PART I. NUTRIENTS FOR HEALTHY VISION: CATARACTS & GLAUCOMA
Our eyes and ears are critical connections to the world around us. When either sense decreases, it can be isolating, lead to emotional withdrawal and even depression. Impaired vision also increases the risk of falling and breaking bones. Those who cannot see well enter nursing homes 3 years earlier than those with adequate sight.
If you're over 40, you may have noticed a change in your vision. You’re not alone because about 16 million over-forty people in the U.S. report some vision loss. Maybe you're having trouble adjusting to glare, distinguishing some colors, or maybe you are experiencing the normal, age-related loss of focusing on things close by, known as “presbyopia”. Don’t worry these changes are a normal part of aging.
However, aging & health problems can increase our risk of developing age-related eye diseases and conditions, which are more problematic. This can include cataract, glaucoma, age-related macular degeneration (ARMD), and diabetic retinopathy. Cataract is most common and most easily treated by surgery. This newsletter originally addressed all 4 of these conditions. But it grew to 15 pages, so I am dividing the information into 2 separate newsletters beginning with cataracts and glaucoma for this edition.
WHAT IS A CATARACT?
Cataracts are the most common cause of vision loss in people over age 40 and are the leading cause of blindness in the world. Almost all of us know someone with cataracts. Many take for granted that if they live long enough they will develop this eye problem, but you don't have to.
By age 80, more than half of all people in the United States either have a cataract or have had cataract surgery. In the U.S. 20.5 million suffer from cataract induced vision loss. Sadly, 50% of the 30-50 million cases of blindness worldwide result from un-operated cataracts. Cataracts occasionally occur in infants and young children and remain one of the leading causes of legal blindness for children in undeveloped countries worldwide.
Cataract occurs when there is an abnormal buildup of protein in the lens or lens capsule of the eye. There is a gradual yellowing and opacification of the lens. This clouding prevents light from entering the eye. It is similar to the vision blocking effect of frost or steam on a window. The lens of the eye is directly behind the pupil and works much like the lens of a camera. It focuses light onto the retina lining in the back of the eye where an image is recorded. This image is then passed through the retinal cells, into the optic nerve, and finally to the back of the brain where it is processed to become a visual image in the brain. An untreated cataract can also lead to glaucoma.
Symptoms of cataract can be: increased difficulty seeing at night, reduced intensity of colors, a brownish tint to vision making it difficult to identify blues & purples, blurred or hazy vision, increased sensitivity to glare from lights especially at night while driving, a change in the refractive error of the eye on vision testing.
WHAT FACTORS CONTRIBUTE TO CATARACT FORMATION?
Age-related cataracts are often the cumulative result of various nutritional deficiencies, the result of drug induced side effects or drug induced nutritional deficiencies, or the result of certain chronic exposures or from injuries. Long term exposure to the ultraviolet light of sunlight or to ionizing radiation (radiation which can disrupt atoms and molecules in the body) can increase cataract risk. Most of us are exposed to this if we are outside at all or near windows. For instance, commercial airline pilots were found to have a greater risk for cataracts which was thought to derive from excessive radiation exposure to the radiation coming from outer space. Wearing sunglasses partially reduces the ultraviolet light risk. Diabetes, high blood pressure, and advanced age also increase risk.
Smoking and alcohol use increase risk for cataract formation. Some medications can actually have the side effect of causing eye disorders. If you are using any medication, prescription or over the counter, be sure to see the list of drugs harmful to your eyes and take appropriate precautions, especially if you notice you have had a vision change.
For example, the much prescribed SSRI class of antidepressants is associated with a higher risk of cataracts. A study printed in the Journal of Ophthalmology reported that long–term aspirin use increases your risk of cataracts by forty four percent. Tylenol poses a risk for cataracts for reasons I’ll explain later. Lead toxicity also increases the risk of cataract formation
Some drugs hamper vision by blocking the effects of nutrients which are critical for healthy eyes. If you are using any of these drugs, it is essential you supplement the nutrients the medication depletes. In fact if you are taking any kinds of medications you would do well to have a copy of the book, "Drug Muggers, Which Medications Are Robbing Your Body of Essential Nutrients—and Natural Ways to Restore Them", by Suzy Cohen, RPh (Pharmacist). Who should know better than a pharmacist?
Drugs which can increase your sensitivity to the sun can also cause a chemical modification of tissue making you more susceptible to cataracts and to macular degeneration.
Here is a general list of drugs which can cause cataract formation:
- Birth control pills
- Sulfa drugs
- Oral anti-diabetic drugs
- Antidepressants (fluvoxamine (Luvox), venlafaxine (Effexor), and paraxetine (Paxil) raise risk of cataracts by 23-39%
- NSAIDS (eg. aspirin, ibuprofen, advil, meclofen)
- Steroids: “Long-term steroid use can cause cataracts and increases in intraocular pressure in up to 50% of people who take daily doses of 10 to 15 milligrams of prednisone over a period of one to two years.” Cataracts caused by steroids are dense and can cause a rapid loss of vision.
- Fluroquinone, terbinafine, mefloquine type antibiotics
- Eretinate, isoretinoin
WHAT HELPS PREVENT THE DEVELOPMENT OF CATARACTS?
The primary mechanism for the eye changes which lead to cataract formation is oxidative damage, which is one of the primary causes of many eye health problems. The oxidative injury to the eye contributes to the buildup of abnormal proteins in the eye which cloud the lens. Oxidative damage/stress is caused by an imbalance between chemically reactive molecules containing oxygen and the body’s ability to readily detoxify these reactive molecules &/or to repair the damage they have created.
You’ve no doubt heard the term “free radicals” which are a type of reactive oxygen species which can attack and degrade tissue & functioning. Free radicals set off a chain reaction which can damage all cells, including DNA. You have also no doubt heard the terms free radical quenchers or antioxidants. These are substances in the body, usually introduced through the diet, which help to neutralize the damaging free radicals. These various antioxidants have been clinically proven to slow down the progression of age-related eye diseases. A solution as simple as an improved diet and guaranteeing adequate amounts of certain nutrients by supplementation can dramatically prevent many cases of vision loss.
There are many antioxidants which function to protect your body from the damaging byproducts of millions of chemical reactions continuously taking place inside you. Glutathione is one of the most important natural protectors and the major antioxidant produced by your cells. Glutathione concentrations are higher in the eyes than in other body tissues. Cataracts are particularly linked to low levels of this powerful & critical antioxidant. Glutathione participates directly in neutralizing free radicals and reactive oxygen compounds. It also maintains other antioxidants such as vitamins C and E in their reduced (active) forms. It regulates the critical for life nitric oxide cycle and is used in multiple metabolic and biochemical reactions. Thus, every part of the body can be affected by the glutathione status, especially the immune system, the nervous system, the gastrointestinal system, the eyes, and the lungs. Glutathione also plays a vital role in iron metabolism.
The commonly used Tylenol (Acetaminophen) interferes with glutathione in the body. By this mechanism daily use of Tylenol can contribute to vision loss in later life. Numerous other medications and substances deplete glutathione, such as acid blockers, various pain meds, antacids, some antibiotics, some antidepressants, some antivirals, alcohol, and smoking.
Your body can make glutathione from the precursor amino acids, L-Glycine, L-Glutamine, and L-Cysteine together with selenium and the Vitamins C, B2, B3, B6, and B12. This occurs if you have adequate levels of all these precursor nutrients. Glutathione is also available as a dietary supplement, but you have to be careful because many forms are not absorbed well gastro-intestinally. Other nutrients which increase glutathione levels and activity are: Lipoic Acid, Vitamin E, and N-Acetyl-Cysteine (NAC). The NAC can also convert to glutathione in the body and is used to help raise glutathione levels. Lipoic acid delayed cataract development in rats exposed to cataract inducing substances. It also reduced cataract formation in diabetes.
Studies have found cataract patients to be deficient in Vitamin A, the carotenes lutein and zeaxanthin, Vitamin B2, folic acid, polyphenols, iron, vitamin C, & phytates. In rat studies both green tea and black tea equally inhibited the formation of diabetic cataract. In another study cataract patients on Lutein experienced improved vision.
Conversely, studies have shown the prevalence of cataracts is significantly lower in those in the highest nutrient category for vitamins E, B2, folic acid, beta carotene, lutein/zeaxanthin, and the most significantly associated is vitamin C.
The concentration of the amino acid taurine is high in the lens. Studies from other tissues suggest that in addition to several other modes of action, it acts as an antioxidant. Taurine may be a part of the antioxidant defense mechanism involved in protecting the lens against oxidative stress and consequent cataract formation. The amino acid taurine may help protect the lens from damage in those with high blood sugar. Another study on rats concluded that “The intervening effect of taurine on STZ-induced diabetic cataract is dose-dependent. This effect is not only related to decreases in the levels of blood sugar and triglycerides, but is also related to an increase in the taurine level in the aqueous humor and lens of diabetic rats, which enables the lens to escape from oxidant injury.” Taurine also prevented the development of selenite induced cataract in rats.
Curcumin suppressed selenite-induced oxidative stress and cataract formation in rat pups.
Resveratrol suppressed selenite-induced oxidative stress and cataract formation in rats.
WHAT IS GLAUCOMA?
Glaucoma is a group of diseases caused by increased pressure inside the eye which damages optic nerve and retina and can lead to progressive permanent vision loss. This increased pressure is caused by a buildup of aqueous humor, the fluid normally present in the front and rear chambers of the eye. This fluid normally drains from the eye through channels in the front of the eye in an area called the anterior chamber angle. When these channels are blocked, the aqueous humor does not filter normally and pressure builds in the eye. Normal intro ocular pressure (IOP) is 10-20 mmHG. Sometimes glaucoma changes can even occur with normal pressure.
The increased pressure of glaucoma disrupts normal blood flow in the eye, decreasing oxygen and nutrient delivery. This leads to impaired mitochondrial function and excessive production of free radicals. The free radicals destroy neighboring cell structures and ultimately initiate cell death which eventually leads to the blindness in glaucoma.
There is also a genetic predisposition so if family members have had glaucoma it is important to be very careful about getting eye pressure checks.
There are the four major types of glaucoma:
1. Open-angle (chronic) glaucoma is the second most common cause of blindness in our country and is the most common type of glaucoma affecting 70 to 80% of those with this disorder. It can progress gradually and go unnoticed for many years which makes it particularly dangerous! A regular eye exam which includes a simple & painless pressure test is the only way to detect the disease before it becomes serious. Open angle glaucoma usually affects both eyes.
2. Angle-closure (acute) glaucoma is far less common comprising fewer than 10% of glaucoma cases in the US. As we age, the lens of the eye enlarges pushing the iris forward increasing the risk of developing angle-closure glaucoma. This is a medical emergency and requires immediate treatment. People with farsightedness have an increased risk of developing acute angle-closure glaucoma. Their anterior chambers are shallower and their angles are narrower than people with normal eyesight.
3. Congenital glaucoma is usually diagnosed at birth or during the first year of life, though its symptoms may not be recognized until early childhood. Fortunately it is rare in the US. Approximately 75% of cases occur in both eyes. There have been various studies suggesting 2-15% of children in institutions for the blind have primary congenital glaucoma. Early detection & treatment by an ophthalmologist can significantly improve the child's visual future and prevent blindness.
4. Secondary glaucoma may be of the open or closed angle type. This occurs as a complication of various medical conditions such as eye surgery, advanced cataracts, eye injuries, some eye tumors, various inflammations, uveitis, diabetes, high blood pressure, thyroid disorders, or drugs.
Drug induced glaucoma is relatively common and very preventable. Most drug induced cases of glaucoma occur with the angle-closure form of glaucoma except for steroids which are heavily implicated in both forms of glaucoma. You may notice the list is similar to the drugs causing cataracts, but not identical.
Here is a list of drugs which can cause glaucoma; (and is summarized below)
- Any drug that dilates your pupils may increase the risk of angle closure glaucoma (narrow angle glaucoma).
- Antihistamines (both prescription and non-prescription, such as alta-seltzer) can be harmful for people with angle closure glaucoma (narrow angle glaucoma) - triggering an attack of angle closure glaucoma- resulting in blurred vision, redness, halos around lighted objects, and pain. This is an emergency condition.
- NSAIDs, non-steroidal anti-inflammatory drugs
- Steroids. All steroid preparations can be damaging whether topical, oral, mist inhaler, or injectable. Some steroids are potentially more eye damaging than other. You can see the relative steroid risk on a chart at this link.
- Simvastatin, prescribed for high cholesterol
- Fenfluramine, prescribed for weight loss
- Gastric antispasmodics, such as Pro-Banthine, and Bentyl prescribed to stop muscle spasms
- Antidepressants, such as Amitriptyline , Tofranil, Prozac, Luvox, Venlafaxine, Mirtazapine , Nardil and Parnate increase the risk of acute angle closure glaucoma.
- Antipsychotic medications, such as Haldol, Trilafon, Prolixin, Mellaril, increase the risk for angle closure glaucoma, but do not increase the risk for "open angle" glaucoma.
- Stimulants such as ephedrine, giving rise to dilation of the pupils, may increase risk of angle closure glaucoma.
- Sexual Enhancers Cialis, Viagra, Levitra
- Stimulants such as Epinephrine, Ephedrine, Phenylephrine, and Amphetamines lead to a reduced focusing capacity and a risk for acute angle-closure glaucoma, a serious eye emergency.
- Drugs for parkinson"s
- Cardiac Agents such as Norpace
- Antibiotics such as Sulfa
- Acid blockers such as Tagamet, and Zantac
- Inhalers for lung disease such as Atrovent
- Synthetic Vitamin A related products such as Renova and Retin-A
Similar to cataract, those with glaucoma often have compromised antioxidant defense systems. Additionally, faulty glycosaminoglycan (GAG) synthesis has been implicated in the development of glaucoma. Nutrients that impact GAG are Vitamin C and glucosamine sulfate. These may hold promise for glaucoma treatment when more is understood. High dose vitamin C has been found to decrease the intra ocular pressure (IOP) due to osmotic effect. Other nutrients with potential glaucoma effect are Lipoic Acid, Vitamin B12, Magnesium, Melatonin, French maritime pinebark, and bilberry. Also botanicals such as Ginko Biloba, which increases circulation in the optic nerve, forskolin (which has been used successfully as a topical agent to lower IOP) and IM injection of Salvia Miltiorrhiza have been shown to benefit glaucoma.
”Human studies have shown a powerful effect of French maritime pine bark and bilberry extract on the underlying symptoms of glaucoma. Pine bark and bilberry may act on a molecular level to decrease the production of aqueous humor, improve blood vessels structure and function, and decrease the resistance to fluid drainage. These two nutrients are rich in proanthocyanidins, powerful antioxidants known for their ability to neutralize harmful free radicals." (Nishioka 2007).
"In a 2010 study combining treatment with French maritime pine bark and bilberry with the traditional glaucoma drug Latanoprost - a prostaglandin analog that increases aqueous fluid drainage - researchers found a clear benefit of the combination treatment (Steigerwalt 2010). "
Along with traditional treatment for glaucoma which is usually eye drops but is sometimes surgery, supporting mitochondrial function with scientifically studied nutrients such as Co-Enzyme Q10 may mitigate the production of tissue-destroying free radicals.
Innovative Vision Products (IVP) Inc., an intellectual and scientific research group, have developed a natural di-peptide N-acetylcarnosine for the treatment of human senile cataract and other eye problems. It is called Can-C®.
Animal studies found that N- acetyl-Carnosine reduced cloudiness in rat lenses which were exposed to guanidine to cause cataracts. Human studies on Can-C have been very promising. A study in 50,500 humans demonstrated Can-C provided beneficial results with the following eye-disorders
- Open-angle primary glaucoma
- Corneal disorders
- Computer vision syndrome
- Ocular inflammation
- Blurred vision
- Dry eye syndrome
- Retinal diseases, vitreous opacities and lesions
- Complications of diabetes mellitus and other systemic diseases
- Contact lens difficulties, particularly with soft contact lenses
Most glaucoma cases are treated with medicinal eye drops. As glaucoma progresses they may use higher doses or combination therapies. Surgery may be recommended for patients whose IOP is not responsive to medicines, whose glaucoma continues to worsen, or who experience uncomfortable side effects from glaucoma medications.
Writing this newsletter has caused me to think more about the vision I take for granted. It has motivated me to get more regular eye exams, something about which I have been rather lax, though I have supplemented with vision supportive nutrients.
I HOPE IT HAS MOTIVATED YOU TO GET YOUR EYES CHECKED AND TO CHECK YOUR MEDS! If your medications can contribute to cataracts talk to your Dr about changes, if possible.
Until next newsletter, wishing you peace, health, and all of your heart’s desires.
Priscilla Slagle M.D.
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