What should be done to preserve vision, how to get something that is not preserved, — issue of concern to all, and a lack of publications on this subject does not happen ever. We offer readers news from the front edge of science, and start with the good: the summer in the middle lane is not only useful because you can eat a lot of fruits and berries, and go on vacation away from your computer …
Long spring and summer days are pleasing to the eye, literally — at this time the development of myopia in children is slowing, myopia is trying to take its only with the arrival of autumn and winter. This is confirmed by a study conducted in Denmark. The authors observed how changed for six months at the sight of 235 boys and girls 8-14 years, depending on the length of daylight. In processing the results they helped Chinese experts.
We are talking about the day, «outer» bright light, and the positive trend is likely not affect holiday lifestyle — exercise, instead of reading and sitting at the computer or TV (after all, a vacation is not only in summer). This is evidenced, in particular, the data obtained by scientists Singapore: Singapore daylight hours changes little and the development of myopia in children 7-12 years is almost linear. And in the central part of the United States, where daylight is subject to seasonal changes, the boys of the same age myopia progression in a dark time of the year and slowed down — in daylight. In Denmark, where the day is not more than seven hours in December and in June lasts 17.5 hours, fluctuations in the development of myopia expressed even more clearly. Probably, it is not necessary to take into account summer and winter diets — mostly Danish stores a set of products is roughly the same regardless of the season, winter fruits and vegetables imported from tropical countries. Hardly affected and high summer temperatures, as in the hot Singapore children are also not immune from short-sightedness.
Experimental data suggest a protective role of light designed to prevent excessive increase in the axial length of the eye and the development of myopia. Perhaps process involves dopamine D2 receptors, in any case, considerably less dopamine in retinal blind animals. An important role in the response of retinal pigment epithelium and its adenosine plays. It is possible that his myopic children have a surplus in periods when daylight is not too much causes the disease to progress.
Researchers advise parents force children to spend more time outside, and if this is not possible — to buy the lamp as accurately simulate daylight.
Researchers from the Center for Stem Cell Berkeley (Department of the University of California, Berkeley) created a gene therapy technique, which will provide new opportunities for the treatment of hereditary and age-related diseases of view. Now people with congenital retinal degeneration and macular (blindness elderly) will have a chance to get rid of the disease.
David Schaffer and John Flannery, a professor of molecular and cell biology from the University of California, together with colleagues from the Institute of Neurology, Helen Wills, and the University of Rochester in New York, created a virus that delivers the genetic information even in hard-to retinal cells. The entire procedure, as reported by the authors of the work, takes fifteen minutes.
Scientists have long been used for gene therapy adeno-associated virus (AAV), placing the desired gene into the viral coat, instead of its own genes. Adeno-associated virus is harmless, its carriers — 90% of people. This help before trying to treat the visual disease, but not always effectively. Normal AAV can not reach the photoreceptor and other cells of the retinal pigment epithelium. Its thickness is in the tens of thousands of times greater than the diameter of the virus (approximately 20 nm). Therefore, the virus is not able to deliver the gene to all the light-sensitive receptors that then they start up the synthesis of the desired protein, and his sight.
Success came only after many attempts. Artificially accelerating the evolution of the virus, David Shaffer has received more than 100 million variants of the virus particles, differing in the structure of the protein shell. The ability to penetrate into the cells of the retina has only five of them. Well it proved the virus, designated 7t8. He was forced to carry the genes for the treatment of two types of hereditary blindness — amaurosis Leberai juvenile X-linked Retinoschisis, in which there is separation of the retina from the men.
After tests on mice and monkeys, scientists have suggested that such viruses could not only restore the function of damaged genes, but also completely stop the process of destruction of retinal cells when age-related macular degeneration.
The new treatment is very attractive for doctors and patients. «Put the virus behind the retina with a needle — a very risky surgical procedure, — said David Shaffer. — However, after 14 years of research, we have created a virus that can be administered in liquid vitreous, and he delivers genes in all cell inaccessible without surgery. «
Hard to believe but true: researchers from Nottingham University with whom (UK) have discovered hitherto unknown anatomical structure of the human eye, namely the sixth layer of the cornea. He was named Dua layer, or Dyua named professor Harmine-dera Dua, the first author of the article. «This important discovery is that the textbooks on ophthalmology literally have to be rewritten,» — says the professor.
The cornea — the transparent protective cover of the eye. Until now, there are five layers, from the outer to the inner front epithelium, Bowman’s membrane, stroma, Descemet’s membrane and the corneal endothelium. The new layer is located between the stroma and Descemet’s membrane. Its thickness is 15 microns (the thickness of the entire cornea — about 550 microns, or 0.5 mm), but it is very durable and able to withstand pressure in the two bars. It is formed layers of collagen fibers arranged in different directions.
Scientists have discovered a layer Dua, simulating the operation of corneal transplantation to the human eye, bequests for research purpose. In this operation, the thickness of the cornea is administered to the air bubbles to separate the damaged layer (for example, to remove stroma, but to leave Descemet’s membrane and endothelium to reduce the likelihood of rejection). Bubbles examined under a microscope and found that they are of two kinds. Some bubbles are obtained, rounded, smooth and not blown away, even when the upper layers were removed. Others were large, thin-walled, and, as soon as the stripping of Descemet’s membrane, the air went out of them. As you might guess, in the first case, the air got under Dua layer, and the second — on him.
The value of this discovery not only that students preparing to set off on the anatomy of the eye, will have to learn on one name more. Now microsurgeons during operations on the cornea can take into account the mechanical features Dua layer, it will reduce the likelihood of damage to the delicate structures of the eye and, therefore, the operation will be successful. In addition, it became clear the causes of diseases such as acute keratoconus (corneal edema), herniation of Descemet’s membrane (descemetocele) and some types of corneal dystrophy. Thus, the first of which — the corneal swelling induced damage layer Dua, through which water penetrates from the interior portions of the eye.
Cataracts, clouding of the lens of the eye — the most common cause of blindness; every second blind in the world has this diagnosis. According to the World Health Organization, because of cataract lost 20 million people, 90% of them live in developing countries. The disease is age, the older the person, the greater the likelihood of developing cataracts. In developed countries, it has successfully treated surgically, with replacement darkened lens. This procedure is often performed on an outpatient basis and the patient can almost immediately return to everyday life. Surely some of our readers are now seeing this phrase because of the artificial lens. But if we can cure all 20 million?
Researchers from the UK have calculated the carbon footprint of cataract surgery, many equivalents of C02 released into the atmosphere, to provide a single operation. (Emissions of various greenhouse gases decided to count with the help of special factors in the amount of carbon dioxide that would cause the same effect.) The calculation is made for one patient, who was operated on at the University Hospital of Wales (Cardiff). It turned out that one operation is accompanied by the emission of 181.8 kg of C02 equivalents. Over 36.1% of emissions responsible energy consumption of buildings for 10.1% — work vehicles and 53.8% -work equipment, including proper medical — 32.6%. In 2011, only operated in Cardiff in 2230 cataract patients, giving 405.4 tons of C02 equivalents. It would seem ridiculous figure — a large plant emits tens of thousands of tons per year, the largest city — hundreds of thousands of tons, all EU countries and all Russia — billions. But large numbers are made up of small, and if we are ever to help all people suffering from cataracts have here to introduce «green» technology.