OCTA评估高度近视合并原发性开角型青光眼血管密度与视野缺损的相关性

目的：评估高度近视（HM）合并原发性开角型青光眼（POAG）血管密度及视盘形态学特点，分析血 管密度与视野缺损的相关性。方法：横断面研究。连续选取2019年3─12月就诊于长沙爱尔眼科 医院的HM合并POAG患者24例（44眼），按视野平均偏差（MD）值将其分为早期POAG组（13例， 20眼）和中晚期POAG组（15例，24眼），同时选取单纯HM 37例（50眼）作为对照组。所有患者均使用 光学相干断层扫描血管成像（OCTA）测量视盘和黄斑血管密度及结构参数，眼底照相计算视盘椭圆 度并行视野检查。单因素方差分析比较各组间血管密度、结构及视野参数的差异性，采用Pearson 或Spearman相关分析各指标与MD及视盘椭圆度的相关性。结果：与对照组相比，HM合并POAG 视盘旁毛细血管密度、中心凹深层血管密度及旁中心凹浅层血管密度降低（F=86.340、18.620、 42.757，均P<0.001），并随病程的进展而加重。早期POAG组与对照组视盘椭圆度差异无统计学意 义（P=0.077），中晚期POAG组视盘椭圆度小于对照组和早期POAG组，差异有统计学意义（P<0.001， P=0.028）。与MD相关性最高的参数是平均视网膜神经纤维层（RNFL）厚度（r=0.782，P<0.001）， 其次是平均神经节细胞层（GCC）厚度（r=0.621，P<0.001）、旁中心凹浅层毛细血管密度（r=0.621， P<0.001）、视盘旁毛细血管密度（r=0.599，P<0.001）、中心凹深层毛细血管密度（r=0.420，P=0.002）。 视盘椭圆度与视盘旁毛细血管密度（r=0.318，P=0.002）、视盘面积（r=0.405，P<0.001）、平均RNFL 厚度（r=0.476，P<0.001）、平均GCC厚度（r=0.375，P<0.001）呈正相关。结论：HM合并POAG血管 密度的降低与视野缺损的相关性低于平均RNFL及GCC厚度，视盘椭圆度与血管密度的降低及结构 损伤存在相关性。OCTA可用于HM合并POAG的早期诊断。

Evaluation of the Correlation between Vessel Density and Visual Field Loss in High Myopic Patients with Primary Open-Angle Glaucoma Using OCTA

Objective: To evaluate the vessel density and optic disc morphological characteristics in high myopic (HM) patients with primary open-angle glaucoma (POAG), and to investigate the association between vessel density and visual field loss. Methods: This was a cross-sectional study. A total of 24 HM patients (44 eyes) with POAG and 37 HM patients (50 eyes) without POAG (control group) were enrolled in this study. The glaucoma patients were additionally classified into a mild POAG group (13 patients, 20 eyes) and moderate and severe POAG group (15 patients, 24 eyes) according to the visual field mean deviation (MD). All patients underwent imaging using optical coherence tomography angiography (OCTA) to measure vessel density and structural parameters of the optic disc and macula, fudus photography to calculate the optic disc ovality index, and standard automated perimetry. The differences in vessel density, structural parameters and visual field variables between the groups were compared by one-way analysis and the correlation between MD and the optic disc ovality index was performed by Pearson correlation or Spearman correlation analysis. Results: Compared with the control group, the HM patients with POAG showed reduced peripapillary capillary density, deep foveal vessel density and superficial parafoveal vessel density (F=86.340, 18.620, 42.757, all P<0.001), which aggravated the progression of glaucoma. There was no significant difference in the optic disc ovality index between the mild POAG group and control group (P=0.077), while the moderate and severe POAG group showed a decreased optic disc ovality compared to the control group and mild POAG group, and the difference was significant (P<0.001, P=0.028 respectively). The parameter with the highest correlation coefficient to visual field MD was average retinal nerve fiber layer (RNFL) thickness (r=0.782, P<0.001), followed by average ganglion cell complex (GCC) thickness (r=0.621, P<0.001), superficial parafoveal vessel density (r=0.621, P<0.001), peripapillary capillary density (r=0.599, P<0.001) and deep parafoveal vessel density (r=0.420, P=0.002). The disc ovality index was positively associated with the peripapillary capillary density (r=0.318, P=0.002), disc area (r=0.405, P<0.001), average RNFL thickness (r=0.476, P<0.001) and average GCC thickness (r=0.375, P<0.001). Conclusions: In contrast to average RNFL thickness and GCC thickness, decreased vessel density in HM patients with POAG is associated less with visual field loss. The disc ovality index is correlated with a decrease in vessel density and structural damage. The OCTA can be used for early diagnosis of HM with POAG.