Abstract
In blind patients with degenerated photoreceptors a large percent of inner retinal neurons remain histologically intact and stay functionally alive (1). Without visual input, the retinal ganglion cells continue to transmit spontaneously generated action potentials through the optic tract to the visual centers. They can also be artificially activated by trains of short electrical impulses and such stimuli were shown to elicit localized perceptions of light, called phosphenes ((2)–(5)). This finding opened the possibility to restitute basic vision with retina implants by delivering electrical stimuli to the retina. Two main types of retina implants are currently developed using either sub- or epiretinal electrode arrays (see the other reviews in this Volume). Subretinal devices are implanted between the pigment epithelial layer and the outer layers of the retina so that they can activate the outer plexiform layer and bipolar cells (6). Epiretinal implants are placed from the vitreous side onto the ganglion cell and nerve fiber layer of the retina (7). Epiretinal implants can evoke action potentials in retinal ganglion cells and/or their axons (8). Finally, both types of implants send visual information in the form of spike patterns through the axons of retinal ganglion cells along the optic nerve to central visual structures. One crucial question remains regarding the type of neural responses evoked in the visual cortex by stimulation with retina implants. Are the spatial, temporal, and intensity resolutions obtainable with current technologies sufficient, in order to provide useful vision for discriminating objects in a static environment and to perceive motion in dynamic scenes of everyday life? Data for estimates of perceptual resolutions achievable with retina implants are rare.
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References
Santos A, Humayun M, de Juan E, et al. Preservation of the inner retina in retinitis pigmentosa. Arch Ophthal 1997;115:511–515.
Humayun MS, de Juan E, Dagnelie G, Greenberg RJ, Probst RH, Phillips DH. Visual perception elicited by electrical stimulation of retina in blind humans. Arch Ophthalmol 1996;114:40–46.
Humayun MS, de Juan E, Weiland JD, et al. Pattern electrical stimulation of the human retina. Vision Res 1999;39:2569–2576.
Humayun MS, Weiland JD, Fujii GY, et al. Visual perception in a blind subject with a chronic microelectrode retinal prosthesis. Vision Res 2003;43:2573–2581.
Rizzo JF, Wyatt JL. Prospects for a visual prosthesis. Neuroscientist 1997;3:251.
Zrenner E. Will retinal implants restore vision? Science 2002;295:1022–1025.
Eckmiller R. Learning retina implants with epiretinal contacts. Ophthalmic Res 1997;29:281–289.
Eckhorn R, Wilms M, Schanze T, et al. Visual resolution with retinal implants estimated from recordings in cat visual cortex. Vision Res 2006;46:2675–2690.
Orban GA. Neuronal Operations in the Visual Cortex. Springer, Berlin, New York, 1984.
Tovee MJ. An introduction to the visual system. Cambridge Univ. Press, 1996.
Darian-Smith C, Gilbert CD. Topographic reorganization in the striate cortex of the adult cat and monkey is cortically mediated. J Neurosci 1995;15:1631–1647.
Bullier J, Hupe J-M, James AC, Girard P. The role of feedback connections in shaping the responses of visual cortical neurons. Progr Brain Res 2001;134:193–204.
Legge GE, Ahn SJ, Klitz TS, Luebker A. The visual span in normal and low vision. Vision Res 1997;37:1999–2010.
McCreery DB, Agnew WF, Yuen TG, Bullara L. Charge density and charge per phase as cofactors in neural injury induced by electrical stimulation. IEEE Trans Biomed Eng 1990;37:996–1001.
Wilms M, Eger M, Schanze T, Eckhorn R. Visual resolution with epi-retinal electrical stimulation estimated from activation profiles in cat visual cortex. Visual Neurosci 2003;20:543–555.
Reitböck HJ. Fiber microelectrodes for electrophysiological recordings. J Neuosci Meth 1983;8:249–262.
Schanze T, Wilms M, Eger M, Hesse L, Eckhorn R. Activation zones in cat visual cortex evoked by electrical retina stimulation. Graefe’s Arch Clin Exper Ophthalmol 2002;240:947–954.
Rizzo JF, Wyatt J, Loewenstein J, Kelly S, Shire D. Methods and perceptual thresholds for short-term electrical stimulation of human retina with microelectrode arrays. Invest Ophthalmol Vis Sci 1992;44:5355–5361.
Stone JL, Barlow WE, Humayun MS, de Juan E, Milam AH. Morphometric analysis of macular photoreceptors and ganglion cells in retinas with retinitis pigmentosa. Arch Ophthalmol 1992;110:1634–1639.
Wilms M, Eckhorn R. Spatiotemporal receptive field properties of epiretinally recorded spikes and local electroretinograms in cats. BMC Neurosci 2005;6:50.
Rattay F, Resatz S. Effective electrode configuration for selective stimulation with inner eye prostheses. IEEE Trans. Biomed Engin 2004;51:1659–1664.
Cha K, Horch KW, Normann RA, Boman D. Reading speed with a pixelized vision system. J Optical Soc Am A 1992;9:673–677.
Sommerhalder J, Oueghlani E, Bagnoud M, Leonards U, Safran A, Pellizone M. Simulation of artificial vision: I. Eccentric reading of isolated words, and perceptual learning. Vision Res 2003;43:269–283.
Geruschat DR, Turano KA, Stahl JW. Traditional measures of mobility performance and retinitis pigmentosa. Optometry Visual Sci 1998;75:525–537.
Grinvald A, Lieke E, Frostig R, Hildesheim R. Cortical point spread function and long-range lateral interactions revealed by real-time optical imaging of macaque monkey primary visual cortex. J Neurosci 1994;14:2545–2568.
Waessle H, Boycott BB. Functional architecture of the mammalian retina. Physiol Rev 1991;71:447–480.
Nirenberg S, Carcieri SM, Jacobs AL, Latham PE. Retinal ganglion cells act largely as independent encoders. Nature 2001;411:698–701.
Shannon CE. A mathematical theory of communication. Bell Syst Tech J 1948;27:623–656.
Eckhorn R, Pöpel B. Rigorous and extended application of information theory to the afferent visual system of the cat. II. Experimental results. Biol Cybernetics 1975;17:7–17.
Eckhorn R, Pöpel B. Responses of cat retinal ganglion cells to the random motion of a spot stimulus. Vision Res 1981;21:435–443.
Rieke F, Warland DK, de Ruyter van Steveninck RR, Bialek W. Spikes: Exploring the Neural Code. MIT Press, Cambridge, 1998.
Eger M, Wilms M, Eckhorn R, Schanze T. Information transmission from a retina implant to the cat visual cortex. BioSystems 2005;79:133–142.
König P, Engel AK, Singer W. Integrator or coincidence detector? The role of cortical neuron revisited. Trends Neurosci 1996;19:130–137.
Agmon-Snir H, Segev I. Signal delay and input synchronization in passive dendritic structures. J Neurophysiol 1993;70:2066–2085.
Nelson ME. A mechanism for neuronal gain control by descending pathways. Neural Computation 1994;6:242–254.
Shapley RM, Victor JD. How the contrast gain control modifies the frequency responses of cat retinal ganglion cells. J Physiol 1981;318:161–179.
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Eckhorn, R. (2007). Spatial-, Temporal-, and Contrast-Resolutions Obtainable With Retina Implants. In: Tombran-Tink, J., Barnstable, C.J., Rizzo, J.F. (eds) Visual Prosthesis and Ophthalmic Devices. Ophthalmology Research. Humana Press. https://doi.org/10.1007/978-1-59745-449-0_2
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