Eye Health and Diet

Healthy vision is important in ensuring quality of life. Two common threats to aging eyes are cataracts and age-related macular degeneration (AMD) which can, however, be prevented to some extent by a good diet.

Close up of the senile cataract during eye examination, senile cataract, mature cataract, neuclear sclerosis cataract. Image Credit: ARZTSAMUI / Shutterstock

 

Some important nutrients are found in common foods, and including them in the daily diet will help to preserve good vision throughout life. Antioxidants protect tissues from the toxic effects of free radicals which lead to a breakdown of cell membranes and nucleic acids. Free radicals are formed when tissue is exposed to ultraviolet radiation as from direct sunlight, in cigarette smoke, and other air pollutants. The retina is exposed to a lot of light and is therefore a prime spot for free radical damage, which makes it all the more important to provide antioxidants that reduce the high level of oxidative stress.

Specific Nutrients

Lutein and zeaxanthin: Found in spinach and kale, as well as other green leafy vegetables, and also eggs, these powerful antioxidants, which are typically found together in food, are known to reduce the risk of AMD as well as cataracts. They enter the retina and the lens and prevent degenerative changes, absorbing light frequencies such as blue and ultraviolet frequencies, which promote free radical formation, especially the vulnerable macular area. Other sources include kiwis, grapes, collard greens, and broccoli.

Lutein and zeaxanthin foods, info graphic food, fruit and vegetable icon vector. Image Credit: Plalek / Shutterstock

Vitamin C or ascorbic acid is found in fruits and vegetables, and may reduce the risk of cataracts. AMD may also be slowed if vitamin C and other nutritional factors are taken in combination. Vitamin C is found in grapefruit, strawberries, Brussels sprouts, ripe papayas, oranges, and green peppers.

Vitamin E or alpha-tocoferol is another powerful antioxidant found in nuts, sweet potatoes, and fortified cereals. It is also found in sunflower seeds, wheat germ oil, and vegetable oils.

Essential fatty acids: these fats are not synthesized in the human body but are required for the proper health and functioning of the nervous system, for energy metabolism and immunity. Among these, omega-3 fatty acids like DHA (docosahexaenoic acid) are vital for retinal function and for the development of vision, being concentrated in the outer parts of the photoreceptor cells. These are anti-inflammatory agents, which helps to prevent AMD. These fatty acids are found in salmon, herring and sardines, as well as tuna, halibut and flounder. Two servings or more a week are advised.

Zinc: this trace mineral is a cofactor in the transport of vitamin A from its storage site in the liver to the retina, where it is converted to melanin. This black pigment is essential in protecting retinal tissues against photodamage. High concentrations of zinc are present in the retina and the choroidal vascular tissue under the retina. Zinc is found in white meats from turkey, oysters, and crab meat, as well as eggs, peanuts, whole grains, and red meats.

Beta carotene which is found in all vegetables and fruits that are deep yellow or orange is part of the essential visual pigments, and its deficiency causes night blindness. Pumpkins, red peppers, kale, carrots, sweet potatoes and winter squash are all prime sources.

Supplements – Do They Play a Role?

AMD may be prevented or slowed using supplements made to AREDS standards. AREDS stands for the pivotal Age-Related Eye Disease Studies which tested the formula of this mix of antioxidants clinically. The current AREDS 2 version contains more lutein and zeaxanthin than before, which covers any dietary deficiency. Unlike many other supplements, it does not have beta-carotene and is therefore safe for smokers or those who have just quit. In this subgroup, this nutrient could cause a higher risk of lung cancer, though only at very high doses.

While no research suggests exactly how much of each of these nutrients is necessary to keep vision in good working order, the good old rule of five or more servings of colorful fruits and vegetables every day, with fish at least twice a week, seems to be most helpful in preventing eye problems with age.

Sources
www.aoa.org/…/diet-and-nutrition
www.health.harvard.edu/…/top-foods-to-help-protect-your-vision
https://www.health.ny.gov/publications/0911/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3693724/
https://www.moorfields.nhs.uk/content/your-eye-health

Written by

Dr. Liji Thomas


Glaucoma: Symptoms, treatment and prevention

 

Glaucoma is often called the “silent thief of sight,” because most of its types typically cause no pain and produce no symptoms until noticeable vision loss occurs.

For this reason, glaucoma often progresses undetected until the optic nerve already has been irreversibly damaged.

What is glaucoma?

Glaucoma is a group of related eye disorders that cause damage to the optic nerve that carries information from the eye to the brain.

In most cases, glaucoma is associated with higher-than-normal pressure inside the eye — a condition called ocular hypertension. But it can also occur when intraocular pressure (IOP) is normal. If untreated or uncontrolled, glaucoma first causes peripheral vision loss and eventually can lead to blindness.

Glaucoma is the second-leading cause of blindness worldwide (behind cataracts).

Types of glaucoma

The two major categories of glaucoma are open-angle glaucoma and closed angle glaucoma. The “angle” in both cases refers to the drainage angle inside the eye that controls the outflow of the watery fluid (aqueous) which is continually being produced inside the eye.

If the aqueous can access the drainage angle, the glaucoma is known as open angle glaucoma. If the drainage angle is blocked and the aqueous cannot reach it, the glaucoma is known as closed angle glaucoma.

Glaucoma symptoms

Most types of glaucoma typically cause no pain and produce no symptoms until noticeable vision loss occurs, but with acute angle-closure glaucoma, one experiences sudden symptoms like blurry vision, halos around lights, intense eye pain, nausea and vomiting.

If you have these symptoms, see an optician so steps can be taken to prevent permanent vision loss.

Diagnosis, screening and tests for glaucoma

During routine eye exams, a tonometer is used to measure your intraocular pressure, or IOP. Your eye typically is numbed with eye drops, and a small probe gently rests against your eye’s surface. Other tonometers send a puff of air onto your eye’s surface.

An abnormally high IOP reading indicates a problem with the amount of fluid (aqueous humour) in the eye. Either the eye is producing too much fluid, or it’s not draining properly.

Normally, IOP should be below 21 mmHg (millimeters of mercury) — a unit of measurement based on how much force is exerted within a certain defined area.

If your IOP is higher than 30 mmHg, your risk of vision loss from glaucoma is 40 times greater than someone with intraocular pressure of 15 mmHg or lower. This is why glaucoma treatments such as eye drops are designed to keep IOP low.

Other methods of monitoring glaucoma involve the use of sophisticated imaging technology to create baseline images and measurements of the eye’s optic nerve and internal structures.

Then, at specified intervals, additional images and measurements are taken to make sure no changes have occurred that might indicate progressive glaucoma damage.

Glaucoma treatments

Treatment for glaucoma can involve surgery, laser treatment or medication, depending on the severity. Eye drops with medication aimed at lowering IOP are usually tried first to control glaucoma.

Because glaucoma is often painless, people may become careless about strict use of eye drops that can control eye pressure and help to prevent permanent eye damage.

In fact, not complying to prescribed glaucoma medication program one of the major reasons for blindness caused by glaucoma.

If you find that the eye drops you are using for glaucoma are uncomfortable or inconvenient, never discontinue them without first consulting your optician about a possible alternative therapy.

Exercise may cut glaucoma risk

Can you reduce the glaucoma risk? According to a recent European study, exercise lessens the chance that some people will develop glaucoma because it helps improve blood flow in your body and your eyes.

In addition to regular exercise and an active lifestyle, you also can reduce your risk for glaucoma by not smoking, maintaining a healthy weight, and eating a varied and healthy diet.

Source:

allaboutvision.com/en-gb/conditions/glaucoma/

 


How to Boost Your Diet and Nutrition to Protect Aging Eyes

Age-related eye diseases such as macular degeneration and cataracts commonly cause impaired vision and blindness in older adults. But lifestyle changes including good nutrition, could help delay or prevent certain eye problems.

Besides adopting a healthy diet, we can also protect our eyes by avoiding intense ultraviolet (UV) light, quitting smoking and having regular check-ups that may help detect chronic diseases contributing to eye problems. Diabetes for example, increases your risk for age-related eye diseases and may cause diabetic retinopathy.

Regular eye exams are essential for maintaining eye optimum health. If eye problems and chronic diseases are detected early enough, appropriate treatment may prevent permanent vision loss.

Diet, Antioxidants and Healthy Eyes

A healthy, balanced diet is an important consideration when making daily lifestyle choices. Foods we eat and the dietary supplements we take, affect both overall wellbeing and ocular health.
Eat plenty of colourful fruits and vegetables for optimum eye health.

A diet high in saturated fat and sugar may increase the risk of eye disease. On the other hand, healthy foods such as greens and fruits may help prevent certain eye diseases and other health problems.

Cardiovascular disease, diabetes and eye conditions including cataracts and age-related macular degeneration (AMD) have been shown to occur less frequently in people who eat diets rich in vitamins, minerals, healthy proteins, omega-3 fatty acids and lutein.

A healthy diet should include ample amounts of fresh, colourful fruits and vegetables. In fact, experts recommend that you consume at least five to nine servings of these foods daily.

Dark green or brightly coloured fruits and vegetables which contain antioxidants, have been shown to protect the eyes from free radical damage, thus reducing the risk of certain eye diseases.
Lutein and zeaxanthin are plant pigments called carotenoids and these are known to protect the retina from oxidative changes caused by ultraviolet light. Spinach and kale are excellent food sources of lutein and zeaxanthin.They are also found in sweet corn, peas and broccoli.

Vitamin A, vital for healthy vision, is found in orange and yellow vegetables such as carrots and squash. Fruits and vegetables also provide essential vitamin C, another powerful antioxidant.

Other Guidelines for Diet and Eye Health

Try following these diet guidelines to improve your chance of healthy vision for a lifetime:


Supplements, such as these containing essential fatty acids and vitamin E, can help maintain vision.

  1. Eat whole grains and cereals. Sugars and refined white flours commonly found in breads and cereal may increase your risk of age-related eye diseases. Choose instead 100 percent whole-grain breads and cereals that have lots of fibre. This slows down the digestion and absorption of sugars and starches. Fibre also keeps us feeling full, which makes it easier to limit the amount of calories we consume. Experts suggest that at least half of our daily grains and cereals be 100 percent whole grains.
  2. Make sure fats are healthy. The omega-3 essential fatty acids found in fish, flaxseed oil, walnuts and canola oil help to prevent dry eyes and possibly cataracts. Eat fish or seafood twice weekly, or take flax oil every day. .
  3. Choose good sources of protein. Remember that the fat content of meats and the cooking method used to prepare them contribute to making them healthy or unhealthy. Also, limit the consumption of saturated fats from red meats and dairy products as this may increase the risk of macular degeneration. Choose lean meats, fish, nuts, legumes and eggs for proteins. Most meats and seafood also are excellent sources of zinc. Eggs are a good source of lutein.
  4. Avoid sodium. High sodium intake may add to the risk of cataract formation. Use less salt, and look for sodium content on the labels of canned and packaged foods. Stay below 2,000 mg of sodium each day. Choose fresh and frozen foods whenever possible.
  5. Stay hydrated. Consider a diet with low-fat dairy products such as skimmed milk for calcium, and healthy beverages such as 100 percent vegetable juices, fruit juices, non-caffeinated herbal teas and water. Proper hydration may also reduce irritation from dry eyes.

Always wear sunglasses for protection from the sun’s harmful UV rays.

Eye Vitamins and Vision Supplements

In additional to a healthy, balanced diet and exercise, taking a daily nutritional supplement may further protect the eye from disease and age related ocular changes.

Two large, five-year clinical trials called the Age-Related Eye Disease Studies (AREDS and AREDS2) have provided valuable information about the benefits of vision supplements.

Sponsored by the National Eye Institute, AREDS and AREDS2 specifically investigated the effect of taking a daily antioxidant multivitamin on the development and progression of AMD and cataracts among adults ages 55 to 80.

The original AREDS study found that a supplement containing the following ingredients reduced the risk of advanced AMD among study participants at high risk of vision loss due to pre-existing intermediate AMD (or advanced AMD in one eye) by 25 percent:

  • beta-carotene (15 mg)
  • vitamin C (250 mg)
  • vitamin E (400 IU)
  • zinc (80 mg)

The AREDS2 study investigated whether including or substituting other nutrients in the original AREDS formulation might provide even greater eye benefits.

Specifically, AREDS2 investigated the effect of adding either a combination of lutein and zeaxanthin (10 mg and 2 mg, respectively) or omega-3 fatty acids (350 mg DHA and 650 mg EPA) to the original AREDS supplement.

AREDS2 also removed beta-carotene from the original AREDS formulation, since other studies have found too much of this vitamin A precursor, particularly when taken in supplement form, is associated with increased risk of lung cancer among smokers and previous smokers.

AREDS2 also decreased the amount of zinc — from 80 mg in the original AREDS formulation to 20 mg — to reduce the potential for stomach upset some people experience when taking the higher dose.

Results of the AREDS2 study showed that use of a daily multivitamin supplement that also contained lutein and zeaxanthin (and no beta-carotene) reduced the risk of progression of AMD to advanced stages by up to 25 percent, with the greatest risk reduction occurring among participants whose diets were low in lutein and zeaxanthin at the time of enrolment in the study.

Daily multivitamin supplements containing omega-3 fatty acids (and no lutein, zeaxanthin or beta-carotene), on the other hand, failed to show any benefit toward reducing the risk of progressive AMD.

Neither AREDS nor AREDS2 found that use of daily multivitamins — with or without lutein/zeaxanthin or omega-3 fatty acids — prevented or reduced the risk of cataracts among the study participants.

Also, the AREDS and AREDS2 supplements did not prevent or reduce the risk of AMD among study participants who had no signs of macular degeneration at the onset of the five-year studies.

Another influential and large-scale nutritional study is the Blue Mountains Eye Study. Conducted in Australia, this study found that daily multivitamins and B vitamin supplements — especially those containing folic acid and vitamin B12 — reduced the risk of cataract formation in study participants. Results also showed that daily omega-3 fatty acid supplements also reduced the risk of cataracts.

The Blue Mountains Eye Study also reported on the long-term effects of adherence to a healthy diet. The study authors found that individuals who were 65 and older and had maintained a better diet had less risk of visual impairment over a 10-year follow-up period.

Based on the results of these and other studies, and because it can be difficult to obtain the same level of nutrients investigated in these studies by diet alone, taking a daily eye supplement should be considered.

Experts suggest high-quality eye and vision supplements should contain at least the following ingredients for optimum effect:

  • vitamin C (250 to 500 mg)
  • vitamin E (400 IU)
  • zinc (25 to 40 mg)
  • copper (2 mg)
  • vitamin B complex that also contains 400 mcg of folic acid
  • omega-3 fatty acids (2,000 mg)

Taking eye vitamins and vision supplements is generally very safe, but be sure to check with your doctor first if you are on medications, are pregnant or nursing, or are considering taking higher daily doses than those listed above.