Blindness has yet to be cured, and throughout the years many different experiments and theories have been made and tested. Our technological advances dealing with vision restoration have varied through the years, and especially as we go off into the distant future different theories are created, and the cure for blindness seems to come closer within our grasp.

Three years ago scientists went about trying to restore vision using electronic devices which was a new concept for many. This device called for a way of stimulating the neurons in the retina that were still left from various patients who were blind from end-stage photoreceptor deteriorating diseases like the common RP (retina pigmentosa) along with AMD (age-related macular degeneration). It was founded that before death, RP eyes that have slight or absolutely no light perception sight just had a small percentage of 4% or less of the nuclei left in the outer nuclear layer while the ganglion cell layer had 30% and inner layer 80% of its nuclei. Because of this partial degeneration, the retinal implant could stimulate electrically the retinal neurons that are still left and give functional sight (Humayun et al., 2

As for in the "vivo" imaging results, the fluorescence of green had not become evident in eight weeks, but soon after at twelve weeks had amazing turnouts. The rAAV-injected eyes had detected green fluorescence just four weeks after there had been no trace of it at all, had now been abundant in three out of four primates. And by eighteen weeks, all four monkeys rAAV.CMV.EGFP contained eyes had EGFP (Bennett et al., 9923).

The final outcome of retinal degenerative diseases can consequently lead to photoreceptor apoptosis, which is the concluding irreversible stage in most of the retina degenerative diseases. This stage is the worst-case scenario, which is the loss of eyesight completely in both eyes if not treated. Treatment for this stage has not been very useful, and presently there is no such care that can be given to those diagnosed with photoreceptor apoptosis, and for that reason, scientists are in the process of using gene therapy to try and stabilize the threat (M. Sanftner et al., 688).

In all the animals, only one eye was injected with the Ad-CNTF vector (known as the controlled eye) while the other eye would be injected with vehicle solution or a similar copy of the defective vector or even uninjected. All of the eyes that were injected with Ad-CNTF traced positive CNTF-immunofluorescent cells. Also, the majority of the eyes saw CNTF-immunofluorescent cells in the RPE (retinal pigment epithelium. In the noninjected, vehicle only injected, and in the similar vector eyes the CNTF like immunofluorescense were not seen at all. In conclusion, the immunofluorescense were only seen through the eyes if they were injected with the Ad-CNTF cells. All in all, this experiment had proved to restore some sight and proved to be a success (Cayouette et al., 4-5).

The components of this device consisted of a camera, and an image-processing chip, which would be carefully mounted on an eyeglass frame. The way in which it would work is that the mechanism would take and transform a view through as person's eyes into pixels (tiny dots). From there the data would be made into a frequency signal and sent to a retinal microchip that was implanted in the eye. The frequency sent would then be converted by the retinal chip to form a pattern of tiny electrical currents that would be put through a two dimensional grid of electrodes that are placed near each other over the retina. Hence every electrode site would excite the primary neurons, which in effect creates a single dot of light at every stimulation point. As a result, multiple electrodes give visual patterns of single dots forming given images (Humayun et al., 2570).

In the first test, the gentleman could tell the difference between a horizontal line and vertical line, which were both initiated for the patient to see. These given images were shown as lines and not dots, which is what they were in fact composed of. Secondly, a "U" shape was projected, but read as an "H" to the patient. Another patient was subjected to identifying a box of 3 x 3 of electrodes, but the patient had originally explained the image as bigger than given. She identified the box shape correctly. All in all, tests proved to be successful with minor complications (Humayun et al., 2572-73). This device conclusively forms partial visual images and patterns, but without the accessibility of being able to test the process in daily real life situations, than it is inconclusive whether or not one can function with this device beneficially everyday of their lives. But, the results that have been gathered are a positive outlook on the future developments and improvements of these types of devices (Humayun et al., 2575).

Although using electrical devices was a good concept, using live animals intrigues scientists to be more useful using gene therapy. The first known experiment to find ways to restore vision using live animals and gene therapy would be mice. At this point it was apparent that intrao

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NGF CNTF, LCA Leber, Therapy Blindness, EGFP Bennett, United RAAV, RP Cayouette, et al, La Vail, gene therapy, bennett et al, bennett et, acland et, acland et al, et al 9923, raav vectors, al 9923, lavail et al, lavail et, al 92, et al 92, degenerative diseases, retinal degeneration, Vision Restoration,
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