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澳大利亚科学家最近得出一个结论：老人容易同时发生耳聋和目盲。这项结论是检查了新南威尔士州悉尼西部蓝岭地区1911名成年人后得出的。研究对象平均年龄为70岁。其中178名有裸眼视力缺损，视力低于20/40；56名为矫正后视力缺损，他们的视力使用镜片或隐形眼镜矫正后仍然低于20/40。而这234名视力缺损的研究对象中，共有206名还同时存在听力障碍。

初始研究完成5年后，在1997至1999年间，研究对象接受了回访，同时检查了视力和听力。此时，他们的年龄在55至98岁之间。研究人员发现，眼科医生使用的视力表上，研究对象所能看到的最小值每提高一行，就会伴随出现听力丧失18％（裸眼视力缺损组）或13％（矫正后视力缺损组）。听力损害组出现视力问题的几率是听力正常组的1.5倍。伴随有老年性黄斑退行性改变或者白内障的老人比没有这些视力问题的老人更容易发生听力损害。

总之，视力受限的研究对象更容易发生听力损害，反之亦然。

由于老人们发生双重的感觉障碍或者聋盲同存的情况很是常见，因此研究人员推测在这些感觉损害的背后，真正病因可能是同一个。该研究的作者来自悉尼大学国家听力实验室，他提到这种视力和听力间的联系是可以解释的，二者都是老化的结果。这也提示人们，有共同的危险因素使得人们易患这两种感觉损害。

研究人员认为，氧化应激、吸烟、动脉粥样硬化及其危险因子分别与老年性黄斑退行性改变、白内障以及听力损害有关。糖尿病也是常见的导致白内障及其他视、听损害的危险因素。

该研究的负责人Ee-Munn Chia, M.B.B.S.及其同事谈到，即便不考虑其病因，视听障碍给人们带来的身心影响也是显而易见的。进一步的研究将致力于了解老年人视、听损害间的内在联系，以及证实改善视听损害的措施能否延缓人体老化进程。

这项研究发表在JAMA/Archives journals 之一的Archives of Ophthalmology10月刊上。

注：20/40相当于国内采用的标注视力表或对数视力表的0.5；同理，20/20相当于1.0，20/10相当于2.0。这种视力表示法称为Snellen视力，美国采用20作为分子，英国等国家采用6作为分子，即：20/40=6/12=0.5 。

http://www.news-medical.net/?id=20473
Going deaf and blind happens simultaneously in old age
Medical Studies/Trials
Published: Wednesday, 11-Oct-2006
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According to Australian scientists, vision and hearing loss happens almost simultaneously in older people.
The researchers arrived at this conclusion after examining 1,911 adults living in the Blue Mountains region, west of Sydney, in New South Wales.

The participants had an average age of 70, and among the group, 178 had a visual impairment, categorised as eyesight worse than 20/40, 56 had 'best-corrected' visual impairment, meaning even when using glasses or contact lenses their eyesight was worse than 20/40 and 206 of this combined group also had a hearing problem.

They found the volunteers with restricted eyesight were more likely to suffer hearing impairments and vice-versa.

It is common for people to experience dual sensory impairment or deaf-blindness in their old age and the researchers suspect the underlying causes for these sensory impairments may be the same.

Five years after the original study, between 1997 and 1999, participants, then age 55 to 98, underwent a medical interview along with vision and hearing examinations.

The researchers discovered that, for each line of the eye chart used by ophthalmologists that a participant could not see, there was an 18% (for the visually impaired) and 13% (for the best-corrected visually impaired) increase in the likelihood of hearing loss.

Those in the group that suffered hearing loss were 1.5 times more likely to have eyesight problems than those with good hearing.

The researchers also found that both those suffering age-related macular degeneration and cataracts were more likely to suffer hearing loss than those without these disorders.

The authors, from the University of Sydney and the National Acoustics Laboratories, Sydney, said the connection between vision and hearing could be explained by the fact that both are consequences of ageing and suggest common risk factors can predispose people to such sensory impairments.

They believe exposure to oxidative stress, cigarette smoking and atherosclerosis and its risk factors, have been linked respectively to age-related macular degeneration, cataract and hearing loss.

Diabetes is also a common risk factor for cataract and visual and hearing impairments.

Study leader Ee-Munn Chia, M.B.B.S., and colleagues say that irrespective of the cause of sensory impairment, the two impairments were found to significantly affect both physical and mental well being.

They say further studies are needed to understand the relationship between visual and hearing impairments in older persons and to determine whether intervention to improve these impairments could delay biologic aging.

The study is published in the October issue of Archives of Ophthalmology, one of the JAMA/Archives journals.

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