129 results about "Gangliocyte" patented technology

Methods for analyzing retinal tomography maps to detect patterns of optic nerve diseases such as glaucoma, optic neuritis, anterior ischemic optic neuropathy are disclosed in this invention. The areas of mapping include the macula centered on the fovea, and the region centered on the optic nerve head. The retinal layers that are analyzed include the nerve fiber, ganglion cell, inner plexiform and inner nuclear layers and their combinations. The overall retinal thickness can also be analyzed. Pattern analysis are applied to the maps to create single parameter for diagnosis and progression analysis of glaucoma and optic neuropathy.

Existing epiretinal implants for the blind are designed to electrically stimulate large groups of surviving retinal neurons using a small number of electrodes with diameters of several hundred μm. To increase the spatial resolution of artificial sight, electrodes much smaller than those currently in use are desirable. In this study we stimulated and recorded ganglion cells in isolated pieces of rat, guinea pig, and monkey retina. We utilized micro-fabricated hexagonal arrays of 61 platinum disk electrodes with diameters between 6 and 25 μm, spaced 60 μm apart. Charge-balanced current pulses evoked one or two spikes at latencies as short as 0.2 ms, and typically only one or a few recorded ganglion cells were stimulated. Application of several synaptic blockers did not abolish the evoked responses, implying direct activation of ganglion cells. Threshold charge densities were typically below 0.1 mC / cm2 for a pulse duration of 100 μs, corresponding to charge thresholds of less than 100 pC. Stimulation remained effective after several hours and at high frequencies. To demonstrate that closely spaced electrodes can elicit independent ganglion cell responses, we utilized the multi-electrode array to stimulate several nearby ganglion cells simultaneously. From these data we conclude that electrical stimulation of mammalian retina with small-diameter electrode arrays is achievable and can provide high temporal and spatial precision at low charge densities. We review previous epiretinal stimulation studies and discuss our results in the context of 32 other publications, comparing threshold parameters and safety limits.

A method, device and system for stimulating visual tissue, typically in the retina or visual cortex, to achieve an artificial percept of light or image. The method includes providing stimulating electrodes suitable for placement in proximity to the visual tissue and generating a series of short-duration stimulation signals having a duration of less than about 0.5 milliseconds each. The short-duration stimulation signals are applied through the stimulating electrodes with varying frequencies that are substantially matched to a spiking range of frequencies of at least one ganglion cell for perceiving brightness or image.

Provided are methods and compositions for maintaining the viability of retinal ganglion cells in a subject with an ocular disorder including, for example, glaucoma and optic nerve injury. The viability of the retinal ganglion cells can be preserved by administering a necrosis inhibitor either alone or in combination with an apoptosis inhibitor to a subject having an eye with the ocular condition. The compositions, when administered, maintain the viability of the cells and / or promote axon regeneration, thereby minimizing the loss of vision or visual function associated with the ocular disorder.