StemCell Therapy

Blindness is the condition of poor visual perception.

Various scales have been developed to describe the extent of vision loss and define blindness.[1] Total blindness is the complete lack of form and visual light perception and is clinically recorded as NLP, an abbreviation for "no light perception."[1] Blindness is frequently used to describe severe visual impairment with some remaining vision. Those described as having only light perception have no more sight than the ability to tell light from dark and the general direction of a light source. The World Health Organization defines low vision as visual acuity of less than 20/60 (6/18), but equal to or better than 20/200 (6/60), or visual field loss to less than 20 degrees, in the better eye with best possible correction. Blindness is defined as visual acuity of less than 20/400 (6/120), or a visual field loss to less than 10 degrees, in the better eye with best possible correction.[2][3]

As of 2012 there were 285 million visually impaired people in the world, of which 246 million had low vision and 39 million were blind.[3] The majority of people with poor vision are in the developing world and are over the age of 50 years.[3]

Blindness is defined by the World Health Organization as vision in a person's best eye of less than 20/500 or a visual field of less than 10 degrees.[4] This definition was set in 1972, and there is ongoing discussion as to whether it should be altered somewhat.[5]

Blind people with undamaged eyes may still register light non-visually for the purpose of circadian entrainment to the 24-hour light/dark cycle. Light signals for this purpose travel through the retinohypothalamic tract and are not affected by optic nerve damage beyond where the retinohypothalamic tract exits.

In 1934, the American Medical Association adopted the following definition of blindness:

"Central visual acuity of 20/200 or less in the better eye with corrective glasses or central visual acuity of more than 20/200 if there is a visual field defect in which the peripheral field is contracted to such an extent that the widest diameter of the visual field subtends an angular distance no greater than 20 degrees in the better eye."[6]

The United States Congress included this definition as part of the Aid to the Blind program in the Social Security Act passed in 1935.[6][7] In 1972, the Aid to the Blind program and two others combined under Title XVI of the Social Security Act to form the Supplemental Security Income program[8] which currently states:

"An individual shall be considered to be blind for purposes of this title if he has central visual acuity of 20/200 or less in the better eye with the use of a correcting lens. An eye which is accompanied by a limitation in the fields of vision such that the widest diameter of the visual field subtends an angle no greater than 20 degrees shall be considered for purposes of the first sentence of this subsection as having a central visual acuity of 20/200 or less. An individual shall also be considered to be blind for purposes of this title if he is blind as defined under a State plan approved under title X or XVI as in effect for October 1972 and received aid under such plan (on the basis of blindness) for December 1973, so long as he is continuously blind as so defined."[9]

In the UK, the Certificate of Vision Impairment (CVI) is used to certify patients as severely sight impaired or sight impaired.[10] The accompanying guidance for clinical staff states: "The National Assistance Act 1948 states that a person can be certified as severely sight impaired if they are so blind as to be unable to perform any work for which eye sight is essential (National Assistance Act Section 64(1)). The test is whether a person cannot do any work for which eyesight is essential, not just his or her normal job or one particular job."[11]

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Blindness - Wikipedia, the free encyclopedia

If you have low vision, eyeglasses, contact lenses, medicine, or surgery may not help. Activities like reading, shopping, cooking, writing, and watching TV may be hard to do. The leading causes of low vision and blindness in the United States are age-related eye diseases: macular degeneration, cataract and glaucoma. Other eye disorders, eye injuries and birth defects can also cause vision loss.

Whatever the cause, lost vision cannot be restored. It can, however, be managed. A loss of vision means that you may have to reorganize your life and learn new ways of doing things. If you have some vision, visual aids such as special glasses and large print books can make life easier. There are also devices to help those with no vision, like text-reading software and braille books.

The sooner vision loss or eye disease is found and treated, the greater your chances of keeping your remaining vision. You should have regular comprehensive eye exams by an eye care professional.

NIH: National Eye Institute

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Vision Impairment and Blindness: MedlinePlus

From Nobel Prizewinning author Jos Saramago, a magnificent, mesmerizing parable of loss

A city is hit by an epidemic of "white blindness" that spares no one. Authorities confine the blind to an empty mental hospital, but there the criminal element holds everyone captive, stealing food rations and assaulting women. There is one eyewitness to this nightmare who guides her c

A city is hit by an epidemic of "white blindness" that spares no one. Authorities confine the blind to an empty mental hospital, but there the criminal element holds everyone captive, stealing food rations and assaulting women. There is one eyewitness to this nightmare who guides her chargesamong them a boy with no mother, a girl with dark glasses, a dog of tearsthrough the barren streets, and their procession becomes as uncanny as the surroundings are harrowing. As Blindness reclaims the age-old story of a plague, it evokes the vivid and trembling horrors of the twentieth century, leaving readers with a powerful vision of the human spirit that's bound both by weakness and exhilarating strength.

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Blindness (Blindness, #1) by Jos Saramago Reviews ...

Color blindness, or color vision deficiency, is the inability or decreased ability to see color, or perceive color differences, under normal lighting conditions. Color blindness affects a significant percentage of the population.[1] There is no actual blindness but there is a deficiency of color vision. The most usual cause is a fault in the development of one or more sets of retinal cones that perceive color in light and transmit that information to the optic nerve. This type of color blindness is usually a sex-linked condition. The genes that produce photopigments are carried on the X chromosome; if some of these genes are missing or damaged, color blindness will be expressed in males with a higher probability than in females because males only have one X chromosome (in females, a functional gene on only one of the two X chromosomes is sufficient to yield the needed photopigments).[2]

Color blindness can also be produced by physical or chemical damage to the eye, the optic nerve, or parts of the brain. For example, people with achromatopsia suffer from a completely different disorder, but are nevertheless unable to see colors.

The first scientific paper on this subject, Extraordinary facts relating to the vision of colours, was published by the English chemist John Dalton in 1798[3] after the realization of his own color blindness. Because of Dalton's work, the general condition has been called daltonism, although in English this term is now used only for deuteranopia.

Color blindness is usually classified as a mild disability, however there are occasional circumstances where it can give an advantage. Some studies conclude that color blind people are better at penetrating certain color camouflages. Such findings may give an evolutionary reason for the high prevalence of redgreen color blindness.[4] There is also a study suggesting that people with some types of color blindness can distinguish colors that people with normal color vision are not able to distinguish.[5]

Color blindness affects a large number of individuals, with protanopia and deuteranopia being the most common types.[6] In individuals with Northern European ancestry, as many as 8 percent of men and 0.4 percent of women experience congenital colour deficiency.[7] The typical human retina contains two kinds of light cells: the rod cells (active in low light) and the cone cells (active in normal daylight). Normally, there are three kinds of cone cells, each containing a different pigment, which are activated when the pigments absorb light. The spectral sensitivities of the cones differ; one is most sensitive to short wavelengths, one to medium wavelengths, and the third to medium-to-long wavelengths within the visible spectrum, with their peak sensitivities in the blue, green, and yellow-green regions of the spectrum, respectively. The absorption spectra of the three systems overlap, and combine to cover the visible spectrum. These receptors are often called S cones, M cones, and L cones, for short, medium, and long wavelength; but they are also often referred to as blue cones, green cones, and red cones, respectively.[8]

Although these receptors are often referred to as "blue, green, and red" receptors, this terminology is inaccurate. The receptors are each responsive to a wide range of wavelengths. For example, the long wavelength, "red", receptor has its peak sensitivity in the yellow-green, some way from the red end (longest wavelength) of the visible spectrum. The sensitivity of normal color vision actually depends on the overlap between the absorption ranges of the three systems: different colors are recognized when the different types of cone are stimulated to different degrees. Red light, for example, stimulates the long wavelength cones much more than either of the others, and reducing the wavelength causes the other two cone systems to be increasingly stimulated, causing a gradual change in hue.

Many of the genes involved in color vision are on the X chromosome, making color blindness much more common in males than in females because males only have one X chromosome, while females have two. Because this is an X-linked trait, an estimated 23% of women have a 4th color cone[9] and can be considered tetrachromats, although it is not clear that this provides an advantage in color discrimination.

Color vision deficiencies can be classified as acquired or inherited.

Based on clinical appearance, color blindness may be described as total or partial. Total color blindness is much less common than partial color blindness.[17] There are two major types of color blindness: those who have difficulty distinguishing between red and green, and who have difficulty distinguishing between blue and yellow.[18][19]

Immunofluorescent imaging is a way to determine red-green color coding. Conventional color coding is difficult for individuals with red-green color blindness (protanopia or deuteranopia) to discriminate. Replacing red with magenta (top[where?]) or green with turquoise (bottom[where?]) improves visibility for such individuals.[20][not in citation given]

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Color blindness - Wikipedia, the free encyclopedia

P-SPAN #411: "Treating Blindness with Stem Cells"
On February 5, 2015, the Science/Biotechnology Department at Berkeley City College kicked off their Spring 2015 Seminar Series, sponsored by the California Institute for Regenerative Medicine....

By: Peralta Colleges

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P-SPAN #411: "Treating Blindness with Stem Cells" - Video

Can Stem Cell Injections Cure Blindness?
Stem cells may be able to cure blindness through injecting them into the eyes of people who are blind. The procedure worked over a three year period in restoring the vision of eighteen patients...

By: TheLipTV

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Can Stem Cell Injections Cure Blindness? - Video

Stem Cells, Blindness And Why The Media Loves Miracle Cures
Scientists researching the safety of stem cells have found the cells can help improve sight in patients with vision impairments. Follow Sebastian Martinez: http://www.twitter.com/sebastiansings...

By: Newsy Science

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Stem Cells, Blindness And Why The Media Loves Miracle Cures - Video

Stem-cell treatment for blindness
A legally blind Bexley man will undergo an experimental eye procedure that offers the promise of better vision.

By: TheColumbusDispatch

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Stem-cell treatment for blindness - Video

Stem-cell help for blindness
A legally blind Bexley man will undergo an experimental eye procedure that offers the promise of better vision.

By: TheColumbusDispatch

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Stem-cell help for blindness - Video

Can Stem Cells Cure Blindness?
Scientists have collected stem cells that were primed to transform into photoreceptors then injected them into the eyes of blind mice.

By: NewsyScience

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Can Stem Cells Cure Blindness? - Video

Trial to cure age related blindness to begin in London
Clinical trials could soon begin in a project aimed at restoring sight for some patients. Experts at Moorfields Eye Hospital and University College London (UCL) aim to use stem cells to restore...

By: bbcnews098

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Trial to cure age related blindness to begin in London - Video

Stem Cell Treatment Cures Blindness

By: GlobalUSANews

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Stem Cell Treatment Cures Blindness - Video

Stem Cell Treatment Restores Man #39;s Vision
Stem cell treatment restores man #39;s vision A man has undergone successful stem cell treatment to restore his eyesight. While he was on a humanitarian work mission in Haiti, Taylor Binns experienced extreme pain in his eye and his vision started to become blurry. After a couple of years, Binns became legally blind; progressively losing his sight due to corneal problems that may have been brought on by wearing contact lenses that were not properly disinfected. There were no other treatment options that would have worked to improve his eyesight, so doctors at Toronto Western Hospital decided to try a new treatment that involved the use of a limbal stem cell transplant. Binns #39; sister turned out to be a perfect match as a donor for the stem sell transplant, so doctors took stem cells from her eyes and put them on the surface of his damaged eyes after removing the scar tissue. Embryonic stem cells have also been used successfully to treat people with blindness by improving their eyesight. One of the women who underwent the embryonic stem cell treatment suffered progressively worsening eyesight, but after the surgery she can use her computer and she is able to see more color and contrast. Do you think stem cell procedures should be an option for medical treatment?From:GeoBeatsNewsViews:1 0ratingsTime:01:10More inNews Politics

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Stem Cell Treatment Restores Man's Vision - Video

ABC NEWS: Stem Cells Cure Blindness
ABC NEWS: Stem Cells Cure BlindnessFrom:stopevilViews:3 0ratingsTime:02:16More inNews Politics

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ABC NEWS: Stem Cells Cure Blindness - Video

Perceptions of Promise art show opens at UAlberta
Perceptions of Promise, the visionary University of Alberta art show that created an interdisciplinary dialogue between artists and scientists, has come home after a successful run that included a high-profile exhibition in New York. "We #39;re so happy that it #39;s finally come home," said U of A printmaking professor Liz Ingram. "Our students can now see it, and that is so important for teaching." The exhibition explores legal, ethical and social issues about stem-cell research through the eyes of U of A and other internationally known artists. Originally conceived by Sean Caulfield, U of A professor of printmaking, and his brother Tim, research director of the U of A #39;s Health Law and Science Policy Group, it brings scientists and visual artists together to broaden discussion of complex topics involving biotechnology. The aim, say contributors, is not to take positions on either side of what can often be a divisive debate, but to provoke thought and inspire questions. "Biomedical research, especially stem-cell research, tends to be very emotional," says Sean Caulfield. "People have this polarized reaction to it. If we had one broad objective, it would be to see how art might bring a more sophisticated dialogue to the debate, because art tends to be able to articulate emotional and psychological things much more effectively. And I think it can bring people together." The works include an elaborately beaded sculpture created from CT scans of a human torso, a luminous tent with ...From:UniversityofAlbertaViews:25 0ratingsTime:04:42More inEducation

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Perceptions of Promise art show opens at UAlberta - Video

25. Medical Biotechnology: Part Ib. Stem Cells-Therapy and Medical Research NQ
Stem cell research has created national, if not global controversy. Why? What divides our thinking about stem cell research? This section provides the basics on stem cell research including: embryonic stem cells; adult stem cells; and, induced pluri-potent stem cells. Also discussed are their potential therapeutic application for degenerative diseases.From:Albert KauschViews:1 0ratingsTime:36:03More inScience Technology

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25. Medical Biotechnology: Part Ib. Stem Cells-Therapy and Medical Research NQ - Video

April Flowers for redOrbit.com Your Universe Online

Columbia University ophthalmologists and stem cell researchers have developed an experimental treatment for blindness using the patients skin cells, which has improved the vision of blind mice in testing.

The findings of this research, published online in the journal Molecular Medicine, suggest that induced pluripotent stem cells (iPS) could soon be used to improve vision in people with macular degeneration and other eye retina diseases. iPS cells are derived from adult human skin cells but have embryonic qualities.

With eye diseases, I think were getting close to a scenario where a patients own skin cells are used to replace retina cells destroyed by disease or degeneration, says Stephen Tsang, MD, PhD, associate professor of ophthalmology and pathology & cell biology. Its often said that iPS transplantation will be important in the practice of medicine in some distant future, but our paper suggests the future is almost here.

Scientists were very excited by the advent of human iPS cells when they were discovered in 2007, as they provide a way to avoid the ethical complications of embryonic stem cells. Another advantage is that the iPS cells are created from the patients own skin, eliminating the need for anti-rejection medications. Like the ethically challenged embryonic cells, iPS cells can develop into any type of cell. To-date, no iPS cells have been implanted into people, but many ophthalmologists say that the eye would prove to be ideal testing ground for iPS therapies.

The eye is a transparent and accessible part of the central nervous system, and thats a big advantage. We can put cells into the eye and monitor them every day with routine non-invasive clinical exams, Tsang said. And in the event of serious complications, removing the eye is not a life-threatening event.

Professor Tsang is running a new preclinical iPS study using human iPS cells derived from the skin cells of a 53-year-old donor. The cells were first transformed with a cocktail of growth factors into cells in the retina that lie underneath the eyes light-sensing cells.

Retina cells nourish the light-sensing cells and protect the fragile cells from excess light, heat and cellular debris. In macular degeneration and retinitis pigmentosa, retina cells die, which allows the photoreceptor cells to degenerate causing the patient to lose their vision. It is estimated that 30 percent of people will have some form of macular degeneration by the time they are 75 years old, as it is the leading cause of vision loss in the elderly. Currently, it affects 7 million Americans and that is expected to double by 2020.

The Columbia research team injected the iPS-derived retina cells into the right eyes of 34 mice that had a genetic mutation that caused their retina cells to degenerate. In many of the mice, the iPS cells assimilated into the retina without disruption and functioned as normal retina cells well into the animals old age. Mice in the control group, who received injections of saline or inactive cells, showed no improvement in retina tests.

Our findings provide the first evidence of life-long neuronal recovery in a preclinical model of retinal degeneration, using stem cell transplant, with vision improvement persisting through the lifespan, Tsang says. And importantly, we saw no tumors in any of the mice, which should allay one of the biggest fears people have about stem cell transplants: that they will generate tumors.

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Blind Mice Get Experimental Stem Cell Treatment For Blindness

ScienceDaily (Oct. 1, 2012) An experimental treatment for blindness, developed from a patient's skin cells, improved the vision of blind mice in a study conducted by Columbia ophthalmologists and stem cell researchers.

The findings suggest that induced pluripotent stem (iPS) cells -- which are derived from adult human skin cells but have embryonic properties -- could soon be used to restore vision in people with macular degeneration and other diseases that affect the eye's retina.

"With eye diseases, I think we're getting close to a scenario where a patient's own skin cells are used to replace retina cells destroyed by disease or degeneration," says the study's principal investigator, Stephen Tsang, MD, PhD, associate professor of ophthalmology and pathology & cell biology. "It's often said that iPS transplantation will be important in the practice of medicine in some distant future, but our paper suggests the future is almost here."

The advent of human iPS cells in 2007 was greeted with excitement from scientists who hailed the development as a way to avoid the ethical complications of embryonic stem cells and create patient-specific stem cells. Like embryonic stem cells, iPS cells can develop into any type of cell. Thousands of different iPS cell lines from patients and healthy donors have been created in the last few years, but they are almost always used in research or drug screening.

No iPS cells have been transplanted into people, but many ophthalmologists say the eye is the ideal testing ground for iPS therapies.

"The eye is a transparent and accessible part of the central nervous system, and that's a big advantage. We can put cells into the eye and monitor them every day with routine non-invasive clinical exams," Tsang says. "And in the event of serious complications, removing the eye is not a life-threatening event."

In Tsang's new preclinical iPS study, human iPS cells -- derived from the skin cells of a 53-year-old donor -- were first transformed with a cocktail of growth factors into cells in the retina that lie underneath the eye's light-sensing cells.

The primary job of the retina cells is to nourish the light-sensing cells and protect the fragile cells from excess light, heat, and cellular debris. If the retina cells die -- which happens in macular degeneration and retinitis pigmentosa -- the photoreceptor cells degenerate and the patient loses vision. Macular degeneration is a leading cause of vision loss in the elderly, and it is estimated that 30 percent of people will have some form of macular degeneration by age 75. Macular degeneration currently affects 7 million Americans and its incidence is expected to double by 2020.

In their study, the researchers injected the iPS-derived retina cells into the right eyes of 34 mice that had a genetic mutation that caused their retina cells to degenerate.

In many animals, the human cells assimilated into mouse retina without disruption and functioned as normal retina cells well into the animals' old age. Control mice that got injections of saline or inactive cells showed no improvement in retina tests.

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Stem cells improve visual function in blind mice

Two teams including UC Irvine scientists will receive $37 million to push stem-cell treatments toward human testing one for a condition that leads to blindness, another for Alzheimers disease.

The awards, made Wednesday by the states stem-cell funding agency, include $17.3 million for a team that will cultivate retinal progenitor stem-cells to treat a disease known as retinitis pigmentosa.

Human neural stem cell.

COURTESY STEMCELLS, INC.

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The team includes Henry Klassen, a UC Irvine associate opthalmology professor, as well as researchers from UC Santa Barbara and Cedars-Sinai Medical Center. The UC Irvine share of that award is about $6 million.

The disease is often diagnosed when patients are in their teens or young adulthood, and progresses into middle age.

First theres night blindness, Klassen said. Then tunnel vision, and eventually, complete blindness.

The treatment hes developing relies on retinal stem cells that have matured enough to be specific to eye function. In previous testing, it has restored vision in rats.

The funding will allow more preliminary work in preparation for human testing. Food and Drug Administration approval, Klassen said, could come as soon as the end of next year.

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Stem-cell research: $37 million

by KING 5 News

KING5.com

Posted on July 26, 2012 at 12:27 PM

University of Washington researchers may have found a key to helping people with degenerative blindness restore their sight.

UW Medicine researchers, working with researchers at the University of California and the University of Munich, say they have discovered a chemical that temporarily restores some vision to blind mice.

Theyre now working on an improved version that may someday work on people with retinitis pigmentosa, a genetic disease that is the most common inherited form of blindness, as well as age-related macular degeneration, the most common cause of acquired blindness in the developed world.

Researchers say because the chemical eventually wears off, it may offer a safer alternative to other experimental approaches for restoring sight, such as gene or stem cell therapies, which permanently change the retina. It is also less invasive than implanting light-sensitive chips in the eye.

The findings appear in the July 26th issue of the journal Neuron.

Information compiled by KING5's Travis Pittman

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UW discovery could be cure for some blindness