|MadSci Network: General Biology|
Dear Berkay, Yes it is possible to produce artificial cornea. It is also possible to surgically implant a human cornea taken from a cadaver. This corneal grafting (keratoplasty) works relatively well but may lead to some problems such as rejection due to the poor vascularisation of the diseased cornea. That’s why artificial cornea or “hybrid” cornea (containing both biological and artificial components) seems to be a very encouraging alternative and is constantly improving (3). Another technique that seems very promising is to use genetically modified human cells grown on a collagen frame closely resembling human connective tissue (2). On the other hand, producing a complete artificial retina is illusive to my opinion since it is made of neuronal tissue that contain many types of neurons including ganglion cells which axons form the optic nerve that project to the brain. However, it may be possible to implant artificial devices at the first stages of retinal processing, i.e. at the level of photoreceptors. This interesting device, a silicon microchip 2mm in diameter, contains many microscopic solar cells that convert light into electrical impulses. The basic idea is that “current generated by the device in response to light stimulation will alter the membrane potential of overlying neurons and thereby activate the visual system.” (1). Although (to my knowledge) it remains to be demonstrated that such functional connections will indeed take place, I believe that this is a very interesting area of research. Regards, Eric 1. Peachey NS, Chow AY. Subretinal implantation of semiconductor-based photodiodes: progress and challenges. J. Rehabil. Res. Dev. 1999 36:371-6. 2. Griffith, M. et al. Functional Human Corneal Equivalents Constructed from Cell Lines Science 1999, 286: 2169-2172 3. Legeais JM, Renard G. A second generation of artificial cornea (Biokpro II). Biomaterials 1998 19:1517-22
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