By using the different light stimuli, the flash ERG of 32 cases of central retinal vein occlusion(CRVO) (13 of ischemic type,19 of non-ischemic type) during acute phase were examined. The results showed that the a-wave and b-wave latency of CRVO elongated,while the b-wave amplitude of ischemie type decreased and that of non-ischemic type varied in different stimulus: decreased,increased or normal.Therefore,b-wave amplitude and b/a ratio,and selection of suitable ERG condition of stimulus are thought to be important in differetiating ischemic from non-ischemic CRVO. (Chin J Ocul Fundus Dis,1994,10:7-10）
ObjectiveTo use flash electroretinogram (F-ERG) and optical coherence tomography (OCT) to examine patients with primary retinitis pigmentosa (RP), and analyze the specificity of the disease on F-ERG and OCT. MethodsThirty-seven patients (74 eyes) diagnosed with primary retinitis pigmentosa in the Department of Ophthalmology, West China Hospital between September 2013 to October 2014 and 38 normal volunteers (76 eyes) were included in this study. F-ERG and OCT examinations were performed on all the patients. Then, we analyzed the differences between the two groups of subjects. ResultsFor RP patients undergoing P-ERG examination with the dark adaptation of 0.01 ERG, the latency of b wave was (73.24±6.42) ms and the amplitude of b wave was (22.87±22.48) μV; when dark adaptation of 3.0 ERG was adopted, the latency of a wave was (24.57±6.30) ms, the amplitude of a wave was (35.45±25.54) μV, the latency of b wave was (48.19±8.18) ms, and the amplitude of b wave was (119.47±50.89) μV; with the light adaptation of 3.0 ERG, the latency of a wave was (21.01±4.86) ms, the amplitude of a wave was (12.59±13.43) μV, the latency of b wave was (38.43±5.00) ms, and the amplitude of b wave was (27.19±38.12) μV. For normal volunteers undergoing F-ERG examination with the dark adaptation of 0.01 ERG, the latency of b wave was (72.63±3.49) ms and the amplitude of b wave was (86.36±21.57) μV; when the dark adaptation was 3.0 ERG, the latency of a wave was (22.88±1.62) ms, the amplitude of a wave was (210.74±43.57) μV, the latency of b wave was (42.59±2.60) ms, and the amplitude of b wave was (398.29±62.42) μV; when the light adaptation of 3.0 ERG was adopted, the latency of a wave was (16.61±0.87) ms, the amplitude of a wave was (54.26±19.64) μV, the latency of b wave was (33.29±1.11) ms, and the amplitude of b wave was (176.98±63.44) μV. There were no significant differences between the two groups when dark adaptation ERG was 0.01 (P=0.48), but for other adaptations, there were significant differences in the latency and amplitude of a and b wave between the two groups (P<0.05). The results of OCT showed that the retinal thickness of the RP patients with a range of 1 mm diameter centered on macular center concave was (218.66±74.14) mm, 3 mm diameter was (275.03±47.85) mm, and 6 mm diameter was (247.37±46.44) mm. For normal volunteers, OCT showed that the retinal thickness with a 1 mm range centered on macular center concave was (250.38±15.79) mm, 3 mm was (323.64±17.26) mm, and 6 mm was (283.44±12.50) mm. The differences between the two groups were statistically significant for each range (P<0.01). ConclusionFor patients with RP, F-ERG shows latency delay and amplitude decrease for each response, while OCT displays a thinning thickness of macular fovea. Therefore, F-ERG and OCT can not only effectively evaluate the functions of macular and the surrounding retina, but can also be used as an effective method for the diagnosis of RP.