial infection, chemical exposure, irritants such as sand or stray eyelashes, or an allergic reaction. Rubbing the eyes makes any form of pinkeye worse, but especially when a chemical or other irritant, or an allergy, is the cause. Bacterial conjunctivitis is possibly the most recognizable form, causing a greenish-yellow discharge that is responsible for a "stuck shut" feeling. Sometimes, pinkeye due to bacterial infection can be associated with a sexually transmitted disease, although this accounts for a very small percentage of eye infections. Bacterial conjunctivitis, left untreated, can cause long-term damage to eye health.

Both the bacterial and viral forms of pinkeye are highly contagious. Someone who has pinkeye should be aware of that and try to take precautions to avoid infecting others, if only out of courtesy. For everyone else, prevention an play a big role in avoiding the disease. Rubbing the eyes can cause or worsen any eye irritation already present, whatever the cause, as well as bringing any microbes on the hands into contact with the eye. Regular hand-washing, such as after cooking using the restroom, or coming in from outside—particularly after using public transit—can also make a significant difference.

Once someone has pinkeye, it is likely to go away on its own faster than most treatments are likely to be effective, particularly it there is no bacterial infection. However, people who have or who have recently had a bout of pinkeye should not wear contact lenses until it is completely cleared up. Eye drops can provide some relief and mitigate irritation.

How Cataracts Happen

As people age, the body’s ability to self-repair starts to diminish. One effect of this is that tissue in the eye starts to stiffen and break down. When the bits of tissue accumulate and block vision, cataracts form—half of all people in the United States of 80 have had cataracts. They are particularly likely in people who have a family history of cataracts or who have type 2 diabetes, who smoke, who drink heavily, who have high blood pressure, who are obese, who spend a lot of time in the sunlight, or who have a history of using corticosteroids, including be prescription for inflammation.

Interestingly, in light of the connection between obesity and cataracts, one thing that prevents cataracts from developing is cholesterol. That’s why, if some studies are accurate, cholesterol-lowering drugs called statins may actually make cataracts more likely to occur. However, different studies have produced different findings. One large-scale study found that statin users are 27 percent more likely to get cataracts the people who never took statins, after taking into account other contributing factors.

Other studies have shown no connection, with researchers noting that both cataracts and use of cholesterol-lowering medications are common among older people. In fact, a study presented in 2013 at the European Society of Cardiology Congress suggested that statins could actually protect patients from cataracts. In this study, statins appeared to lower cataract risk 20 percent. When treatment was given to patients under 50, cataract risk was cut in half. Whatever the reality is, patients who have been prescribed statins are advised to take them, but also to alert their eye care specialists and to be vigilant about cataracts.

Scientists are also working on developing a better understanding of the process by which cataracts form. There are three types of protein in the lens of the eye. Two are the actual material that does into the lens; the third, known as the chaperone protein, ordinarily prevents clumping and helps maintain the shape of the lens. These chaperone proteins, however, are not in unlimited supply. Once they are used up, late in life, the structural proteins have nothing stopping them from forming clumps and causing clouded vision. Researches hope that by studying this system in more depth they will be able to prevent cataracts rather than treating them after they occur.

Looking At Pinkeye

The conjunctiva is a membrane on the inside of the eyelid. Most people would never even realize it was there but for itchiness, eye watering, and light sensitivity when it gets inflamed. Called conjunctivitis—or pinkeye, for the pinkish tinge that develops on the cornea—this inflammation may be caused by viruses, bacteria, or an allergic reaction. When it’s caused by viruses or bacterial infection, pinkeye is contagious, and bacterial conjunctivitis can actually damage the eye if left untreated. Bacterial conjunctivitis is also the most noticeable form, causing a greenish-yellow discharge that tends to glue the eye shut overnight.

Both the viral and bacterial types of conjunctivitis pass easily from person to person. That’s why it’s important for someone who has pinkeye to take steps to avoid spreading the condition. That means wiping down surfaces when possible and maintaining good hygiene techniques. Pinkeye is highly contagious for up to three weeks, so developing and maintaining habits is important. Someone with pinkeye should also avoid touching or rubbing their eyes, or at the very least, use hand sanitizer afterward. Something disposable, such as paper towels or cotton balls, should be used for compresses or applying topical treatments.

Compresses are the best way to deal with conjunctivitis—for viral or allergic conjunctivitis, the only way. Antibiotics can be given, topically or as drops, for the bacterial variety, but when a virus is responsible there’s usually nothing to do except wait it out, which takes about two or three weeks. To help alleviate some of the discomfort, wet a paper towel with cool but not cold water, wring it out and place it on the eyes. This should not be reused, even by the same person. Teabags can also be used as compresses, particularly green tea and chamomile. The teabags should be wettened but not dripping, and should be thrown away after.

When conjunctivitis is an allergic reaction, it isn’t contagious but it also isn’t going to go away as long as exposure to the allergen continues. Pinkeye can be a reaction to dust, dander, pollen, or any other sort of airborne particle. Allergy treatments such as antihistamines can help with this. Another option when it’s an allergic reaction is anti-inflammatory rugs such as decongestants or in severe cases, steroids. Avoiding the allergen, when possible, also helps.

Gene Therapy Helps Restore Sight For Some

The degenerative eye disease choroideremia affects about one in 50,000 Americans. It is a progressive form of blindness in which parts of the eye called the choroid and the retinal pigment epithelium, along with the retina, gradually decay. Ordinarily the epithelium provides materials and protection for the choroid and the retina, while the choroid lines the eye and helps get nourishment to the retina. When these layers start to break down, they can no longer support optical function and vision loss results. The disease runs in families, but the rate and degree of loss varies from person to person. The degeneration is irreversible, and there is currently no treatment that can stop its progress.

Now, however, researchers say a new approach using gene therapy may hold the key to not just stopping the degradation of the eye layers, but restoring sight already lost. Patients are injected with a clean copy of the gene that is damaged in people with the disease. This is intended to supplant the damaged gene and stop the destruction of cells in the eye. The treatment has only been tested in half a dozen patients, but all of them report success. In fact, one of the two patients in the study who had the most advanced choroideremia, with the most profound vision loss, was able to read four lines further down an eye chart six months after treatment, and night vision, in which the loss generally starts, improved in all six subjects.

Researchers warn, however, that these are only preliminary results, and it remains to be seen how well the treatment will work in the long term. In particular, scientists suspect that the treatment slows degeneration, but does not stop it entirely. Even if that is the case, however, the added years of functioning vision are a benefit to patients. Furthermore, the scientists note that the success of this genetic therapy for choroideremia suggests both other avenues to pursue in efforts to battle the disease—which has not proven treatable until this study—and ways to use gene therapy or similar approaches to treat other eye diseases, which may have similar pathologies, be likewise genetically linked, or both.

About Glaucoma

There is fluid in your eye called aqueous humor that helps maintain the shape of the eye and provide necessary nutrients. It circulates, flowing in from ducts in the area around the lens and out between the lens and the iris, maintaining the proper level of pressure in the lens. When the drainage channels are blocked, the fluid builds up, creating too much pressure, resulting on primary open-angle glaucoma, the most common kind.

Primary open-angle glaucoma is painless, but it can rob someone of their sight, and it happens so gradually it may not even be noticeable until it’s too late. The damage caused by glaucoma is irreversible even once treatment has started, so it’s important to get regular eye examinations. That is the only way to detect the condition while it is still easily treatable and before too much vision is lost.

Possibly one of the best known treatments for glaucoma, in certain circles, is medical marijuana. While it does relieve the pressure, the effect fades with the others after a few hours. Eye-drops and oral medications offer longer term relief, as can relaxation techniques, with medicine or by themselves. Scientists recently developed a contact lens that dispenses glaucoma medication, so patients don’t have to remember the drops or work to get the proper dose. In some cases, surgery may be needed to clear the blocked channels and let the aqueous humor flow out of the eye.

Because the damage can’t be reversed, glaucoma prevention is important, particularly in people who are especially susceptible, such as African Americans, people with a family history of glaucoma, people with type 2 diabetes, or anyone over 60. Steroid use can lead to glaucoma. This can’t always be avoided, but if you are at risk, talk to your doctor about an alternative to steroids for asthma or auto-immune disease. Similarly, there appears to be a connection with certain types of oral contraceptives. Studies have linked some surprising things to the development of glaucoma. People who consume caffeine seem to be at increased risk of the condition, though the precise mechanism is not clear. People who already have glaucoma may find it getting worse if they sleep on one side, in the lower eye.

The Downside Of Statin Drugs

Cholesterol is so often treated as poison that one might be tempted to wonder what purpose it serves. It is produced in the body, after all, which suggests that it is not completely useless or entirely malevolent. And in fact, while the tendency is to assume less is better, the reality is more complicated than that. Modern science knows of several important functions served by cholesterol in the body—functions that can be negatively affected by statin drugs that lower cholesterol levels.

Cholesterol is used in the construction of hormones, the chemical signals used to regulate most of what the body does. Hormones guide things like breathing and digesting food and turning it into energy. Bile, which is also part of the digestive process, is another cholesterol product. Even so-called bad cholesterol is used by the body in this way.

Another thing cholesterol does is helping to keep the lens of the eye clear and free of cataracts. The clouding in the eyes caused by characteristics results, in many cases, from flaws in cell regeneration, which cholesterol prevents. That may be why, in a recent study, statin users had as much as a 27 percent higher risk of cataracts than non-users. Cataract risk increases with age in any event, with nearly three in four 80-year-olds having had cataracts at some point.

Statin drugs do two things. They prevent the formation of cholesterol within the body, and they increase absorption of cholesterol that’s already there. Patients who take statins have lower cholesterol levels in part because more of it is simply metabolized. The result of both modes of action is that there’s less cholesterol to form arterial plaque and cause heart disease, but there’s also less available for eye health, resulting in heightened cataract risk.

Other side effects of statin drugs include the possibility of muscle weakness, muscle inflammation, and liver disease, as well as an increased likelihood of type 2 diabetes. Because of the risk, some doctors are moving away from prescribing statin drugs, and there are concerns that they are overused. In many people, dietary changes are sufficient to reduce high cholesterol, without levels dropping so far as to cause problems.

Diabetes And Your Eyesight

Blindness is one of the most common complications of diabetes—80 percent of people who have type 1 or type 2 diabetes for more than a decade have some degree of eye damage, a condition called diabetic retinopathy. Diabetic retinopathy becomes more and more likely as time goes on. It occurs because diabetes is particularly hard on smaller blood vessels, such as those in the eye. These blood vessels are highly prone to damage from the buildup of glucose that occurs in diabetes. Left unchecked, the blood vessels burst, damaging the retina. There are usually no symptoms at first. Once significant damage has occurred, a person with diabetic retinopathy will have blurred or fluctuating vision, missing parts in their vision, floaters, or trouble seeing colors properly. These symptoms happen in both eyes.

Everyone who has type 1 or type 2 diabetes is at risk for diabetic retinopathy, and the risk grows over time. However, there are some factors that can make it more likely. Gestational diabetes can also lead to eye damage, and in fact pregnant women are at even higher risk of eye damage. The damage remains even if the diabetes goes away after pregnancy. Smokers are at high risk of diabetes generally, and at high risk of vision problems if they are diabetic. Smoking also raises blood pressure, and high blood pressure is a risk factor, as is high cholesterol.

There are some steps you can take to lower your risk. The most important is to keep your diabetes under control. High blood sugar is what is responsible for the retinal damage, so managing glucose levels will help protect your eyes. The other important step is to be sure to get your eyes checked regularly, and let your ophthalmologist know that you are diabetic so they know to specifically check for diabetic retinopathy. Just because you have no symptoms doesn’t mean there’s no damage, and if tests find a problem you can work with the doctor to contain it. You may need laser surgery to keep your eyes from getting worse.

Other things you can do are eat a healthy diet and exercise regularly. Keeping yourself at a healthy weight will make controlling your diabetes easier, which in turn will make protecting your eyes easier. Get your cholesterol checked so you can manage that, and talk to your endocrinologist about eye health.

Eye Protection In Winter

You may think of ultraviolet danger in terms of beaches, pools, and other places of summer fun—one survey found nearly a third of people only use eye protection in warm weather—but UV radiation knows no season. In fact, winter snows can reflect the light, making the danger worse. However, precautions are important on cloudy days or when there’s no snow on the ground as well. Any time you are outside, you are exposed to UV and risking associated vision issues, such as cataracts or skin cancer around the eyes. The damage starts early, too. By age 15, 80 percent of children show some sign of UV damage to their eyes, indicating a risk of cataracts, glaucoma, or macular degeneration years or decades down the road, or a condition called pterygium. UV light damages every part of the eye over time.

Pterygium, also known as surfer’s eye, results from exposure to sun, sand, and wind damaging the front layer of the eye, called the conjunctiva. It usually occurs on the side of the eye closest to the nose, a result of the way ultraviolet light beds as it passes through the cornea. The damage results in a growth that is considered benign, but can cause vision problems if it grows in front of the pupil. Symptoms include redness, blurred vision, eye irritation, and sometimes burning. Pterygium can usually be safely left untreated, but sometimes they have to be surgically removed.

Some forms of glaucoma are also caused by UV exposure. That can lead to blindness if left untreated, and in fact is the second-leading cause of blindness worldwide, affecting 10 percent of people over 80. People with glaucoma generally have pressure in the eye, which causes damage to the optic nerve. As the disease progresses, patients often gradually lose peripheral vision or experience eye pain, nausea, or vomiting. However, glaucoma can progress a significant amount before it becomes noticeable, which is why it’s important to get regular exams. Because the damage can be halted but not reversed, treatment for glaucoma is more effective the earlier it’s started. Medicated eye drops—including beta blockers and prostaglandins—are used to reduce eye pressure by slowing the production of fluid or improving drainage. In severe cases, glaucoma, too, may require surgery.

Eye Injury Prevention

Eye injuries are believed to be the most common preventible cause of blindness in the United States. More than a million people suffer eye injuries annually, typically from scratching due to excessive rubbing, chemicals splashing in the eye or an object penetrating it, bleeding, or getting struck and having swelling. Most of those injuries could have been prevented by a few simple precautions, particularly safety goggles:

  • When doing yardwork, such as with a power mower or similar equipment. Grass clippings can fly up and hit you in the eye, and small stones and pebbles that get into the mechanism will come out, and often up, at high speeds.
  • When playing sports, which is one of the leading causes of eye injuries. Baseball is a particular offender, with a relatively hard ball thrown at high speeds, but any sport can cause eye injuries, and a hockey puck travels even faster than a thrown baseball.
  • Around the house. Chemical damage can be as bad as physical. Read labels carefully, looking for warnings not only about eye protection but about what products are not safe to mix together. When you’re working with chemicals make sure you’re in a well-ventilated area.

In addition, it’s important to be careful around fireworks, which can cause serious harm to the eyes as well as everything else if not handled properly.

If you do experience an eye injury, contact a health care professional immediately. Even a seemingly minor injury can cause serious damage if left untreated. In severe cases—such as an eye coming out of the socket entirely—go to the emergency room right away. For swelling, an ice pack should only be used while the person has his or her eye closed. The same types of injury can also cause the bones around the eye socket to fracture, which is a medical emergency. For chemical burns, after—or better yet, while—calling the doctor, flush the eye with clean water to get the chemical out. Always treat eye injury as a medical emergency.