PURPOSE: To explore the effects of stimulus duration, stimulus intensity, and background luminance on the amplitude and waveform of the ON- and OFF- responses of photopic ERG and to provide standard parameters of ON- and OFF- responses for normal Korean populations. METHODS: Twenty normal subjects (20 eyes) were enrolled to record photopic ON-and OFF-responses using a contact lens electrode with built-in LEDs and an LED-driver. The influence of stimulus duration on wave amplitudes was studied at flash durations that varied from 5 to 200 ms. The influence of stimulus intensity was studied with 0.4, 0.7, 1.1, 1.4, 1.7, 1.9, 2.0, and 2.1 log cd/m2. In addition, the influence of background luminance was studied with 20, 30, 40, and 50 cd/m2. RESULTS: Among 20 normal subjects, the d-waves in 16 subjects were isolated from b-waves with more than 50 ms of stimulus duration. The d-wave was observed for a 30-ms stimulus duration in 3 subjects and for a 100-ms duration in 1 subject. The amplitudes of the b-and d-waves increased as stimulus intensity was increased. The amplitudes of b-and d-waves decreased as background luminance was increased. CONCLUSIONS: Our results suggest that the clinical use of ON-and OFF-response recording can be obtained with stimulus parameters from 100 to 150 ms in duration and a 1.7-2.1 log cd/m2 intensity under 30-40 cd/m2 background luminance.
Electrodes ; Electroretinography

ERG was checked by an instrument set up by authors in eyes with vitreous opacity with and without retinal disorders. It is composed of a preamplifier(frequency response of 0.3Hz~240Hz, gain of 80 decibel), Tektronix 5103N oscilloscope(with 5A18N dual trace amplifier and 5B12N dual time base). Retina was stimulated by Grass P22 photostimulator at settings of 1, 4, 8, and 16 light in tensities. Following findings were obtained; 1. Voltage of a-wave was much increased with little change of b-wave, when intensities of photostimulation was increased. 2. Definite ERG waves were recorded with high intensities of light stimulation, when low intensities failed to produce them. 3. Even in high intensities of light stimulation, oscillatory potentials were not recorded. 4. In case of diffuse retinal damage and vitreous opacities, peak time of a and b wave were markedly delayed as well as decrease of voltages.
Electroretinography* ; Poaceae ; Retina ; Retinaldehyde

The purpose of this study is to evaluate the parameters of electroretinography[ERG]in eyes with diabetic retinopathy. The ERG responses were recorded in 46 normal subjects and 72 diabetic patients.We obtained the values of 12parameters from 5 basic responses and compared the changes of ERG parameters with the stages of diabetic retinopathy. The amplitude of oscillatory potentials decreased progressively from normal to severe nonproliferative diabetic retinopathy[NPDR].The b-wave implicit time of cone response was delayed in eyes with moderate NPDR to high risk proliferative diabetic retinopathy[PDR]. The b-wave amplitude of rod response was reduced in eyes with mild to moderate NPDR.The a-wave amplitude of maximal combined response significantly decreased between severe NPDR and early PDR.
Diabetic Retinopathy* ; Electroretinography

Specific values for amplitude and implicit time may differ among laboratory due to normal variations in recording electrodes, equipment, and protocol. We presented the results of fulHield and focal macular electroretinography in normal subjects using MacADIOS 411 and Maculoscope. Full-field electroretinograms were obtained in 87 normal subjects (65 males, 22 females) and focal macular electroretinograms were recorded in 33 valunteers(18 males, 15 females) under controlled condition. Age-matched norms were given in table, and for the purpose of clinical application, range of values was given for each group.
Electrodes ; Electroretinography* ; Humans ; Male

PURPOSE: To obtain normal values of positive wave (b-wave) in the multifocal ERG in terms of age and sex of Koreans. METHODS: The multifocal ERGs by using RETIscan visual evoked response imaging system were tested for 80 eyes. 61 retinal locations were stimulated concurrently. We analyzed the average responses of 5 concentric rings. RESULTS: In the amplitudes of b-wave, ring 1, 84.1 5.4 nV/deg, was the largest of all the other rings and ring 5, 23.1+/-1.5 nV/deg, was the smallest of all the other rings (P<0.05). No statistically significant difference was observed in amplitude between sexs. The implicit time of b-wave was the longest in the ring 1, 40.8 1.6 ms, and shortest in the ring 4, 36.7+/-0.9 ms (P<0.05). CONCLUSIONS: The amplitude of b-wave was the largest in the fovea, and became smaller with eccentricity. The largest amplitude of b-wave was observed in the age of twenties. The amplitude of b-wave was decreased with age in the ring 3, 4, and 5. The interindividual variation of the amplitude of b-wave was greatest in the fovea. The implicit time of b-wave in the fovea was the longest, and that in the ring 4 was the shortest. It became longer from the ring 5, again.
Electroretinography* ; Evoked Potentials, Visual ; Reference Values* ; Retinaldehyde

This study was conducted to determine the safe intravitreal dosage of ciprofloxacin. Twenty-four phakic eyes of New Zealand pigmented rabbits were used. Each group(4 eyes) received midvitreal ciprofloxacin of 100, 200, 400, 600, 800 micro gram in 0.1ml BSS Plus, or 0.1ml BSS Plus only as control. We evaluated retinal function by measuring the electroretinograms for a graded series of flash intensities and fitting b-wave amplitudes to the Naka-Rushton equation. At a dose of greater than 600 micro gram, Rmax decreased signifantly and log K increased signifantly. N-value decreased slightly. B-wave amplitude decreased as a toxic response of intravitreal ciprofloxacin in a dose dependent manner, and this response was best detected using lower luminance stimuli. Lower luminance electroretinography revealed a significant decrease in b-wave amplitude in eyes injected with a dose of 400 micro gram or more. We concluded that 200 micro gram will be the safe intravitreal dosage of ciprofloxacin in phakic rabbit eyes.
Ciprofloxacin* ; Electroretinography* ; New Zealand ; Rabbits ; Retinaldehyde

OBJECTIVE: To study the characters of oscillatory potentials (OPs) of electroretinogram (ERG) after methanol intoxication in rats. METHOD: The SD rat models of methanol intoxication were established and divided into control group, 3-day intoxication group, 7-day intoxication group. The changes of OPs of ERG were recorded in a dark room. RESULTS: The total amplitudes of 3-day and 7-day intoxication groups decreased approximately 50% compared with that of the control group, while the schedule delayed approximately 16% and 61%, respectively. CONCLUSION The characters of methanol intoxication in rats included delay in schedule and decline in the total amplitude of OPs.
Animals ; Electroretinography ; Methanol/poisoning* ; Rats ; Retina/physiopathology*

OBJECTIVE: This study was performed to evaluate the effect of panretinal photocoagulation (PRP) on parameters of electroretinograms (ERG). METHODS: Retrospective study was performed on 58 eyes of 29 patients with proliferative diabetic retinopathy (PDR) who underwent PRP. ERG was performed in each patient before and after PRP, and each ERG parameters were compared between the pre- and post-PRP state. Also, the results of ERG performed after PRP were compared between two groups: one group showing obvious new vessels regression and the other group showing poor regression after PRP. RESULTS: Marked reduction in amplitude and delay in implicit time were observed in all patients (P<0.05). The results also showed larger reduction of amplitude and delay in implicit time in b-wave than a-wave (P<0.05). There were no significant differences in ERG parameter changes after PRP between the group showing obvious new vessel regression and the group showing poor new vessel regression after PRP (P>0.05). CONCLUSION: PRP in diabetic retinopathy patients may affect not only the outer retina but also the cells within the inner nuclear layer, causing changes in ERG parameters. However, ERG was not a good indicator for representing the amount of new vessel regression in PDR.
Diabetic Retinopathy* ; Electroretinography ; Humans ; Light Coagulation* ; Retina ; Retrospective Studies

Using Burian-Allen bipolar contact lens electrode, Authors examined the normal 120 eyes of 120 subjects(male 57, female 63), age ranged 7 to 83 years(mean 44.5 years), with the method which was same as the ISCEV standard. There was no statistically significant differences between the value obtained using Burian-Allen electrode and the value obtained using ERG-jet electrode(p>0.05). We expect that this data would be useful testing method to evaluate the retinal disease. And this data may provide new reference value in the study of electroretinogram.
Electrodes* ; Electroretinography* ; Female ; Humans ; Reference Values* ; Retinal Diseases

Electroretinography has been used clinically for more than 50 years as useful retinal function test. But there has been no uniform recording signals, since various laboratories have employed different technologies and recording condition. Therefore, in 1989, International Society for clinical Electrophysiology of Vision (ISCEV) published Standard for clinical ERG, to ensure that ERG performed simply and uniformly worldwide for clinical and research purpose. We performed this standard ERG to 100 normal subjects whose range of ages were 8-79 years old. We obtained normal values of standard 5 basic response parameter. Additionally, we studied the parameter change according to age and sex. We found significantly decreased amplitude in the b-wave with age (p<0.05), and also obtained decreased rate b-wave amplitude with age. But no relation between b-wave implicit time and change of age was noted. B-wave amplitude found to be higher in women than in men (p<0.05).
Electrophysiology ; Electroretinography* ; Female ; Humans ; Male ; Reference Values* ; Retinaldehyde