scholarly journals Рhotopic Negative Response for Testing the Function of Inner Retina: Registration Requirements and Comparison in the Eyes with Natural Pupil Width and in Conditions of Drug Mydriasis

2020 ◽  
Vol 17 (3) ◽  
pp. 398-406
Author(s):  
V. I. Kotelin ◽  
M. O. Kirillova ◽  
M. V. Zueva ◽  
I. V. Tsapenko ◽  
A. N. Zhuravleva ◽  
...  
Keyword(s):  
Pupil Size ◽  
Amplitude Ratio ◽  
Negative Response ◽  
Photopic Negative Response ◽  
Healthy Individuals ◽  
Inner Retina ◽  
Irregular Distribution ◽  
Ganzfeld Stimulation ◽  
Blue Background ◽  
Healthy Persons

Purpose: To evaluate the possibility of registration of the photopic negative response (PhNR) without pupil dilatation in healthy individuals to determine the dysfunction of neurons of the inner retina.Methods: 12 healthy persons (23 eyes) aged 24 to 40 years were examined. Refraction anomalies did not exceed 0.5 diopters. A PhNR was evaluated in photopic ERGs recorded on a blue background with red flashes of four intensities (0.375, 0.75, 1.5, 3.0 cd·s/m2) using the RETIport/scan21 (Roland Consult). First, ERG was recorded with the natural pupil (3.5 ± 0.2 mm). Then, the recording was repeated after drug mydriasis (average pupil size 8.7 ± 0.1 mm).Results. In eyes with natural pupil width, in comparison with drug mydriasis, PhNR amplitudes in responses to weakest stimuli (0.375 cd·s/m2) were significantly reduced. The effect of pupil size on the PhNR amplitude from a baseline was virtually absent in responses to higher strength flashes. This phenomenon can be associated with an irregular distribution of light over the retina with small pupil size, the effect of which is maximal in responses to weak flashes. For the maximal brightness stimuli (3.0 cd·s/m2), differences were found between groups of non-dilated and dilated pupils in the amplitudes of the b-wave and PhNR from the b-peak, which may reflect a decrease in the number of stimulated photoreceptors during ganzfeld stimulation when the pupil is not dilated.Conclusion. The effect of pupil size on the parameters of the PhNR was most significant in the ERG with minimal flash strength and it decreases in responses to flashes of higher brightness. If it is necessary to record the ERG without drug mydriasis, especially in screening studies, it is recommended to limit the protocol to estimate the PhNR from a baseline in responses to maximal flashes, and use the relative parameter — the amplitude ratio of PhNR/b. Keywords: photopic negative response, electroretinography, pupil width

scholarly journals Comparison of Photopic Negative Response of Full-Field and Focal Electroretinograms in Detecting Glaucomatous Eyes

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Shigeki Machida ◽  
Kunifusa Tamada ◽  
Taku Oikawa ◽  
Yasutaka Gotoh ◽  
Tomoharu Nishimura ◽  
...  
Keyword(s):  
Receiver Operating Characteristic ◽  
Operating Characteristic ◽  
Negative Response ◽  
Photopic Negative Response ◽  
Diagnostic Ability ◽  
Full Field ◽  
Receiver Operating Characteristic Curves ◽  
Advanced Glaucoma ◽  
Blue Background ◽  
Higher Sensitivity

Purpose. To compare the photopic negative response (PhNR) of the full-field electroretinogram (ERG) to the PhNR of the focal ERGs in detecting glaucoma.Methods. One hundred and three eyes with glaucoma and 42 normal eyes were studied. Full-field ERGs were elicited by red stimuli on a blue background. The focal ERGs were elicited by a15∘white stimulus spot centered on the macula, the superotemporal or the inferotemporal areas of the macula.Results. In early glaucoma, the areas under the receiver operating characteristic curves (AUCs) were significantly larger for the focal PhNR (0.863–0.924) than those for the full-field PhNR (0.666–0.748) (P<.05). The sensitivity was significantly higher for the focal PhNR than for the full-field PhNR in early (P<.01) and intermediate glaucoma (P<.05). In advanced glaucoma, there was no difference in the AUCs and sensitivities between the focal and full-field PhNRs.Conclusions. The focal ERG has the diagnostic ability with higher sensitivity in detecting early and intermediate glaucoma than the full-field ERG.

Functional Loss of the Inner Retina in Childhood Optic Gliomas Detected by Photopic Negative Response

2015 ◽  
Vol 56 (4) ◽  
pp. 2469 ◽  
Author(s):  
Edoardo Abed ◽  
Marco Piccardi ◽  
Daniela Rizzo ◽  
Antonio Chiaretti ◽  
Lucia Ambrosio ◽  
...  
Keyword(s):  
Negative Response ◽  
Photopic Negative Response ◽  
Inner Retina ◽  
Functional Loss

scholarly journals Comparison of Machine Learning Approaches to Improve Diagnosis of Optic Neuropathy Using Photopic Negative Response Measured Using a Handheld Device

2021 ◽  
Vol 8 ◽  
Author(s):  
Tina Diao ◽  
Fareshta Kushzad ◽  
Megh D. Patel ◽  
Megha P. Bindiganavale ◽  
Munam Wasi ◽  
...  
Keyword(s):  
Machine Learning ◽  
Time Series ◽  
Optic Neuropathy ◽  
Negative Response ◽  
Photopic Negative Response ◽  
Learning Approaches ◽  
Data Set ◽  
Full Field ◽  
Handheld Device ◽  
Technical Requirements

The photopic negative response of the full-field electroretinogram (ERG) is reduced in optic neuropathies. However, technical requirements for measurement and poor classification performance have limited widespread clinical application. Recent advances in hardware facilitate efficient clinic-based recording of the full-field ERG. Time series classification, a machine learning approach, may improve classification by using the entire ERG waveform as the input. In this study, full-field ERGs were recorded in 217 eyes (109 optic neuropathy and 108 controls) of 155 subjects. User-defined ERG features including photopic negative response were reduced in optic neuropathy eyes (p &lt; 0.0005, generalized estimating equation models accounting for age). However, classification of optic neuropathy based on user-defined features was only fair with receiver operating characteristic area under the curve ranging between 0.62 and 0.68 and F1 score at the optimal cutoff ranging between 0.30 and 0.33. In comparison, machine learning classifiers using a variety of time series analysis approaches had F1 scores of 0.58–0.76 on a test data set. Time series classifications are promising for improving optic neuropathy diagnosis using ERG waveforms. Larger sample sizes will be important to refine the models.

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