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Category Archives: Retinitis Pigmentosa

Retinitis Pigmentosa – Fighting Blindness

Posted: October 15, 2015 at 4:43 am

9Retinitis pigmentosa (RP) refers to a group of inherited diseases that affect the photoreceptor (light sensing) cells responsible for capturing images from the visual field. These cells line the back of the eye in the region known as the retina. People with RP experience a gradual decline in their vision because the two types of photoreceptor cells rod and cone cells die. Rod cells are present throughout the retina, except for the very centre, and they help with night vision. Cone cells are also present throughout the retina, but are concentrated in the central region of the retina (the macula). They are useful for central (reading) vision and for colour vision. In RP, the rod cells, and eventually the cone cells stop working, causing vision loss; however, many people with RP retain useful central vision well into middle age.

Rod cells are usually initially involved as previously mentioned, and difficulty seeing in dim light, including transitioning from light to dark and vice versa, is one of the earliest symptoms experienced. There can be a very variable range in the onset of RP. Some people are diagnosed in childhood while others are not affected until they are adults. The condition is slowly degenerative, but the rate of progression and degree of visual loss can vary from person to person and even among affected members of the same family. It is therefore very difficult to predict what an individuals vision will be like at a specific time in the future. Both eyes are usually affected in a similar way.

In Ireland, it is estimated that one in 4,000 people has RP, which equates to approximately 1,500 individuals. RP is one of the most complicated genetic conditions of all, and over 50 different genes have been identified to be causative for various forms of RP. There are various inheritance patterns for RP, including autosomal dominant (30-40%), autosomal recessive (50-60%) and X-linked (5-15%). Approximately 50% of RP patients will have a history of at least one other family member being affected. 50% of patients will not have a family history of the condition. While their RP is still caused by a gene alteration, it might not be possible to determine the inheritance pattern in these patients. Click here for more information about inheritance patterns.

The autosomal dominant form of disease tends to follow a milder course with maintenance of preserved vision well into late middle age. The X-linked form is the most severe and central vision may be lost by the third decade. RP is a genetic disease, but cases with no family history also commonly occur. If a family member is diagnosed with RP, it is strongly advised that other members of the family also have an eye exam by an eye doctor (ophthalmologist) who is specially trained to detect retinal diseases.

Maximising the remaining vision that an individual has is a crucial first step to take. There are many new low vision aids including telescopic and magnifying lenses. The wide range of assistive technologies for people with visual impairments provides plenty of choice for users at all stages of sight loss, and this technology has also removed many barriers to education and employment.

There are, as of yet, no proven or effective cures for RP, although research in this area has recently accelerated. The term RP represents an extremely varied number of diseases, as scientists have now identified more than 50 genes that can have mutations causing RP. A number of these were discovered in Irish individuals by research performed in Trinity College, Dublin. It is likely that mutations in more than 100 different genes will eventually be identified in coming years.

Typically, each person with RP only has damage in one pair of genes, and gene therapy to replace defective genes by inserting healthy genes into the retina via harmless viruses is being explored in clinical trials for a small number of RP genes. Scientists have also begun to treat animals with many other forms of RP with this approach and several more treatment trials in humans are expected to begin in the near future. Each of these hoped for new treatments will be specific for the gene responsible for the individual patients form of RP. This is the reason why Fighting Blindness considers Target 5000, designed to identify the genes responsible for inherited retinal degenerations in Irish patients, including those with RP, to be so important.

Another research area currently being explored is the area of promising drug treatments which aim to preserve the function of the rod and cone photoreceptor cells, thereby keeping them alive for longer. Many of these drugs are re-purposed drugs, which may have already been approved for a different disease, and are now being tested for their effectiveness in RP. It is estimated that as few as 5% of cone cells need to be preserved by such a treatment in order to have a huge impact on quality of life by the maintenance of a small but significant amount of central vision.

Gene therapy and drug therapies hold huge promise to treat individuals at an early to mid-stage of disease progression, where there are still some viable rod and cone cells present. For individuals who may have lost a significant portion or all of their vision, there are other technologies that are being investigated, such as stem cell therapies and retinal implant technologies.

Stem cell technology holds great potential to replace retinal cells that have already died due to degeneration. Scientists are currently working on replacing two different cell types by stem cell therapy retinal pigment epithelium (RPE) cells and photoreceptor cells. RPE cells are a special type of cell that support the photoreceptor cells, but are not responsible for seeing, therefore it is hoped that replacement of RPE cells will help the retina function better, prevent further vision loss, and help nourish surviving retinal cells. This cell type would need to be replaced in time to help support a retina that is still working. Efforts at transplanting stem cell-derived photoreceptor cells are at an even earlier stage of research, however a number of recent animal studies have shown the potential to restore function in the eye, which may pave the way for human studies in the future.

Retinal implants are a form of biomedical technology currently being developed for retinitis pigmentosa. A number of these implants have shown success in delivering a form of artificial vision to individuals with total vision loss due to RP. When all or most of the photoreceptor cells have died, they can theoretically be replaced by an electronic microchip that brings a visual image to the remaining cells of the retina. These microchips electronically signal the remaining retinal cells which pass the signal down the optic nerve for processing as a visual image by the brain. At the moment, these devices do not restore natural vision, but can help to restore mobility, by allowing an individual to see a difference in light and dark to the point where they can tell how to walk through a doorway.

Despite the lack of current treatments for RP, it is still very important to continue having regular general eye check-ups. This is because people with RP are still at risk for other kinds of eye problems that can affect the general population, and may be treatable. RP patients tend to develop cataracts at an earlier age than the non-RP population and can do very well from cataract surgery, although the visual outcome obviously depends on the severity of the retinal degeneration. Regular visits to your eye doctor can also make you aware of current advances as we learn
more about RP.

Information about clinical trialsthat are currently being conducted worldwide can be found onwww.clinicaltrials.govand can be searched by condition and trial location.

Target 5000 is a Fighting Blindness research project whichaims to provide genetic testing for the estimated 5,000 people in Ireland who have a inheritedretinal condition. The purpose of this project is to provide a precise diagnosis and more detailed information about the nature and inheritance pattern of the condition. This information will beto a national patient registry which will enable patients who are eligible for clinical trials to be identified.Click here for more information about Target 5000 and how you can get involved.

Being diagnosed with a condition causing sight loss can be very difficult. The Fighting Blindness Insight Counselling Service provides a range of supports for people affected by sight loss and their families. Click here for more information about the Insight Counselling Service or contact Insight on 01 674 6496 [email protected].

RP Fighting Blindness http://www.rpfightingblindness.org.uk

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Retinitis Pigmentosa – Fighting Blindness

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Retinitis Pigmentosa – VisionAware

Posted: October 8, 2015 at 4:43 am

By Frank J. Weinstock, MD

Retinitis pigmentosa (RP) is part of a large group of hereditary retinal conditions or dystrophies. There is considerable overlap among the various types. It usually refers to a group of hereditary conditions involving one or several layers of the retina, causing progressive degeneration. Primarily the rods (light-sensitive, specialized retinal receptor cell that works at low light levels and provides night visionnormal retina contains 150 million rods) of the retina are involved, but there may also be some involvement of the cones. With this progressive degeneration of the retina, usually you retain central vision until late in the disease as the periphery slowly constricts.

Retinitis pigmentosa is primarily a bilateral inherited condition which involves both eyes and is generally diagnosed later in life. If it starts in one eye, the other eye usually develops the same condition in a number of years. It is essential that you undergo a thorough genetic pedigree with the aid of a genetic counselor.

It occurs in 1 in 4,000 people in the United States. A related condition, Usher syndrome may show up early in life. This is accompanied by hearing loss which might be significant. Here is a first-hand account of what it is like to live with Usher Syndrome.

Since retinitis pigmentosa is a rod dystrophy, starting in the periphery of the visual field, you will start to notice an increasing difficulty in night vision with progressive constriction of the visual field to tunnel vision (a visual field: the total area an individual can see without moving the eyes from side to side) of 20 degrees or less (often known as “tunnel vision”) in the better-seeing eye, and total blindness eventually.

Article originally published: http://www.medicinenet.com/retinitis_pigmentosa/article.htm Adapted for VisionAware: August 2013

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Retinitis Pigmentosa – VisionAware

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Retinitis Pigmentosa Overview, Risk Factors, Signs …

Posted: August 12, 2015 at 9:42 am

Overview of Retinitis Pigmentosa

Retinitis pigmentosa is a term that refers to group of hereditary disorders that affect the retina’s ability to respond to light. The condition primarily affects rod cellsthe photoreceptor cells that are responsible for night vision, seeing in dim light, and peripheral vision. Cone cells, which are responsible for color vision and seeing in bright light, may also be affected as the disease progresses.

Retinitis pigmentosa may be caused by mutations in any one of at least ten different genes, resulting in a malfunction in the retinal pigment epithelial (RPE) cells and a breakdown of a portion of the outer segment disc membrane of photoreceptor cells. When cells are destroyed at an abnormal rate, the build-up of waste products interferes with normal retinal function. The result is the occlusion (blockage) of small blood vessels, an abnormal increase in the number of RPE cells (hyperplasia), and the loss of photoreceptor cells.

Retinitis pigmentosa is relatively rare. It affects 50,000 to 100,000 people in the United States. Worldwide, approximately 1.5 million people are afflicted.

Retinitis pigmentosa is caused by a genetic defect. Patterns may be of three types:

Ocular signs start with the breakdown of rod cells. Rods are present both within and outside the macula (center of the retina). The peripheral retina, responsible for side vision and vision in low light conditions, is predominantly rods.

Symptoms of RP usually manifest between the ages of 10 and 30. At first, there is a decrease in night vision and the inability to see in dimly lit places such as movie theaters. The progressive loss of peripheral sight leads to what is called tunnel vision.

The gradual reduction in the ability to see peripherally may cause tripping over objects or a motor vehicle accident. This occurs when rod cells and outer cone cells are affected.

The rate of progression of the disease varies among patients and the type. Most patients are legally blind by around age 40.

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Retinitis Pigmentosa (RP) – what is it, symptoms …

Posted: July 3, 2015 at 9:44 am

Reviewed by Grant M. Comer, M.D. and John R. Heckenlively, M.D.

On this page:

Retinitis Pigmentosa (RP) refers to a group of diseases which cause a slow but progressive vision loss. In each of them there is a gradual loss of the light-sensitive retinal cells called rods and cones.

Most forms of RP are inherited or genetic, though its signs do not necessarily appear in every generation. Learning more about your family history may help you and your doctor to make informed decisions about treatment and eventually a cure for RP.

In some cases, RP may be associated with other health problems, such as hearing loss. People with RP may also develop other treatable eye diseases, such as glaucoma and cataract.

Symptoms usually start during young adulthood, although RP may be seen at any age.

The symptoms described above may not necessarily mean that you have retinitis pigmentosa. However, if you experience one or more of these symptoms, contact your eye doctor for a complete exam.

Currently, very few treatments exist for persons with RP. Occasionally, the degeneration can be slowed to preserve vision for a longer time. Genetic studies of RP are a significant factor in finding a cure or prevention for this disease. The U-M is performing research on genetic factors of RP.

Researchers at the Center for Retinal and Macular Degeneration are not only conducting cell-biological research on these eye diseases, they are vigorously working on molecular genetic aspects of X-chromosomal retinal/macular dystrophies. The molecular information obtained in testing has become critical, in some cases, for refining diagnosis. The investigators at the University of Michigan Department of Ophthalmology have broad experience with the molecular genetics of a number of retinal conditions, including X-linked blue cone monochromacy, X-linked cone dystrophy, Best’s macular degeneration, Stargardt’s macular degeneration, Sorsby’s hemorrhagic macular dystrophy, choroideremia, and Usher’s syndrome.

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Retinitis Pigmentosa | blindness.org

Posted: June 1, 2015 at 2:46 am

Retinitis pigmentosa (RP) refers to a group of inherited diseases causing retinal degeneration. The cell-rich retina lines the back inside wall of the eye. It is responsible for capturing images from the visual field. People with RP experience a gradual decline in their vision because photoreceptor cells (rods and cones) die. Forms of RP and related diseases include Usher syndrome, Lebers congenital amaurosis, rod-cone disease, Bardet-Biedl syndrome, and Refsum disease, among others.

Symptoms depend on whether rods or cones are initially involved. In most forms of RP, rods are affected first. Because rods are concentrated in the outer portions of the retina and are triggered by dim light, their degeneration affects peripheral and night vision. When the more centrally located cones – responsible for color and sharp central vision – become involved, the loss is in color perception and central vision.

Night blindness is one of the earliest and most frequent symptoms of RP. People with mainly cone degeneration, however, first experience decreased central vision and ability to discriminate color.

RP is typically diagnosed in adolescents and young adults. It is a progressive disorder. The rate of progression and degree of visual loss varies from person to person. Most people with RP are legally blind by age 40, with a central visual field of less than 20 degrees in diameter. In families with X-linked RP, males are more often and more severely affected; females carry the genetic trait and experience vision loss less frequently.

An estimated 100,000 people in the U.S. have RP, mainly caused by gene mutations (variations) inherited from one or both parents. Mutated genes give the wrong instructions to photoreceptor cells, telling them to make an incorrect protein, or too little or too much protein. (Cells need the proper amount of particular proteins in order to function properly.) Many different gene mutations exist in RP. In Usher syndrome, for example, at least 14 disease-causing genes have been identified.

Genetic mutations can be passed from parent to offspring through one of three genetic inheritance patterns autosomal recessive, autosomal dominant, or X-linked.

In autosomal recessive RP, both parents carry one copy of the mutated gene but have no symptoms themselves. Children have a 25 percent chance of being affected by inheriting a mutated copy from each parent.

In autosomal dominant RP, usually one parent is affected and is the only parent with a mutated gene. A child has a 50 percent chance of being affected by inheriting the mutated gene from that parent.

In families with X-linked RP, the mother carries the mutated gene,and her sons have a 50 percent chance of being affected. Daughters are carriers and arent usually affected. However, some daughters are affected, but with milder symptoms.

If a family member is diagnosed with RP, it is strongly advised that other members of the family also have an eye exam by a physician who is specially trained to detect and treat retinal degenerative disorders. Discussing inheritance patterns and family planning with a genetic counselor can also be useful.

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Retinitis Pigmentosa Cure? – Video

Posted: April 26, 2015 at 12:43 pm



Retinitis Pigmentosa Cure?
If you believe it is possible to improve your wellbeing naturally, without drugs or surgery, apply to access your personal Health Coaching program at tryunity.net/my-biofield-analysis Retinitis…

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Retinitis Pigmentosa Cure? – Video

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TheBlindJournalist: An Insight Into Retinitis Pigmentosa RP Radio Documentary – Video

Posted: April 23, 2015 at 12:42 pm



TheBlindJournalist: An Insight Into Retinitis Pigmentosa RP Radio Documentary
Radio Documentary about the eye condition Retinitis Pigmentosa. For a full transcript of this documentary and more of my work, please visit http://theblindjournalist.blogspot.co.uk/2015/04/theblind…

By: TheBlindJournalist Mohammed Salim Patel

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TheBlindJournalist: An Insight Into Retinitis Pigmentosa RP Radio Documentary – Video

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Living with Retinitis Pigmentosa: My RP Experience – Molly Burke – Video

Posted: April 17, 2015 at 8:46 pm



Living with Retinitis Pigmentosa: My RP Experience – Molly Burke
OPEN ME! http://mollyburke.ca Thank you for watching my very long and rambling RP experience video. I hope this educated and helped some of you, and remember, no two RP patients are the same.

By: Molly Burke

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Living with Retinitis Pigmentosa: My RP Experience – Molly Burke – Video

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Antioxidant gene delivery protects photoreceptors – Video

Posted: April 12, 2015 at 1:49 am



Antioxidant gene delivery protects photoreceptors
The inherited form of blindness retinitis pigmentosa (RP) results in a progressive loss of photoreceptors. RP-associated mutations directly promote the death of rod cells, which are required…

By: Journal of Clinical Investigation

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Antioxidant gene delivery protects photoreceptors – Video

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Who says treatment of Retinitis Pigmentosa is not possible..? Its Possible now – Video

Posted: at 1:49 am



Who says treatment of Retinitis Pigmentosa is not possible..? Its Possible now
http://www.ayurprakash.com/retinitis-pigmentosa/ In this video, a father sharing his experience of treatment of his son suffering from Retina Problem of the eyes. check It out. If You also…

By: Dr. Dinesh Sharma

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Who says treatment of Retinitis Pigmentosa is not possible..? Its Possible now – Video

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