Changes of photopic negative response of multifocal electroretinogram after treatment with Aflibercept in patients with diabetic macular edema / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To observe the changes of photopic negative response(PhNR)of multifocal electroretinogram(mf-ERG)in patients with diabetic macular edema(DME)before and after treatment with Aflibercept.METHODS: A total of 37 patients(37 eyes)with DME who visited the Aier Eye Hospital of Wuhan University(Wuhan Aier Eye Hospital)from May 2019 to June 2022, and 0.05 mL of aflibercept was injected per month for consecutive 3mo were included in this retrospective cohort study. Another 20 cases(20 eyes)with normal physical examination to exclude related eye diseases were selected as the control group. The PhNR amplitude of mf-ERG, best-corrected visual acuity(BCVA; LogMAR), central retinal thickness(CRT), capillary plexus in macular area and vessel density(CPVD)of the participants between the two groups were compared before and after treatment.RESULTS: The PhNR amplitude of mf-ERG in DME patients before treatment(201.69±80.92nV)was significantly lower than that in the normal control group(398.87±77.92nV; P<0.01), and the average PhNR amplitude of mf-ERG in DME patients at 6mo after treatment was significantly higher than that before treatment(P=0.036), but it was still significantly lower than the normal control group at 6mo after treatment(P=0.031). In addition, the BCVA(LogMAR)of DME patients increased from 0.64±1.33 to 0.37±1.39(P=0.021)at 6mo after treatment, and CPVD significantly increased compared to that before treatment(P=0.029). Meanwhile, the PhNR amplitude of mf-ERG in DME patients at 6mo after treatment was positively correlated with CPVD at 6mo after treatment(r=0.448, P=0.043), and negatively correlated with BCVA(LogMAR)and CRT(r=-0.647, P=0.011; r=-0.337, P=0.032).CONCLUSION: The PhNR amplitude of mf-ERG in DME patients increased significantly after receiving aflibercept, and it can be used to observe and evaluate the functional changes of retinal ganglion cells in DME patients.

Electroretinogram changes in patients and carriers with Leber hereditary optic neuropathy / 中华眼底病杂志

Objective:To observe the characteristics of pattern electroretinogram (PERG) and the photopic negative response (PhNR) of flash electroretinogram (FERG) in patients and carriers with Leber hereditary optic neuropathy (LHON).Methods:A cross sectional, observational study. Thirty-two patients (64 eyes) diagnosed with LHON (LHON group) and 15 normal members with the same mutation in patient's family (carrier group) were included in this study from February 2021 to November 2021 in the Department of Ophthalmology of Renmin Hospital of Wuhan University. All patients in LHON group were males (100.0%, 32/32) and the average age was 23.34±7.41 years. In the carrier group of 15 cases (30 eyes), there were 2 males (13.3%, 2/15) and 13 females (86.7%, 12/15). The average age was 43.44±7.65 years. Twenty-four healthy subjects (48 eyes) in the same period were selected as the control group. Among them, there were 8 males (33.3%, 8/24) and 16 females (66.7%, 16/24). The average age was 23.42±2.54 years. All subjects were examined with the GT-2008V-VI visual electrophysiology instrument of Chongqing Gotec Medical Equipment Limited Company for PERG and FERG. P50 and N95 amplitudes of PERG and PhNR, a wave and b wave amplitudes of FERG were recorded. The peripapillary retinal nerve fiber layer (pRNFL) thicknesses of the nasal, superior, temporal, inferior and average quadrants were measured by spectral domain optical coherence tomography (SD-OCT). The amplitudes of a wave, b wave, PhNR, P50 wave, N95 wave and pRNFL thickness between the three groups were compared by one-way ANOVA. Pearson correlation analysis was used to analyze the correlation between different parameters.Results:Compared with the control group, the amplitudes of PhNR in LHON group and carrier group decreased significantly ( F=11.973, P<0.001). The results of correlation analysis showed that the amplitude of PhNR in LHON group was significantly correlated with the thickness of nasal and temporal pRNFL ( r=0.249, 0.272; P=0.048, 0.030). There was no significant difference in P50 wave amplitude between patients, carriers and controls ( F=1.342, P=0.265). There was no significant difference in N95 wave amplitude between patients and controls ( P=0.960). Conclusion:The PhNR amplitudes of FERG in LHON patients and carriers decrease significantly compared to controls.

Blue-on-Green Flash Induces Maximal Photopic Negative Response and Oscillatory Potential and Serves as a Diagnostic Marker for Glaucoma in Rat Retina

The purpose of this study was to investigate the application of various electroretinography (ERG) to the diagnosis of inner retinal dysfunction induced by mild intraocular pressure (IOP) elevation in a rat glaucoma model. For inner retinal function measurements, available photopic ERG protocols were applied under various light conditions including monochromatic combinations, which complement conventional scotopic ERG. Three episcleral veins in the right eyes of Sprague-Dawley rats were cauterized to induce an experimental model of glaucoma, leading to mild IOP elevation. ERG responses were measured before surgery and at 1, 2, 4, and 8 weeks after cauterization. We first confirmed that the amplitude reduction in the standard photopic b-wave was almost comparable to the amplitudes of scotopic a- and b-waves in glaucomatous eyes over time. We have implemented additional photopic ERG protocols under different stimulus conditions, which consisted of a longer duration and different monochromatic combinations. Such a change in the stimulations resulted in more pronounced differences in response between the two groups. Especially in normal animals, blue stimulation on a green background produced the largest b-wave and photopic negative response (PhNR) amplitudes and caused more pronounced oscillatory potential (OP) wavelets (individual components). In glaucomatous eyes, blue stimulation on a green background significantly reduced PhNR amplitudes and abolished the robust OP components. These results, by providing the usefulness of blue on green combination, suggest the applicable photopic ERG protocol that complements the conventional ERG methods of accessing the progression of glaucomatous damage in the rat retina.

Significance of visual electrophysiological techniques in the early diagnosis of glaucoma / 国际眼科杂志(Guoji Yanke Zazhi)

Glaucoma is a group of diseases which can threaten and damage the optic nerve and its visual pathway, leading to visual impairment as a result. Glaucomatous optic neuropathy is a chronic disease accompanied by apoptosis of retinal ganglion cells ( RGCs ) , visual field defect and cupping of optic nerve head. The gold standard in functional glaucoma evaluation is standard automated perimetry ( SAP) , but it is often limited to the subjective feelings of the patients. Still, visual electrophysiological techniques cannot replace the conventional inspection, but with its rapid development, it has provided a new strategy for the early diagnosis of glaucoma as a supplement because it can show changes in amplitude and latency before visual field defect. Here we review three special electroretinograms and multifocal focal visually evoked potentials in the early diagnosis of glaucoma.

ON and OFF Responses of the Electroretinogram in Patients with Glaucoma

PURPOSE: To investigate whether there is a difference in ON- and OFF-responses of the photopic electroretinogram (ERG) in glaucomatous eyes. METHODS: Photopic ERG and optical coherence tomography were performed in 15 normal, 13 glaucoma suspect, and 22 glaucoma subjects. Amplitudes and implicit times for a, b, d, i, photopic negative response (PhNR), and retinal nerve fiber layer thickness were compared among the three groups. RESULTS: The PhNROFF amplitude (microV) was 19.05 +/- 11.41 in the glaucoma group, 14.24 +/- 10.37 in the glaucoma suspect group, and 2.69 +/- 12.16 in the normal group, demonstrating a significant difference among the three groups (p < 0.01). The PhNRON amplitude (microV) was 20.15 +/- 13.99 in the glaucoma group, 31.49 +/- 17.09 in the glaucoma suspect group, and 37.59 +/- 9.53 in the normal group, a significant difference (p < 0.01). However, there was no significant difference between the three groups. The ON-OFF response PhNR amplitude was correlated with retinal nerve fiber thickness (r = 0.481, r = -0.480, respectively), and areas under the receiver operating characteristic curve were 0.782, and 0.718, respectively. CONCLUSIONS: There is a potential role for the ON-OFF response PhNR in early detection of glaucomatous damage.

Changes of photopic negative response after intravitreal injection of triamcinolone acetonide for macular edema caused by central retinal vein occlusion / 中华实验眼科杂志

Background Intravitreal injection of triamcinolone acetonide (TA) can effectively eliminate central vein occlusion macular edema and improve visual acuity, and photopic negative response (PhNR) can reflect the inner retinal function of RGCs and their axons. It is possible there is a correlation between these two observations.Objective This study was to evaluate the changes of PhNR of flash electroretinogram (F-ERG) after intravitreal injection of TA for macular edema in central retinal vein occlusion ( CRVO ). Methods Thirteen eyes of 12 patients with macular edema caused by CRVO received an injection of 0. 1 ml (4 rg) of TA. PhNR,visual acuity and retinal thickness of macular area were assessed with Roland RETI scan 3. 15 system,decimal visual chart and Stratus optical coherence tomography (OCT) before and 4 weeks after the administration of TA. Written informed consent was obtained from each subject before any medical procedure. Results Visual acuity was improved in 12 eyes and stable in 1 eye 4 weeks following the intravitreal injection of TA. OCT showed that the retinal thickness of the macular area was reduced ;meanwhile,elevation of the amplitude of PhNR also was seen in the F-ERG after the administration of TA in comparison with before the administration of TA. The calculated results determined that the visual acuities were 0. 32t0. 12 and 0. 48±0. 09 (t=6. 325 ,P=0. 000) ,and the retinal thickness values of the macular area were (459.46± 131.31 ) μm and ( 297.54 ±43.31 ) μm ( t = 5.961, P = 0. 000 ), and the average amplitude of PhNR were ( 80. 23±22.96 ) μV and (61.28 ±20. 16 ) μV ( t = 4. 438, P = 0. 001 ) before and after the intravitreal injection of TA, respectively,showing significant differences. No significant correlation was found between PhNR amplitude and retinal thickness of the macular area both before and after the administration of TA ( before: r = 0. 587, P = 0. 035; after:r=-0. 011 ,P = 0. 971 ). Conclusion PhNR can be used for evaluating the status of inner retina after intravitreal injection of TA for macular edema of CRVO.

Advanced progress of the electroretinogram photopic negative response / 中华实验眼科杂志

The photopic negative response(PhNR)from photopie electroretinogram(ERG)is a slowly negative potential following positive b wave.The experimental study of primates and clinieal observation of patients determined that PhNR arise from retinal ganglion cells(RGCs)and their axons.But the research result of rodents suggested that PhNR of mice and rats,unlike in human and primates,originate from amaerine cells.Recently,the study progress in PhNR is eoncemed by more and more researchers.The study of PhNR in the focal ERG,the influence of different recording conditions on PhNR wave and the character as well as recording condition of PhNR wave in rodents were introduced in this paper.

The Role of Electroretinography in Assessing the Progression of Diabetic Retinopathy

PURPOSE: To investigate the clinical significance of electroretinographic (ERG) responses, including the photopic negative response parameter, in assessing the progression of diabetic retinopathy. METHODS: Standard flash ERG was tested on 28 normal controls and 143 patients who were diagnosed with diabetes mellitus. Of those, 97 patients had diabetic retinopathy in different stages. Electroretinography was performed according to the International Society for Clinical Electrophysiology of Vision (ISCEV) standards. Amplitudes and implicit times of ERG responses, including the photopic negative response (PhNR), were compared at different stages of diabetic retinopathy. RESULTS: Amplitudes of oscillatory potentials were significantly reduced in mild NPDR. Cone b-wave amplitude, 30--Hz flicker response, and PhNR were significantly reduced in moderate NPDR. CONCLUSIONS: These results suggest that oscillatory potentials are good indicators of retinal function change in the early stage of diabetic retinopathy, and the appropriate results of the cone b-wave, 30-Hz flicker response and PhNR tests are good indicators of moderate NPDR.

A Clinical Applications of Photopic Negative Response (PhNR) for the Treatment of Glaucoma and Diabetic Retinopathy

PURPOSE: To determine the clinical utility of using photopic negative response (PhNR) by comparing the parameters for normal, primary open angle glaucoma (POAG) and diabetic retinopathy (DR). METHODS: Electroretinography (UTAS E-3000) was performed in 12 normal, 12 POAG, and 12 DR subjects. Amplitudes and implicit times for PhNR were compared among the three groups. The mean deviation (MD) and pattern standard deviation (PSD) were evaluated using standard automated perimetry (SAP). The mean retinal nerve fiber layer (RNFL) thickness and cup-disc ratio were measured using optical coherence tomography. RESULTS: The a-waves and b-waves were not different among the three groups. However, compared to normal subjects, the PhNR amplitudes were reduced, and the PhNR implicit times were prolonged in the POAG and DR patients (p<0.001, p<0.001). The MD and RNFL thickness were correlated with the amplitudes and implicit times for the PhNR. CONCLUSIONS: PhNR may be useful for the detection of inner retinal dysfunction, which is seen in patients who have glaucoma or diabetic retinopathy.

Changes of photopic negative response in patients with exudative age-related macular degeneration and proliferative diabetic retinopathy after intravitreal injections of bevacizumab / 眼科

Objective To evaluate the changes of the waveform of the photopic negative response in flash-electroretinogram, visual acuity and central retinal thickness in the treatment of intravitreal injections of bevacizumub. Design Retrospective self-comparative case series. Partidpants 8 subjects (9 eyes) with exudative age-related macular degeneration and 3 subjects (3eyes) with proliferative diabetic retinopathy. Method Evaluation protocol included examinations of the Early Treatment Diabetic Retinopathy study visual acu-ity, visual field, intraocular pressure, fundus fluorescein angiography, optical coherence tomography and flash-electroretinogram. Intravit-real injections of bevacizumab, 1.25 mg (0.05ml), were given under an operating microscope and aseptic conditions. All the subjects were followed-up one month later. Main outcome Measure The amplitudes of PhNR, visual acuity and central retinal thickness. Re-sult At 1 months, the mean amplitudes of PhNR and mean visual acuity in all cases had no obvious change (n=12, P>0.05).The central retinal thickness reduced obviously (n=12, P<0.05), but it was neither significantly correlated with PhNR (r=0.294, P=0.145) nor with visual acuity(r=-0.358, P=0.073). Conclusion The single intravitreal injection of bevacizumab is showed promising in absorption of in-traretinal edema and subretinal fluid in patients with exudative age-related macular degeneration and proliferative diabetic retinopathy, but the changes of visual function (including PhNR) might need further investigation. (Ophthalmol CHN, 2009, 18: 243-246)

Photopic Negative Response (PhNR) in Normal Subjects

PURPOSE: To evaluate the nature of photopic negative response (PhNR) in normal subjects. METHODS: The electroretinogram (ERG) waves were recorded in 52 eyes of 26 normal subjects with UTAS E-3000(R) (LKC Technologies Inc., Gaithersberg, MD, USA). Photopic cone response was obtained for analysis from a white flash with white background illumination (group 1) and a red flash with blue background illumination (group 2), after stimulations ranging from 0.007674 cd.s/m2 (-25dB) to 7.736 cd.s/m2 (5dB) with a 5dB interval. RESULTS: PhNRs were observed in all 52 eyes in group 1 stimulated with the white flash at 0.9933 cd.s/m2 (-4dB). PhNRs were also observed in all 52 eyes in group 2 at 2.4297 cd.s/m2 (0dB) after stimulation with the red flash. There was correlation between the amplitudes of PhNR and intensity of stimuli (p<0.001). Implicit times of PhNR were correlated with age in both groups, but amplitudes decreased with age in group 1. CONCLUSIONS: The amplitudes of PhNR were correlated with intensity of stimuli and age had an influence on PhNR. Standardization of examination conditions is necessary when recording PhNR.

The significance of photopic negative response in early diagnosis of primary optic nerve atrophy / 眼科

0.05). But the amplitudes of the PhNR were significantly reduced in group of primary optic nerve atrophy (P