摘要目的:观察高度近视脉络膜新生血管（mCNV）患眼光相干断层扫描血管成像（OCTA）影像特征及黄斑区脉络膜毛细血管密度（CCD）变化。方法:病例对照研究。2018年1月至2020年10月于首都医科大学附属北京同仁医院眼科检查确诊的mCNV患者50例50只眼（mCNV组）纳入研究。其中，男性18例，女性32例；年龄（42.11±11.66）岁。选取近视屈光度（≥6.00 D）与mCNV组匹配的眼底正常者50例50只眼作为单纯高度近视组，正常志愿者（屈光度-0.25~0.25 D）50名50只眼作为正常对照组。三组患者间年龄（ F=0.028 ）、性别构成比（ χ2=0.136）比较，差异均无统计学意义（ P>0.05）；最佳矫正视力比较，差异有统计学意义（ F=14.762， P=0.004）。mCNV组、单纯高度近视组受检眼屈光度（ t=-0.273 ）、眼轴长度（ t=0.312）比较，差异无统计意义（ P>0.05 ）。采用OCTA仪测量受检眼CCD。三组间计量资料比较采用方差分析；分类变量比较行 χ2检验。mCNV患者患眼与对侧眼CCD比较行配对 t检验。 结果:mCNV组50只眼中，Ⅰ型、Ⅱ型、混合型脉络膜新生血管（CNV）分别为12 （24%，12/50）、34 （68%，34/50）、4 （8%，4/50）只眼。病灶处对应OCTA横断面像可见边界清晰的"花团"样强血流信号。其中，焦点状、丝条状、团网状分别为6 （12%，6/50）、8 （11%，8/50）、36 （72%，36/50）只眼。mCNV组、单纯高度近视组、正常对照组受检眼CCD分别为（57.39±3.24）%、（59.33±2.23）%、（61.87±1.62）%。mCNV组患眼CCD显著低于单纯高度近视组（ P=0.030 ）、正常对照组（ P<0.001）。mCNV组患眼、对侧眼CCD分别为（57.39± 3.24）%、（59.82±3.94）%；患眼、对侧眼CCD比较，差异无统计学意义（ t=-0.496， P=0.100）。Ⅰ型、Ⅱ型、混合型CNV患眼CCD分别为（57.38±3.31）%、（57.39±2.83）%、（57.36±4.21）%。不同CNV分型者CCD （ F=1.476）、年龄（ F=0.274 ）、性别构成比（ χ2=0.825）、屈光度（ F=0.348）比较，差异均无统计学意义（ P>0.05 ）。 结论:mCNV多为Ⅱ型，OCTA表现为异常网状血管的"花团"样外观；CCD显著降低，且呈双侧性。

abstractsObjective:To observe the imaging characteristics of optical coherence tomography angiography (OCTA) and the changes of choroidal capillary density (CCD) in the eyes of patients with high myopia choroidal neovascularization (mCNV).Methods:A case-control study. From January 2018 to October 2020, 50 cases of mCNV patients with 50 eyes (mCNV group) were included in the study. There were 18 males and 32 females; their age was 42.11±11.66 years old. Fifty eyes of 50 patients with normal fundus with matching myopia refractive power (≥6.00 D) were selected as the simple high myopia group, and 50 normal volunteers (refractive power -0.25-0.25 D) while 50 eyes were selected as the normal control group. There was no statistically significant difference in age ( F=0.028) and gender composition ratio ( χ2=0.136) among the three groups of patients ( P>0.05); the difference in best corrected visual acuity was statistically significant ( F=14.762, P=0.004). Compared with mCNV group and pure high myopia group, the refractive index ( t=-0.273) and axial length ( t=0.312) of the examined eyes were not statistically significant ( P>0.05). OCTA instrument was used to measure the CCD in the macular area of the examined eye. Analysis of variance was used for comparison of measurement data among the three groups; χ2 test was used for comparison of categorical variables. The paired t test was performed to compare the CCD of the mCNV patient's eye and the contralateral eye. Results:Among the 50 eyes in the mCNV group, Ⅰ , Ⅱ, and mixed choroidal neovascularization (CNV) were 12 (24%, 12/50), 34 (68%, 34/50), and 4 (8%, 4/50) eyes, respectively. Corresponding to the OCTA cross-sectional image of the lesion, there was a clear "flower cluster" -like strong blood flow signal. Among them, the focal shape, the filament shape, and the group net shape were 6 (12%, 6/50), 8 (11%, 8/50), and 36 (72%, 36/50) eyes, respectively. The CCD of the eyes in the mCNV group, the pure high myopia group, and the normal control group were (57.39±3.24)%, (59.33±2.23)%, and (61.87±1.62)%, respectively. The CCD of the eyes in the mCNV group was significantly lower than that of the simple high myopia group ( P=0.030) and the normal control group ( P<0.001). The CCD of the affected eye and the contralateral eye in the mCNV group were (57.39±3.24)% and (59.82±3.94)%, respectively; there was no statistically significant difference between the CCD of the affected eye and the contralateral eye ( t=-0.496, P=0.100). The CCDs of eyes with Ⅰ, Ⅱ and mixed CNV were (57.38±3.31)%, (57.39±2.83)%, and (57.36±4.21)%, respectively. There were no statistically significant differences in CCD ( F=1.476), age ( F=0.274), sex ratio ( χ2=0.825), and diopter ( F=0.348) in different CNV types ( P>0.05). Conclusion:The mCNV is mostly type Ⅱ, and OCTA has a "bloom" appearance of abnormal reticular blood vessels; the CCD is significantly reduced, and it is bilateral.