Electroretinogram in Hereditary Retinal Disorders

Gündoğan, Fatih Ç.; Taş, Ahmet; Sobacı, Güngör

doi:10.5772/21704

Cited by 3 publications

(1 citation statement)

References 141 publications

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“…The ERG is used in scientific research and clinical ophthalmology to study various eye diseases such as cone-rod dystrophy, rod-cone dystrophy, retinitis pigmentosa or diabetic retinopathy ( Camuglia et al, 2011 ; Takao et al, 2017 ). In scientific research, in vivo and ex vivo ERG techniques are usually employed to explore the cellular and physiological origins of the ERG components, which in turn can help our understanding of visual processing and mechanisms that might lead to retinal disorders ( Gundogan et al, 2011 ).…”

Section: Introductionmentioning

confidence: 99%

The origins of the full-field flash electroretinogram b-wave

Bhatt

Hunt

Carvalho

2023

Front. Mol. Neurosci.

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The electroretinogram (ERG) measures the electrical activity of retinal neurons and glial cells in response to a light stimulus. Amongst other techniques, clinicians utilize the ERG to diagnose various eye diseases, including inherited conditions such as cone-rod dystrophy, rod-cone dystrophy, retinitis pigmentosa and Usher syndrome, and to assess overall retinal health. An ERG measures the scotopic and photopic systems separately and mainly consists of an a-wave and a b-wave. The other major components of the dark-adapted ERG response include the oscillatory potentials, c-wave, and d-wave. The dark-adapted a-wave is the initial corneal negative wave that arises from the outer segments of the rod and cone photoreceptors hyperpolarizing in response to a light stimulus. This is followed by the slower, positive, and prolonged b-wave, whose origins remain elusive. Despite a large body of work, there remains controversy around the mechanisms involved in the generation of the b-wave. Several hypotheses attribute the origins of the b-wave to bipolar or Müller glial cells or a dual contribution from both cell types. This review will discuss the current hypothesis for the cellular origins of the dark-adapted ERG, with a focus on the b-wave.

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Section: Introductionmentioning

confidence: 99%

The origins of the full-field flash electroretinogram b-wave

Bhatt

Hunt

Carvalho

2023

Front. Mol. Neurosci.

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Decreased retinal–choroidal blood flow in retinitis pigmentosa as measured by MRI

et al. 2013

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Purpose To evaluate retinal and choroidal blood flow (BF) using high-resolution magnetic resonance imaging (MRI) as well as visual function measured by the electroretinogram (ERG) in patients with retinitis pigmentosa (RP). Methods MRI studies were performed in 6 RP patients (29-67 years) and 5 healthy volunteers (29-64 years) on a 3-Tesla scanner with a custom-made surface coil. Quantitative BF was measured using the pseudo-continuous arterial-spin-labeling technique at 0.5x0.8x6.0mm. Full-field ERGs of all patients were recorded. Amplitudes and implicit times of standard ERGs were analyzed. Results Basal BF in the posterior retinal-choroid was 142±16 ml/100ml/min (or 1.14±0.13 μl/mm2/min) in the control group and was 70±19 ml/100ml/min (or 0.56±0.15 μl/mm2/min) in the RP group. Retinal-choroidal BF was significantly reduced by 52±8% in RP patients compared to controls (P<0.05). ERG a- and b-wave amplitudes of RP patients were reduced and b-wave implicit times were delayed. There were statistically significant correlations between a-wave amplitude and BF value (r=0.9, P<0.05) but not between b-wave amplitude and BF value (r =0.7, P=0.2). Conclusions This study demonstrates a novel non-invasive MRI approach to measure quantitative retinal and choroidal BF in RP patients. We found that retinal-choroidal BF was markedly reduced and significantly correlated with reduced amplitudes of the a-wave of the standard combined ERG.

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Deconvolution of high rate flicker electroretinograms

Alokaily

Bohórquez

Özdamar

2014

2014 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society

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Flicker electroretinograms are steady-state electroretinograms (ERGs) generated by high rate flash stimuli that produce overlapping periodic responses. When a flash stimulus is delivered at low rates, a transient response named flash ERG (FERG) representing the activation of neural structures within the outer retina is obtained. Although FERGs and flicker ERGs are used in the diagnosis of many retinal diseases, their waveform relationships have not been investigated in detail. This study examines this relationship by extracting transient FERGs from specially generated quasi steady-state flicker and ERGs at stimulation rates above 10 Hz and similarly generated conventional flicker ERGs. The ability to extract the transient FERG responses by deconvolving flicker responses to temporally jittered stimuli at high rates is investigated at varying rates. FERGs were obtained from seven normal subjects stimulated with LED-based displays, delivering steady-state and low jittered quasi steady-state responses at five rates (10, 15, 32, 50, 68 Hz). The deconvolution method enabled a successful extraction of "per stimulus" unit transient ERG responses for all high stimulation rates. The deconvolved FERGs were used successfully to synthesize flicker ERGs obtained at the same high stimulation rates.

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Electroretinogram in Hereditary Retinal Disorders

Cited by 3 publications

References 141 publications

The origins of the full-field flash electroretinogram b-wave

The origins of the full-field flash electroretinogram b-wave

Decreased retinal–choroidal blood flow in retinitis pigmentosa as measured by MRI

Deconvolution of high rate flicker electroretinograms

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