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）
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)
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 explore the effect of ischemia-reperfusion injury on the retinal functions of rats. Methods Seventy Wistar rats were selected, 20 of which were selected randomly and divided into two groups (control group and single-irrigated group). The rats were anesthetized and their anterior chambers of the right eyes were cannulated with a 7-gauge needle connected to a reservoir containing ringers balanced salt solution, which was maintained at the same level o f the eye for 1 hour. After that, ERG was recorded in both eyes of all rats. All the left rats were divided randomly into 10 groups and they were treated as the single-irrigated group. Retinal ischemia was induced by raising the reservoir to a height of 150 mm Hg. One hour later except the single ischemia group, all o f t he groups resumed perfusion after 3,6,12,and 24 hours and 3,5,7,14,and 21 days s eparately. ERG was recorded in both eyes of all rats.Results There was no difference in the results of ERG between left and right eyes in either the control group or the single-irrigated group. All the waves of ERG vanished in the single-ischemia group after 1 hour. In the ischemia-reperfusion groups, the waves of ERG partly recovered and the amplitude reduced persistently and progressively.Conclusion Ischemia-reperfusion injury may affect the function of the retina persistently and progressively. (Chin J Ocul Fundus Dis，2003，19：201-268)
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.
Purpose To investigate the relationship between the changes of the thickness of retina in macula and the abnormalities in multifocal electroretinog rams (mERG) in diabetic retinopathy. Methods mERG and optical coherence tomography (OCT) examination were performed in 38 patients (60 eyes) with DR (phase Ⅲ～Ⅳ). The data were processed with software SPSS and line relation analysis was done. Results The response densities of N1, P1 and N2 in central 5deg; area was significantly negative related to the thickness of neuroretina in macular fovea (correlation efficient -0.252～-0.266，Plt;0.05). The response density of N2 in central 10deg; area was also significantly negative related to the thickness of neuroretina in macular fovea (correlation efficient -0. 332，P=0.01).There was no significant relationship between the latencies of N1 in central 5deg;, 10deg; area and the thickness of macula, whereares the latenc ies of P1 and N2 in central 5deg; were negatively related to the thickness of retinal pigment epithelium in the macular fovea (correlation efficient-0.271～ - 0.322，Plt;0.05). Conclusion The changes of the thickness of neuroretina in macula may affect the local retinal function in macula, which may be revealed by the reduction of response densities in mERG in patients with diabetic retinopathy. (Chin J Ocul Fundus Dis, 2001,17:257-259)
ObjectiveTo observe the features of the full field electroretinogram (FF-ERG) in type 1 diabetes (T1D) children without diabetic retinopathy (DR). MethodsRetrospective case study. Forty-one T1D children and 25 age-matched normal controls underwent a complete ophthalmic examination, including best-corrected visual acuity, refraction, intraocular pressure, slit lamp, fundus photography, indirect ophthalmoscopy, and spectral domain optical coherence tomography to exclude DR. All FF-ERG tests were performed by an experienced technician. The ERG series includes six protocols: dark-adapted 0.01 ERG (r-b 0.01); dark-adapted 3 ERG (mix-a 3.0, mix-b 3.0); dark-adapted 10 ERG (mix-a 10.0, mix-b 10.0); dark-adapted oscillatory potentials (OPS); light-adapted 3 ERG (c-a 3.0, c-b 3.0); light-adapted 30 Hz flicker (30 Hz FP) ERG. To compare the amplitudes and implicit times of the FF-ERG between the T1D and control group children. ResultsCompared with the control subjects, the FF-ERG amplitudes decreased and the implicit times increased in T1D. Except for r-b 0.01 (t=-0.228, P > 0.05), the amplitudes of other FF-ERGs were all significantly attenuated (t=-1.664, -3.645, -4.324, -6.123, -5.846, -12.9, -14.4, -5.23; P < 0.05) in T1D children. The implicit times of mix-b 3.0, mix-b 10.0, c-b 3.0 and OP2 significantly increased (t=5.242, 2.879, 5.378, 3.506; P < 0.05). The implicit times of r-b 0.01, mix-a 3.0, mix-a 10.0, c-a 3.0 and 30Hz FP changes were not significantly (t=2.331, 1.677, 0.557, 0.84, 0.064; P > 0.05). ConclusionThe FF-ERG amplitudes decreased and implicit times increased in T1D children compared with the control normal subjects.
Objective To investigate the early effects of intervention with tanakan on retinal function in diabetic retinopathy(DR) after laser photocoagulation. Methods Prospective random controlled study was performed on 60 Patients (60 eyes) from 23 to 69 years old with DR(phase Ⅲ～Ⅳ). The multifocal electroretinograms (MERG) were tested with VERIS Ⅳ before, the 3rd day and the 7th day after photocoagulation. Results No significant differences were found in the latencies and response densities of N1,P1 and N2 between the two groups before photocoagulation. Compared with that before photocoagulation, three days after photocoagulation the latencies in tanakan group had no significant change. The response densities of N1,P1 and N2 reduced and the changes were much smaller than that in control. Three days after photocoagulation, the response densities of P1 and N2 in the central macula 5°area were much higher and the latencies of P1 and N2 were significantly shorter than that in control group. There were no significant differences in the response densities in the 7th day and the differences in the latencies between two groups still existed. Conclusion Tanakan may be effective in preventing the retina from damage of retinal photocoagulation in some degree in DR. (Chin J Ocul Fundus Dis, 2002, 18: 208-211)
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 changes of visual acuity、multifocal electroretinogram (mfERG) and optical coherence tomogram（OCT）before and after successful idiopathic macular hole (IMH) surgery, and evaluate the efficiency of the IMH surgery. Methods A total of 28 eyes of 28 patients with IMH who underwent vitrectomy during February 2001 and May 2002 in our hospital were collected. visual acuity, mfERG, and OCT were examined preoperatively and 1, 3, 6, and 12 months postoperatively, respectively. The results were analyzed statistically compared with 33 eyes in control group. Results (1) OCT showed that 27 eyes (96.43%) had anatomic closure of the macular hole 1 month after the surgery without recurrence in 12 months. Just 1 eye (3.57%) failed in the closure within 1 year. (2) The visual acuity was much higher in the eyes 1 year after surgery, especially within 6 months postoperatively, than that before the vitrectomy（P＜0.01）. (3) Before the operation, the mfERG topographies of IMH eyes seem like volcanoes becase the response densities of wave P1 of ring 1 and ring 2 were lower than control group while the other three rings kept in normal. The central peaks of mfERG topographies reappeared little by little during 1 year after the surgery, and the response densities of wave P1 of ring 1 and ring 2 were higher than before, which was still lower than the control group（P＜0.05）. (4) The thickness of neuroepithelial layer (NEL) of fovea measured by OCT of 27 eyes with anatomic closure was no longer varied and kept lower than control group throughout the follow-up time （P＜0.05）. (5) One year after the operation, there were positive correlations among visual acuity, mfERG and NEL（P＜0.05）. Conclusions Vitrectomy is useful for IMH, which could be evaluated by visual acuity mfERG and OCT efficiently. The three factors had consistency. (Chin J Ocul Fundus Dis，2004，20：221-225)