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June 1st 2018
Scientists create the first 3D-printed human corneas
Newcastle University researchers have devised a groundbreaking experimental technique that could help millions on the corneal transplant waiting list. By using a simple 3D bio-printer, Professor of Tissue Engineering Che Connon and his team of scientists were able to combine healthy corneal stem cells with collagen and alginate (a type of sugar sometimes used in tissue regeneration) to create 'bio-ink' -- a printable solution that enabled them to reproduce the shape of a human cornea in just 10 minutes.
The cornea has a significant role in helping us focus and barricading our eyes against dirt and bacteria. However, since it's located on the outermost layer of the eye, it's also pretty vulnerable to injury. Worldwide, approximately 10 million people risk corneal blindness due to infectious disorders like trachoma, but there's a dearth of readily available transplants. Because Connon's 3D-printed corneas utilize stem cells, corneal replicas could potentially provide a limitless supply of much-needed transplants.
"Our unique gel - a combination of alginate and collagen - keeps the stem cells alive whilst producing a material which is stiff enough to hold its shape but soft enough to be squeezed out the nozzle of a 3D printer," Connon said.
Before printing the corneal replicas, researchers scanned patients' eyes to ascertain the necessary dimensions and coordinates. While it's likely patients will have to wait "several years" before these 3D-printed corneas are available in an official capacity, they still represent incredible hope for those with more severe corneal-related impairments.
Sep 4th 2016
Stanford researchers, funded in part by the National Eye Institute and the Glaucoma Research Foundation, make discovery that may lead to help for glaucoma patients who have lost vision. Study points toward potential regenerative therapies for damaged cells.
New research by Andrew Huberman, PhD, associate professor of neurobiology at Stanford University, has taken a novel approach to the study of nerve regeneration in glaucoma. In a study published in the scientific journal Nature Neuroscience, Dr. Huberman describes conditioning injured optic nerve cells to regenerate. Blind mice treated with this approach regained partial eyesight—a surprising discovery that has significant implications for neurodegenerative diseases like glaucoma.
In glaucoma, the retinal ganglion cells—which collect visual information and send it to the brain—suffer the most damage. Dr. Huberman and his colleagues have been exploring ways to help these cells regrow and reconnect to the brain. The researchers adopted a combined approach that uses both genetic and visual stimulation to enhance neural activity. They activated common growth mechanism in cells, called the mTOR signaling pathway, in the severed retinal ganglions of mice and also repeatedly exposed the damaged eye to high-contrast oscillating black-and-white images. The researchers discovered that this regimen was able to trigger the once-injured retinal cells to regrow optic nerve fibers along damaged pathways to the brain, giving the mice limited eyesight.
Huberman’s research demonstrated for the first time that repaired retinal ganglion cells, when treated with combination therapy, have the capacity to re-establish connections to the brain to restore vision. This is just the beginning: Ocular repair and strategies to correct diseases like glaucoma may well lead to treatments for other causes of blindness and for neurodegenerative diseases that affect other parts of the body and brain, offering hope to millions of afflicted people worldwide.
The study, funded in part by the San Francisco-based Glaucoma Research Foundation, is part of the National Institutes of Health’s “audacious goals” in vision research, which aims to develop new treatments for major eye diseases, including glaucoma, by 2022. “What they have shown in an animal model is that maybe we can restore vision by reconnecting the nerve cells that are damaged,” said Thomas M. Brunner, President and CEO of the Glaucoma Research Foundation. “Their research shows that there may be promise for people, where we think vision is permanently gone, to restore it.”
Andrew Iwach, MD, the executive director of the Glaucoma Center of San Francisco and a professor of ophthalmology at UC San Francisco, said the new research highlighted an opportunity for doctors to take a more active role in treatment, instead of just prevention. “This may help us open another area of exploration for research, not only to play defense and protect what’s left, but also go on the offense to help patients,” Dr. Iwach said.
I have just discovered that that some types of decongestant sprays carry a glaucoma warning read the small print.
March 12th 2016 News
A pioneering procedure to regenerate the eye has successfully treated children with cataracts in China.
More than half of all cases of blindness are caused by cataracts - the clouding of the eye's lens.
An implanted lens is normally needed to restore sight, but the operation described in Nature activated stem cells in the eye to grow a new one.
Experts describe the breakthrough as one of the finest achievements in regenerative medicine.
The lens sits just behind the pupil and focuses light on to the retina.
About 20 million people are blind because of cataracts, which become more common with age - although some children are born with them.
Conventional treatment uses ultrasound to soften and break up the lens, which is then flushed out.
An artificial intraocular lens must then be implanted back into the eye, but this can result in complications, particularly in children.
Image copyright SPL Image caption Close up of a cataract clouding the normally transparent lens
The technique developed by scientists at the Sun Yat-sen University and the University of California, San Diego removes the cloudy cataract from inside the lens via a tiny incision.
Crucially it leaves the outer surface - called the lens capsule - intact.
This structure is lined with lens epithelial stem cells, which normally repair damage.
The scientists hoped that preserving them would regenerate the lens.
The team reported that tests on rabbits and monkeys were successful, so the approach was trialled in 12 children.
Within eight months the regenerated lens was back to the same size as normal.
The study is one of the finest achievements in the field of regenerative medicine until nowDr Dusko Ilic, King's College London
Dr Kang Zhang, one of the researchers, told the BBC News website: "This is the first time an entire lens has been regenerated. The children were operated on in China and they continue to be doing very well with normal vision."
It also showed a dramatically lower complication rate "by almost every measure, supporting the superiority of the treatment".
However, he says larger trials are needed before it should become the standard treatment for patients.
The procedure was tried in children because their lens epithelial stem cells are more youthful and more able to regenerate than in older patients.
Yet the overwhelming majority of cataracts are in the elderly.
Dr Zhang says tests have already started on older pairs of eyes and says the early research "looks very encouraging".
Commenting on the findings, Prof Robin Ali from the UCL Institute of Ophthalmology, said the work was "stunning".
He told the BBC News website: "This new approach offers greatly improved prospects for the treatment of paediatric cataracts as it results in regeneration of a normal lens that grows naturally."
He said getting similar results in adults "is likely to be more difficult to achieve" but could "have a major impact".
"It might be superior to the artificial lenses that are currently implanted, as the natural lenses should be able to accommodate looking at different distances more effectively," he added.
Dr Dusko Ilic, a reader in stem cell science at King's College London, said: "The study is one of the finest achievements in the field of regenerative medicine until now.
"It is science at its best."
Dr Zhang believes that targeting stem cells already sitting in the eye could have "great potential" for treating a wide range of diseases from macular degeneration to glaucoma.
A separate study by Osaka University in Japan and Cardiff University, used stem cells to mirror the development of the eye.
They were able to produce a range of specialised eye tissues including those that make the cornea, conjunctiva, lens and retina.
The findings, also published in Nature, showed the lab-grown tissues could restore sight to rabbits with corneal blindness.
One of the researchers, Prof Andrew Quantock, said: "Our work not only holds potential for developing cells for treatment of other areas of the eye, but could set the stage for future human clinical trials of anterior eye transplantation to restore visual function."
Glaucoma is a condition affecting your eyes that if not treated will blind you.
People don't often realise their sight is being damaged because the first part of the eye to be affected is the outer field of vision (peripheral vision). there are usually no noticeable symptoms because the condition develops very slowly, vision is lost from the outer rim of the eye, slowly working inwards towards the center.
You want to get your eyes tested at least every 12 months by someone who also measures the pressure of the fluid in your eyeballs, if he considers this to be too high he will recommend you go to see your doctor and he will give you a backup letter explaining the situation. The doctor will then refer you to a glaucoma specialist doctor.
There are four different types of glaucoma listed here.
Acute angle-closure glaucoma
This type of glaucoma develops very rapidly and you will experience severe pain, possibly a headache and strange disturbances to your vision many people feel nauseous or actually vomit these symptoms can last one or two hours but each attack damages your vision so the best advice I can give you is to get yourself down to the hospital as soon as you possibly can even if it's the middle of the night.
May be caused by eye injuries and certain treatments, such as medication or operations, but can also be caused by other conditions such as inflammation of the middle layer of the eye the medical name for this is uveitis, this is why you need to see a medical specialist without delay to check your secondary glaucoma situation,some of these conditions are very complicated and the symptoms can be very confusing so it's essential that you get the best optical care that you possibly can.
Parents should pay special attention to the eyes of their young children, if you see anything peculiar about the condition of their eyes, such as abnormal movements, watery eyes that are sensitive to light or a tendency to squint you must take them straight away to your family doctor or optometrist.
There are many research organisations that are desperately trying to find better treatments and maybe a cure for these terrible conditions, we have hopes for treatments with stem cells or alternatively with nano particles, so we hope and pray that we shall soon see a result that will bring a cure.
Latest news March 9th 2016
Scientists have demonstrated a method for generating several key types of eye tissue from human stem cells in a way that mirrors whole eye development.
When transplanted to an animal model of corneal blindness, these tissues are shown to repair the front of the eye and restore vision, which scientists say could pave the way for human clinical trials of anterior eye transplantation to restore lost or damaged vision. A collaborative team comprising researchers from Cardiff University and Osaka University in Japan describe their findings today in Nature. The eye is composed of highly specialized tissues that are derived from a variety of cell lineages during development. Previous studies have demonstrated that particular cell types, such as those that constitute the retina or cornea, can be created in the laboratory from pluripotent stem cells. However, these studies do not represent the complexity of whole eye development. This latest study reports the generation of multiple cell lineages of the eye, including the lens, cornea, and conjunctiva, using human induced pluripotent stem cells. The scientists have been able to show that the corneal epithelial cells can be cultivated and transplanted onto the eyes of rabbits with experimentally induced blindness to surgically repair the front of the eye. Study co-author Professor Andrew Quantock, from Cardiff University's School of Optometry and Vision Sciences, said: "This research shows that various types of human stem cells are able to take on the characteristics of the cornea, lens and retina. "Importantly, it demonstrates that one cell type -- the corneal epithelium -- could be further grown in the lab and then transplanted on to a rabbit's eye where it was functional, achieving recovered vision. "Our work not only holds potential for developing cells for treatment of other areas of the eye, but could set the stage for future human clinical trials of anterior eye transplantation to restore visual function." Around 4000 corneal grafts are performed by the NHS annually, which rely on human organ donation. The research was funded by the Japanese government's Agency for Medical Research and Development.
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