New Research Explains How UV Exposure May Contribute to Cataracts

UV exposure may contribute to cataracts

Photo credit: Morguefile

A new study, funded in part by the National Eye Institute (NEI), explains how the sun’s damaging rays can increase the risk of cataracts, firming up a link between ultraviolet (UV) rays and oxidative stress, the harmful chemical reactions that can occur when our cells consume oxygen and other fuels to produce energy.

When a cataract forms, the proteins inside the lens cells show signs of oxidative damage and clump together, scattering light instead of transmitting it. How this oxidative damage occurs in the lens, where cells receive little or no oxygen, had not been explained. The study theorizes that oxidative stress is responsible for this clumping effect, essentially substituting UV light for oxygen to trigger harmful oxidative reactions in the lens. And while prior studies have supported this theory, this new study has unveiled a play-by-play of the chemical changes induced in the lens by UV light.

In this new study, researchers tested the effects of UVA light on proteins and chemicals found in lens cells. They found that in the absence of oxygen, UVA light can trigger a chain reaction that begins with amino acid derivatives called kynurenines and ends with protein glycation in the lens, which is typical of cataracts.

While UV light has long been suspected to play a role in cataract formation, this study firms up the link, and reiterates the importance of wearing UV-blocking sunglasses to protect your eyes the sun’s harmful rays.

June is Cataract Awareness Month: How Much Do You Understand About the Disease?

cataract FAQs

Photo credit: Morguefile

June is Cataract Awareness month. According to the American Academy of Ophthalmology (AAO), approximately 24.5 million Americans suffer from cataracts. If not treated through surgery, cataracts can lead to severe vision impairment. Also, the longer cataracts are left untreated, the more difficult it can be to treat the disease and restore vision. To help raise awareness of the eye disease and promote early detection, the AAO has answered hundreds of questions from the public about cataracts, including the following five frequently asked questions:

Can you have 20/20 vision and still have cataracts?

Yes. According to AAO member Jeffrey Whitman, M.D., “Having a cataract just means that the lens of your eye has become cloudy and hardened — a process that begins at around 50 years of age and does not preclude 20/20 vision. It is only when it becomes visually significant — that is, when it degrades your vision, changes color perception, or causes glare at nighttime, that it requires surgical care.”

How can I keep cataracts from getting worse?

According to AAO member Charles P. Wilkinson, M.D., complete prevention is difficult, but most helpful practices include wearing sunglasses and avoiding UV exposure, avoiding steroid eye drops unless absolutely necessary, and avoiding medications that may be associated with cataract progression, including psoralens, chlorpromazine, and certain glaucoma medications. Talk with your doctor for more specifics, and to help you weigh any risks versus benefits with these and other drugs.

Are cataracts painful?

According to Wayne Bizer, D.O., “Cataracts do not cause pain except if they have been allowed to remain untreated for too long. In this case they cause a lot of pain and light sensitivity. Consult your ophthalmologist immediately if you are having eye pain.”

Are there alternative treatments to cataract surgery, such as eye drops or other drugs?

According to David F. Chang, M.D., “No, there is no medical or drug treatment to reverse the progressive aging changes that produce a cataract.”

How long is recovery time after cataract surgery?

Recovery time is typically several days, although there are several factors that may influence your recovery time, and individual results may vary. “Some issues may occur that require a longer recovery period, such as other eye conditions or rare surgery complications,” says Gary Hirshfield, M.D. “Additionally, if both eyes need to be done and you are significantly near- or far-sighted, then there may be a period of time in between the surgery for each eye where the differences between the eyes may make your tasks difficult. Also, depending upon the surgical approach you may need a change in your eyeglass prescription, which is usually done at about four weeks. However that can be accelerated to just several days provided you understand that the prescription may need to be revised in several weeks or months.”

For all more questions on cataracts, or to ask your own, please visit www.geteyesmart.org/ask.

5 Tips for Optimal Eye Health

Photo credit: Morguefile

Photo credit: Morguefile

While millions of Americans suffer from eye diseases such as cataracts, glaucoma, AMD and diabetic retinopathy, there is much that patients can take on themselves that generally benefit their long-term eye health, and may even slow the progression of some of these diseases:

  1. Quit smoking. Smoking has been linked to visual impairment among older adults with cataracts and AMD, according to the National Institute of Health. In fact, studies have shown smoking increases the risk of AMD by three to four times.
  2. Control your cholesterol. Studies have correlated high plasma cholesterol levels and a high intake of saturated fat with AMD, according to the National Institute of Health. To reduce the risk of AMD or to prevent further damage, patients are advised to reduce their cholesterol and saturated fat intake.
  3. Eat a diet rich in green, leafy vegetables and fish. In addition to low cholesterol, patients should aim to eat a diet rich with vegetables and fish, which are high in vitamins A, C and E, as well as omega-3 fatty acids. According to the Harvard Health Letter, in addition to fish and green vegetables, consider eggs, strawberries, almonds and grapefruit.
  4. Wear a hat and sunglasses when outdoors. Whether it’s a sunny day or overcast, be sure to wear a brimmed hat and UVA/UVB sunglasses, as prolonged sun exposure may increase the chances of getting cataracts.
  5. Get your eyes checked. According to the National Eye Institute, everyone after age 50 should have a comprehensive dilated eye exam. Many eye diseases have no warning signs in their early stages, and regular eye exams could identify many diseases before significant vision loss occurs.

Claude Monet’s productive ‘ultraviolet period’

A wonderful aspect of being responsible for this blog is that is that I never know what I am going to be writing about next.

One day I might be exploring the vision of animals or discussing the latest vision-related technology; on another I might be looking into what a hit movie can teach us about the history of eye care or learning more about the incredible capacity humans have to overcome adversity.

So, although I never thought that I would someday use this forum to discuss the connection between cataracts and the art
movement known as impressionism, I really shouldn’t be surprised!

Claude Monet, who lived from 1840 to 1926, actually gave impressionism its name when he entitled one of his paintings “Impression:
Sunrise.”

Monet and fellow impressionists did nothing short of revolutionize painting, which formerly was extremely literal; an artist painting a water lily, for example, would most likely seek to replicate it – the water lily on the canvas would be instantly recognizable as such.

Impressionists, however, would seek to convey the feeling of a water lily by focusing on how the light was affecting them and using unique visual angles.

I chose water lilies as my example, of course, because Monet is probably most famous for his 250 oil paintings of water lilies that graced the pond at his home outside of Paris.

“Filling the canvas, the surface of the pond becomes a world in itself, inspiring a sense of immersion in nature,” says one art historian. “Monet’s observations of the changing patterns of light on the surface of the water become almost abstract.”

Monet himself said about his approach, “The subject is not important to me; what I want to reproduce is what exists between the subject and me.”

You may be wondering what all this talk about  impressionism and water lilies is doing on a vision blog. The connection is cataracts: a clouding of the cornea that is a very common disease of aging. By some estimates, more than half of all adults 60 years old have cataracts.

Monet was a prolific painter well into old age, but as he grew older, cataracts caused his vision to become cloudy.

“He complained to friends that he felt as if he saw everything in a fog,” writes Carl Zimmer. “After years of failed treatments, he agreed at age 82 to have the lens of his left eye completely removed. Light could now stream through the opening unimpeded. Monet could now see familiar colors again. And he could also see colors he had never seen before. Monet began to see—and to paint—in ultraviolet.”

That’s remarkable, of course, because humans don’t usually see “in ultraviolet,” although birds, bees and some other animals do. In some butterfly species, for example, the males and females look identical to humans. But in UV light, it’s clear that males are decked out in
patterns invisible to us. Humans can’t see those patterns because, as Zimmer points out, the lenses of our eyes filter out most ultraviolet rays.

That explains why, when Monet had the lens of eye his removed, he saw a world that few of us will ever experience.

“Flowers remained one of his favorite subjects, Zimmer writes.  But with the lens removed “…now the flowers were different. When most people look at water lily flowers, they appear white. After his cataract surgery, Monet’s blue-tuned pigments could grab some of the UV light bouncing off of the petals. He started to paint the flowers a whitish-blue.”

If we live long enough, the odds are good that, like Monet, you and I will develop cataracts. Today, cataract surgery is routine, with an estimated 1.5 million cataract surgeries performed every year in the United States alone, so the chances of us ever seeing “in ultraviolet” like Monet are extremely slim.

Visual Hallucinations: Not Necessarily a Sign of Mental Illness or Serious Disease

Illustration by: casajordi

Chances are you’ve never heard of Charles Bonnet, or even of the eye condition that bears his name. But his story, and the nature of the condition was the first to diagnose, are both very interesting.

Bonnet was a Swiss philosopher and naturalist who lived from 1720-1793. In 1760, he noted that his 87-year-old grandfather, who suffered from near-total vision loss due to cataracts, was seeing things. Literally. His complex, vivid visual hallucinations included men, women, birds, buildings, tapestries and carriages. His grandfather was otherwise in good health, both mentally and physically.

The condition Bonnet first noted 250 years ago is now known as Charles Bonnet syndrome. One reason for a lack of general awareness about it may be due to the stigma associated with visual hallucinations: people who experience them may naturally fear they have a mental illness, and thus be reluctant to report them.

But, as is the case with Charles Bonnet syndrome, visual hallucinations are not necessarily symptomatic of mental illness, or of an underlying serious condition such as Parkinson’s disease and Alzheimer’s disease, with which they are sometimes associated.

According to Lighthouse International, roughly one third of people with low vision develop Charles Bonnet syndrome. That includes people with serious eye conditions including age-related macular degeneration, cataracts, diabetic retinopathy, and other eye disorders. The hallucinations are more likely to occur while awake, alone, and in dim light, or during periods of physical inactivity.

The visual hallucinations associated with Charles Bonnet syndrome usually dissipate within a year or 18 months, apparently because of adjustments the brain makes to accommodate vision loss. Although treatment is available, once patients are reassured that their visual hallucinations are not symptomatic of mental illness or serious disease, many learn to live with them.

It goes without saying that you should report any changes to your vision—which certainly includes seeing things that you know aren’t there—to a physician, but I will say it anyway. It may be a difficult call to make, but it will be an important one.

Current News in Eye Health

Photo by: Denise A. Wells

Here’s a roundup of some the eye-health related news that has crossed my desk in recent weeks.

Study links diabetic retinopathy and diminished brainpower

The results of a recent study in the United Kingdom indicate a connection between diabetic retinopathy (which is the leading cause of blindness in that country’s working-age population) and diminished brainpower, including poor memory, in people with Type 2 diabetes. The study looked at 1,066 people with Type 2 diabetes aged between 60 and 75 years old. The results were announced earlier this year at Diabetes UK’s Annual Professional Conference.

Subretinal implants restore vision to blind patients in clinical trial

A German company recently reported success in the first human trial of its subretinal implants for the visually impaired. The company says the results of the trial in 11 blind patients exceeded its expectations. One patient who received the implant said: “When the microchip was turned on, I immediately was able to distinguish light from dark and see outlines of objects. As I got used to the implant, my vision improved dramatically. Most impressively, I could recognize the outlines of people and differentiate heights and arm movements from 20 feet away.”

Connection seen between antidepressants and cataracts

Canadian researchers say the results of a recent study show that people who take selective serotonin reuptake inhibitors (SSRIs) to treat their depression may have a higher-than-average risk of developing cataracts. The study found that people taking SSRIs were 15 percent more likely to be diagnosed with cataracts than those not taking these drugs; however, the researchers do not see this correlation as a reason to stop taking the drugs.

Can “Avatar” and “Alice” diagnose vision problems?

If watching the 3D versions of “Avatar” or “Alice in Wonderland” gave you a headache or made you feel a bit queasy, you might have an undiagnosed vision problem. In a recent interview, Doctor David Granet, director of pediatric ophthalmology at the UCSD School of Medicine, said most people feel somewhat fatigued after experiencing a 3D movie, but others are affected more dramatically, which can indicate eye problems. And he cautions parents to listen to their children. “If they say it looked like every other movie or say their eyes felt funny, I got a bad headache or I felt sick to my stomach, it’s time to say ‘let’s go to the ophthalmologist and get checked.’”

Don’t Let the Smoke Get in Your Eyes

Photo by: loungerie

According to a recent study, we can add another serious eye disease—uveitis—to the list of those associated with smoking, which already includes age-related macular degeneration (AMD) and cataracts.

The study, which was reported in Ophthalmology, the journal of the American Academy of Ophthalmology, is the first to specifically examine the impact of smoking on uveitis, which is a major cause of blindness in the United States and around the world.

Uveitis causes swelling and irritation of the uvea, a layer of the eye that provides most of the blood supply to the retina. Uveitis can affect one or both eyes with rapidly developing symptoms that can include blurred vision, dark, floating spots; eye pain, redness of the eye and sensitivity to light.

Although uveitis can affect people of any age, it is most often seen in middle-aged adults, and it tends to primarily affect women.

“Cigarette smoke includes compounds that stimulate inflammation within the blood vessels, and this may contribute to immune system disruption and uveitis,” said one of the study’s authors.

If the results are this study can be replicated, physicians will have one more reason to advise their patients not to smoke (although there are plenty of them already!).

Prevent Blindness America, a leading volunteer eye health and safety organization, has put together a comprehensive online resource about uveitis that I highly recommend. The Uveitis Learning Center for Patients and Consumers provides useful information about the causes, diagnosis and treatment of the condition.

Doctor’s orders (for the sake of more than just your vision): If you don’t smoke, don’t start. If you smoke, stop. If you can’t stop, get help.

My Top Ten Tips to Improve Eye Health

Photo by: woodleywonderworks

Photo by: woodleywonderworks

Thanks in large part to the regular David Letterman feature, “Top Ten” lists are a very popular, so I thought I would offer one of my own. Here is my list of the Top Ten things you can do today on behalf of your eye health.

Number 10
Take regular breaks when you are using computer. Remember the “20/20 Rule”: look away from your computer every 20 minutes for at least 20 seconds.

Number 9
Ladies–throw out that old eye makeup, which can irritate your eyes.

Number 8
Don’t smoke. Smoking is as bad for your eyes as it is for the rest of your body. It has been linked to age-related macular degeneration (AMD), cataracts and optic nerve damage, all of which can lead to blindness.

Number 7
If you are heading out to play racquetball, hockey, lacrosse or any other sport that can pose a risk to your eyes, make sure you pack your eye protection. If you don’t have goggles or a mask, stop and pick one up—then have some fun!

Number 6
If you don’t know your family’s eye health history, find out about it. A family history of glaucoma, for instance, greatly increases the chance that you will suffer from it, too. That’s something that you and your eye physician should know about.

Number 5
Eat vision-friendly foods. That means, of course, carrots (which are indeed good for your eyes), but other vegetables and fruits are also good. Dark, leafy greens like spinach, kale and collard greens provide great vision nutrients, and your vision will also benefit from eating fish high in omega-3 fatty acids.

Number 4

If you wear contact lenses, use them hygienically. Always wash your hands thoroughly before putting them in or taking them out. Disinfect them as instructed and replace them as appropriate.

Number 3
If you are overweight, do something about it! Carrying extra weight increases your risk of developing diabetes and other conditions that can lead to vision loss, such as diabetic retinopathy and glaucoma. Get out and exercise today!

Number 2
Wear your shades. Sure, they look good, but what’s more important is that they will protect your eyes from the sun’s ultraviolet rays. Look for sunglasses that block out 99 to 100 percent of both UV-A and UV-B radiation.

Number 1
If you are over 40 and have not had a comprehensive eye exam in over a year, schedule one today. Ditto if you are not yet 40 and have not had a comprehensive eye exam in the last two years. Changes to your vision can occur so gradually that you can’t notice them—but your physician will.