Category Archives: Food for thought

Vision & Vitamins: Can supplements prevent/treat nearsightedness (myopia)?

By | Calgary, Eye health, Food for thought, Vision & Vitamins | No Comments

Beautiful young woman wearing glasses portrait.If you or your children wear glasses for nearsightedness (myopia) you have probably seen advertisements for vitamins and supplements that claim to prevent or reduce nearsightedness.  Approximately 1.6 billion people were nearsighted in 2000, and up to 2.5 billion worldwide are expected to be nearsighted by 2020.  The myopia boom in East Asia has resulted in an increase in myopia from 10-20% in China in the mid-twentieth century to up to 90% of teens and young adults with nearsightedness today.  According to a recent article in the journal Nature up to 96% of 19 year olds in Seoul are nearsighted.  While there is a genetic or hereditary cause for nearsightedness, this increase in myopia worldwide indicates that other factors may be important.

It has been a longstanding theory that prolonged near work including reading and screen time may lead to an increase in nearsightedness.  A newer finding is that light levels and time spent outdoors in natural light may be protective in preventing myopia progression – and in some countries public health posters tell children to “Keep Myopia Away, Go Outside And Play!”  There does seem to be a positive effect of natural light (and not just that playing outside does not involve reading or near work) since some animal studies confirm this finding.

Can vitamins prevent increasing nearsightedness?  There is little evidence to prove most of the various vitamins and supplements that are marketed to reduce myopia, except more recently for Vitamin D.  There may be a connection between the findings that more time in natural light seems to reduce increases in nearsightedness and the Vitamin D findings.  When UVB from sunlight shines on bare skin the body produces Vitamin D.  This vitamin can also be found in fortified milk, cereal, and other foods.  In spite of this many people may be deficient.  A blood test can determine your Vitamin D levels to find out if you are deficient.  Supplements can boost your Vitamin D levels, but too much can lead to dangerously high calcium levels – so as with all supplements and vitamins more isn’t always better.  It is advisable to work with a nutritionist or physician to determine the dose that is right for you.

While there is no strong studies to support taking other supplements to prevent increasing nearsightedness, it is a good idea to have a diet which includes colored fruits and veggies, fish, and nuts.

If you have questions about laser vision correction or wish to book a complimentary evaluation with Dr. Anderson Penno, contact Western Laser Eye Associates.

 

Vision & Vitamins: Ginkgo Biloba, Glaucoma, and Macular Degeneration

By | Epi-lasik, Epilasik, Eye health, FDA, Food for thought, Ginkgo Biloba, glaucoma, Health Canada, Laser Eye Surgery, Laser vision correction, macular degeneration, Mayo Clinic, Ophthalmologist, Ophthalmology, Opthamologist, Optometry, Pubmed, Refractive Surgery, science, Uncategorized, Vision & Vitamins | No Comments

Vitamins and natural herbs have become more and more popular for alternative treatment as additional treatments for medical conditions.  Ginkgo Biloba has been used for centuries as a traditional treatment which may help blood flow to the brain and aid in treatment of dementia or Alzheimer’s disease.  It might help treat leg pain that results from blood vessel disease, and there is some suggestion that ginkgo biloba might also help PMS symptoms, depression, multiple sclerosis, and ADHD.  Ginkgo Biloba is extracted from the leaves of the Ginkgo Biloba tree.  As far as vision and eye health are concerned, it is possible that Gingko Biloba might be helpful to eye health but as with many natural products the scientific studies show some favorable and some unfavorable results.

There are some scientific studies that have been reported in the peer reviewed literature which is a data base of articles that have been reviewed by scientists with expertise in the particular field of study before the article is allowed to be published.  Peer review helps to make sure that studies are done in a way that will provide strong statistical evidence for or against a specific area of study.  The most powerful studies are randomized and double-blinded which means the researcher and the subject who is taking the supplement do not know if it is the actual supplement or a placebo being taken.  The “placebo” effect has been well studied and up to 30% of people taking a fake pill who are told it will have beneficial effects will report that it helps whether or not there is any measurable effects.  By double-blinding and using large and randomized numbers of subjects the results will show with more confidence that a particular supplement is helpful or not for a specific condition.  Because there are a lot of different conditions that are being studied, so far there are only a few published peer reviewed scientific studies that have been done to find out if Ginkgo Biloba is good for your eyes.

According to the Mayo Clinic there is some scientific evidence suggesting that Ginkgo Biloba may be helpful in preventing worsening in age related macular degeneration which can lead to central vision loss, but there is little evidence to suggest it might be helpful for treatment of glaucoma.  In the peer reviewed literature there are a few studies including this 2012 study by Cybulska-Heinrich, Mozafferieh and Flammer that suggests supplementation with Ginkgo Biloba might be helpful in addition to traditional medical treatment in cases that are not responding as well as needed to these traditional treatments.  They suggest that antioxidant effects along with a variety of other effects on blood flow might be responsible for the beneficial effects of supplementation with Ginkgo Biloba.  The American Academy of Ophthalmology reported there was a single small randomized trial that showed promise for using Gingko Biloba to slow macular degeneration.

A commonly reported dose of Ginkgo Biloba is a standardized extract, standardized to 24% flavone glycosides and 6% terpene lactones starting at 40 milligrams of that extract three times daily, but there does not seem to be enough evidence in the scientific studies to prove the most effective doses for a specific condition.  Risks and side effects of Ginkgo Biloba supplements include headaches and dizziness, bleeding, and other side effects.  If you are on a blood thinner or aspirin, or are on other medications you should talk to your pharmacist and/or doctor to make sure that there won’t be dangerous interactions.  There is also some question about the quality of the products in some cases and as with all supplements it is important to be sure you are getting a high quality product.  In Canada a DIN or NPH number can be found on products that have been reviewed by Health Canada.  In the US the FDA does not require approval of supplements before the product is marketed but does collect information on adverse events.  The other thing to consider is the cost of a product like Ginkgo Biloba versus the proof that it will be helpful for your health.

Whether you already had LASIK, Intralasik, EpiLasik, PRK, wear glasses or contacts, reading glasses or no glasses at all you should be sure to get regular checks with your eye care specialist (optometrist or ophthalmologist) in order to optimize your vision for the rest of your life.  If you have questions about laser vision correction or wish to book a complimentary evaluation with Dr. Anderson Penno, contact Western Laser Eye Associates.

 

 

Bionic Lens: can everyone have perfect vision?

By | Food for thought, Keratectomy, Laser Eye Surgery, Laser vision correction, LASIK, Optometry, Photorefractive, PRK, Refractive Surgery, Surgeon | No Comments

There has been a lot of talk recently about the “Bionic Lens” which has been invented by an optometrist from British Columbia.  CBC news recently ran a story about the new lens implant.  According to this news story, “Pending clinical trials on animals and then blind human eyes, the Bionic Lens could be available in Canada and elsewhere in about two years, depending on regulatory processes in various countries.”  If there are problems in the back of the eye involving the retina, such as macular degeneration, this lens would not be able to correct the poor vision.  So vision improvement using this lens would be helpful to people who can correct their vision with glasses or contact lenses.  At this time vision correction surgeries are able to allow people to see as well without glasses or contact lenses as they do with their eyewear – for most people they would not be expected to see better than their best corrected vision.

The photographs of the lens looks similar to some of the designs currently available for intraocular lens implants used most frequently in cataract surgery.  It is not clear from the news reports what makes this lens design so revolutionary.  There do not appear to be reports yet in the peer reviewed literature which would fit with the reports that animal and blind human eye trials have not been done yet.  These steps are needed to prove that the lens is safe before proceeding to sighted human eye studies.  In people younger than 45 years old, lens replacement surgery is not usually recommended due to the fact that reading glasses may be required unless a multifocal lens is used or unless one eye is left near-sighted for reading (monovision).

The most common treatment for reducing dependence on glasses in this age range is laser vision correction.  The original photorefractive keratectomy (PRK) techniques were developed in the 1980’s and have been refined over the following decades.  This is still a reliable way to improve uncorrected vision in people who meet the safety criteria including thick enough corneas, prescriptions that are within the range of correction, healthy eyes, and no health problems that might cause problems in healing or risk of infection (such as immunosuppression).  For people younger than 45 but with high corrections outside the range of laser vision correction the implantable contact lens is usually the next option.

Will the Ocumetrics Bionic Lens replace laser vision correction and standard lens implants used for cataract surgery?  The reports are optimistic according to the news stories, but the proof will be coming in the next few years as preliminary studies and then sighted human eye studies are done.  There is a lot of excitement about this new lens implant and if it lives up to expectations it is possible that it may become a common option for vision correction in the future.  For now though, laser vision correction is the first option to consider as a way to reduce the need for glasses or contact lenses.

If you have questions about laser vision correction or wish to book a complimentary evaluation with Dr. Anderson Penno, contact Western Laser Eye Associates.

Vision & Vitamins: eat your carrots!

By | Eye health, Food for thought, Laser Eye Surgery, Laser vision correction, Ophthalmologist, Refractive Surgery, Uncategorized, Vision & Vitamins | No Comments

Is the old wives’ tales about eating carrots fact or fiction?  Carrots are high in beta-carotene which the body converts to vitamin A.   Carrots also provide vitamin C, iron, calcium and fiber.  Carrots and other foods rich in vitamins C and E, zinc, lutein, zeaxanthin, and omega-3 fatty acids DHA and EPA benefit eye health and general health, as hown by the the Age-Related Eye Diseases Study (AREDS), funded by the National Eye Institute. These nutrients are linked to lower risk for age related macular degeneration (AMD) and cataracts.

The myth that eating carrots can improve your vision seems to have been made popular during World War II when a propaganda campaign was run to convince the Germans that Royal Air Force pilots had superior night vision due to eating carrots.  This campaign was started to cover up the fact that the pilots were using a secret new radar technology that allowed them to strike under cover of darkness.  According to the Smithsonian Magazine and the World Carrot Museum (a virtual museum about all things carrot) RAF fighter pilots told newspaper reporters that carrots improved their night vision and it was picked up in the popular press of the time.

In reality carrots and other deeply colored fruits and vegetables do contain vitamins that are important for healthy eyes, but in most developed countries vitamin A deficiency is rare so eating carrots is not likely to result in a noticeable improvement in vision.  It is possible that in ancient societies there may have been improvements in vision from eating carrots in areas where vitamin A deficiency may have been common due to seasonal changes in diet.

Eating too many carrots will turn your skin orange but is not likely to harm you.  According to the USDA 1 cup of chopped carrots contains 0 fat, 0 cholesterol, 88mg sodium, 12gm carbohydrate (4gm dietary fiber, 6 gm sugar), 1 gm protein, 428% daily recommended Vitamin A, 13% daily recommended Vitamin C, 4% daily recommended calcium, and 2% daily recommended iron.  There are some reports that pesticides can build up in the skin so peeling carrots may be a healthier option.

In general it is good advice to –  eat a little bit of everything and not too much of any one thing.  As it turns out the stories about carrots are both fact and fiction!

 

If you have questions about laser vision correction or wish to book a complimentary evaluation with Dr. Anderson Penno, contact Western Laser Eye Associates.

 

What is up with that White&Gold (or is it Blue&Black) Dress?

By | Fashion, Food for thought, Ophthalmologist, Uncategorized | No Comments

Most people who spend even a little time on the internet will have seen this photograph of the striped dress that has created a firestorm of debate about the true colors.  This explanation from an article on the New York Times site is probably the most concise, however it is not completely understood even by eye specialists why there is such a difference in perceptions between different people viewing the same picture.  Interestingly there is still a difference when the picture is printed which means that the viewing angle when looking at an electronic display versus paper does not completely explain the effect.  Although not a scientific study, in a small sample size of ophthalmologists and engineers, the ophthalmologists all saw the dress as White and Gold and the engineers all saw Blue and Black.

There have been reports that the split is from 70% white and gold to 50/50 in on each side.  It is possible that there may be genetic tendency to view the dress as one color or the other due to either retinal differences (the retina lines the back of the eye like film in a camera and the center of the retina is responsible for color vision) or due to differences in the brain or both.  Another interesting fact is that for some people the dress changes from white and gold to blue and black which indicates some adaptation in the brain’s interpretation of the images that are formed on the retina.  How Your Eyes Trick Your Mind shows a number of different optical illusions and explains some of the science behind them.  In some cases MRI images will show the involvement of specific parts of the brain when people are viewing an optical illusion.  The White/Gold/Blue/Black dress is a bit different than classic optical illusions in that it involves color.

In many ways we ultimately do see with our brains.  For example it is well established that people can adapt to glasses that turn everything upside down.  This is called perceptual adaptation. Another well known phenomenon is inattention blindness. This is an effect where when attention is focused on a specific detail a person will not see things that may be right in front of them.  There is likely to be continued debate about why this particular photograph of what should be referred to simply as the “striped dress” for now creates such a large difference between viewers.  For now it is nice to know that these perceptual differences are a normal part of the visual system (and whether you see it Blue&Black or White&Gold you are not right or wrong – just different).

If you have questions about laser vision correction or wish to book a complimentary evaluation with Dr. Anderson Penno, contact Western Laser Eye Associates.