Saturday, December 27, 2008
Baran Brothers: Going for Green Keeps Vision Golden
Age-related macular degeneration, or ARMD, causes almost half of all cases of impaired vision or blindness in this country. This disease, which causes the macula (part of the retina that controls central vision) to gradually break down, is chronic and degenerative.
There are two types of ARMD: “dry” and “wet,” with over 90% of cases being of the form characterized by progressive deterioration of the retina (dry). Although laser treatments seem to benefit the wet version of the disease, there is very little in the way of treatment for the more common dry form. There is some good news, however, as research is beginning to suggest various nutrients and supplements may help to slow or stop the disease.
A controlled study reported in Optometry (2004;74:1-15) found that supplementation of lutein, either combined with antioxidants and other nutrients or alone, actually improved vision in people with ARMD, in both early and advanced stages.
Lutein is in the carotenoid family of molecules (most famous of these being beta carotene) and in the body actually concentrates itself in the macula portion of the retina. There it filters out the very damaging blue light component of sunlight. It is found in large amounts in kale and spinach, and in lesser amounts in other dark green leafy vegetables, egg yolk, and corn.
In the study, 90 people with ARMD were divided into three groups and were given daily treatments for 12 months. Group 1 received 10 mg of lutein daily (amount present in about two ounces of spinach); group 2 received the same amount of lutein coupled with nutrients to enhance retinal health, such as antioxidants, bilberry, quercetin, taurine, zinc, N-acetyl cysteine and others; group three was the placebo control.
For both groups receiving lutein there was an improvement in visual acuity (equivalent to an improvement of up to one line on a standard eye chart) and in contrast sensitivity. Using certain parameters, combination therapy seemed more effective than lutein alone, and using other measures lutein by itself seemed more effective. Both active groups showed an improved capacity to filter out toxic blue light, and both showed beneficial effects in both early and later stage ARMD subjects.
Because lutein is a potent antioxidant, it may possess health related benefits beyond eye health. Studies now suggest that lutein may possibly protect the circulatory system from deadly plaque build-up, rejuvenate lungs, lower the risk of arthritis of the knee, protect an aging brain, and help to reduce oxidative damage to the skin. Another closely related antioxidant, called zeaxanthin, also concentrates itself in the macula and is typically found in the same food sources as lutein. When supplementing with lutein, look for products that supply zeaxanthin along with lutein. Researchers typically recommend five to 10 mg of lutein per day for optimum eye health.
As always consult your physician or health care practitioner in all these matters that impact your health, seek corroboration of information, and most of all, educate yourself.
Andre Baran IV and his brother Bernard Baran, are co-owners of Brothers Nutrition in Edgewater. They can be reached via e-mail at edge@
brothersnutrition.com.
Tuesday, December 23, 2008
Eye Health 9 Simple Ways to Keep Your Eyes Healthy
Do you eyes feel tired and sore by the end of the day? Modern life puts a lot of stress on our bodies and eyes are among the first things to suffer. But it doesn't have to be this way. Learn simple things you can do for your eye health and your eyes will feel and look much better in only a few days.
Have your eyes checked every 12 month
Uncorrected vision problems can progress, and wearing corrective contact lenses or glasses that are no longer right for you can cause vision problems and severe headaches.
If your contacts don't feel right in your eyes, it is probably time to visit an eye doctor, even if it hasn't been a year since your last visit.
Go for the best quality contact lenses
Not all contact lenses are equal. Some are safe for you, while others put you at risk of damaging your eyes.
See reviews of quality contact lenses. Knowing what the modern contact lens industry has to offer will help you make an educated choice, not just blindly follow what your doctor says.
In summer, always wear sunglasses
It is proven that UV rays can seriously damage your eyes, but good sunglasses can prevent this damage. When buying sunglasses, make sure that they block at least 98% of UV radiation. Contrary to popular belief, light sunglasses can block UV as well as very dark ones, even though dark glasses usually offer more protection against bright sunlight.
By the way, did you know that you need sunglasses on cloudy days as well? Clouds might provide shade, but they are no barrier for UV light. Clouds are basically water, and water is UV-transparent.
Finally, remember that you would need sunglasses even if your contact lenses offer UV protection. Even a very high quality lens can only protect the area it covers, but the entire surface of your eye needs protection.
Eat what is good for you and your eyes
The good news is that there are no foods that would be harmful for your eyes. Most foods don't affect your eyesight at all, although the right vitamins and minerals are helpful. Recent studies have shown that vitamins of the antioxidant group can prevent, or at least slow down, age-related conditions like macular degeneration and the development of cataracts. So a healthy diet won't restore eyesight that is already lost, but it can definitely slow down the process of the disease, or prevent one from starting.
Vitamins C, A and E, folic acid, selenium and zinc are definitely beneficial for the health of your eyes. The effects of the other vitamins and minerals aren't determined yet, but it seems likely that they affect your eyesight as well. Thousand-page books have been written on the topic of nutrition for eye health but, to summarize, it is known that whatever is good for your body is good for your eyes, too. So put a carrot and a bunch of grapes into your lunch box.
When you read or work on the computer make sure that the light is right
It is a common knowledge that working with poor light can cause eyestrain, but light that is too bright can do as much damage.
Keep your blinds down on sunny days and switch off half of the household lights, if possible. The best lighting for working on the computer is a soft desk light, coming from the side. Also, you can try decreasing the brightness of your monitor. The colors won't be so vivid, but your eyes will feel much better by the end of the day
Give your eyes a health break
The great invention of the 20th century - computers - is not so great from the point of view of health. Almost everybody feels discomfort in their eyes after peering at a computer screen all day long. This is because people blink about 25% less often then usual, while working at the computer, which causes eye dryness.
I won't advise you to blink more often - it is almost impossible to control natural reflexes. One thing you can do, though, is close your eyes and count to 5 before opening them, whenever your computer decides to take its sweet time doing something. Another thing is to look away from the screen and focus on some faraway object, as often as possible. If you train yourself into the habit, your eyes should feel much better at the end of your working day.
If you wear contact lenses, take proper care of them
Contact lenses don't require a lot or fuss, but you can't neglect their cleanliness. Every time you put your lenses in or take them out, rinse them. You should also take care to change the solution, when you are putting your lenses to rest for the night.
Wear your contact lenses to the recommended schedule
Daily disposable lenses should be replaced daily, two weeks replacement lenses should be replaced every two weeks, and so on. Some people try to save money by wearing their lenses for much longer than is intended. This isn't a good idea. Even though the quality of the lens itself might not decline, protein build-up will make your vision less clear. Another thing to consider is that the longer you wear your lenses, the higher is your risk of eye infections.
There are other ways to save on your contacts without risking your eye health. See suggestions on how to get discount contact lenses.
Try not to wear your contact lenses from 6 in the morning until midnight. Most lenses aren't designed to be worn for longer than 12 hours. If this doesn't suit your life style, though, try using extended wear lenses. You can wear Acuvue contacts for a week without removing them, or Focus Night and Day lenses for up to 30 days.
If you want to change the color of your eyes, choose only top quality color contact lenses
Color contact lenses are great fun. If you didn't try them yet, maybe you should. But only high quality color contacts, like Freshlook or Acuvue 2 Colors, are as safe and comfortable as they are beautiful. Many beauty salons, however, sell color contacts lenses of questionable quality, and these can do serious damage to your eyes.
If you follow these simple rules, your eyes should feel much better. They will look better too - you might notice that your eyes shine and their whites are actually white, again.
Tuesday, December 16, 2008
Macular Degeneration Study Links Behavior, Visual Improvement
"I see a clear picture; however, it's my peripheral. So we have a central vision loss."
It's unlikely Gina's condition will worsen. That's not the case for most macular degeneration, or "M-D", patients who develop it later in life. Their vision loss starts as a dark, central blur that expands over time.
So, like most with M-D, Gina uses her peripheral vision to compensate for her loss in central vision.
"So we don't see blank, we see a full picture, but it's going to look as though I'm looking to the left or up or down and not straight at you, when I feel I am"
Helping at her brother's pizza parlor in Norcross, Gina demonstrates how she compensates. It's a process of using peripheral vision, memorizing her surroundings and relying on her acute sense of touch as she demonstrates while cutting a lime.
"I very much use my sensory. I don't realize I do. And when people watch me they'll get very nervous that I'll slash my wrist or break something. But I have a system that works, and I've always done it that way."
Gina's brain--and her eyes--made her a perfect candidate for participation in a study by Georgia Tech and Atlanta's Emory Eye Center.
"The question we asked was, 'Does using those peripheral regions cause a change in the brain?'"
That's Eric Schumacher, a Georgia Tech psychology professor and the study's author.
He and a graduate student wanted to know how M-D patients' use of peripheral vision potentially re-wired their brains.
"It'll be different area in different patients, but it will tend to be stable within a patient they'll tend to choose one region to use as their PRL." meaning the part of the eye they use to see best.
Now this is where the science comes in. What we see straight-on largely comes from the part of our eye called the fovea. This fovea 'thing' lets us see small and vivid details, things like words on a page or the color of a traffic light.
But seeing is only partly done with the eye.
What the fovea senses is carried to the very back of the brain where the images are put together. It's an area just loaded with neurons that get all excited when we see. But in a patient with macular degeneration, those neurons don't get stimulated because the fovea doesn't send along any information.
Instead, they just sit there.
What the team found, though, is that that by identifying and stimulating parts of the eye that are strongest, those bored neurons can become re-energized.
"So that's the idea that something about the change in their behavior that they begin to use this one peripheral region drives reorganization of the primary visual cortex to begin to activate to that region."
In other words, the part of the brain the fovea stimulates in most people can become the same area M-D patients use. They won't see perfectly. But they might see better.
Dr. Susan Primo of the Emory Eye Center says the next step is to take that science to the bedside.
"...and in turn the patients will be trained to use that particular point and then to be able to use that every day in functioning, whether it is for work, school or for reading."
While science has long known the brain can reorganize itself, this study is the first to show a person's behavior can directly reorganize the brain, at least as it relates to vision.
Researchers stress the results are small steps in a long journey
Jim Burress, WABE News.
Friday, December 12, 2008
NEW YORK (Reuters Health) Nov 27 - Patients who lower their waist-to-hip ratio, particularly those who are obese, can decrease their odds of developin
A new study indicates that the carotenoids lutein and zeaxanthin may help improve vision under glare conditions such as bright sunlight or the beams of car headlights.
Scientists at the Vision Science Laboratory at the University of Georgia recently studied the relationship of lutein and zeaxanthin on macular pigment (MP), glare disability, and photostress recovery.
The macula helps filter damaging light rays. When the concentration of lutein and zeaxanthin in the macula is higher, the higher density of macular pigment enables the macula to absorb the light rays more efficiently.
Researchers studied forty healthy subjects (average age of 23.9) for six months, giving assessments at baseline, 1, 2, 4, and 6 months. Subjects were given 12mg daily of lutein and zeaxanthin supplements.
After 6 months, the lutein and zeaxanthin supplementation was shown to significantly reduce the negative effects of glare for both the visual performance tasks assessed for most of the subjects.
Read other studies about lutein and zeaxanthin, including their role in preventing macular degeneration and cataracts.
Learn more about natural leutein and zeaxanthin supplements
SOURCE: “Macular pigment and visual performance under glare conditions”, Stringham and Hammond, Optom Vis Sci., 2008 Feb;85(2):82-8
Tuesday, December 9, 2008
Flexible Dosing of Ranibizumab Safe, Maintains Efficacy in Age-Related Macular Degeneration: Presented at AAO
Frank G. Holz, MD, University of Bonn, Bonn, Germany reported findings from the phase 3b Study of Ranibizumab in Patients With Subfoveal Choroidal Neovascularization Secondary to Age-Related Macular Degeneration (SUSTAIN) here at an oral session on November 11.
SUSTAIN was designed to assess the safety and efficacy of ranibizumab in choroidal neovascularisation secondary to AMD, using a guided, individualised, as-needed, dosing schedule.
The study included 531 individuals who were either ranibizumab-naïve or had completed the Anti-VEGF (vascular endothelial growth factor) Antibody for the Treatment of Predominantly Classic Choroidal Neovascularization in AMD (ANCHOR) trial.
The current analysis was a preplanned interim analysis of 69 of the ranibizumab-naïve patients. Patients received 3 fixed monthly injections of either 0.3 or 0.5 mg ranibizumab in the initial phase and then returned every 4 weeks in the maintenance phase for a total study period of 12 months.
Criteria for retreatment in the maintenance phase included visual deterioration greater than 5 letters or a greater than 100-mcm increase in central retinal thickness.
Ocular adverse events occurred in 55.1% of study eyes and were mostly mild in nature, Dr. Holz explained during his presentation. Adverse events included reduced visual acuity, transiently increased intraocular pressure, retinal or conjunctival haemorrhage, and blepharitis. Serious adverse events included a retinal haemorrhage in one patient and retinal pigment epithelium detachment in another patient.
In ranibizumab-naïve patients, visual acuity was maintained over the course of 12 months using guided, individualised, as-needed dosing; there was a decrease from 9.2 letters to 6.7 letters from months 3 to 12, but this difference was not significant. Likewise, the decrease in central retinal thickness was maintained, with a decrease of 89.6 mcm at month 3 and 78.7 mcm at month 12.
The average number of injections given in the initial phase was 3.0 (range: 2 to 3) and 2.3 (range: 0 to 7) in the maintenance phase, indicating that only minimal doses are needed when using a flexible dosing schedule.
At month 3 and month 12, the change in visual acuity from baseline was within 15 letters for approximately 74% and 71% of patients, respectively, indicating that as-needed treatment maintained visual acuity.
"These results suggest that flexible dosing based on predefined treatment criteria with monthly monitoring results in fewer injections overall and can maintain efficacy outcomes," said Dr. Holz.
Funding for this study was provided by Novartis Pharmaceuticals Corporation.
[[Presentation title: Flexibly Dosed Ranibizumab in Patients With Neovascular AMD: Twelve-Month Interim Results of the SUSTAIN Trial. Abstract PA078]
Saturday, November 22, 2008
Canadian Bio Med Systems, Inc. Opens $10 million funding project, for two new drugs for the treatment of eye diseases
Nov. 17, 2008 09:01 AM
NEW YORK, MONTREAL and SAN DIEGO, CA, Nov. 17 /PRNewswire-FirstCall/ - Canadian Bio Med Systems Inc., a subsidiary of ICBS Limited (OTCPK: ICBT),) announced $10 million funding project for the development of two new drugs for age related macular degeneration (AMD) , and Glaucoma, being developed in conjunction with the university of Arizona .
Canadian Bio Med Systems, Inc. (CBMS) today announces that it is developing a drug to help cure the leading cause of blindness for persons over 50 years of age, for macular degeneration of the eye. The drug is being developed in conjunction with its partner Ocular Therapeutics, Inc. of San Diego, CA. The company has opened a $10 million dollar funding project through ICBS, which is targeting Federal funding along with private equity sources.
The company is currently involved in talks with a major Canadian University to work in conjunction with the University of Arizona. The company will also be taking advantage of the Research & Development grants offered by the Quebec and Canadian governments that will refund up to 70% of the companies R&D costs.
Wet age-related macular degeneration (AMD) is one of the leading causes of severe vision loss and blindness in the adult population. In the United States, there are more than 1.6 million cases of wet AMD and approximately 200,000 new cases of wet AMD are reported each year. A majority of wet AMD patients experience dramatic vision loss within months after diagnosis. Because AMD generally affects adults over 50 years of age, it is expected that the incidence of AMD will increase as the baby-boom generation ages and life expectancy increases and it has been estimated by the National Eye Institute that by 2030, an estimated 2.8 million Americans will suffer from visual impairment as a result of AMD.
While several treatment options for wet AMD are available, each has its disadvantages such as increased risk of stroke, failure to show improvement, and cost. There is no indication that any of these drugs is effective enough that it obviates the need for additional drugs to treat this disease, leaving the opportunity for novel new compounds to enter the market. The advantage of the drug under development at CBMS lies in the unique mechanism by which it manages the cause of AMD, inhibition of migration, which is distinct from the current treatments. This drug, therefore, will not compete directly with other marketed treatments and may be used as a replacement for or in conjunction with these therapies to increase the efficacy of treatment.
Glaucoma is the second most common cause of blindness in the United States, accounting for (greater than)11% of all cases of blindness in the country. The various glaucomas are estimated to affect (greater than)2.2 million individuals in the United States who are (greater than)40 years old with primary open angle glaucoma, the most common form. Glaucoma is the leading cause of blindness among African-Americans, and African-Americans are three to five times more likely to have the disease than Caucasians.
"These new compounds being developed by our two companies can be quite important in treating this very debilitating ocular diseases" said Dr. Richard Keates, MD, Chairman of Ocular Therapeutics. "Because of the unique method of action, it has the capability of becoming a very large component in the treatment of AMD and Glaucomas"
NB. This news release includes statements that constitute forward-looking statements. Please be aware that any such forward-looking statements are not guarantees of future performance and involve significant risks and uncertainties, and that actual results may vary materially from those in the forward-looking statements as a result of any number of factors, including the risk factors contained in the Company's disclosure documents.
SOURCE Inter Canadian Business Service
My sister went to a naturopathic physician who gave her an intravenous infusion of nutrients. What's this all about?
Why isn't oral supplementation sufficient?
Oral supplements and medication are convenient to take, but they are only as good as one's digestive and absorptive capabilities. When there are problems with digestion and assimilation, the recipient may be getting only a fraction of the intended benefit. When this happens, intravenous nutrients can be useful in treating illnesses that do not respond to other therapies. Additionally, some illnesses are best treated with nutritional concentrations higher than one could achieve with oral administration, and intravenous infusions can deliver a concentration of a nutrient that could not be obtained with an equivalent oral dose.
What conditions are treated with intravenous infusion?
Intravenous nutrition can be helpful in treating fibromyalgia, chronic fatigue and exhaustion. It is beneficial in supporting the immune system and treating the symptoms of the common cold, flu, and other viral illnesses. Macular degeneration and glaucoma are also improved with intravenous nutritional therapy as well as Parkinson's disease and arrhythmias of the heart. It has tremendous benefits is tissue and would healing, arresting asthma and as adjunctive treatment for many cancers.
Hanna Ian, M.S., N.M.D, is a naturopathic physician. She is in private practice at
The Naturopathic Physician located in Surprise. Reach Dr. Ian at 623-792-8889 or www.thenaturopathicphysician.com.
Age Related Macular Degeneration Therapy
This procedure uses laser to destroy the fragile, leaky blood vessels. A high energy beam of light (argon or krypton laser) is aimed directly onto the new blood vessels and destroys them, preventing further loss of vision. Though thermal laser treatment has been shown beneficial at reducing the likelihood of developing severe visual loss, there is usually an immediate decrease in visual acuity especially in subfoveal choroidal neovascularization (CNV). A CNV membrane is described as subfoveal if any part of the lesion lies beneath the centre of the foveal avascular zone (FAZ). The concern of subfoveal lesions is due to the fact that photocoagulation of such a CNV membrane necessarily results in the destruction of the overlying retina.2 Moreover, thermal laser is effective only in a small subgroup of patients with small, well-demarcated lesions that include a component of classic CNV. Therefore, many alternatives to laser photocoagulation are evolving mainly for subfoveal CNV.
(b) Photodynamic Therapy (PDT):
In 2000, USFDA approved Visudyne™ (Verteporfin for injection) for the treatment of predominantly classic subfoveal choroidal neovascularization due to AMD, pathologic myopia or presumed ocular histoplasmosis. It was the first approved drug therapy for the treatment of wet AMD. Visudyne™ is injected systemically and activated by a non-thermal laser to destroy leaking vessels.3 This therapy utilizes low-intensity light exposure (689 nm, 50 J/cm2 dose, for 83 s in Verteporfin PDT) which causes selective destruction of CNV with preservation of the overlying neuro sensory retina. There are various photosensitizing agents available for treatment. However, currently only Verteporfin is approved for the treatment of CNV. 4 Patients who receive this therapy become temporarily photosensitive and should avoid direct sunlight for 5 days.
(c) Anti Vascular endothelial growth factor (anti-VEGF)
VEGF is a naturally occurring large lipoprotein molecule consisting of at least 6 structurally related proteins. Studies have shown elevated VEGF levels in areas of laser induce CNV in primates and clinically in AMD patients. Macugen (Pegabtanib) was approved in 2004 to treat wet AMD, and is used solely or in combination with other AMD treatments.
The drug Lucentis (Ranibizumab) was approved by FDA for treating AMD in June 2006. It is a humanized antibody fragment designed to bind and inhibit the action of VEGF and thus prevent blood vessel growth and leakage. Avastin (Bevacizumab) is a drug similar to Lucentis that is used to treat colon cancer. Ophthalmologists may prescribe Avastin off label for the treatment of AMD.
VEGF Trap is a substance that blocks the action of vascular endothelial growth factor (VEGF), and prevents the growth of new blood vessels in a tumor. It belongs to the family of drugs called angiogenesis inhibitors. Angiogenesis is the term used to describe the proliferation of blood vessel growth. Substances that stop the growth of excessive blood vessels are anti-angiogenic .Bayer Healthcare and Regeneron have initiated a Phase 3 study of the VEGF Trap -Eye in the neovascular form of wet AMD. 5
(d) Combination therapy of Triamcinolone and Verteporfin
Triamcinolone acetonide has been used to modify the process of choroidal neovascularization. Corticosteroids have a multitude of anti-inflammatory effects and also seem to have direct anti-angiogenic properties. Steroids have an inhibitory effect on angiogenesis, fibrotic activity and inflammatory reaction by reducing the migration and activation of inflammatory cells. Up-regulation of extracellular matrix protein plasminogen activator inhibitor by steroids results in direct angiostatic effect. Corticosteroids stabilize endothelial and basement membranes and also reduce vascular permeability with beneficial effects.
PDT provides immediate angio-occlusion of CNV and intravitreal triamcinolone acetonide (IVTA) , prevents inflammation and up-regulation of VEGF, decreases subsequent regrowth of CNV and finally improves VA outcome. This provides substantial reasons for using verteporfin and triamcinolone in combination. 6, 7,8
Significant improvements in best-corrected visual acuity (VA) after 1 month and their maintenance over a 3-month period were observed after verteporfin Photodynamic therapy combined with intravitreal bevacizumab. These results should be confirmed in larger and long-term prospective randomized trials. 9
Alternative Therapies:
(a) Radiation Therapy:
Radiotherapy affects the evolution of exudative macular degeneration directly by endothelial toxicity, leading to capillary closure and/or indirectly through its attenuating effects on the inflammatory response, mediated by macrophages and other inflammatory cells.10 Low-dose ionizing radiation has been shown to prevent proliferation of endothelial cells of newly formed subretinal capillaries and may induce destruction of abnormal CNV tissue.
(b) Submacular Surgery:
Surgical removal of CNV with large subfoveal hemorrhages can limit toxicity to overlying photoreceptors by prompt evacuation of blood . 11 By preserving the overlying neurosensory retina it can limit visual field defect enlargement and central vision loss.
Moreover,surgery may apply to a wide range of lesions and adjunctive procedures such as RPE transplantation. However, the risks with submacular surgery are considerable and include acceleration of cataract, development of retinal tears and retinal / choroidal detachments.
(c) Retinal translocation:
Retinal translocation and limited macular translocation are being used with rationale to move the macular area from the underlying CNV to a healthier RPE region. The Choroidal neovascular membrane can then be treated with laser photocoagulaton, while sparing the foveal center. 12 However, there is risk of development of intractable proliferative vitreoretinopathy, total retinal detachment, and unpredictable long-term visual prognosis.
(d) Transpupillary thermotherapy (TTT):
A slit lamp delivery system is used to project a beam of diode laser on the lesion thereby causing heat transmission to RPE and choroid. Studies by Reichel et al 13 showed benefit for patients with occult CNV in terms of improvement of visual acuity and decreased exudation.
Prevention:
There is evidence that dietary supplements can help prevent the onset and progression of age-related macular degeneration. Lutein and zeaxanthin is found in leafy green vegetables, corn, egg yolk, squash, broccoli and peas. These carotenoids are proposed to reduce the risk of AMD by absorbing the blue light that could damage the macula, by preventing free radicals from damaging eye cells and by strengthening eye cell membrane. 14
Undergoing Research
Research is in progress to transiently enhance vascular permeability in PDT to selectively release an anti-angiogenic or anti-inflammatory factor to prevent recurrence of neovasculature in case of AMD or to release chemotherapeutic agents in the case of PDT of a malignant tumour. 15
A study was done to evaluate the safety, efficacy & durability of systemic Bevacizumab therapy for neovascular ARMD. The results were good for a small group of patients however the risks associated with systemic anti-VEGF therapy versus the safety of intra vitreal therapy deters the involvement of a large number of patients. 16
Micro and nano particulates have been used primarily on a pre-clinical basis as new drug delivery devices in experimental models of neovascular AMD 17 .The development of polymeric micelles with smart functions such as environment-sensitivity and specific tissue-targetability may enhance the activity of potent bioactive compounds, facilitating their clinical applications. Also, polymeric micelles response to external stimuli, such as light, might exert the activity of the loaded compounds in a site-directed manner, ensuring the effectiveness and safety of the nanocarrier-mediated targeting therapy. Thus, polymeric micelle-based nanocarriers will continue to hold promise for the delivery of drugs and genes . 18
All types of nucleic acids have been developed for the treatment of infectious and cell proliferative diseases affecting mostly the posterior segment of the eye. The eye is therefore a good target for this type of molecules mainly because it is a confined compartment and their delivery is close to the target site. However, to improve the efficiency of such molecules, the use of controlled and/or targeted delivery systems is needed since they allow protection against degradation, increase intracellular penetration and permit long-term delivery avoiding repeated administrations. 19
Conclusion:
Early detection of AMD can stop the progress of the disease. Patients need to be educated about the condition and consistent follow up is required. Drug delivery to the posterior segment of the eye still remains a challenge. Rapid pre corneal elimination, poor corneal absorption, rapid anterior chamber elimination and large diffusional path lengths combine to prevent topically administered drugs from reaching the posterior segment of the eye.
Lot of research is being undertaken and many Pharmacophores are being investigated. A fundamental understanding of the patho physiology of AMD integrated with a mechanistic understanding of drug delivery to the posterior segment is requisite for the design of drugs and drug delivery systems for macular degeneration.
References:
1. Verma L, Das T, Binder S. Heriot W.J., New approaches in the management of choroidal neovascular membrane in age-related macular degeneration, Current Ophthalmology, (48) (4) (2000) 263-78.
2. Beatty et al, Photocoagulation of subfoveal choroid neovascular membrane in age related macular degeneration, British Journal of Ophthalmology (83) (1999) 1103-1104.
3.Orest O., Patrick H., Drug delivery strategies to treat age related macular degeneration, Advanced drug delivery reviews (57) (14) (2005) 1991-1993.
4. Kulkarni A. D., Kuppermann B. D., Wet age related macular degeneration, Advanced drug delivery reviews (57) (14) (2005) 1994-2009.
5. http://www.fiercebiotech.com/press-releases/press-release-bayer-healthcare-regeneron-initiate-phase-3-vegf-trap-
6. Kumar A., Visual acuity and contrast sensitivity outcomes in Indian eyes undergoing photodynamic therapy with intravitreal injection of triamcinolone acetonide in age-related macular degeneration, Indian journal of ophthalmology (55) ( 3)(2007) .
7.Gillies M. C. ,Sompson J. M. ,Luo W, Penfold P., Hunyor A. B.,Chua W., A randomized clinical trail of a single dose of intravitreal Triamcinolone Acetonide for neovascular age-related macular degeneration: One-year results. Arch Ophthalmol (121) (2003) 667-673.
8. Jonas J. B.,Kreissing I.,Hugger P., Sauder G , S. Panda-Jonas, Degenring R., Intravitreal triamcinolone acetonide for exudative age-related macular degeneration, British Journal of Ophthalmology (87) (2003) 462-468.
9.Lazic R., Gabric N., Verteporfin therapy and intravitreal bevacizumab combined and alone in choroidal neovascularization due to age-related macular degeneration, Ophthalmology (114) ( 6) (2007) 1179-1185.
10. Munshi A. , Age related macular degeneration: A study of patients managed with radiotherapy, Journal of cancer research and therapeutics (3) (1) (2007) 12-16
11. Lewis H , Intraoperative fibrinolysis of submacular haemorrhage with tissue plasminogen activator and surgical drainage, American.Journal of Ophthalmology (118) (1994) 559-568.
12. Potter M., Improvement in macular function after translocation surgery in a patient with age-related macular degeneration, American Journal of Ophthalmology (129) ( 4) (2000) 547-549
13. Reichel E.,Berrocal A. M ,Desai V., Duker J.S. ,Pulfiafito C. A, Transpupillary thermotherapy of occult subfoveal choroidal neovascularization in patients with age related macular degeneration, Ophthalmology (106) (1999) 1908-1914.
14. http:// www.nutraingredients .com Europe 16/08/2006.
15. Debefve E., Combination therapy using aspirin-enhanced photodynamic selective drug delivery, Vascular Pharmacology (46) (3) (2007) 171-180.
16. Rosenfeld J. P, Systemic bevacizumab (Avastin) Therapy for neovascular age-related macular degeneration twenty-four-week results of an uncontrolled open-label clinical study, Ophthalmology (11 ) (113) (2006) 2002-2011.
17. Moshfeghi A.A ,Peyman G. A., Micro and nano particulates, Advanced Drug Delivery Reviews (57) (14) (2005) 2047-2052.
18. Nobuhiro N; Current state, achievements, and future prospects of polymeric micelles as nanocarriers for drug and gene delivery, Pharmacology and Therapeutics (112) (3) (2006) 630-648.
19. Fattal E. , Ocular delivery of nucleic acids: antisense oligonucleotides, aptamers and siRNA, Advanced Drug Delivery Reviews (58) (11) (2006) 1203-1223.
Friday, November 21, 2008
Angiogenesis Inhibitors
Lucentis® (Generic name: ranibizumab injection)
Year Approved by the FDA: 2006
Effective for: Wet macular degeneration
How it works: Lucentis®is an antibody fragment that binds to and inhibits the biologic activity of human Vascular Endothelial Growth Factor A (VEGF-A), a protein that is believed to play a critical role in the formation of the new abnormal and leaky blood vessels, characteristic of wet macular degeneration. The drug is injected into the vitreous portion of the eye (the clear jelly-like substance that fills the eye from the lens back to the retina). Due to the fact that the production of VEGF-A is ongoing, routine administration of this drug is required.
According to data collected during clinical trials, nearly 95 percent of the participants who received a monthly injection maintained their vision at 12 months following the beginning of treatment compared to approximately 60 percent of patients who received the control treatment. Approximately one-third of patients in these trials had improved vision at 12 months.
Most common side effects: The most commonly reported adverse events included hemorrhage of the conjunctiva (the membrane that covers the white part of the eye), floaters, eye pain, increased eye pressure, and inflammation of the eye. Serious adverse events such as endophthalmitis (severe inflammation of the interior of the eye), retinal detachment, retinal tear, increased eye pressure and traumatic cataract were rare and often related to the injection procedure. There is also a small increase in the risk of stroke. Clinical trial data indicated that approximately .3 percent of patients suffered a stroke when given a .3 milligram dose of Lucentis®compared to 1.2 percent of patients who received a .5 milligram dose. In addition, patients who have previously suffered a stroke may be at greater risk of having another stroke.
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