Archive for August, 2009
Phytosterols May Prevent the Development of Cancer
08.30.2009
Phytosterols, long known for their cholesterol-lowering action, are emerging as cancer-fighting powerhouses.
Phytosterols, the structural components in the cell membranes of plants, have long been known to reduce serum total and LDL cholesterol levels. Now, new research indicates that they may help to prevent cancer as well. A study published in the European Journal of Clinical Nutrition last month found that phytosterols, also known as plant sterols, inhibit cancers of the stomach, lung, ovaries and breasts.
Phytosterols are plant-derived compounds similar in structure and function to cholesterol. They are found in most plant foods in low concentrations. The foods with higher concentrations include nuts, legumes, oranges, bananas, beetroot and Brussels sprouts. The highest concentrations are found in unrefined plant oils including vegetable, nut and olive oils. Whole grains, wheat germ and flax seeds are also good dietary sources of plant sterols.
According to this latest research, not only do phytosterols prevent the production of carcinogens, promote the death of cancer cells, and help prevent metastasis, but they also seem to increase the activity of antioxidant enzymes which help to reduce oxidative stress on the cells.
The researchers in the study wrote that “mounting evidence supports a role for phytosterols in protecting against cancer development. Hence, phytosterols could be incorporated in the diet not only to lower the cardiovascular disease risk, but also to potentially prevent cancer development.”
Including phytosterols in your diet appears to be an important strategy in protecting against cancer development.
Dr. Krawitz’s addendum: Phytosterols are also critical to eye health, forming the oily outer layer of the natural tear film which then acts as a “vapor barrier” against the evaporation of tears. That’s why it’s included in my Dry Eye Relief Tear Stabilization Formula.
Nancy Hirsch VisiVite.Com Certified Nutritionist
Scientists Morph Human Retinal Cells From Skin Cells - Wow!
08.26.2009It was just a few months ago on the VisiVite Blog that we published studies regarding stem cell research for treatment of eye disease which shortly followed the new federal laws that were enacted.
But in a scientfic stem-cell breakthrough today out of the University of Wisconsin (Madison), researchers have suggested a new way to treat eye disease in which new retinal cells could be created from the patient’s own skin - thus matching their DNA and starting a discussion as to whether in the future, patients could provide their own retinal transplants.
Diseases such as this eye with Dry Macular Degeneration might some day respond to new genetic treatments.
The first step was that the scientists turned the skin cells into Induced Pluripotent Stem Cells (IPS cells), the stem cells derived from skin that have emerged as an alternative to embryonic stem cells. Using chemical techniques, the IPS cells were then morphed into a variety of retinal cells. What is all the more impressive is that some of these retinal cells included rods and cones, which are the photoreceptors that translate light signals into electrical signals that our brain interprets as an image.
There are several benefits to this new method.
First, skin cells are readily available from each patient, thus bypassing most ethical arguments.
Second, in diseases that are acquired but not hereditary, the cells are an automatic genetic match.
Finally, in diseases that are hereditary, the mutated skin cells could be subjected to various treatments in the laboratory before determining which treatments work and should be applied directly to the patient’s eye.
Paul Krawitz, M.D., President
Vitamin Science Inc
Lasik and Laser Refractive Surgery - What You Need to Know
08.22.2009
In Lasik, a flap is created and the laser reshaping is then performed below the flap.
Laser treatment to treat near-sightedness, far-sightedness and astigmatism, is not benign.
All of the available treatments for this condition have the potential to dramatically improve vision at distance. Worldwide, there is a 95% satisfaction rate with these treatments.
But considering that the treatment is being performed on healthy eyes, the 5% of patients who are dissatisfied is a high number. And most alarming, most of these people have excellent visual acuity as measured by an eye chart.
You Can’t Have It All
In young people between age 21 and 40 who still maintain their ability to see up close, even while wearing their eyeglasses or contact lenses, Laser Vision Correction can improve distance vision without adversely affecting near vision.
But beginning at age 40, and continuing until age 70, there is progressive hardening of the natural lens inside the eye. This makes the lens less capable of changing shape during focusing, resulting in decreased ability to read with increasing age. This process is known as presbyopia, and Benjamin Franklin invented bifocals in 1760 to cope with this condition.
Nearsighted or myopic people who take off their glasses to read also develop presbyopia. But the symptoms are hidden from them until they wear their contact lenses or distance eyeglasses. This is because their natural focal point is close to the eye and they don’t require their focusing muscles to work to make this distance clear to them. Unfortunately, nearsighted people often poorly understand the consequences of Lasik, believing that they will obtain distance vision while having little effect on their near vision.
Because Laser Vision Correction is primarily designed to correct distance vision, in nearsighted people, there is a tradeoff between gaining distance vision and losing near vision, especially after age 40. In essence, Laser Vision Correction makes the nearsighted person a “normal sighted” person. And since normal sighted (emmetropic) people require reading glasses or bifocals beginning around age 40-45, the same will be true for myopic people after Laser Vision Correction.
The use of contact lenses to the prospective myope what his or her vision will be like following laser vision correction is a very good idea if the doctor is not convinced that the patient understands this future handicap. The loss of the ability to read in bed or see near vision details, such as text on a cellular phone without the aid of reading glasses, can be upsetting for people who have enjoyed this capability for many years.
Being able to see the television, but not the remote control, is a frequent frustration of presbyopia.
Some doctors will purposely under-correct one of the eyes with laser, leaving the eye slightly nearsighted so that some near and intermediate vision is possible without the use of glasses. This is called “monovision” (one eye corrected for distance, the other for near work). However, it is not always well tolerated, and even in patients who do tolerate it, there is a tradeoff in distance clarity compared with having both eyes corrected for distance vision.
Patients who are treated using a monovision technique have to be exquisitely careful when driving a car to make sure that the rear view mirrors are aligned with the distance corrected eye. And patients who are symptomatically blurry with monovision, but who don’t want to give up the ability to read without glasses, should wear eyeglasses when driving, with a clear lens in front of the distance corrected eye and a prescription lens in front of the near corrected eye.
Different Types of Laser Vision Correction
Lasik
Lasik, or laser in-situ keratomilieusis, is a two-step procedure in which a sliver of the cornea is angled backward while the laser is applied underneath. The thin sliver of cornea is then placed back onto the surface.
Intralase uses laser light to perform the first step in Lasik - the creation of a corneal flap.
A microkeratome uses an oscillating steel blade to create the corneal flap.
The sliver of cornea can be created using a metal oscillating blade (microkeratome) or a separate laser known as Intralase. The latter is, in my opinion, more precise and creates a better-fitting flap. However, a minority of eye surgeons are certified in its use.
The actual laser reshaping of the cornea underneath the flap is performed with an Excimer laser using a computer controlled ultraviolet beam of light that reshapes the cornea, or outer window of the eye, in an effort to allow light to focus more directly on the retina. The Excimer has been used since the early 1980’s and underwent numerous clinical trials since that time to refine its use and determine its safety and effectiveness. Now in its third decade of use, the Excimer laser is routinely used to treat nearsightedness, farsightedness and astigmatism.
Each pulse of the laser disrupts the molecular bonds between the corneal cells with accuracy up to 0.00004 of an inch, which makes it extremely accurate. Often, tissue measuring about 1/2 the thickness of a human hair is removed to achieve the proper amount of correction.
The Excimer laser produces a cool or non-thermal light beam. This makes it ideal for corneal surgery because it eliminates the possibility of thermal damage to surrounding tissue. Its accuracy provides surgeons with a tool that can deliver highly predictable results.
Epi-Lasik
Epi-Lasik is similar to Lasik, but creates a much thinner flap of tissue compared with Lasik. The recovery from this procedure is similar to PRK, listed below.
PRK
In PRK (photorefractive keratectomy), the Excimer layer is used exclusively to reshape the cornea. To accomplish this, the surface layer of the cornea, known as epithelium, is also removed. Although the PRK procedure itself is painless, patients may experience blurry or hazy vision for one to five days afterward and variable discomfort until the epithelium heals and covers the treated area. Final visual results may be realized anywhere from several days to a month or more. Anti-inflammatory eyedrops are taken for one to three months. Like Lasik, PRK is often used to treat low to moderate amounts of nearsightedness, farsightedness and astigmatism, but because it spares more cornea tissue that Lasik, it is often used to treat higher refractive errors as well.
My Recommendations
Laser vision correction is a fabulous procedure for a large majority of patients. And even in those patients in whom the outcome is less than perfect, the advantages of not having to deal with strong glasses and uncomfortable contact lenses can be dramatic.
Glare, a frequent published side effect of laser vision correction, is less pronounced than in previous years with the advent of custom computer algorithms. But glare is a universal occurrence in all natural optical systems. Patients who wear strong glasses or contact lenses have glare. And glare exists, to some extent, in all patients who undergo laser vision correction, even when it is perfectly performed.
It is not necessarily true that the highest volume Lasik surgeons have the best results. In fact, in many of these practices, there is a lack of contact with the surgeon both before and after the procedure. Measurements are often performed by ancillary staff, and the post-operative care often does not involve a physician. Because laser vision correction is largely an automated procedure, I recommend that you seek the care of a physician who is actively involved in the pre and post-operative care.
Paul Krawitz, M.D., President
VisiVite.Com
One Person’s Inspiring Cure From Macular Degeneration
08.19.2009
The letters and testimonials we receive about the benefits of VisiVite inspire all of our staff.
I was leafing through some old letters from our customers and came upon one of the most dramatic ones that we have ever received at VisiVite.Com since 2001.
It is inspiring not only for the wonderful outcome that this man had in treating his macular degeneration, but in the active research he performed in treating his own eye health. Although eye doctors now universally recommend nutritional supplements for the treatment of macular degeneration, what is even more impressive is at the time he wrote the letter, Western medicine was still dubious of the benefits.
Click the image of the letter to download. It’s a 2-page Word document.
Enjoy.
Paul Krawitz, M.D., President
VisiVite.Com
Diabetes Mellitus and The Eye
08.18.2009Insulin, a hormone manufactured by the islet cells in the Pancreas, is critical to good health. Insulin doesn’t dissolve glucose; rather, it moves glucose (simple sugar) out of the bloodstream and into the cells in muscle and the liver, where it is converted into glycogen, an energy storage molecule.
There are two forms of Diabetes, which adversely affect the action of Insulin:
Home glucose testing is critical for control.
Type I, or Insulin Dependent Diabetes Mellitus: 80% of these cases are in children with no family history. Believed to be viral in origin or possibly related to not enough exposure to bacterial antigens due to an overly sterile childhood, the pancreas in Type I Diabetes mellitus makes very little or no insulin.
Insulin Dependent Diabetes mellitus requires insulin be brought in externally to the body, either via periodic injections, an insulin pump, or inhalation.
And it is not only high glucose levels that can be dangerous in Type I diabetics. Diabetic ketoacidosis can occur. This is a life-threatening condition that develops when cells in the body are unable to get the sugar (glucose) they need for energy. When the cells do not receive sugar, the body begins to break down fat and muscle for energy. If this happens, ketones, or fatty acids, are produced and enter the bloodstream, causing a chemical imbalance called diabetic ketoacidosis (DKA). Although more common in Type I diabetics, it can also occur less commonly in uncontrolled Type II diabetes, described below.
Type II or Non-Insulin Dependent Diabetes mellitus occurs most commonly in adults with a family history of the disease, obesity, or both. Unlike Type I Diabetes mellitus, Type II Diabetes can usually be controlled with oral medications and diet. Although metabolic acidosis is not usually a complication of Type II Diabetes, glucose levels can be much higher, especially on initial diagnosis. It is not unusual to have glucose levels of several hundred milligrams per deciliter (normal glucose levels are 70-120 mg/dl).
Both Type I and Type II Diabetes mellitus can damage the eye, particularly if glucose is routinely uncontrolled. The most common complications that can occur are cataracts and diabetic retinopathy. Less common are traction retinal detachments and neovascular glaucoma.
What is Diabetic Retinopathy?
Diabetes, when uncontrolled, damages the delicate inner lining of the smallest arteries and capillaries (blood vessels) in the body. These small blood vessels are found in the distal extremities (toes), kidney, heart and eyes.
In the early stages of diabetic retinopathy, the small blood vessels become weak, forming tiny balloons along their walls called microaneuryms. Later, the weak blood vessels can weaken further, leaking plasma, protein and blood which can dramatically worsen central vision. This early stage is known as Background Diabetic Retinopathy.
Treatment for Background Diabetic retinopathy is performed using laser cauterization if the leaks are threatening or reducing central vision, and sometime injection of steroids or Anti-VEGF inhibitors into the vitreous gel if the leaks are unresponsive to laser or are too close to the center of the retina to treat.
Diagnosis of diabetic retinopathy is best performed by an ophthalmologist (M.D.) or optometrist (O.D.) using direct visualization, optical coherence tomography (OCT) or fluorescein angiography.
Diabetic retina as seen using Fluorescein Angiography
Fluorescein angiography is a simple and highly informative test. A water soluble dye is injected into a vein in one of the patient’s arms. The dye circulates everywhere, including into the eye. A precise microscopic camera creates a flash using a blue filter. This excites the dye, which causes it to glow green. Photographs are then taken of the green-glowing dye as it circulates throughout the retina. If there is a small leak from a tiny blood vessel, it will be readily seen and can then be treated accurately using laser by the eye doctor.
Background diabetic retinopathy does not occur immediately, but rather 5-10 years after the onset of disease, if the glucose levels fail to be controlled. Damage to the small blood vessels is permanent; therefore it is not uncommon to require repeated laser treatments over several years once background diabetic retinopathy has begun.
Proliferative Diabetic Retinopathy (PDR)
The more aggressive form of diabetic retinopathy is the proliferative form. This occurs due to the tiny blood vessels closing off, creating small areas of the retina that are not obtaining enough oxygen. In response, there is formation of abnormal new and very fragile blood vessels, which is called neovascular growth. Rather than being helpful in bringing oxygen to the retina, these neovascular vessels form a disorganized tangle that not only leak large amounts of blood and plasma, but can contract, lifting off the retina and creating a traction retinal detachment.
Treatment of PDR is aimed at reducing the oxygen need of the non-critical areas of the retina using hundreds of peripheral laser burns (PRP, or pan-retinal photocoagulation) and in reducing the chemical signal to form these blood vessels by injecting Avastin or Lucentis into the vitreous gel.
Proliferative Diabetic Retinopathy
In advanced cases of proliferative diabetic retinopathy, a retinal surgeon may my required to evacuate blood inside the vitreous or to repair the traction retinal detachment.
In Summary
Because the consequences of diabetic retinopathy are so severe if the disease remains uncontrolled, it is my recommendation that you take the following measures if you have diabetes mellitus:
1. Obtain Hemoglobin A1c levels every three months.
This tracks your overall glucose control. Non-diabetics have Hemoglobin A1c levels less than 6%. The American Diabetes Association recommends a Hemoglobin A1c level of less than 7%, while the American Association of Clinical Endocrinologists recommends a level of less than 6.5%.
The following table is instructive in correlating Hemoglobin A1c levels with average glucose levels:
A1c(%) Mean blood sugar (mg/dl)
6 135
7 170
8 205
9 240
10 275
11 310
12 345
2. Watch Your Diet and Your Weight
The percentage of Americans who are obese, as measured by Body Mass Index (BMI) is over 30%. Twenty years ago it was only 18%. This is a direct effect of our changing diet, and not just the convenience of fast food, but additionally the preponderance of processed carbohydrates and high caloric fat products that populate the grocery store aisles.
David Kessler, the former head of the Food and Drug Administration has written a book entitled, The End of Overeating: Taking Control of the Insatiable American Appetite. His premise is that the food scientists that work for the companies that manufacture processed and cooked foods have mastered the science of combining fat, sugar and salt into a concoction that creates food cravings with resultant overeating.
Do what I did to lose 30 pounds – join Weight Watchers and do most of your shopping along the perimeter of the grocery stores where the food scientists can hurt you – fish, chicken, skim milk, fruits and vegetables and fat free cheeses.
3. See an endocrinologist
Primary doctors cannot be entirely blamed for wanting to care for your every illness. But if your Hemoglobin A1c is more than 6.5%, you need to gently suggest to him or her that it is time to put the treatment of your diabetes in the hands of a good endocrinologist.
Diabetes mellitus is the bread-and-butter illness for endocrinologists. They will help you to reign in your diet, instruct you when and how many times to measure your blood sugar, and are more likely to be obsessive about following your laboratory results and less inhibited about telling you when you’re not doing as well as you could.
A good endocrinologist takes a personal interest in your diabetes control and administers “tough love.”
4. Get regular eye examinations
If you do not yet have diabetic retinopathy, examinations should be performed annually at least. If you do have diabetic retinopathy, examinations and treatments can range between every month to every six months.
Seek an ophthalmologist or optometrist who sees a lot of diabetics and performs Optical Coherence Tomography, Digital Retinal Photography and Fluorescein Angiograms, since these are frequent diagnostic tests required for this condition.
If you have questions about your own eye health, why not post them for me on our new “Ask The Eye Doctor” form at VisiVite.com?
–
Paul Krawitz, M.D., President
VisiVite.Com
