Optometrists are receiving more

calls and questions about

Marijuana and the treatment of

eye diseases

Medical Marijuana Fails full disclosure and eye doctors must work to provide clear education about what is known at this point.

Reports circulating the last few years indicate that there may be no increases risk of lung cancer associated with smoking marijuana. What they fail to mention is a rapid increase in chronic lung disease. Other studies have been quoted showing a decrease in VEGF (vascular endothelial growth factor) and supposed value in treating macular degeneration. VEGF stimulates new blood vessel growth. Decreasing VEGF would theoretically lower the conversion rate of dry macular degeneration to the more sight threatening wet form.

Unfortunately, the chronic lung disease and damage combined with the blood pressure lowering effect of marijuana will probably prove the reverse and show it accelerates the risk for macular degeneration. Decreased oxygen to the retinal tissues is a primer driver in the transformation of dry macular degeneration to wet macular degeneration.

Isolating the VEGF may someday prove useful in the treatment of macular degeneration by your optometrist, but for today it is still best to stay with the documented nutritional interventions and current VEGF treatments available,  Avastin and Lucentis.

Don’t be timid in asking your optometrist for advice about medical marijuana and eye problems. The facts can potentially save your vision and prevent a lifetime of blindn

Glaucoma Treatment

ess.

Age Related Macular Degeneration

Several exciting new advances are going on in the treatment of macular degeneration. AREDS 2 is a refinement of the original age related eye disease study that showed a significant correlation between certain supplements and a decrease in progression of dry macular degeneration to the more sight threatening wet form.

Eye Doctors to Start New Age Related Eye Disease Study-AREDS-2

AREDS 2 will add and refine the supplements being tested. They will also be tested to see if there is a reduction in the development of cataracts. Omega 3 (fish oils) will be added to the supplements.

Omega-3 Fatty Acids Have Proven Effects on Dry Eye Treatment and are widely used by Optometrists Today. Now they may prove just as beneficial in Macular Degeneration Treatment.

Omega 3 oils contain docosahexaenoic acid (DHA) and decrease the production of inflammatory compounds like prostaglandins and Leukotrienes. They may possibly offer some form of neuroprotection to the cells of the retina and delay cellular death.

Lutein  and zeaxanthin are the major phytopigments.

Phytopigments are pigments found in vegetables like broccoli, spinach, peas and a number of other foods. They are the major components of the pigment found in the macula, the area of retinal tissue effected by macular degeneration. They help prevent damage to the retinal cells from free radicals (oxidative damage) and may also offer some neuroprotective benefits. Beta-carotene, the precursor for vitamin A, may be tested to see if it has any impact on results. While included in the original studies, there have been questions raised about the possibility of beta-carotene increasing the risk of lung cancer in smokers. Smoking is one of the major risk factors that makes people susceptible to developing macular degeneration.

With about 4000 patients to be enrolled, this is an exciting move forward in studying the effects of nutrition and supplementation on eye diseases. The results of the original trial were as good as any major drug used in treating health problems, I expect this trial will only improve those outcomes.

Marijuana use has drastically increased recently in areas like Colorado that have passed amendments legalizing the medicinal use for certain chronic conditions. Glaucoma is listed as one of the main reasons for obtaining a registry identification card under Colorado‘s amendment 20, allowing the holder to use and retain limited quantities of marijuana. Cities like Fort Collins have had to react to the rapid proliferation of medical marijuana dispensaries and the lack of regulation and planning that has subsequently occurred. Federal law does not recognize the legality of state medical marijuana laws and the enforcement is still in question, even as the dispensaries proliferate.

The approval of marijuana for the treatment of glaucoma is lacking in justification and is not an FDA endorsed treatment. Glaucoma is a disease where the visual nerve cells degenerate and result in blindness over time if left untreated. Increased pressure inside the eye and impaired blood circulation to the optic nerve are part of the cycle that damages eyesight.

Research on the medical use of marijuana started to appear in the 1970’s. It does lower eye pressures in about 2/3 of the subjects by about 25-30%. This is an acceptable range for glaucoma drugs that are in use today. Unfortunately, the effect only lasts 3-4 hours and is probably not a steady state lowering over the time period. Effective treatment would require smoking marijuana every 2-3 hours. Eye pressure often spikes up at night and it would require use every few hours all night. Lowering eye pressure does not always treat glaucoma and there is currently little evidence to support that the eye pressure reduction from marijuana use has an effect on vision preservation. It has been postulated that the active ingredients of marijuana may increase the outflow of fluid from the eye through it’s drainage system to achieve the lowering effect. Unfortunately, there are also some effects on lowering blood pressure and episodes of systemic hypotension (sudden lowering of the blood pressure when standing). Since compromised  blood flow to the optic nerve is a vital factor in glaucoma, there is the possibility it could worsen glaucoma even though the eye pressure has been lowered.

There are over 400 active components in marijuana with Delta9-tetrahydrocannabinol being the most studied component. Like any herbal medicine, the concentration of these components varies as does the effectively of the product provided by dispensaries. Inhalation is more effective than oral dosing and carries risks to the lungs and other body systems. Consuming adequate dosing by consumption every 2-3 hours would create a high health hazard to the body. Unfortunately, eye drop application of the active ingredients has not proven to be effective in lowering pressure. Eye side effects include a drastic increase in dry eyes, redness, and eye irritation. The inhalation properties may increase the risk of macular degeneration and cataracts.

The possibility of isolating the active ingredients and separating them from the euphoric effects do warrant further studies. The possibility of a topical preparation that is effective is being studied. Studies show a direct correlation between lower frequency of drug administration and patient compliance. Any medication that needs to be used more than four times per day is unlikely to be used correctly over a long period of time, and once or twice a day is today’s goal. Any viable preparation of a marijuana derivative treatment for glaucoma will need to meet these criteria. Until that day arrives, seek treatment from an eye doctor with traditional prescription eye medications and if desired, supplement that treatment with acceptable alternative medical care that will not cause damage and possibly end in blindness.

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Have you ever felt concern over prescription eye drops or dilation drops used by your eye doctor?

The most common eye drop is rated category c as outlined below. Nursing can be a higher risk period than pregnancy due to drugs being secreted directly through the milk. In our Fort Collins Optometry Practice we usually don’t dilate pupils during these critical time periods unless their are other potential eye problems;  like retina changes from diabetes or high blood pressure caused by the pregnancy. Fortunately, there is very little absorption of eye drops into the blood stream and by applying lite pressure to the drainage ducts even this small amount can be largely eliminated. And information about side effects is in process to greatly improve our knowledge.

Currently prescription medications including eye drops are rated by the Federal Drug Administration for safety during pregnancy and nursing. The FDA uses the five following categories:
Pregnancy Category A: Adequate and well-controlled studies have failed to demonstrate a risk to the fetus in the first trimester of pregnancy (and there is no evidence of risk in later trimesters).
Pregnancy Category B: Animal reproduction studies have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant women OR Animal studies have shown an adverse effect, but adequate and well-controlled studies in pregnant women have failed to demonstrate a risk to the fetus in any trimester.
Pregnancy Category C: Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.
Pregnancy Category D: There is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience or studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.
Pregnancy Category X: Studies in animals or humans have demonstrated fetal abnormalities and/or there is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience, and the risks involved in use of the drug in pregnant women clearly outweigh potential benefits.

While this database has been limited due the unethical nature of testing on humans a new research program called the Medication Exposure in Pregnancy Risk Evaluation Program (MEPREP) should help fill in some of the current gaps. The FDA will study mothers and their children born 2001-2007.  This will cover  almost one million births at eleven participating centers. Since a large number of these women took some prescription medication during their pregnancy it should greatly to our limited knowledge base in the current rating system.

While eye drops are usually low risk due their minute quantities and limited absorption,  these studies should help you rest more comfortably at the eye doctors office and with any other prescription. Of course, when contact lenses used to deliver prescription drugs are introduced in the next year or two they will need to be added to future research like this.

A swollen, yellowish raised area on the white of the eye located towards the outside can be very alarming when first noted on a child’s eye. Demolipoma is a congenital condition present at birth. It is a benign growth of normal tissue in a place they are not usually found. The area is not tender or red, and typically grows very slowly or is stable. It may show a growth spurt in adolescence. After diagnosis, it is normally managed conservatively by observation. Vision may be mildly effected in some cases by the development of astigmatism. To prevent amblyopia (lazy eye), vision should be checked on an annual basis. While a dermolipoma can be surgically removed, multiple complications can occur. Dry eyes from damage to the lacrimal gland, double vision from damage to the lateral rectus eye muscle, droopy eyelids from eye nerve damage, are a few of the possible complications. Since surgery is for cosmetic concerns and not for visual problems, it is normally not performed. If the eye appearance very disturbing to the child, surgery may be considered. It is important to find a well qualified oculoplastic surgeon. This is an  ophthalmologist who is also a facial surgeon and ideally a fellow of the American Society of Ophthalmic Plastic and Reconstructive Surgery. If surgery is chosen as an option, it requires an eye physician that is very careful and does minimal removal of tissue to prevent complications.

Occasionally, dermolipoma can occur in conjunction Goldenhar syndrome where one side of the face may have incomplete development of the ear, nose. lips, and jaw. Other organs in the body may be effected. This is apparent from facial appearance at an early age so there is not a concern about it developing after dermolipoma is diagnosed. Since serious conditions can appear similiar, the most important part of managing a dermolipoma is an accurate initial diagnosis.

As the H1N1 Swine Flu continues to spread pinkeye (conjunctivitis) is still uncommon and very mild. Rare cases have been showing up involving neurological complications that sometimes do manifest other eye problems.  Encephalopathy is a neurological syndrome that disrupts large areas of the brain. This has been seen in a limited number of patients and can result in eyes turning up or to the side, usually accompanied by a seizure. Other problems that may be seen in the future with encephalopathy are photophobia (light sensitivity) and nystagmus  (eyes rapidly moving in a tremor like manner). By this point the patient would normally be hospitalized from the other problems so it is highly unlikely to be seen in a home setting.

An unknown at this point is if the  influenza can be transmitted from the tears in the eye. The normal routes of transmission are through airborne droplets created by coughing or sneezing or touching a surface that has been contaminated. While the HIV virus is present in tears there are no known cases of transmission by this route. It is unknown if this will be the same with the new Flu virus.  Also, airborne droplets could contact the eye, drain into the sinuses and possibly result in infection. Until more is known it is probably best to err on the side of caution and wear some form of protective eyewear if you are around someone with flu symptoms.

Incredible images of a normal retina on the left and a damaged retina (tissue lining the back of the eye) courtesy of Robert N. Fariss, Ph.D., chief of the NEI Biological Imaging Core, and Ann H. Milam, Ph.D., former professor in the Department of Ophthalmology at the University of Washington.

Retinitis Pigmentosis is an eye disease that is primarily genetic and causes a slow, progressive loss of vision starting in the periphery and moving in, resulting in tunnel vision. Often eyesight will remain 20/20 until very late in the disease but with the extreme loss of side vision it can be very debilitating. Vitamin A has been used to slow the progression but doses of Vitamin A as low as twice the suggested normal dosage may increase the risk of hip fracture.

Ushers Syndrome, a combination of retinitis pigmentosa and hearing loss is common in Louisiana in the Acadian and Cajun population, French settlers that fled Canada and settled along the bayous of Louisiana. It is very uncommon to see this eye disease in Fort Collins since only a small percentage of cases result from spontaneous mutations.

If you are aware of any loss of peripheral or side vision it is important to schedule an appointment with your optometrist since other eye conditions like pituitary tumors and glaucoma can also create slowly progressive loss of side vision.

We still see allergies to the preservatives in contact lens solutions in our Fort Collins Contact Lens Clinic but at a much lower frequency than in the past.

Thimerosal, (sodium ethylmercurithiosalicylate)  is an older contact lens solution preservative whose composition is about half mercury. It as commonly used in very low doses in contact lens disinfecting solutions is an excellent preservative but causes a reasonably high number of allergic reactions. It has been used in childhood vaccines and a subject of controversy over the years as a possible cause of autism. There are no significant studies to confirm a relationship,  but similar to contact lens solutions, it is being phased out. You will often see vaccines that are touted as mercury free.

Chlorhexidine is a chemical antiseptic that is very effective at killing bacteria. It was also widely used in the past in contact lens solutions prescribed by eye doctors but frequently caused red eyes, vague forms of  eye irritation, and sometimes significant conjunctivitis and  discomfort. Like Thimerosal, it has largely been phased out of contact lens care and we never reccomend it in our Ft Collins Eye Practice. It is still widely used in the dental field to treat gum disease and as a disinfectant.

Benzalkonium chloride was used in the past and is still used today is some nasal sprays, cleaning solutions, and various other hygienic products. It is a good disinfectant but at high enough levels may not only serve as an allergen but cause serious damage to the corneal tissue the contact lens rests on.

The next generation of sensitive eyes contact lens solutions proved to have about the same rate of allergic reactions, just for different people. Switching often cured the problem for those allergic to former solutions but created problems for new users.

Many generations of solutions have since come to pass. Today the large molecule preservatives are favored by optometrists since they fail to build up in the contact lens matrix, exceeding the pore size of the lenses.

The problem today rests in generic contact lens solutions, often colored and labeled to look like the brand solutions. Sometimes they are OK, at other times they are using these older toxic preservatives that should have been off the market a long time ago. To compound the confusion, the formulations may change in the middle of the shelf for the same generic brand, even though the box appears identical.

The best bet today is to stick with a brand name solution your eye doctor reccomends or use one of the hydrogen peroxide based systems. The drawback to hydrogen peroxide has always been it is too easy to make a mistake, and hydrogen peroxide is very uncomfortable when placed in your eye without neutralization!

Spend a few extra minutes during your next visit to the optometrist and ask their advice on what is the best contact lens care regimin avaialbe to keep your eyes healthy and seeing well.

The Optometric Nutrition Society

A Professional Society Whose Time Has Come

Dr.David Kisling of Fort Collins,Colorado has become an active member of The Optometric Nutrition Society.  Lifestyle modification and nutrient intake are proving to play an important role in vision health and eye disease prevention. Several studies have shown a correlation with nutrition and chronic eye disease. This area of study has become a focus of primary vision care doctors.

The purpose of the Optometric Nutrition Society is to:

To promote excellence in the care of optometric patients through nutritional support of eye health and the prevention and control of ocular and systemic disease.
To sponsor professional symposia as well as a website, and to generate materials to educate professionals regarding the role of nutrition in systemic and ocular health.
To provide a collegial atmosphere where health care professionals can exchange ideas and concepts regarding nutritional influences on vision.
Provide a resource pool of clinically relevant refereed studies that support the role of safe nutritional support for the management of ocular and systemic disease.
To monitor and validate claims made by industry regarding the quality and efficacy of nutritional supplements.
To encourage the inclusion of nutrition education in the curricula of optometry schools.

The society closely monitors peer-reviewed published science on nutritional influence on eye health, as well as safety and ethical issues regarding specific micronutrients included in supplements being marketed to vision patients.

For more information contact:

Name:    Dr David Kisling, O.D.
Address 181 West Boardwalk Ste. 201
Fort Collins,CO. 80525
Phone:     (970) 226-0959
Email       info@harmonyeyes.net

Contact lens solutions will soon be required to have two new additions to their labeling. Although most manufacturers no longer label solutions “no rub” the F.D.A. will require rubbing lenses as part of disinfecting cycle on labeling for all multipurpose contact lens solutions. The other change will be to add a discard after opening date in addition to the expiration date already required..

Two separate incidences of outbreaks of serious eye infections the last several years have prompted theses changes. While the evidence points to non compliance with manufacturer recommendations of product use, it is felt that a higher error of margin needs to be built into the solutions regimens.

Testing of solutions is not as simple as you would think at first glance. Historically, the FDA has required two different methods of testing. Simplifying the process it can be viewed as primarily two different tests. The first is adding bacteria and fungal microorganisms to samples of the solutions and after the manufacturers specified time period for disinfecting they must reduce the number of bacteria by 99.9%  and the fungi by 90%. The second method of testing involves soaking the contact lenses in the microorganisms and then being disinfected as the manufacturer recommends. The lenses are then used to grow the bacteria and fungus on a special type of growth media. After a specific time period the number of live organisms are counted. These are referred to as colony forming units and less than 10 gives a passing grade. Tests must also be done to show that the solutions are not toxic or irritating to the eyes.

Bacteria chosen for testing in the past include Pseudomonas aerginosa, Serratia marcescens, and  Staphylococcus aureus. The first two are in a category called gram negative bacteria and the third is gram positive. Bacteria can be classified gram negative or positive by how their cell wall retains dye, and gram negative bacteria tend to be responsible for more serious infections. While most tropical and semi tropical climates show gram negative bacteria and fungal eye infections are more prevalent, temperate northern climates tend to have more gram positive bacterial infections associated with contact lens related eye infections. Pseudomonas is present almost everywhere in humid climates. While these three bacteria do cause a high incidence of contact lens related eye infections, there are numerous other bacteria that cause infections. While fungal eye infections are rare, Candida albicans and Fusarium solani are the two tested for. One of the recent outbreaks was caused by Fusarium.

We can’t test for every possible microorganism, the time and cost would be prohibitive. This is the best mix determined in the past. With Acanthamoeba being the organism resulting in the other recent outbreak it may be added to testing procedures in the future.

Reducing microorganisms to a level that the eyes immune system can handle is one assumption for test requirements. Bacteria are present at low levels at any given time in most peoples eyes. Many variables are left out of the testing protocols. The age of a lens may effect how well bacteria adhere. The condition of the contact lenses case, the wearers personal hygiene and individual variation in immune response, all factor in bacterial growth. The therapeutic dose of a disinfecting agent shows individual variation. Some bacteria mutate and become resistant to disinfectants, and also can develop coatings on the lens to render the solutions less effective. Some microorganisms may become more common, virulent, or our daily exposure to them may increase  for various reasons. For example, hot tubs have increased our exposure to acanthamoeba. The use of antimicrobial hand soaps may result in mutations to bacteria that were not a problem for the eyes in the past. Incomplete use and under dosing of antibiotic treatment may result in the same problem. The microorganisms used for testing are standardized and not necessarily representative of the current existing strain of that microorganism. Even the culture media used is standardized and different from the eye contact lens environment presented for the bacteria to develop in.

Rubbing a contact lens helps remove surface films and debris and allows the disinfecting solutions to work better. In the imperfect world of solution testing it is expected to help reduce eye infections.

The second change is more questionable. Solutions do have a lifespan when the disinfecting action drops below an effective level. They also could remain unopened until close to this date and then be used, resulting in usage past the time the solution was effective. Alternatively, once opened, the solution is subject to environmental contamination from bacteria that could exceed its capacity over time. The problem is putting two different dates on a bottle can be confusing. Proper wording can help, but one glance in any refrigerator will likely reveal we all aren’t very good at the two date dilemma. Time will tell, but short expiration dates on all solutions might be a better approach. Best of all would be a solution that changes into a horrible color after it has been open for a month. Of course with teenagers, that unfortunately might be an incentive to continue using it.

Contact lens solutions will soon be required to have two new additions to their labeling. Although most manufacturers no longer label multipurpose solutions “no rub” the F.D.A. will soon require adding a rubbing step to the care instructions. The other change will be to add a discard after opening date in addition to the expiration date for multipurpose contact lens solutions.

Two separate incidences of outbreaks of serious eye infections the last several years have prompted theses changes. While the evidence points to non compliance with manufacturer recommendations of product use as the cause, it is felt that a higher error of margin needs to be built into the solutions.

Testing of solutions is not as simple as you would think, with multiple requirements specified by the Food and Drug Administration. Simplifying the process it can be viewed as primarily two different tests. The first is adding bacteria and fungal microorganisms to samples of the solutions and after the manufacturers specified time period they must reduce the number of bacteria by 99.9%  and the fungi by 90%. The second method of testing involves soaking the contact lenses in the microorganisms and then being disinfected as the manufacturer recommends. The lenses are then used to grow the bacteria and fungus on a special type of growth media. After a specific time period the number of live organisms are counted. These are referred to as colony forming units and less than 10 gives a passing grade. Tests must also be done to show that the solutions are not toxic or irritating to the eyes.

Bacteria chosen for testing in the past include Pseudomonas aerginosa, Serratia marcescens, and  Staphylococcus aureus. The first two are in a category called gram negative bacteria and the third is gram positive. While most tropical and semi tropical climates show gram negative bacteria and fungal infections are more prevalent, temperate northern climates tend to have more gram positive bacterial infections. Pseudomonas is present almost everywhere in humid climates. While these three bacteria do cause a high incidence of contact lens related eye infections, there are numerous other bacteria that cause infections. While fungal eye infections are rare, Candida albicans and Fusarium solani are the two tested for. One of the recent outbreaks was caused by Fusarium.

We can’t test for every possible microorganism, the time and cost would be prohibitive. This is the best mix determined in the past. With Acanthamoeba being the organism resulting in the other recent outbreak it may be added in the future.

Reducing organisms to a level that the bodies immune system can handle is one assumption for test requirements. Many variables are left out. The age of a lens may effect how well bacteria adhere. The condition of the contact lenses case, the wearers personal hygiene, individual; variation in immune response, all factor in. The therapeutic dose of a disinfecting agent shows individual variation. Some bacteria mutate and become resistant to disinfectants and also can develop coatings on the lens to render the solutions less effective. Some microorganisms may become more common, virulent, or our daily exposure to them may increase  for various reasons. This is probably the case with acanthamoeba. The use of antimicrobial hand soaps may result in mutations to bacteria that were not a problem for the eyes in the past. Incomplete use and under dosing of antibiotic treatment may result in the same problem. The microorganisms used for testing are standardized and not necessarily representative of the current existing strain of that microorganism. Even the culture media used is standardized and different from the environment the eye contact lens environment presents for the bacteria to grow in.

Rubbing a contact lens help remove surface films and debris that allow a the disinfecting solutions to work better. In the imperfect world of solution testing it is expected to help reduce eye infections.

The second change is more questionable to me. Solutions do have a lifespan when the disinfecting action drops below an effective level. They also could remain unopened until close to this date and then be used, resulting in usage past the time the solution was effective. Alternatively, once opened, the solution is subject to environmental contamination from bacteria that could exceed its capacity over time. The problem is putting two different dates on a bottle is confusing. Proper wording can help, but one glance in any refrigerator will likely reveal we all aren’t very good at the two date dilemma. Time will tell, but short expiration dates on all solutions might be a better solution (pardon the pun). Best of all would be a solution that changes into a horrible color after it has been open a month. Of course with teenagers, that unfortunately might be an incentive.