Study Of Correlations Of The Vitreous Level Of VEGF In Patients With Diabetic Macular Edema With Central Macular Thickness And Retinal Non-perfusion Area

Objective: To investigate the correlations of the vitreous level of vascular endothelial growth factor in patients with diabetic macular edema(DME)with central macular thickness and retinal non-perfusion area.Method:1 DME group:patients in the Department of Ophthalmology of the Second Hospital of Hebei Medical University were selected from January2016 to December 2016,referring to the Chinese Clinical Guidelines of Diabetic Retinopathy(2014).Eighteen patients were diagnosed with diabetic macular edema.Eleven patients were treated with standard vitrectomy,while the other seven with intravitreal injection.Specimens of anterior vitreous were extracted for 0.10 – 0.2 ml preoperatively.Vitreous levels of VEGF were tested with enzyme-linked immunosorbent assay(ELISA).The technology of spectral-domain optical coherence tomography(SD-OCT)was utilized to measure the values of central macular thickness(CMT).Retinal non-perfusion areas were traced in fundus fluorescence angiography(FFA),and the disc area(DA)were measured as well.The ratio of NPA/DA was calculated and recorded.2 Control group:patients in the Department of Ophthalmology of the Second Hospital of Hebei Medical University from January 2016 to December2016 were collected,referring to the Gass Staging System.3 eyes in 3 patients were diagnosed with idiopathic macular holes(IMH),which were treated with vitrectomy.Specimens of anterior vitreous were extracted for 0.10 – 0.2 ml preoperatively as well.Vitreous levels of VEGF were tested with ELISA.The technology of SD-OCT was utilized to measure the values of CMT.Non-perfusion areas in each region were traced in FFA,and DA weremeasured as well.The ratio of NPA/DA was calculated and recorded.Relationships between the levels of VEGF in vitreous specimens and CMT and NPA/DA were studied,respectively.Parametric test would be selected for data with normality distribution,while nonparametric methods would be chosen for data without.Results:1 The vitreous level of VEGF in patients of DME group was342.4479±209.0934 ng / L,the vitreous level of VEGF in patients of the control group were 24.9163±6.0916ng/L.Statistically significant difference was detected in the vitreous levels of VEGF between DME group and the control group(P<0.05).2 The level of CMT of DME group was 526.333±151.0578μm,while the level of CMT of the control group were 225±26.5141μm.The difference of the level of CMT between DME group and the control group was found statistically significant(P<0.05).With linear correlation analysis,the vitreous level of VEGF was correlated with the level of CMT(r=0.499,P<0.05).3 The level of NPA/DA of DME group was 6.1667±3.8692,all of the levels of NPA/DA of the control group were 0.The difference of the level of NPA/DA between DME group and the control group was statistically significant(P<0.05).With linear correlation analysis,the vitreous level of VEGF was not significantly correlated with the level of NPA/DA(r=-0.221,P>0.05).Conclusion:1 Compared to the control group,the vitreous level of VEGF,CMT and NPA/DA were higher in DME group.Positive corelationship with the vitreous level of VEGF and CMT in patients of DME group.2 Higher level of VEGF in vitrous of patients with DME will be noted in more severe cases.