增殖性糖尿病视网膜病变虹膜新生血管的多模态临床研究

Multimodal characteristics of iris neovascularization in patients with proliferative diabetic retinopathy

目的探讨增殖性糖尿病视网膜病变(PDR)伴虹膜新生血管患者行虹膜血管造影图像的特征。方法选取2017年9月至2018年12月就诊于首都医科大学附属北京同仁医院眼科中心及首都医科大学教学医院石景山医院眼科确诊为增殖性糖尿病视网膜病变患者32例(64只眼)的临床资料进行研究。检查并记录患者的年龄、糖尿病病程、眼压及视力,并同时对全部患者行荧光素虹膜血管造影(IFA)和吲哚菁绿虹膜血管造影(IICGA)检查,由两名临床经验丰富的医师判读检查结果是否存在虹膜新生血管(NVI);记录其血管形态和分布范围,并总结两种虹膜血管造影图像的特点。通过活动轮廓模型(snake算法)对虹膜区域的造影图像进行提取,并利用大津阈值算法(Otsu算法)对提取后的虹膜造影区域进行分割,计算NVI所占总虹膜面积的比例。年龄、糖尿病病程、眼压、视力及虹膜新生血管面积的比例,以均数±标准差进行描述。虹膜新生血管面积的占比与糖尿病病程、眼压及视力的相关性,采用Spearman法进行相关分析。结果NVI在IFA检查中表现为渗漏的血管丛,在虹膜色素较深或血管渗漏严重时,表现为背景高荧光,无法显示血管形态。在IICGA检查中可以很好地显示NVI的形态及细节,基本不会出现造影剂渗漏的现象。两种NVI造影检出率与临床医师判读的符合率为100%。在IFA及IICGA中确诊为NVI的22例(38只眼)患者中,虹膜有粘连者6例(10只眼),占26.3%;虹膜形态不规则者7例(12只眼),占31.6%;新生血管多出现在瞳孔缘附近9例(17只眼),占45%。在IICGA中显示有NVI虹膜的的22例(38只眼)患者中,NVI显示在瞳孔缘者10例(17只眼);其范围为1个象限者4例(5只眼),2个象限者2例(2只眼),3个象限者1例(1只眼),4个象限者8例(13只眼)。NVI患者的NVI面积占比与眼压呈正相关,检验结果具有统计学意义(r=0.567,P<0.05);NVI面积占比与糖尿病病程的相关性检验结果无统计学意义(r=-0.167,P>0.05);与视力的相关性检验结果亦无统计学意义(r=0.115,P>0.05)。结论在本研究病例中,IICGA及IFA检查均可发现PDR合并NVI患者的NVI,两种检查结果的诊断一致。其中,IICGA检查可以清晰地显示NVI的形态细节、分布范围,且能对其面积进行定量分析,故对于NVI的早期诊断更有优势。此外,本研究结果还提示患者NVIR面积的占比与眼压呈正相关。

Objective To investigate the characteristics of iris angiography in patients with proliferative diabetic retinopathy(PDR)and iris neovascularization.Methods 32 patients(64 eyes)diagnosed as PDR in the Ophthalmology Center of Beijing Tongren Hospital and Beijing Shijingshan Hospital,affiliated to Capital Medical University from September 2017 to December 2018 were collected.The age,course of diabetes,intraocular pressure and visual acuity of patients were examined and recorded.All patients were underwent both iris fluorescein angiography(IFA)and indocyanine green angiography(IICGA).Two experienced ophthalmologists analyszed the imaging of IFA and IICGA for iris neovascularization(NVI),recorded the vascular morphology and distribution of NVI,and summarized the characteristics of two kinds of iris angiography images.The iris region was extracted by the Snake algorithm,then angiography region was segmented by Otsu algorithm,and the proportion of NVI in the total iris area was calculated.The age,course of diabetes,intraocular pressure,visual acuity and the proportion of NVI area were described by mean±standard deviation.Spearman correlation analysis was used to analyze the correlation between NVI area,diabetes duration,intraocular pressure and visual acuity.Results In IFA images,NVI manifested as leaking vascular plexus.The morphology of NVI in IFA for some severe cases was invisible because of rapid leak fluorescence and deep iris pigmentation.While for IICGA images,these were not found.The detection rate of two kinds of NVI angiography was about 100%in accordance with the clinician’s interpretation.Among of 22 patients(38 eyes)diagnosed with NVI by IFA and IICGA,6 cases(10 eyes)had iris synechia,accounting for 26.3%;7 cases(12 eyes)had irregular iris morphology,accounting for 31.6%and 9 cases(17 eyes)had neovascularization near the pupil margin,accounting for 45%.IICGA showed the distribution of NVI in 22 patients(38 eyes):10 cases(17 eyes)with pupil margin involvement,4 cases(5 eyes)with 1 quadrant,2 cases(2 eyes)with 2 quadrants,1 case(1 eye)with 3 quadrants and 8 cases(13 eyes)with 4 quadrants.The proportion of NVI area in NVI patients was positively correlated with intraocular pressure,and there was statistically significant differences between them(r=0.567,P<0.05),but non-significant difference with the course of diabetes mellitus(r=-0.167,P>0.05)and visual acuity(r=0.115,P>0.05).Conclusions NVI could be found in both IICGA and IFA in patients with PDR,and there was non-significant difference between two angiographic methods in detecting NVI.IICGA could clearly show the morphology and distribution of NVI,which has more advantages in the early diagnosis of NVI,and is suggested to be used for quantitative analysis for neovascularization.In addition,proportion of NVI area was positively correlated with intraocular pressure significantly.