Yes / Purpose To record transient ERGs from the lightadapted
human retina using silent substitution stimuli
which selectively reflect the activity of rod photoreceptors.
We aim to describe the morphology of these
waveforms and examine how they are affected by the
use of less selective stimuli and by retinal pathology.
Methods Rod-isolating stimuli with square-wave
temporal profiles (250/250 ms onset/offset) were
presented using a 4 primary LED ganzfeld stimulator.
Experiment 1: ERGs were recorded using a rodisolating
stimulus (63 ph Td, rod contrast,
Crod = 0.25) from a group (n = 20) of normal
trichromatic observers. Experiment 2: Rod ERGs
were recorded from a group (n = 5) using a rodisolating
stimulus (Crod = 0.25) which varied in
retinal illuminance from 40 to 10,000 ph Td. Experiment
3: ERGs were elicited using 2 kinds of nonisolating
stimuli; (1) broadband and (2) rod-isolating
stimuli which contained varying degrees of L- and
M-cone excitation. Experiment 4: Rod ERGs were
recorded from two patient groups with rod monochromacy
(n = 3) and CSNB (type 1; n = 2).
Results The rod-isolated ERGs elicited from normal
subjects had a waveform with a positive onset
component followed by a negative offset. Response
amplitude was maximal at retinal illuminances\100
ph Td and was virtually abolished at 400 ph Td. The
use of non-selective stimuli altered the ERG waveform
eliciting more photopic-like ERG responses. Rod
ERGs recorded from rod monochromats had similar
features to those recorded from normal trichromats, in
contrast to those recorded from participants with
CSNB which had an electronegative appearance.
Conclusions Our results demonstrate that ERGs
elicited by silent substitution stimuli can selectively
reflect the operation of rod photoreceptors in the
normal, light-adapted human retina. / Deutsche Forschungsgemeinschaft (DFG) (KR1317/13-1) and Bundesministerium für Bildung und Forschung (BMBF) (01DN14009) provided financial support for JK.
| Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/11360 |
| Date | 13 January 2017 |
| Creators | Maguire, John, Parry, Neil R.A., Kremers, Jan, Murray, I.J., McKeefry, Declan J. |
| Source Sets | Bradford Scholars |
| Language | English |
| Detected Language | English |
| Type | Article, published version paper |
| Rights | The Author(s) 2017. This article is published with open access at Springerlink.com This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http:// creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. |
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