Correlation Analysis Among Macular Ischemia Caused By Branch Retinal Vein Occlusion, Retinal Thickness And Multifocal Electroretinogram

Purpose: To investigate the influence of macular ischemia caused by branch retinalvein occlusion (BRVO) on therapeutic effect, retinal thickness and the parameters ofmultifocal electroretinogram (mf-ERG).Method: Data from36eyes of36cases with branch retinal vein occlusion inAffiliated Hospital of Zunyi Medical University from February to December2013wasretrospectively analysed. These patients were divided into2groups according to the resultsof fluorescein fundus angiography (FFA) and multifocal electroretinogram, namely,group A (19eyes), non-perfusion area involved in approximately0-0.5mm away frommacular fovea, group B (17eyes), the area of0.6-1.3mm away from macular fovea wasinvolved in.18eyes from same patients were selected as control to compare mf-ERGresults. The best corrected visual acuity (BCVA), retinal thickness of the macular area andparameters of mf-ERG were to evaluate therapeutic effect of group A and group B atpost-therapy1month and3month (intravitreal triamcinolone acetonide injection+Argonlaser photocoagulation). The correlation among macular ischemia, retinal thickness andparameters of mf-ERG were analysed.Result:(1) Compare with pretherapy, the best corrected visual acuity atpost-therapy1month and3month was improved in two groups, the difference wasstatistically significant (group A: t=3.572,3.351, P=0.002,0.002; group B: t=-5.407、7.179,P＜0.001), compare with post-therapy1month, there was no statistical significance atpost-therapy3month (t=-0.302,0.764, P=0.767,0.460). The best corrected visual acuity oftwo group was no statistical significance at post-therapy1month and3month (t=1.035,1.257，P=0.426,0.401).(2)Compare with pretherapy, the retinal thickness in1mm,3mm,6mm decreased atpost-therapy1month and3month, the difference was statistical significance (P＜0.05),there is no statistical significance in group1month and group3month (P＞0.05).Comparison between groups: There is no evident difference between group A and group Bin terms of The retinal thickness at1mm,3mm and6mm was no evident difference ingroup A and B at post-tharapy1month and3month (P＞0.05), while at post-therapy, the retinal thickness at1mm in group A was thicker than that in group B (t=6.246,P=0.025).(3)The average amplitude density of P1wave in circle1at post-therapy1month washigher than at pretherapy (t=6.246、3.963，P=0.025、0.002), but there is no evidentdifference in circle2and circle3in group A and B (P＞0.05). There is also no evidentdifference at post-therapy1month and3month the paramerters of multifocalelectroretinogram each circle in group A (P＞0.05), but the incubation period for P1waveof circle1at post-therapy3month was shorter than post-therapy1month in groupB(t=5.36,P=0.000). There were no statistical difference each parameters of multifocalelectroretinogram at pre therapy and post-therapy in group A and B (P＞0.05), but theincubation period for P1wave in circle1at post-therapy3month in goup B was shorterthan in group A (t=4.521,P=0.033).(4)The best corrected visual acuity was negative correlation with the retinalthickness at1mm (r=-0.508, p=0.023) and the incubation period of P1wave in circle1(r=-0.552，p=0.014). The retinal thickness at1mm was also negative correlation withamplitude density of P1wave at circle1of multifocal electroretinogram (r=-0.460,p=0.048).(5)the results by multiple stepwise regression method showed that the amplitudedensity of P1wave at circle1had come into a regression equation at post-therapy3month.The regression coefficient was-0.0032, and the regression equation was Y=1.668-0.0032X (Y was the vision, X was the amplitude density of P1wave in circle1at post-therapy3month).Conclusion:(1) It is safe and effective to use intravitreal triamcinolone acetonideinjection plus multi-wavelength laser photocoagulation to treat BRVO.(2) The range of capillary nonperfusion in macular area is correlation with retinalthickness and incubation period of P1wave in circle1.(3) The visual acuity is negative correlation with retinal thickness at1mm away frommacular fovea and the incubation period of P1wave in circle1of multifocalelectroretinogram, and is also negative correlation with amplitude density of P1wave incircle1of multifocal electroretinogram.