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 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)
OBJECTIVE:To investigate the value of psychophysical testing for the macular function in the diegnosis of diabetic retinopathy(DR). METHODS:To compare the testing results of macular light sensitivity and pattern visual evoked potential(P-VEP)of 30 eyes of 15 normal person with those of 82 eyes of 41 diabetic patients(27 eyes without DR,55 eyes with simple type DR ). RESULTS:The macular light sensitivity of diabetic patients is much lower than that of normal Control group(plt;0.05). In the diabetic group, 62.19% is abnormal in macular light sensitivity, 69.51% in P-VEP. CONCLUSION: Testing of macular light sensitivit y is helpful in finding of diabetic retinopathy and early deterioration of macular visual function in diabetics. （Chin J Ocul Fundus Dis,1996,12: 223-224）
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)
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 assess the effects of 670nm LED (lightemitting diode) to protect the photoreceptor from the lightinduced damage in a rat model. Methods 32 SD rats were randomly assigned to one of eight groups: untreated control group, the LEDtreated control group, three groups of lightinduced damage，and three groups of lightinduced damage treated with LED. Lightinduced damage result from exposing to constant light for 3 hours of different illuminations of 900，1800 and 2700 lx, respectively. The LED treatment (50 mW) was delivered for 30 minutes at 3 hours before the light damage and 0，24 and 48 hours after the light damage. Retinal function and morphology were measured by electroretinogram (ERG) and histopathology assay. Results The illumination of 900 lx for 3 hours did not damage the rat retina. The illumination of 1800 lx for 3 hours resulted in thinner ONL and no OS and IS. The ratio of damaged area/total retinal area was 048plusmn;012， the damaged thickness of ONL/normal ONL (L5 ) was 039plusmn;007，and the amplitude of ERG b wave was (431plusmn;120) mu;V. With the LED treatment the ratio of damaged area decreased (M6=017plusmn;0.12, P5/6=0.002), and the ratio of the damaged thickness of ONL also decreased (L6=0.22plusmn;0.09, P5/6lt;0.01), and the amplitude of ERG b wave increased to (1011plusmn;83) mu;V（P5/6lt;0.001）. The illumination of 2700 lx for 3 hours caused severed damage to the rat retina and the LED could not protect them significantly. Conclusions 670 nm LED treatment has an evident protective effect on retinal cells against light-induced damage, which may be a simple and effective therapy to prevent or to delay agerelated macular degeneration.
ObjectiveTo observe the full-field ERG (ff-ERG) characteristics of patients with acute regional occult outer retinopathy (AZOOR).MethodsA retrospective observational study. From June 2017 to June 2019, 62 eyes of 42 patients (AZOOR group) who were diagnosed with AZOOR in the Department of Ophthalmology of West China Hospital of Sichuan University were included in the study. All patients had no obvious localized disease on the fundus. Among 62 eyes, BCVA of 16 eyes were＜0.1, BCVA of 27 eyes were ≤0.5, and BCVA of 19 eyes were＞0.5. From June 2018 to January 2019, 40 normal volunteers (80 eyes) who attended the outpatient clinic of West China Hospital of Sichuan University and passed detailed ophthalmological examination to exclude all eye diseases including refractive errors were selected as the normal control group. All the examined eyes were tested with ff-ERG using the German Roland visual electrophysiological inspection system. The peak times and amplitudes of the waveforms induced by each response of dark adaptation 0.01 ERG, dark adaptation 3.0 ERG, dark adaptation 3.0 ERG, light adaptation 3.0 ERG, and light adaptation 30 Hz flicker ERG were recorded, respectively. The peak time and amplitude of each ff-ERG response between the two groups were compared by independent sample t test. The peak time and amplitude of each ff-ERG response between different BCVA eyes in the AZOOR group were compared by variance test.ResultsCompared with the normal control group, 0.01 ERG b wave of the dark adaptation of AZOOR group (t=3.601, －6.120), 3.0 ERG a wave and b wave of dark adaptation (t=2.627, －4.263, 3.719, －5.866), 3.0 Oscillation potential P2 wave of dark adaptation (t=－6.625), 3.0 ERG a wave and b wave of bright adaptation (t=3.762, －3.612, 3.648, －3.739) and 30 Hz flicker ERG P wave of bright adaptation (t=－3.832), all peak time of those were significantly delayed, the amplitude decreased, and the difference was statistically significant (P＜0.05). Comparison of different BCVA eyes in the AZOOR group showed that 0.01 ERG b wave amplitude of dark adaptation (F=3.950), 3.0 ERG a peak and b wave amplitude of dark adaptation (F=4.408, 4.876), oscillation potential P2 wave amplitude of dark adaptation (F=4.295), 3.0 ERG b wave amplitude of bright adaptation (F=4.344) and 30 Hz flicker ERG P wave amplitude of bright adaptation (F=4.483) of differences were statistically significant (P＜0.05). There was no statistically significant difference in waveform peak time and amplitude of the other reactions (P＞0.05). Pairwise comparison results showed that, compared with those with 0.1≤BCVA≤0.5 and BCVA＞0.5, those with BCVA＜0.1 dark adaptation to 0.01 ERG b wave, dark adaptation 3.0 ERG b wave, dark adaptation oscillation potential P2 wave, and light adaptation 3.0 ERG b wave and light adaptation 30 Hz scintillation ERG P wave amplitude were significantly reduced, and dark adaptation to 3.0 ERG a peak was significantly delayed, the difference was statistically significant (P＜0.05).ConclusionsThe ff-ERG of patients with AZOOR show delayed peak time and decreased amplitude of each response. The worse BCVA are accompanied by the more obvious decrease of each response amplitude of ff-ERG.
ObjectiveTo evaluate Micron Ⅳ retinal imaging system in three mouse models of retinal diseases. MethodsMouse models of oxygen induced retinopathy (OIR) model (OIR group), N-methyl-N nitrosourea (MNU) model (MNU group) and N-methyl-D-aspartate (NMDA) model (NMDA group) were induced in 24 healthy male C57BL/6J mice. Fundus photograph, fundus fluorescein angiography (FFA) and optical coherence tomography (OCT) and electroretinogram (ERG) were used to evaluate these mice. All the imaging examinations were performed by Micron Ⅳ retinal imaging system. ResultsOIR mice showed tortuous and dilated retinal vessels in fundus photograph, neovascularization plexus and vascular leakage in FFA, and epiretinal fibrovascular tissue and tortuous expansion vascular vessels in OCT. MNU mice showed wax yellow optic disk without retinal pigmentary changes, slight thinning of retinal blood vessels in FFA, and normal structure and thickness in OCT. The a-wave amplitudes of the maximum mixed response decreased significantly, and were (15.38±4.36) μV and (13.78±5.52) μV at 2 or 3 days of modeling, respectively. NMDA mice showed a pale retina with vasospasm. ERG revealed that there was no obvious change in latency of a- and b-wave, but significantly decreased amplitude of b-wave at 12 hours and 24 hours after modeling with (72.28±7.18) μV and (65.35±9.18) μV, respectively. ConclusionMicron Ⅳ retinal imaging system is a real-time, non-invasive tool to study the retinal structure and function in animal models of retinal diseases.
Objectives To observe the clinical characteristics of Leber congenital amaurosis (LCA) and analyze the features to differentiate LCA from other similar disorders.Methods Prospective study of 15 LCA patients which include 10 males and 5 females, aged from 2 to 31 years with the mean age 13.6 years. Medical history, family history, perinatal conditions, as well as complete ocular evaluations were well documented. Among the subjects, 12 patients underwent optometry check, 10 patients underwent ERG and 8 patients had OCT testing. Results All of the patients had nystagmus and sluggish pupillary reflex. The visual acuity distributed from light perception to 0.1. Fivepatients (33.3%) were presented with photophobia, while 7 patients (46.7%) had nyctalopia. Among 12 cases underwent refraction examination, 6 patients (50%) had spherical equivalent of ge;+5D；1 patient（8.3%）had spherical equivalent of ge;+5D; 2 patients (16.7%) had bilateral mild to moderate hyperopia；1 patient (8.3%) had one emmertropic eye and one mild myopic eye; 2 patients (16.7%) had moderate to high myopia. Eight patients (53.3%) had enophthalmus,4 patients (26.7%) had oculodigital sign. All of the 10 patients underwent ERG showed extinguished waveform. Under OCT assesement, 7 patients had decreased fovea thickness; 1 patient had increased fovea thickness, complicated by epiretinal membrane; mild abnormality of microstructure of the retina with diminished and disrupted IS/OS hyperreflectivity were found in 2 cases；while more pronounced disarrangement of the retinal layers were found in 6 cases，inner layers were better reserved in all patients.Conclusions Severe visual impairment or blindness, nystagmus, pupillary reflex, extinguished ERG and hyperopia are main clinical characteristics of LCA.
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)