电子眼研究有新的突破，使失明人士有可能重见光明。南加州大学Doheny眼科研究所的研究人员在视网膜色素变性（ Retinitis Pigmentosa ）患者的视网膜植入人造视网膜，让他们感应到光和分辨对象，若进一步测试取得成功，人造视网膜植入系统将于两年内推出市场，造福全球数以百万名患者。
这项装置第一代已经于2002年进行临床实验。第一代人造视网膜植入六名病人的视网膜上。这些病人患有视网膜色素变性，这是一种无法可治的退化病，每三千五百人中有一人罹患此症。研究人员原本预计他们植入人造视网膜后只能看见光，想不到效果更为理想，可看见大型字母，分辨杯、刀和碟等物体，而且看得见动作。
新仪器名为「 Argus II 人造视网膜系统」，美国当局最近批准南加州大学对五十至七十五名眼疾病人进行临床测试。该校多希尼眼科学院的眼科学授Mark Humayun表示，若研究进度理想，这个电子眼仪器将于2009年初推出市面。
将进行测试的第二代人造视网膜将提供更佳视力，它有六十个感光电极，远较之前的十六个为多。Humayun预测，未来五至七年内人造视网膜将有更大进展，电极数目达千个，可让失明人士能够辨认面孔。研究人员的最终目标是让人们可以辨认面孔，让完全失明的人可以照顾自己。
(资料来源 : Bio.com)
英文原文：
03/21/07 -- Patients who have gone blind are a step closer to perhaps one day regaining some of their sight. Researchers at the University of Southern California (USC), Doheny Eye Institute, announced today the next step in their efforts to advance technology that will hopefully help patients with retinitis pigmentosa and macular degeneration regain some vision using an implanted artificial retina.
The announcement by Mark Humayun, M.D., Ph.D., professor of ophthalmology at the Doheny Eye Institute, Keck School of Medicine of USC came at a press conference at the American Association for the Advancement of Science (AAAS) annual meeting in San Francisco.
The Food and Drug Administration (FDA) recently approved an Investigational Device Exemption (IDE) to conduct a clinical study of the new device- dubbed the Argus II Retinal Prosthesis System.
The implantable technology is a collaborative effort between USC and Second Sight Medical Products, which manufactures the implant. The Argus II is the second generation of an electronic retinal implant designed for the treatment of blindness due to retinitis pigmentosa (RP), a group of inherited eye diseases that affect the retina. RP causes the degeneration of photoreceptor cells in the retina, which capture and process light helping individuals to see. As these cells degenerate, patients experience progressive vision loss. The Argus device is essentially designed to take the place of the photoreceptors.
"The first phase of our implant work began in 2002," says Humayun. "We have successfully implanted six patients in the trial and we have found that the devices are indeed electrically conducting and can be used by patients to detect light or even to distinguish between objects such as a cup or plate."
While the first generation of implants contained 16 electrodes laid out on an array, the Argus II is designed with 60 electrodes, which is intended to allow for higher resolution images.
The new device is also approximately one quarter the size of the original, reducing surgery and recovery times.
The array is attached to the retina and used in conjunction with an external camera and video processing system to provide a rudimentary form of sight to implanted subjects.
The clinical trial of the first generation of implants continues at the Doheny Eye Institute at USC. All six previously blind patients in the first trial have been able to detect light, identify objects in their environment and even perceive motion after implantation with the first generation device.
The device, ultimately, may be used for the millions of people suffering from age-related macular degeneration, or AMD. In fact, Humayun says, there are 25 million people around the world, including 6 million in the United States alone, who have been blinded, or are severely visually impaired, due to diseases like RP and AMD.
By 2020, that figure is expected to double, creating a virtual vision-loss epidemic.
Both AMD and RP destroy vision by annihilating the retinal cells that allow light to be translated into recognizable images.
"Perhaps what we're most excited about in this next study," says Humayun, "is, similar to the first generation Second Sight device, we will be able to test the new device with patients at their homes, churches, schools and similar locations. The importance of this work is going to be reflected in how well this helps them regain some of their lost vision."
The current study will include patients over 50 years of age who have RP or AMD and who have had previous functional vision.
Source: University of Southern California
