Abstract
Visual impairment and blindness is primarily caused by optic neuropathies like injuries and glaucomas, as well as retinopathies like agerelated macular degeneration (MD), systemic diseases like diabetes, hypertonia and hereditary retinitis pigmentosa (RP). These pathological conditions may affect retinal photoreceptors, or retinal pigment epithelium, or particular subsets of retinal neurons, and in particular retinal ganglion cells (RGCs). The RGCs which connect the retina with the brain are unique cells with extremely long axons bridging the distance from the retina to visual relays within the thalamus and midbrain, being therefore vulnerable to heterogeneous pathological conditions along this pathway. When becoming mature, RGCs loose the ability to divide and to regenerate their accidentally or experimentally injured axons. Consequently, any loss of RGCs is irreversible and results to loss of visual function. The advent of micro- and nanotechnology, and the construction of artificial implants prompted to create visual prostheses which aimed at compensating for the loss of visual function in particular cases. The purpose of the present contribution is to review the considerable engineering expertise that is essential to fabricate current visual prostheses in connection with their functional features and applicability to the animal and human eye. In this chapter, 1) Retinal and cortical implants are introduced, with particular emphasis given to the requirements they have to fulfil in order to replace very complex functions like vision. 2) Advanced work on material research is presented both from the technological and from the biocompatibility aspect as prerequisites of any perspectives for implantation. 3) Ultimately, experimental studies are presented showing the shaping of implants, the procedures of testing their biocompatibility and essential modifications to improve the interfaces between technical devices and the biological environment. The review ends by pointing to future perspectives in the rapidly accelerating process of visual prosthetics and in the increasing hope that restoration of the visual system becomes reality.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Agnew WF, McCreery DB (eds) (1990) Neural prostheses. Fundamental studies. Prentice Hall, Englewood Cliffs, New Jersey
Boss JH, Shajrawi I, Aunullah J, Mendes D (1995) The relativity of biocompatibility. A critique of the concept of biocompatibility. Isr J Med Sci 31: 203–209
Cavanagh JB (1970) The proliferation of astrocytes around a needle wound in the rat brain. J Anat 106: 471–487
Cha K, Horch K, Normann RA (1992) Simulation of a phosphenebased visual field: visual acuity in a pixelized vision system. Ann Biomed Eng 20: 439–449
Chow AY, Chow VY (1997) Subretinal electrical stimulation of the rabbit retina. Neurosci Lett 225: 13–16
Eckmiller R (1997) Learning retina implants with epiretinal contacts. Ophthalmic Res 29: 281–289
Ensell G, Banks DJ, Ewins DJ, Balachandran W, Richards PR (1996) Silicon-based microelectrodes for neurophysiology fabricated using a gold metallization/nitride passivation system. J Microelectromech Syst 5: 117–121
Gekeler F, Kobuch K, Schwahn HN, Stett A, Shinoda K, Zrenner E (2004) Subretinal electrical stimulation of the rabbit retina with acutely implanted electrode arrays. Graefes Arch Clin Exp Ophthalmol 242: 587–596
Hambrecht FT (1995) Visual prostheses based on direct interfaces with the visual system. Baillière’s Clin Neurol 4: 147–165
Heiduschka P, Thanos S (1998) Implantable bioelectric interfaces surfaces for lost nerve functions. Progr Neurobiol 55: 433–461
Heiduschka P, Romann I, Stieglitz T, Thanos S (2000) Perforated microelectrode arrays omplanted in the regenerating adult central nervous system. Exp Neurol 171: 1–10
Humayun MS, Propst RH, de Juan E Jr, McCormick K, Hickingbotham D (1994) Bipolar surface electrical stimulation of the vertebrate retina. Arch Ophthalmol 112: 110–116
Humayun MS, de Juan E Jr, Dagnelie G, Greenberg RJ, Propst RH, Phillips DH (1996) Visual perception elicited by electrical stimulation of retina in blind humans. Arch Ophthalmol 114: 40–46
Kovacs GTA, Storment CW, Rosen JM (1992) Regeneration microelectrode array for peripheral nerve recording and stimulation. IEEE Trans Biomed Eng 39: 893–902
Martin GR, Timpl R (1987) Laminin and other basement membrane components. Ann Rev Cell Biol 3: 57–85
Nisch W, Böck J, Egert U, Hämmerle H, Mohr A (1994) A thin film microelectrode array for monitoring extracellular neuronal activity in vitro. Biosens Bioelectron 9: 737–741
Rizzo JF, Miller S, Denison T, Herndon T, Wyatt JL (1996) Electrically evoked cortical potentials from stimulation of rabbit retina with a microfabricated electrode array. Invest Ophthalmol Vis Sci 37: S707
Santos A, Humayun MS, de Juan E Jr, Greenburg RJ, Marsh MJ, Klock IB, Milam AH (1997) Preservation of the inner retina in retinitis pigmentosa. A morphometric analysis. Arch Ophthalmol 115: 511–515
Schmidt EM, Bak MJ, Hambrecht FT, Kufta CV, O’Rourke DK, Vallabhanath P (1996) Feasibility of a visual prosthesis for the blind based on intracortical microstimulation of the visual cortex. Brain 119: 507–522
Thanos S, Naskar R, Heiduschka P (1997) Regenerating ganglion cell axons in the adult rat establish retinofugal topography and restore visual function. Exp Brain Res 114: 483–491
Volcker M, Shinoda K, Sachs H, Gmenier H, Schwarz T, Kohler K, Inhoffen W, Bartz-Schmidt KU, Zrenner E, Gekeler F (2004) In vivo assessment of subretinally implanted microphotodiode arrays in cats by optical coherence tomography and fluorescence angiography. Graefe’s Arch Clin Exp Ophthalmol 242: 792–799
Wyatt Jl, Rizzo JF (1996) Ocular implants for the blind. IEEE Spectrum 33: 47–53
Zrenner E, Miliczek K-D, Gabel VP, Graft HG, Guenther E, Haemmerle H, Hoefflinger B, Kohler K, Nisch W, Schubert M, Stett A, Weiss S (1997) The development of subretinal microphotodiodes for replacement of degenerated photoreceptors. Ophthalmic Res 29: 269–280
Zrenner E (2002) Will retinal implants restore vision? Science 295: 1022–1025
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2007 Springer-Verlag/Wien
About this chapter
Cite this chapter
Thanos, S., Heiduschka, P., Stupp, T. (2007). Implantable visual prostheses. In: Sakas, D.E., Simpson, B.A. (eds) Operative Neuromodulation. Acta Neurochirurgica Supplements, vol 97/2. Springer, Vienna. https://doi.org/10.1007/978-3-211-33081-4_53
Download citation
DOI: https://doi.org/10.1007/978-3-211-33081-4_53
Publisher Name: Springer, Vienna
Print ISBN: 978-3-211-33080-7
Online ISBN: 978-3-211-33081-4
eBook Packages: MedicineMedicine (R0)