Two genes that cause myopia have been discovered for the first time by two independent scientific teams, paving the way for the creation of drugs that may in the future send glasses to the dustbin of history.
Within the next decade, according to British researchers, a drug (in the form of drops or pills) that prevents the onset or progression of myopia could be developed and widely used, freeing millions of people around the world from the hassle of contact lenses, glasses and laser corrective surgery.
Alternatively, it might be possible to have some gene therapy, by introducing «healthy» genes into the eye, which would prevent myopia in the future. But restoring the eyes of adults with advanced myopia is considered much more difficult, either with drugs or genetic therapy.
The discovery of one gene was made by an international research team, led by Dr. Peter Hizzy and Chris Hammond of the Department of Genetic Epidemiology at King's College London, and published in the genetics journal Nature Genetics, according to the British Guardian and Daily Mail.
Myopia (difficulty focusing on distant objects) is the most common eye disorder in the world, yet little is so far known about its genetic background, although 80% of cases with the worst myopia are estimated to be due to genetic factors. Myopia usually begins in childhood and in some cases shows rapid deterioration.
Scientists have long known that myopia also had a genetic cause, as the most important risk factor for the development of myopia in a child is whether a parent has myopia. The researchers analysed and compared the DNA of over 4,000 British twins, as well as 13,000 other British, Dutch and Australian twins.
The identified gene (called RASGRF1) is thought to play a key role in the development of the eye after birth, as well as in the transfer of visual stimuli to the brain for processing. When the gene malfunctions, the eyeball can overgrow, making distant objects appear blurry.
People who have very high myopia (2 - 3%), according to doctors, face an increased risk of losing their vision, as at some point the retinal lens may completely detach from the back of their eye or premature glaucoma may occur. Although certain environmental factors play a role (such as lack of outdoor activity and the view of the horizon or constant preoccupation with nearby objects, such as reading a book or using a computer screen), doctors have yet to understand the cause and mechanism of myopia's progression, with the result that medicine has so far been unable to stop its long-term deterioration.
A second Dutch scientific study, led by Caroline Claver of the Erasmus University Medical Centre in Rotterdam, has uncovered two more genes associated with myopia, and it is very likely that there are many more yet to be discovered. That is why, moreover, a future gene therapy for myopia would be very difficult, because it might have to address many «wrong» genes in parallel. Both ’myopia genes« found are located on chromosome 15.
