Objective To evaluate the variability of four parameters of multi-focal electroretinogram (mERG) a-wave amplitude, b-wave amplitude, awave latent period, b-wave latent period. Methods Sixty normal eyes of 46 volunteers were divided into 3 groups of different ages. RETIscan 3-12 system was used to carry out mERG examination. The stimulus matrix of 61 hexagonal elements spanning the central 24deg;of the visual field. These hexons were scaled with eccentricity and divide d into 5 rings. First-order kernel was selected. Results The variability of four parameters of mERG was great. The variability of b-wave latent period was the smallest, its coefficient of variatian was 4.52%～15.62%；that of a-wave latent period held the second place:10.29%~48.67%；that of b-wave amplitude was greater:25.92%~76.11%；that of a-wave amplitude was the greatest:43.82%~88.23%. The results of three groups showed that b-wave amplitude of ring 1 had the smallest variability. Conclusions The variability of latent period is smaller than that of amplitude; the variability of b-wave was smaller than that of a-wave. The longer the centrifugal distance, the lower the amplitude density of a-wave and b-wave. Physiological and anatomical factors might be important for the variability of parameters of multi-focal electroretinogram. (Chin J Ocul Fundus Dis, 2001,17:277-279)
Objective To explore the clinical application value of multifocal oscillatory potentials (MOPs) in retinal vein occlusion (RVO). Methods MOPs were tested using VERIS 4.0 visual evoked response imaging system for 19 cases (19 eyes) of RVO，among them 8 cases of central retinal vein occlusion (CRVO) and 11 cases of branch retinal vein occlusion (BRVO). Twenty normal subjects were as normal control group. The stimulative visual angles subtended ±26.6°horizontally and ±22.1°vertically. The filter setting was bandpass 100～1000 Hz. The retinal responses from 103 hexagons were recorded in 4 min (8 segments). Results In normal control group, OP-1, OP-2 and OP-3 were recorded during 37 ms for first order and 47 ms for second order first slice in whole test field and 5 ring retinal regions, the oscillatory wave shapes of second order were clearer than those of first order. In RVO groups, 91.6% latencies of OP-1, OP-2 and OP-3 were delayed, and 70.8% amplitudes of OP-1, OP-2 and OP-3 were reduced. The delay of the latencies and the decrease of the amplitude in CRVO were more markedly than those in BRVO. Conclusion MOPs can be effectively and quantitatively used to evaluate the retinal function of the different location in RVO. (Chin J Ocul Fundus Dis,2002,18:20-22)
One eye each in 3 groups of 12 pigmented rabbits after bilateral vitrectomy received 0.5mg, 1mg or 2mg triamcinolone acetonide (TA), respectively. The fellow eye received only balance saline solution as control. Ophthalmoscopy and electroretinography were performed during 1 day to 38 days after vitrectomy and drug injection. Light and electronmicroscopic studies were done on the 28th day. The particles of drug were visible on day 28 in all TA-treated eyes. Administration of 0. 5rug and 1mg TA did not result in different changes in ERG b-wave amplitudes compared with those in control eyes(P＞0. 05). There were significant elevations of ERG b-wave in 2mg TA eyes compared to the control eyes(Plt;0.05), Both ligbt and electronmicroscopy of the retina in these groups were almost normal. The results showed no Toxielties in TA treated eye up to 2mg after vitrectomy. This offers the experimental evidence as a baseline for combining TA with vitrectomy to reduce recurrence of proliferative vitreoretinopathy. （Chin J Ocul Fundus Dis,1996,12: 105- 107）
Flicker and photopic eletroretinogram(ERG)were recorded for 45 eyes of dry type of age-related macular degeneration(AMD)and 24 eyes of wet type of AMD respectively,the amplitud and phase of fundamental response compomeng(30Hz)by discrete Fourier tranform(DFT)were analysed.The abnormality ratios of phases and amplitudes in fundamental responses,amplitudes of photopic white or red b-waves were 48.89%,8.89%,10.11% and 8.89% respectively.The visual acuities of 24 eyes were 1.0 or better,the abnormality ratios of phases were up to 37.50%.These suggest that the change of phases is a sensitive method for detecting the early abnormality of visual function in AMD.The abnormality ratios of phases and amplitudes in fundamental responses were 62.5% and 45.84% in wet type of AMD.The differences between dry type and wet type in amplitudes of fundamental responses and photopic b-waves were statistically significant(P＜0.01).This shows that the change of amplitudes is associated with the degree of pathological change of AMD. （Chin J Ocul Fundus Dis,1996,12: 41-43）
Objective To study the response of the retinal neuronal adaptive system to changes of background illumination (BG) by measuring the oscillatory potentials (OPs) and the a- and b-waves of the electroretinogram (ERG) in different BG illuminations. Methods The a- and b-wave and the digitally filtered OPs were simultaneously recorded from Wistar Fu rats aged from 25 to 29 days during dark adaptation (DA) and during 6~8 minutes of BG illuminations at four levels increased successively by steps of two log units, i.e., ldquo;low scotopicrdquo; level of 1.43times;10-6cd/m2, ldquo;high scotopicrdquo; of 1.43times;10-4cd/m2 , ldquo;low mesopicrdquo; of 1.43times;10-2cd/m2 and ldquo;high mesopicrdquo; of 1.43times;10-2cd/m2. Full field stimulus flashes of 75 msec duration and 1.43times;10-2cd/m2intensity was delivered at an interval of 1 minute. Results Five OP wavelets were recorded in DA and during scotopic BG illuminations. The number of wavelets was reduced to three as the eyes were exposed to mesopic BG levels. However, the sum of OPs amplitudes (SOPs) increased as the BG was intensified, except at ldquo;high mesopicrdquo; level, by which a significant decrease of SOPs occurred. The amplitudes of the a-and b-waves remained unchanged at the two scotopic BG and decreased as the BG intensity increased to mesopic levels. Conclusion The response of retinal neural adaptive system of the Albino rat to changes of BG light is more sensitive and robust than the slow components of the ERG. The enhancement of the oscillatory responses at ldquo;low mesopicrdquo; illumination level suggests that using proper BG light may be conducive to reducing the variation of OPs. (Chin J Ocul Fundus Dis, 2001,17:286-288)
Objective To probe the possibility of electroretinogram(ERG)maximum combined response for typing branch retinal vein occlusion(BRVO). Methods BRVO were divided into ischemic or nonischemic type according to the appearance of fundus fluorescein angiography.The ERG data were used to define the retinl function:a，b-wave amplitude and impact time,b/a-wave ratio,oscillatory potential OP1，OP2，OP3，OP4 amplitude implicit time and Ops amplitude. Results The ERG b-wave and OPs amplitude were significantly lower in ischemic group than those in nonischemic group. Conclusion With the REG test,the decline of b-wave and OPs amplitude of the maximum combined response might be as a reference of ischemic type BRVO. (Chin J Ocul Fundus Dis,1998,14:10-11)
Objective To investigate the degree of retinal development in preterm infants.MethodsFlash electroretinography (ERG) was performed on 25 healthy preterm infants and 25 full-term ones, and the response of rod cells and cone cells and maximal mixed responses were recorded. The delitescence and amplitudes of a-and b-waves and the ratio of amplitudes of b-/a-wave of maximal responses were analyzed. ResultsCompared with the full-term infants, The delitescence of responses of rod cells in preterm infants was statistically longer（t=11.007，P=0.000）but without any significant changes of amplitudes （t=1.836，P=0.069）; statistically longer delitescence (t=2.44, P=0.010; t=10.800, P=0.000) and lower amplitude (t=5804，P=0.000; t=5.809,P=0.000) of a-and b-wave of maximal response were found in preterm infants group. In the response of cone cells, there were significant differences of the delitescence （t=4.444，P=0.000）and amplitude （t=3.819，P=0.000）of a-wave and delitescence of b-wave（t=2.850，P=0.005） between the two groups, and no statistical difference of amplitude of b-wave （t=0.486，P=0.628） between the two groups. The ratio of amplitudes of b-/a-wave of the maximal mixed response was not significantly different between the two groups （t=1.142，P=0.256）.ConclusionsThe development of retinal function is slower in preterm infants than that in full-term ones.(Chin J Ocul Fundus Dis, 2005,21:285-287)
Objective:To observe the effect of beta;estradiol on gluta mate concentration in rabbitsprime; retinae injured by ischemic reperfusion. Methods:Twenty r abbits ware randomly divided into two groups, the control group and the treatmen t group, with 10 rabbits in each group. Before examined by binocular flash elect roretinography (FERG), retinal ischemic reperfusion (RIR) model was induced in t h e right eyes of all the rabbits by increasing intraocular pressure to 120 mm Hg for 60 minutes; the left eyes were as the control eyes. The rabbits were hypoder mically injected with beta;estradiol (0.1 mg/kg) in treatment group and with phys i ological saline in the control group 2 hours before ischemia. The results of FER G of the right eyes in both of the 2 groups 0, 4, 8, and 24 hours after reperfus ion were record respectively and were compared with the results of FERG before r eperfusion. The retina tissue was collected after the last time of FERG. The con c entration of glutamate was detected by Hitachi L8800 amino acid analyzer. Results:In the right eyes in both of the 2 groups, the result of F ERG showed a beeli ne just after reperfusion. There was no significant difference of awave amplit u de between the 2 groups (t=1.357, 0.798, 0.835; Pgt;0.05); the b wave amplitudes i n experimental group were much higher than those in the control group (t=4.447, 2.188, 3.106; Plt;0.01). The concentration of glutamate in retina was (0.265plusmn;0.014) g/L in the right eyes and (0.207plusmn;0.013) g/L in the left eyes in the control group, and (0.231plusmn;0.007) g/L in the right eyes and (0.203plusmn;0 .014) g/L in the le ft eyes in the treatment group; the difference between the 2 groups was signific ant (F=50.807, P=0.000). There was statistical difference between righ t and left eyes both in the 2 groups and the significant difference of the right eyes betw een the two groups was also found (P=0.000); there was no statistical diffe rence of the left eyes between the 2 groups (P＝0.505). Conclusion:beta;-estradiol may prevent the increase of the concentration of glutamate in retina induced by RIR to protect retinal tissue.
ObjectiveTo observe the preliminary clinical application value of the handheld non-mydriatic visual electrophysiological diagnostic system RETeval in screening for diabetic retinopathy (DR).MethodsRetrospective clinical study. Fifty-eight patients with type 2 diabetes mellitus and 16 normal subjects who were admitted to Wuhan General Hospital of the PLA from November 2017 to May 2018 were enrolled in this study. All patients had not received any ophthalmologic treatment. All patients were examined by the default “DR assessment protocol” model of the RETeval device, and the “DR score” were measured by the system. The FFA results were used as the gold standard, and the DR was graded according to the international DR grading standard established in 2002. Patients were divided into vision threatening DR (VTDR) positive group and VTDR (−) group, DR (+) group and DR (−) group. Two independent sample t tests was used to compare the implicit time, amplitude, and pupil area ratio between eyes of different groups. Spearman correlation analysis was used to analyze the relationship between “DR score” and DR severity. The receiver operating characteristic area under the curve (AUC) assesses the sensitivity and specificity of RETeval in detecting DR and VTDR. The threshold of sensitivity and specificity was determined by using the maximum Youden index as a standard.ResultsThe AUC of DR was 0.936, the sensitivity was 81%, the specificity was 92%; the AUC of VTDR was 0.976, the sensitivity was 96% and the specificity was 70%. Compared with DR (−) group, the implicit time of DR (+) group was delayed and the amplitude and pupil area were decreased (t=－13.43, 5.49, 6.09; P=0.000, 0.000, 0.000). Compared with VTDR (−) group, the implicit time of VTDR (+) group was delayed and the amplitude and pupil area were decreased (t=－11.05, 7.46, 5.73; P=0.000, 0.000, 0.000). The “DR score” was significantly correlated with the severity of DR (r=0.89, P＜0.05).ConclusionsThe “DR score” measured by the RETeval instrument has a high degree of specificity and sensitivity in the diagnosis of DR and VTDR. It is highly correlated with the severity of DR.
Purpose To measure and compare the difference of multifocal electroretinogram in normal subjects and patients with age-related macular degeneration. Methods Seventeen cases(20 eyes)of normal subjects,7 cases(10 eyes)of dry form AMD(age-related macular degeneration),8 cases(8 eyes)of wet-form AMD and 11 cases(11 eyes)of idiopathic macular hole(IMH)were tested with VERIS SciencesTM 4.0 made by EDI company of America.The latencies and average response densities of 6 ring retinal regions in normal subjects were compared with those in various types of age-related maculopathies. Results The N1 and P1 wave latencies of all 6 rings in wet-form AMD and the N1 wave latencies of 3～6 rings in dry-form AMD were delayed statistically.The N1 and P1 wave average response densities of 1～4 rings in and the P1 wave average response densities of 1-6 rings wet-form AMD and the N 1 wave average response densities of 1～5 and the P1 wave average response densties of 1-6 rings in dry-form AMD were decreased statistically.The N1 and P1 wave average response densities of 1～2 and the P1 wave average esponse densities of 1～3 rings were decrease statistically in IMH. Conclusion Multifocal electroretinogram can be used to quantitate the visual function of the affected location in age-related macular degeneration. (Chin J Ocul Fundus Dis,2000,16:224-226)