TY - JOUR
T1 - Relationship between transient and steady-state pattern electroretinograms
T2 - Theoretical and experimental assessment
AU - Özdamar, Özcan
AU - Toft-Nielsen, Jonathon
AU - Bohórquez, Jorge
AU - Porciatti, Vittorio
N1 - Publisher Copyright:
© 2014 The Association for Research in Vision and Ophthalmology, Inc.
Copyright:
Copyright 2015 Elsevier B.V., All rights reserved.
PY - 2014/11/18
Y1 - 2014/11/18
N2 - CONCLUSIONS. The study shows that PERGSS results from the overlapping of tr PERGtr waveforms generated at that reversal rate. The first two peaks (NSS and PSS) of the PERGSS reflect N35 and P50 waves of the tr PERGtr. The N95 amplitude is reduced at conventional (16 rps) SS rates, but contributes to the overall PERGSS amplitude.PURPOSE. We determined if the overlap of transient (tr) pattern electroretinograms (PERGtr) can explain the generation of the steady-state (SS) pattern electroretinogram (PERGSS), and investigated the relationship between the two types of responses.METHODS. Slightly jittered pattern reversals were used to generate quasi SS (QSS) PERGSS responses from eight normal subjects, recorded using lower eyelid skin electrodes, at rates between 6.9 and 26.5 reversals per second (rps). Jittered quasi PERGSS were deconvolved using the frequency domain continuous loop averaging deconvolution method. Additionally, conventional PERGtr at 2.2 rps and PERGSS at each of the QSS stimulation rates were obtained from all subjects. Two synthetic PERGSS responses were constructed at each stimulation rate, one using the PERGtr obtained at that rate, and the other using the conventional 2.2 rps PERGtr. Synthetic responses then were compared to the recorded PERGSS using amplitude, latency, and spectral measurements.RESULTS. Findings indicate that the PERGSS obtained at SS rates can be predicted using the superposition of deconvolved tr PERGs at each particular rate. Although conventional PERGtr can explain PERGSS obtained at rates below 15.4 rps (≥97% correlation), for higher reversal rates only deconvolved responses obtained at that rate can produce the recorded SS responses (96% vs. 65% correlation at 26.5 rps).
AB - CONCLUSIONS. The study shows that PERGSS results from the overlapping of tr PERGtr waveforms generated at that reversal rate. The first two peaks (NSS and PSS) of the PERGSS reflect N35 and P50 waves of the tr PERGtr. The N95 amplitude is reduced at conventional (16 rps) SS rates, but contributes to the overall PERGSS amplitude.PURPOSE. We determined if the overlap of transient (tr) pattern electroretinograms (PERGtr) can explain the generation of the steady-state (SS) pattern electroretinogram (PERGSS), and investigated the relationship between the two types of responses.METHODS. Slightly jittered pattern reversals were used to generate quasi SS (QSS) PERGSS responses from eight normal subjects, recorded using lower eyelid skin electrodes, at rates between 6.9 and 26.5 reversals per second (rps). Jittered quasi PERGSS were deconvolved using the frequency domain continuous loop averaging deconvolution method. Additionally, conventional PERGtr at 2.2 rps and PERGSS at each of the QSS stimulation rates were obtained from all subjects. Two synthetic PERGSS responses were constructed at each stimulation rate, one using the PERGtr obtained at that rate, and the other using the conventional 2.2 rps PERGtr. Synthetic responses then were compared to the recorded PERGSS using amplitude, latency, and spectral measurements.RESULTS. Findings indicate that the PERGSS obtained at SS rates can be predicted using the superposition of deconvolved tr PERGs at each particular rate. Although conventional PERGtr can explain PERGSS obtained at rates below 15.4 rps (≥97% correlation), for higher reversal rates only deconvolved responses obtained at that rate can produce the recorded SS responses (96% vs. 65% correlation at 26.5 rps).
KW - Deconvolution
KW - Overlap
KW - Pattern electroretinogram
KW - Steady-state PERG
KW - Superposition
KW - Transient PERG
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U2 - 10.1167/iovs.14-15685
DO - 10.1167/iovs.14-15685
M3 - Article
C2 - 25477321
AN - SCOPUS:84920064515
VL - 55
SP - 8560
EP - 8570
JO - Investigative Ophthalmology and Visual Science
JF - Investigative Ophthalmology and Visual Science
SN - 0146-0404
IS - 12
ER -