From Darkness to Light: Giving Sight to the Blind
Yet another development under way at various institutions -- the Dobelle Institute in New York, the University of Utah, and the Kresge Eye Institute in Detroit -- focuses on creating a new cornea or eye altogether by using some of the mechanics already mentioned but then bypassing the eye entirely.
One version, the Dobelle Eye, consists of a subminiature television camera and an ultrasonic distance sensor, both mounted on a pair of eyeglasses. The sensors connect through a cable to a miniature computer, which is worn in a pack on a person's belt. The computer then sends impulses to electrodes that were implanted directly into the patient's visual cortex area in the brain. In one report, a 62-year-old man blinded in an accident was able to read 2-inch-tall letters at a distance of 5 feet -- enough to help him navigate in unfamiliar environments.
All the developments have merit, says Hessburg. Whichever proves to be the most viable option, they all show that there is hope on the horizon. "I believe there will probably be useful implants within the next five years, but my scientific guess is that implants which would allow somebody to read the printed page are probably 25 to 50 years away," he says.
"I think it's possible, probable, and I believe it will occur. I've been working in the field of ophthalmology since ... 1964, and I've always dreamed this was possible. It's only in the past decade that I have believed that it is probable," Hessburg tells WebMD.
His center has "the largest support groups in the U.S. for visually impaired adults," he tells WebMD. "They have hope, and it isn't false hope. We've talked to them realistically. But the question is, how fast can science move? It's not going to be solved by one university all of a sudden having a light-bulb idea. It's a huge problem in blending electronic mechanisms with biological mechanisms and ending up with a sophisticated output."
"Retinal implants are worthy of investigation, and may turn out to be the answer, but it's been slow in coming," Paul Sternberg, MD, Thomas Aaberg professor of Ophthalmology and director of the retina service at Emory University School of Medicine in Atlanta, tells WebMD. "We've been telling patients for six years and more that it will be along any day. You get to the point where you want to give them something more definite.
"To be truthful, I think that the corneal devices -- those that create a whole new eye of sorts -- show the most promise. Maybe it's best to leave the damaged eyes alone and start over."
Retinal gene therapy, retinal transplantation, neuroregenerative drugs -- growth factors that can stimulate regeneration of retinal tissue -- also give hope to cures for blindness, Sternberg adds.