by Dr. Edward Paul
Eye redness was the clue that something was happening to Celia Ramirez's vision. Although she wasn't having trouble driving or doing other tasks, her children urged her to have a checkup. It turned out she was in the early stages of age-related macular degeneration (AMD), a disease that attacks a person's central field of vision.
Mrs. Ramirez, who lives in the Rio Grande Valley, had surgery that successfully controlled her eye pressure, but her central vision continued to degrade.Eye specialist William Sponsel, Ph.D., associate professor and director of research at the Department of Ophthalmology at the University of Texas Health Science Center at San Antonio (UTHSC).Found a treatment with a new combination of drugs.
The miracle is the carbon dioxide, which is crucial for vision. The healthy eye produces enough carbon dioxide to dilate blood vessels around the retina and maintain proper blood flow. The ailing eye does not produce enough. This holds important implications for the treatment of patients with blinding eye diseases such as AMD and glaucoma, which are marked by diminished circulation of blood in the back of the eye. Eye pressure also is a conventional barometer of eye health.
About 60 of 65 patients have seen their vision improve while receiving treatment at UTHSC's teaching hospital, University Hospital. "The patients are receiving combination drug therapy, including agents that trick the eye into retaining more of its carbon dioxide," Dr. Sponsel said. "We have patients with glaucoma and no AMD, patients with AMD and no glaucoma, and patients with both disorders. All appear to demonstrate benefit in the central visual area, regardless of the cause of that visual loss."
The Health Science Center is the first medical center to initiate this combination therapy for patients with central visual loss, Dr. Sponsel said. Considerable research yielded the conclusions that now help patients. "You don't expect these patients to get better, you expect them to get worse," he said. "We have seen dramatic results that bode well for treatment of these disorders in the future."
The researchers measure patients' sensitivity to light on visual function tests. An increase of 10 points represents more than a million-fold increase in actual visual acuity. Mrs. Ramirez's vision in the macula -- the central visual area that enables perception of letters and colors -- was scored as virtually zero on early tests. After the recent treatment, her score is now 24.
The miracle agents are called "carbonic anhydrase inhibitors" (CAI's). Given as eye drops, CAI's reach the back of the eye rapidly and slow the clearance of carbon dioxide while increasing the supply of nutrients. They help dilate blood vessels within and behind the retina, which is the structure that receives, processes and transmits visual images relayed from the brain.
Dr. Sponsel pursued this line of research in an intriguing way -- after discovering that adults who hyperventilated and rapidly blew off their body's carbon dioxide showed decreased vision, eye pressure and circulation in the back of the eye. He was treating subjects one week with a CAI called dorzolamide and the next week with placebo eye drops. During hyperventilation, the subjects on dorzolamide maintained good light sensitivity in their central field of vision, while the same subjects during placebo treatment showed central visual loss. Dr. Sponsel holds two U.S. patents on this work. One valuable aspect of the research is that it proves increased eye pressure is not necessarily the definitive indicator of eye vessel disease.
Saturday, September 18, 2010
Monday, September 13, 2010
Macular Degeneration and your eyesight
You have most probably heard of this very common condition that damages your eyesight as you age. Because this condition affects more elderly people it is often referred to as age-related macular degeneration. Unfortunately there is no cure available for this condition however there are treatments that can help. This blog outlines the latest in research and treatments regarding macular degeneration and aims to help you make the most out of your eyesight in the mean time.
Now macular degeneration as the name implies affects the macula, which is an area right at the back of the eye on a structure that detects light known as the retina. Your macula is the part of the retina that allows you to see things in great detail. In fact many birds have better maculas than us, as they need to see things in great detail from up in the air. The condition of macula degeneration implies that the macula is damaged and as this damage becomes more extensive your eyesight will be affected. There are two types of macula degeneration and they are known as the wet or the dry type, the most common of the two is ‘dry’ maculae degeneration. In this type you get little yellow patches that pop up around your macula and your vision slowly worsens. In ‘wet’ macula degeneration there are tiny blood vessels in the back of your eye that grow and then leak out blood and other fluid. This tends to make ones vision worse more quickly and you should note that dry degeneration can turn into the wet kind.
Those who present with this condition for the most part have difficulty reading, making out fine detail and even have trouble recognizing friends and families faces. After a few years of having this condition things that are in the middle of your vision will begin to look blurred and you may struggle to make things out. After a while the middle of your vision may just appear black and you often cant see anything in this area, this means that you will be unable to see things that are right in front of you. However your peripheral vision will not be affected.
There are things that you can do to cope with this condition as well as medicines that can help. Your doctor may teach you how to make better use of your peripheral vision and tell you that using bright lighting in your home will help you see better. You may also need to make text on the computer screen bigger and use magnifying glasses when reading a book. Most of the medical treatments are aimed at the treatment of wet macular degeneration and in fact there are not many effective treatments for the dry variety. Laser therapy can be used to stop the macular degeneration from getting worse in the sense that these lasers burn away those yellow patches that form around the macular early in the disease course. Also there is no need to worry as laser therapy is not painful and is quite quick, however the evidence supporting this form of treatment is not great at this stage. In fact some research suggests that laser treatment can cause new blood vessels to from on the back of the eye that can make your sight worse.
Mineral and vitamin supplements may be useful in slowing down or stopping macula degeneration from occurring. You should take zinc, vitamin E and C as well as beta-carotene. Remember here that you will need to take them for a long time and in high doses to be affective and remember that these are not without their side effects. Some people find that they have problems with passing urine, others complain of stomach pains and some people notice that their skin turns a little yellow. If this is that case with you then you should stop taking the tablets and visit your doctor.
Wet macular degeneration can be treated with photodynamic laser surgery whereby a dye that is sensitive to light is injected into your bloodstream and then a laser is shone into your eye. The dye that was injected into the blood helps the laser to destroy all of those leaky blood vessels that are damaging your eye. This method has mixed reviews on effectiveness and one should have a good discussion with their doctor regarding the risks and benefits of this procedure before having it done.
There is another type of laser that can be used to destroy the blood vessels in the eye that leak, but this is only affective in a few people with very severe disease. There is a chance with this procedure that the blood vessels will grow back anyway and the laser can sometimes damage the eye. Radiotherapy is another option but lacks suitable research to say whether or not it works and we always worry that radiation may damage other parts of the eye.
There is an injection that you can have in your eyeball called pegaptanib, however for obvious reasons not many people like the idea of this if they can help it. Also you have to have two injections every month and the evidence is not great that it works wonders, although there are some convincing studies. There is another injection called ranibizumab that you get in your eyeball and this also does not have great results but is indicated in people with wet macular degeneration that is getting worse.
So the most important thing is what will happen to you and in this case the outcome is not fantastic. Over many years your vision will gradually get worse and it will be much worse in the centre of your vision than in the peripheries and you are unlikely to go completely blind. Unfortunately we don’t know how quickly things will turn bad and each patient is different, but most people manage to get around even with severe disease as they are able to use their peripheral vision much more effectively.
Now macular degeneration as the name implies affects the macula, which is an area right at the back of the eye on a structure that detects light known as the retina. Your macula is the part of the retina that allows you to see things in great detail. In fact many birds have better maculas than us, as they need to see things in great detail from up in the air. The condition of macula degeneration implies that the macula is damaged and as this damage becomes more extensive your eyesight will be affected. There are two types of macula degeneration and they are known as the wet or the dry type, the most common of the two is ‘dry’ maculae degeneration. In this type you get little yellow patches that pop up around your macula and your vision slowly worsens. In ‘wet’ macula degeneration there are tiny blood vessels in the back of your eye that grow and then leak out blood and other fluid. This tends to make ones vision worse more quickly and you should note that dry degeneration can turn into the wet kind.
Those who present with this condition for the most part have difficulty reading, making out fine detail and even have trouble recognizing friends and families faces. After a few years of having this condition things that are in the middle of your vision will begin to look blurred and you may struggle to make things out. After a while the middle of your vision may just appear black and you often cant see anything in this area, this means that you will be unable to see things that are right in front of you. However your peripheral vision will not be affected.
There are things that you can do to cope with this condition as well as medicines that can help. Your doctor may teach you how to make better use of your peripheral vision and tell you that using bright lighting in your home will help you see better. You may also need to make text on the computer screen bigger and use magnifying glasses when reading a book. Most of the medical treatments are aimed at the treatment of wet macular degeneration and in fact there are not many effective treatments for the dry variety. Laser therapy can be used to stop the macular degeneration from getting worse in the sense that these lasers burn away those yellow patches that form around the macular early in the disease course. Also there is no need to worry as laser therapy is not painful and is quite quick, however the evidence supporting this form of treatment is not great at this stage. In fact some research suggests that laser treatment can cause new blood vessels to from on the back of the eye that can make your sight worse.
Mineral and vitamin supplements may be useful in slowing down or stopping macula degeneration from occurring. You should take zinc, vitamin E and C as well as beta-carotene. Remember here that you will need to take them for a long time and in high doses to be affective and remember that these are not without their side effects. Some people find that they have problems with passing urine, others complain of stomach pains and some people notice that their skin turns a little yellow. If this is that case with you then you should stop taking the tablets and visit your doctor.
Wet macular degeneration can be treated with photodynamic laser surgery whereby a dye that is sensitive to light is injected into your bloodstream and then a laser is shone into your eye. The dye that was injected into the blood helps the laser to destroy all of those leaky blood vessels that are damaging your eye. This method has mixed reviews on effectiveness and one should have a good discussion with their doctor regarding the risks and benefits of this procedure before having it done.
There is another type of laser that can be used to destroy the blood vessels in the eye that leak, but this is only affective in a few people with very severe disease. There is a chance with this procedure that the blood vessels will grow back anyway and the laser can sometimes damage the eye. Radiotherapy is another option but lacks suitable research to say whether or not it works and we always worry that radiation may damage other parts of the eye.
There is an injection that you can have in your eyeball called pegaptanib, however for obvious reasons not many people like the idea of this if they can help it. Also you have to have two injections every month and the evidence is not great that it works wonders, although there are some convincing studies. There is another injection called ranibizumab that you get in your eyeball and this also does not have great results but is indicated in people with wet macular degeneration that is getting worse.
So the most important thing is what will happen to you and in this case the outcome is not fantastic. Over many years your vision will gradually get worse and it will be much worse in the centre of your vision than in the peripheries and you are unlikely to go completely blind. Unfortunately we don’t know how quickly things will turn bad and each patient is different, but most people manage to get around even with severe disease as they are able to use their peripheral vision much more effectively.
Wednesday, September 1, 2010
FDA grants pSivida, Alimera expedited review for macular degeneration therapy
FDA grants pSivida, Alimera expedited review for macular degeneration therapy
August 31, 2010 by MassDevice staff
pSivida Corp. and Alimera Sciences win priority review status for their Iluvien drug/device combination, designed to treat diabetic macular degeneration.
PSDV, ALIM logos
The Food & Drug Administration put pSivida Corp. (NSDQ:PSDV) and Alimera Sciences Inc. (NSDQ:ALIM) on the fast track, granting an expedited review for their drug/device combination designed to treat diabetic macular edema.
Watertown, Mass.-based pSivida and Alpharetta, Ga.-based Alimera filed a new drug application with the FDA in June for Iluvien, a sustained release drug delivery system that delivers flucocinolone acetonide, a steroid, for the treatment of DME.
The federal watchdog agency granted priority review status to the application, moving the goal for finishing the review from 10 months back to six months.
That means a response could drop during the fourth quarter, pSivida president and CEO Dr. Paul Ashton said in prepared remarks, adding that FDA approval would trigger a $25 million milestone payment from Alimera.
The milestone payment wouldn't be the first time Alimera ponied up for pSivida. Its $72 million IPO in April triggered the repayment of a $15 million loan and $225,000 in interest. The companies are seeking European approval for Iluvien. If it makes it to market, pSivida will collect 20 percent of the net profits.
The FDA has already cleared a pair of pSivida products: Retisert, for the treatment of posterior uveitis, and Vitrasert for the treatment of AIDS-related cytomegalovirus retinitis. Both are licensed to Bausch & Lomb Inc. The company is also developing other ophthalmic products with Pfizer Inc. (NYSE:PFE), its largest shareholder, and has products of its own in the pipeline outside of ophthalmology, according to a press release.
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August 31, 2010 by MassDevice staff
pSivida Corp. and Alimera Sciences win priority review status for their Iluvien drug/device combination, designed to treat diabetic macular degeneration.
PSDV, ALIM logos
The Food & Drug Administration put pSivida Corp. (NSDQ:PSDV) and Alimera Sciences Inc. (NSDQ:ALIM) on the fast track, granting an expedited review for their drug/device combination designed to treat diabetic macular edema.
Watertown, Mass.-based pSivida and Alpharetta, Ga.-based Alimera filed a new drug application with the FDA in June for Iluvien, a sustained release drug delivery system that delivers flucocinolone acetonide, a steroid, for the treatment of DME.
The federal watchdog agency granted priority review status to the application, moving the goal for finishing the review from 10 months back to six months.
That means a response could drop during the fourth quarter, pSivida president and CEO Dr. Paul Ashton said in prepared remarks, adding that FDA approval would trigger a $25 million milestone payment from Alimera.
The milestone payment wouldn't be the first time Alimera ponied up for pSivida. Its $72 million IPO in April triggered the repayment of a $15 million loan and $225,000 in interest. The companies are seeking European approval for Iluvien. If it makes it to market, pSivida will collect 20 percent of the net profits.
The FDA has already cleared a pair of pSivida products: Retisert, for the treatment of posterior uveitis, and Vitrasert for the treatment of AIDS-related cytomegalovirus retinitis. Both are licensed to Bausch & Lomb Inc. The company is also developing other ophthalmic products with Pfizer Inc. (NYSE:PFE), its largest shareholder, and has products of its own in the pipeline outside of ophthalmology, according to a press release.
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