(商台)2010年9月13日 星期一 18:21
【商台 互動國際組】現代人長時間接觸電腦電視，戶外活動量太少，容易患上近視。近日，英國 科學家宣佈已找到誘發近視的基因，還預測十年內將有一種預防近視或抑制近視加深的藥物面世。據說，到時孩子只需滴預防近視的眼藥水便能遠離近視。
倫敦 大學國王學院的海斯特博士和一種研究人員比較過4000多對雙胞胎的基因，區分出先天和後天的不同影響。然後他們又研究了13000名英國人、荷蘭 人和澳洲 人的基因，驗證之前的研究結果，最終找到近視基因。
海斯特指出，即使有矯治近視基因的藥物面世，對目前已患有近視的成年人並沒有療效。深度近視的人老了眼睛很容易出現視網膜剝落的問題，海斯特建議大家多到戶外活動，看遠處的景物避免後天近視。
http://hk.news.yahoo.com/article/100913/18/k74f.html
發現導致近視的基因：現在專家說情況可以用滴眼藥水制止
Found, the gene that causes short-sight: Now experts say condition could be halted by eye drops
By Fiona Macrae
Last updated at 7:52 AM on 13th September 2010
A gene that causes shortsightedness has been pinpointed by British scientists, paving the way for eye drops that could make glasses history.
Within just ten years, a drug that prevents short-sightedness or stops it in its tracks could be in widespread use.
Millions would be spared the inconvenience and expense of contact lenses, spectacles and laser surgery.
Given in childhood, the eye drops could also spare school pupils anxieties about having to wear glasses.
Within just ten years, a drug that prevents short-sightedness or stops it in its tracks could be in widespread use, making the wearing of glasses negligibleShort- sightedness, or trouble in focussing on distant objects, affects more than one in three Britons and is becoming more common as we spend more time indoors and in front of computer screens.
Caused by overgrowth of the eyeball, it usually starts developing in childhood. In some cases vision can rapidly deteriorate. There is no way of halting its progress and, in severe cases, it leads to blindness.
The latest research, by an international team led by experts at King's College London and published in the prestigious journal Nature Genetics, offers hope to millions
To find the gene, the first to be linked to short-sightedness, or myopia, the researchers compared the DNA of more than 4,000 British twins. Twins are often used in such studies because it is easier distinguish the different effects of nature and nurture.
They then confirmed their results by studying the genetics of another 13,000 British, Dutch and Australian individuals.
Some 45 per cent of Britons have the rogue gene and those who have two copies of it are almost twice as likely to be short-sighted as those who are free of it.
KCL researcher Dr Pirro Hysi, the study's lead author, said: 'We have known for many years that the most important risk factor for being short-sighted is having parents who are shortsighted and for the first time we are identifying genes that may be involved in passing on this susceptibility.'
The gene, known as RASGRF1, is thought to play a key role in the development of the eye and the passing of visual signals to the brain for processing. When it is faulty, the eyeball may overgrow, making distant objects seem fuzzy or blurred.
Dr Chris Hammond, also of KCL, said: 'Myopia, or shortsightedness, is the most common eye problem, affecting over a third of adults in the UK.
'People who are extremely short-sighted carry significant risks of future vision loss. The retina can peel away from the back of the eye like wallpaper off a wall.
'While we believe that environmental risk factors such as a lot of close work and lack of outdoor activity are implicated, we have not previously understood how people become short-sighted.
'We hope that by understanding the mechanisms we can stop children from becoming shortsighted and stop short-sighted children from becoming more short-sighted.'
A second study, by Dutch researchers, identified a second short- sightedness gene. Ultimately, there could be dozens behind the condition.
Drugs that counter their effect and stop the eyeball from overgrowing could be available in just a decade, said Dr Hammond. Other options include gene therapy - injecting 'healthy' genes into the eye.
But Dr Hammond said: 'Gene therapy is a major intervention. I think we are going to be looking at developing some kind of eye drop or tablet that interferes with the biological pathway that leads to short-sightedness.'
Although the eye drops would not help adults who are already short-sighted, they could be of huge benefit to their children.
However, today's youngsters can take some simple steps to try to discourage shortsightedness. Terri Young, of Duke University in North Carolina in the U.S., said: 'People need to go outside and look at the horizon.
'Today's near work forces our eyes to be constantly in tension to focus on reading papers and watching monitors.'
Professor Pete Coffey, director of the London Project to Cure Blindness, cautioned that any drug would have to be shown to be extremely safe before it was given to children.
http://www.dailymail.co.uk/health/article-1311437/Found-gene-causes-short-sight-Now-experts-say-condition-halted-eye-drops.html
英學者發現近視基因
(明報)2010年9月13日 星期一 23:05
英國 「每日郵報」報道，英科學家找出一種會導致近視的基因，人類可望研發出杜絕近視的眼藥水，讓眼鏡成為歷史。
報道指，不出10年，一種預防近視或防止度數加深的眼藥水，就可以普及使用。
數以百萬計的人將可免去隱形眼鏡、眼鏡及雷射手術所帶來的不便與開銷。
童年時期開始滴這種眼藥水，學童也不用因為必須帶眼鏡而感到焦慮。
為了找出與近視最有關聯的基因，研究員對英國4000多對雙胞胎的DNA做了比較。因雙胞胎研究較能夠區分出先天和後天因素的影響，這種研究一般都拿雙胞胎來做對照。
學者接著研究另外13000名英國、荷蘭 及澳洲 人的基因，證實了他們的研究結果。
約45%的英國人帶有這種「流氓基因」（rogue gene），擁有2對這種流氓基因的人，罹患近視的風險是沒有這種流氓基因者的2倍。
這個基因稱作RASGRF1，學者認為此基因在眼睛發育及視覺信號傳遞至腦部做處理上，扮演極為重要的角色。當RASGRF1出現缺陷，眼球軸度恐會過度增長，讓遠處物體看起來變得模糊。
http://hk.news.yahoo.com/article/100913/4/k76x.html
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