Witnessing the first sign of retinitis pigmentosa onset in the allegedly normal eye of a case of unilateral RP: a 30-year follow-up

Gauvin, Mathieu; Chakor, Hadi; Koenekoop, Robert K.; Little, J. M.; Lina, Jean‐Marc; Lachapelle, Pierre

doi:10.1007/s10633-016-9537-y

Cited by 14 publications

(11 citation statements)

References 39 publications

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“…According to a previously published method, 2,8,9 the DWT of each ERG signal was computed using the fast wavelet transform algorithm 10 implemented with Matlab R2015a and adapted to achieve shift invariance. In order to reduce edge effects, before DWT computation, each response was padded with 512 additional samples (by repeating the first and last value 256 times on both sides of the signal).…”

Section: Methodsmentioning

confidence: 99%

Quantifying the ON and OFF Contributions to the Flash ERG with the Discrete Wavelet Transform

Gauvin

Šuštar

Little

et al. 2017

Trans. Vis. Sci. Tech.

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PurposeDiscrete wavelet transform (DWT) analyses suggest that the 20- and 40-Hz components of the short-flash photopic electroretinogram (ERG) are closely related to the ON and OFF pathways, respectively. With the DWT, we examined how the ERG ON and OFF components are modulated by the stimulus intensity and/or duration.MethodsDiscrete wavelet transform descriptors (20, 40 Hz and 40:20-Hz ratio) were extracted from ERGs evoked to 25 combinations of flash durations (150–5 ms) and strengths (0.8–2.8 log cd.m−2).ResultsIn ERGs evoked to the 150-ms stimulus (to separate the ON and OFF ERGs), the 40:20-Hz ratio of ON ERGs (mean ± SD: 0.49 ± 0.04) was significantly smaller (P < 0.05) than that of OFF ERGs (1.71 ± 0.18) owing to a significantly (P < 0.05) higher contribution of the 20 and 40 Hz components to the ON and OFF ERGs, respectively. With brighter stimuli, the ON and OFF components increased similarly (P < 0.05). While progressively shorter flashes had no impact (P > 0.05) on the ON component, it exponentially enhanced (P < 0.05) the OFF component.ConclusionsDiscrete wavelet transform allows for an accurate determination of ON and OFF retinal pathways even in ERGs evoked to a short flash. To our knowledge, the significant OFF facilitatory effect evidenced with shorter stimuli has not previously been reported.Translational RelevanceThe DWT approach should offer a rapid, easy, and reproducible approach to retrospectively and prospectively evaluate the function of the retinal ON and OFF pathways using the standard (short-flash duration) clinical ERG stimulus.

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Section: Methodsmentioning

confidence: 99%

Quantifying the ON and OFF Contributions to the Flash ERG with the Discrete Wavelet Transform

Gauvin

Šuštar

Little

et al. 2017

Trans. Vis. Sci. Tech.

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“…As previously demonstrated by us and others [10, 13, 15–18], this time-frequency approach allows for the identification of energy descriptors, each defined with their respective time and frequency coordinates. The DWT yields measurements of the photopic b-wave (found in the 20 and 40 Hz bands) and OPs (found in the 80 and 160 Hz bands) through the quantification of their respective associated wavelet coefficients [10, 16, 17]. As exemplified in the scalogram of Figure 1(a), two DWT descriptors were used to quantify the 20 Hz and 40 Hz b-wave energy (identified as 20b and 40b) and another two were used to quantify the 80 Hz and 160 Hz OPs energy (identified as 80ops and 160ops), each computed by summating values outlined by the white boxes, respectively.…”

Section: Methodsmentioning

confidence: 99%

Assessing the Contribution of the Oscillatory Potentials to the Genesis of the Photopic ERG with the Discrete Wavelet Transform

Gauvin

Dorfman

Trang

et al. 2016

BioMed Research International

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The electroretinogram (ERG) is composed of slow (i.e., a-, b-waves) and fast (i.e., oscillatory potentials: OPs) components. OPs have been shown to be preferably affected in some diseases (such as diabetic retinopathy), while the a- and b-waves remain relatively intact. The purpose of this study was to determine the contribution of OPs to the building of the ERG and to examine whether a signal mostly composed of OPs could also exist. DWT analyses were performed on photopic ERGs (flash intensities: −2.23 to 2.64 log cd·s·m−2 in 21 steps) obtained from normal subjects (n = 40) and patients (n = 21) affected with a retinopathy. In controls, the %OP value (i.e., OPs energy/ERG energy) is stimulus- and amplitude-independent (range: 56.6–61.6%; CV = 6.3%). In contrast, the %OPs measured from the ERGs of our patients varied significantly more (range: 35.4%–89.2%; p < 0.05) depending on the pathology, some presenting with ERGs that are almost solely composed of OPs. In conclusion, patients may present with a wide range of %OP values. Findings herein also support the hypothesis that, in certain conditions, the photopic ERG can be mostly composed of high-frequency components.

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“…The relationship between visual acuity and implicit time is more controversial. Moschos, et al [33], found an inverse relationship between acuity and implicit time. Others have not found this relationship between acuity and implicit time [31].…”

Section: Clinical Manifestations/evaluationmentioning

confidence: 96%

“…Implicit time of the central ring remains at a normal level but increases with increased eccentricity [15,31]. There is a correlation between best-corrected acuity and multifocal electroretinogram amplitude of the central hexagon [31,33]. The relationship between visual acuity and implicit time is more controversial.…”

Section: Clinical Manifestations/evaluationmentioning

confidence: 99%

“…Weller, et al [5], had one patient who showed no changes in the unaffected eye over a time span of 30 years. However, Gauvin and colleagues [33], had a patient present with unilateral retinitis pigmentosa who was seen eight separate times over thirty years during which bilateral retinitis pigmentosa developed. The electroretinogram was the irst assessment to detect the development of signs of retinitis pigmentosa in the contralateral eye.…”

Section: Prognosismentioning

confidence: 99%

See 1 more Smart Citation

Unilateral retinitis pigmentosa: Case report and review of the literature

Goodwin¹,

Olsen²,

Citek³

2019

Int J Clin Exp Ophthalmol

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Witnessing the first sign of retinitis pigmentosa onset in the allegedly normal eye of a case of unilateral RP: a 30-year follow-up

Cited by 14 publications

References 39 publications

Quantifying the ON and OFF Contributions to the Flash ERG with the Discrete Wavelet Transform

Quantifying the ON and OFF Contributions to the Flash ERG with the Discrete Wavelet Transform

Assessing the Contribution of the Oscillatory Potentials to the Genesis of the Photopic ERG with the Discrete Wavelet Transform

Unilateral retinitis pigmentosa: Case report and review of the literature

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