Artificial Vision

There are a number of blinding disorders which are primarily due to photoreceptor or outer retinal degeneration/destruction. These include but are not exclusive to diseases such as retinitis pigmentosa and age related related macular degeneration. We have tested the feasibility of developing a retinal implant/Chip which could provide form vision to this subset of blind patients. This visual prosthesis would be situated in the eye cavity on the retinal surface. It would create the sensation of seeing light by electrical stimulation of the remaining retinal cells which remain relatively intact despite severe photoreceptor loss. Moreover, by converting images into pixels and then electrically stimulating the retina by a pattern of electrodes, this device would recreate at least in part the visual information/scene.

We have conducted labaratory experiments as well as clinical tests in blind humans. Our results show that in an otherwise totally blind eye, controlled electrical stimulation in patterns can produce vision compatible with limited mobility and can generate forms in the shape of large letters. The patients also often described seeing color and direction of movement. The details of these tests are provided in the following select references. However, as a word of caution, these results are from short term tests. We are currently trying to evaluate if these initial encouraging results uphold during more prolonged tests. If you or someone you know is blind especially from a retinal problem such as retinitis pigmentosa and would like furhter information you can call or write to us at the address and phone number below. Additionally, we welcome interested students at all levels who would like to work with us in the development of a retinal based visual prosthesis.

For further information please contact Dr. Mark Humayun, Dr. Wentai Liu, or Elliot McGucken

Selected References

1) Humayun MS, de Juan E Jr., Dagnelie G, et al. Visual perception elicited by electrical stimulation of retina in blind humans. Archives of OPhthalmology; vol 114; pages 40-46, 1996

2) Humayun MS, Propst RH, de Juan E Jr., et al. Bipolar surface electrical stimulation of the vertebrate retina. Archives of Ophthalmology; vol 112; pages 110-116, 1994.

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