目的：观察糖尿病性视网膜病变(DR)患者视网膜内微血管异常(IRMA)及由IRMA来源的视网膜新生血管的临床特征。

方法：本研究为前瞻性、观察性的研究。于2016-10/2017-12期间，经荧光素血管造影(FFA)检查明确有IRMA或者视网膜新生血管的未经治疗的DR患者36例39眼纳入研究。在FFA引导下，对IRMA及视网膜新生血管进行光相干断层扫描血流成像(OCTA)检查。记录并比较IRMA及IRMA来源的新生血管的形态特征、血管来源层次、无灌注区面积、与无灌注区位置关系及病灶在FFA中的渗漏情况。无灌注区面积采用Image J软件进行测量。

结果：OCTA成功扫描到IRMA病灶20个，IRMA来源的新生血管22个。20个IRMA病灶均来源并回流于视网膜静脉，血管分支较少，表现为“经修剪过的树干”样外观； IRMA均从无灌注区的边缘长出，位于视网膜静脉的无灌注区一侧，并且在无灌注区内生长； IRMA均位于视网膜内，没有突破内界膜向玻璃体腔内生长。22个IRMA来源的新生血管病灶，血管分支较多，表现为“海扇”样外观； IRMA来源的新生血管往往横跨视网膜静脉，向视网膜静脉的两侧生长、延伸； 其主要部分在视网膜内，有个别分支突破内界膜沿着玻璃体后皮质生长，与视网膜紧密黏连。IRMA来源的新生血管20个(91%)位于无灌注区当中，2个(9%)位于无灌注区的边缘。IRMA来源的新生血管病灶旁的无灌注区面积为26.1±4.2mm² ，大于IRMA旁的无灌注区面积12.9±4.7mm²(P <0.05)。IRMA及其来源的新生血管的来源层次无差异(P>0.05)。

结论：OCTA是IRMA及增殖期糖尿病性视网膜病变(PDR)新生血管的有效检查手段。IRMA及IRMA来源的新生血管具有明显不同的临床特征，OCTA能够有效地对两者进行鉴别，从而为DR患者的诊断及随访治疗提供重要的临床依据。

METHODS:This was a prospective, observational study. We recruited treatment-naive patients with diabetic retinopathy(DR)with IRMAs or retinal neovascularization, confirmed using fundus fluorescein angiography(FFA)between October 7, 2016 and December 10, 2017. Under the guidance of FFA, IRMAs and neovascularizations were scanned using optical coherence tomography angiography(OCTA). Origins, initial layers, morphologic features, retinal nonperfusion areas(NPAs), location with capillary nonperfusion(CNP)and leakages demonstrated by FFA of IRMAs and associated neovascularization were documented and compared. Retinal nonperfusion areas were measured using Image J software.

RESULTS: Thirty-nine eyes of 36 patients were enrolled in this prospective study. High quality images of twenty IRMAs and 22 IRMA-associated neovascularizations were identified using OCTA. All IRMAs originated from and drained into veins in pruned-tree-like shapes. IRMAs originated from the major retinal vessels at the margin of the CNP, extended into retina and were always confined within a single original nonperfused area. All IRMA-associated neovascularizations originated from IRMAs with a sea-fan-like appearance. The IRMA associated neovascularizations crossed retinal venous and extended to both sides. The main part of these structures was intraretinal, except some advancing tips that breached the internal limiting membrane(ILM)to form neovascularization, and were adhered firmly to the retina; 91%(20/22)of IRMA-associated neovascularizations were located in the CNPs, and 9%(2/22)were located at the margin of CNPs. The affiliated NPAs of IRMA-associated neovascularizations were 26.1mm²±4.2mm², significantly larger than the IRMAs(12.9mm²±4.7mm², P<0.05). The initial layers showed no statistic difference between the groups(P>0.05).

CONCLUSION: OCTA is an effective method for detecting both IRMA and neovascularization in DR. IRMA and associated neovascularization had significantly different clinical characteristics that can be differentiated by OCTA, and therefore may be useful to better understand pathophysiological mechanisms and to guide efficient therapeutic strategies for DR patients.