Pattern-reversal visual evoked potentials in prosthetic vision and simulated visual reduction.

Objective: To quantitatively evaluate visual evoked potentials (VEPs) in prosthetic vision and simulated visual reduction.

Methods And Analysis: Four blind patients implanted with the Argus II retinal prosthesis and seven sighted controls participated. VEPs were recorded with pattern-reversal stimuli (2 cycles of a horizontal square wave grating, 0.

High-Throughput Binocular Pattern Electroretinograms in the Mouse.

The pattern electroretinogram (PERG) reflects the electrical activity of retinal ganglion cells (RGC) and has become the most used technology to assess RGC function in experimental models of glaucoma and optic neuropathies. We describe a novel method for obtaining user-friendly, robust PERG simultaneously from each eye using asynchronous binocular stimulation and one-channel acquisition of signals recorded from a subcutaneous needle in the snout.

Adaptation of retinal ganglion cell function during flickering light in the mouse.

Rapid dilation of retinal vessels in response to flickering light (functional hyperemia) is a well-known autoregulatory response driven by increased neural activity in the inner retina. Little is known about flicker-induced changes of activity of retinal neurons themselves. We non-invasively investigated flicker-induced changes of retinal ganglion cell (RGC) function in common inbred mouse strains using the pattern electroretinogram (PERG), a sensitive measure of RGC function.

High-Throughput Binocular Pattern Electroretinograms in the Mouse.

We describe a new method for obtaining user-friendly, robust pattern electroretinograms (PERG) simultaneously from each eye using asynchronous binocular stimulation and one-channel acquisition of signals recorded from a subcutaneous needle in the snout.

Next Generation PERG Method: Expanding the Response Dynamic Range and Capturing Response Adaptation.

Purpose: To compare a new method for steady-state pattern electroretinogram (PERGx) with a validated method (PERGLA) in normal controls and in patients with optic neuropathy.

Methods: PERGx and PERGLA were recorded in a mixed population ( = 33, 66 eyes) of younger controls (C1; = 10, age 38 ± 8.3 years), older controls (C2; = 11, 57.

Relationship between transient and steady-state pattern electroretinograms: theoretical and experimental assessment.

Purpose: We determined if the overlap of transient (tr) pattern electroretinograms (PERG(tr)) can explain the generation of the steady-state (SS) pattern electroretinogram (PERG(SS)), and investigated the relationship between the two types of responses.

Methods: Slightly jittered pattern reversals were used to generate quasi SS (QSS) PERG(SS) responses from eight normal subjects, recorded using lower eyelid skin electrodes, at rates between 6.9 and 26.

Robust mouse pattern electroretinograms derived simultaneously from each eye using a common snout electrode.

Purpose: We recorded pattern electroretinograms (PERGs) simultaneously from each eye in mice using binocular stimulation and a common noncorneal electrode.

Methods: The PERG was derived simultaneously from each eye in 71 ketamine/xylazine anesthetized mice (C57BL/6J, 4 months old) from subcutaneous needles (active, snout; reference, back of the head; ground, root of the tail) in response to contrast-reversal of gratings (0.05 cycles/deg, >95% contrast) generated on two custom-made light-emitting diode (LED) tablets alternating at slight different frequencies (OD, 0.

Unwrapping of transient responses from high rate overlapping pattern electroretinograms by deconvolution.

Objective: Due to overlapping, temporal information is mostly lost in high rate steady-state pattern electroretinograms (PERGSS). This study develops a deconvolution method and a display/recording system to "unwrap" PERGSS and obtain a transient, "per stimulus" response (PERGtr) regardless of reversal rate.

Methods: Processing and instrumentation, including high temporal resolution display and acquisition were developed for deconvolving PERGs acquired at high rates by slight jittering of reversal onsets at a given mean rate.