方法：横断面研究。35例35眼高度近视伴PICC患眼，40例40眼高度近视不伴PIC患眼及35例35眼正常对照眼纳入研究范围。所有受试者均接受眼底照相及频域光学相干断层扫描(spectral-domain optical coherence tomography，SD-OCT)。同时进行OCT血管成像检查，分别获得视盘周围视乳头(optic nerve head，ONH)层和视盘旁视网膜毛细血管(radial peripapillary capillaries，RPC)层的血流密度图。比较高度近视伴与不伴PICC患眼及健眼视盘形态改变和血流密度的差异，分析PICC与视盘周围血流密度的相关性和PICC患病的独立危险因素。

结果：三组间屈光度、矫正视力、眼轴、视盘周围萎缩β区(peripapillary atrophy β-zone，β-PPA)面积、神经纤维层(retinal nerve fiber layer，RNFL)厚度及视盘倾斜、后巩膜葡萄肿、近视性黄斑病变(myopic maculopathy，MMD)患病率差异均存在统计学意义(P<0.05)。三组间RPC层(54.34±5.58，57.54±7.44，64.42±3.50)与ONH层(51.24±7.43，52.75±9.96，61.25±4.15)视盘周围平均血流密度差异均有显著统计学意义(P<0.001)。与高度近视不伴PICC组及健眼组相比，伴有PICC组RPC和ONH层颞下象限血流密度(56.76±6.62，63.84±6.02，67.52±4.78； 56.47±5.79，60.38±4.72，64.18±4.37)均明显下降，RPC层血流密度与MMD、β-PPA面积和RNFL厚度存在显著相关性，而ONH层血流密度则与MMD、PICC的发生及RNFL厚度存在显著相关性(P<0.05)。Logistic回归分析显示，视盘倾斜和后巩膜葡萄肿是PICC患病的独立危险因素(OR=8.007，95%CI：2.045～31.348； OR=7.558，95%CI：1.398～50.026)。

结论：高度近视伴PICC患眼视盘血流密度明显下降，颞侧下降尤为显著。视盘倾斜与后巩膜葡萄肿是PICC发生的独立危险因素。

METHODS:Cross-sectional study. A total of 35 highly myopic eyes with PICC, 40 highly myopic eyes without PICC and 35 normal eyes were included in this study. All participants underwent fundus photography and spectral-domain optical coherence tomography(SD-OCT). OCT angiography was also performed to image the retinal vasculature in the peripapillary areas of different sectors, including the radial peripapillary capillaries(RPC)and optic nerve head(ONH)layer. The difference of morphology changes in optic disc and peripapillary vessel density between these three groups were compared. Correlations between peripapillary vessel density and PICC and risk factors for the presence of PICC were analyzed.

RESULTS: Significant differences were found among the three groups in spherical equivalent refraction(SER), best-corrected visual acuity(BCVA), axial length, peripapillary atrophy β-zone(β-PPA)area, retinal nerve fiber layer(RNFL)thickness and the presence of tilted optic disc, posterior staphyloma and myopic maculopathy(MMD)(P<0.05). There were significant differences among the three groups in the peripapillary vessel density both in RPC(54.34±5.58, 57.54±7.44, 64.42±3.50)and ONH(51.24±7.43, 52.75±9.96, 61.25±4.15)layers(P<0.001). In highly myopic eyes, vessel density was significantly lower in eyes with PICC than in those without in inferotemporal area both in the RPC(56.76±6.62,63.84±6.02,67.52±4.78)and ONH(56.47±5.79,60.38±4.72,64.18±4.37)layers. The vessel density was significantly correlated with the presence of MMD, β-PPA area and RNFL thickness in the RPC layer, whereas correlated with the presence of MMD, PICC and RNFL thickness in the ONH layer(P<0.05). Tilted optic disc and posterior staphyloma were independent risk factors for the presence of PICC(OR=8.007, 95%CI: 2.045-31.348; OR=7.558, 95%CI: 1.398-50.026).

CONCLUSION:Highly myopic eyes with PICC had relatively lower peripapillary vessel densities, especially in the temporal area, than those without. Tilted optic disc and posterior staphyloma were independent risk factors for the presence of PICC.