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

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

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

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

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

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

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*

To determine the ocular toxicity after intrachoroidal steroid injection in the rabbit eye, 0.15ml(40 mg/ml) triamcinolone acetonide, 0.15ml(40 mg/ml) methylprednisol one acetate and 0.15ml balanced salt solution(as controls) were injected into the choroid. The results were shown normal in fundus examination, electroretinography, and electron microscopy throughout the two weeks course of the experiment. From these result, it would appear that intrachoroidal 6 mg steroid injection demonstrated the lack of ocular toxicity.
Choroid ; Electroretinography ; Microscopy, Electron ; Pathology ; Triamcinolone ; Triamcinolone Acetonide

ID clarify the effects of ouabain on the ERG c-wave, isolated chick retinas were exposed to different concentrations of ouabain and the results noted. Although the c-wave was abolished at a highe. dose of ouabain (10(-4)M), its amp1itude increased in the presence of ouabain at a concentration of 10(-7)M, which was within the range of clinical use of the cardiac glycoside. On the other hand, the standing potential of the retina did not change appreciably until 10(-6)M and then decreased gradually at higher concentrations.In the presence of 10(-4)M ouabain, the concentration which completely blorked Na-K-ATPase, both the c-wave and the standing potential were almost abolished. These phenomena were more conspicuous when ouabain was applied to the vitreous side rather than the choroidal side. In the presence of 10(-7)M ouabain, the light sensitivity of the retina was elevated to 0.5 log unit and the maximum response increased about 30%. This may be a sign of visual complications of ouabain, such as metachromatopsia.
Animals ; Chickens ; Electroretinography ; Ouabain/*pharmacology ; Photic Stimulation ; Retina/*drug effects

The purpose of the study is to evaluate the effects of calcium dobesilate (Doxium) on the electroretinographic changes in 60 non-insulin dependent diabetic patients with mild to moderate diabetic retinopathy, randomly assigned to receive either oral calcium dobesilate l000mg twice 8 day for 6 months or without medication. And also the effects of blood HbAlc and retinal photocoaglulation on the electroretinographic changes were evaluated. All patients were tested electroretinography with UTAS-2000 (LKC co., USA) before treatment and six months later respectively. The time interval changes of the electroretinogram were analyzed with student t-test program. As a result, no interval changes of the electroretinographic b-wave amplitudes and b/a ratio were noted in both groups, but the oscillatory potentials were significantly decreased after 6 months in the non-treated group (p:0.002). As compared to calcium dobesilate treated group, the non-treated group with blood HbAlc over 6.5mg% (p:0.008) or treated with retinal photocoagulation (p:0.001) showed a significant decrease of the oscillatory potentials. In conclusion, the administration of calcium dobesilate in the patients with diabetic retinopathy prevents an oscillatory potentials reduction, especially in patients with blood level of HbAlc below 6. 5mg% or treated with retinal photocoagulation.
Calcium Dobesilate ; Calcium* ; Diabetic Retinopathy* ; Electroretinography ; Humans ; Light Coagulation ; Retinaldehyde