目的：应用光学相干断层扫描血管成像技术(OCTA)观察单眼近视患儿黄斑区视网膜毛细血管血流密度及各层视网膜厚度，并探讨上述视网膜参数与眼轴长度(AL)之间的关系。

方法：横断面研究。选取2020-11/2021-04于南京医科大学眼科医院就诊的单眼近视患儿32例64眼，平均年龄10.88±2.34岁。根据患儿的等效球镜度(SER)分组，SER≤-0.75D纳入近视组，平均SER -2.15±1.10D； 对侧健眼纳入非近视组，平均SER 0.01±0.48D。所有患儿均行眼科一般检查并采用OCTA检查黄斑区浅层视网膜毛细血管(SCP)血流密度、深层视网膜毛细血管(DCP)血流密度及各层视网膜厚度。

结果：近视组UCVA低于非近视组，SER、AL高于非近视组(均P<0.01)，眼压、角膜平坦K值无差异(均P>0.05)。近视组黄斑区上方SCP血流密度及黄斑中心凹DCP血流密度明显大于非近视组(P=0.029、0.010)，余区域视网膜毛细血管血流密度无差异(均P>0.05)。除中心凹以外，近视组黄斑区颞侧、上方、鼻侧及下方的全层视网膜厚度均明显低于非近视组(均P<0.01)。近视组黄斑区颞侧内层视网膜厚度略低于非近视组(P=0.043)。近视组黄斑中心凹、黄斑区颞侧、上方、鼻侧及下方的外层视网膜厚度均明显小于非近视组(均P<0.05)。Pearson相关分析显示，黄斑中心凹SCP、DCP血流密度与AL呈正相关(r=0.432、0.541，均P<0.01)。黄斑中心凹、黄斑区颞侧、上方、鼻侧及下方内层视网膜厚度与AL呈正相关(r=0.452、0.389、0.313、0.401、0.445，均P<0.05)。黄斑区上方、鼻侧及下方外层视网膜厚度与AL呈负相关(r=-0.308、-0.309、-0.330，均P<0.05)。

结论：单眼近视患儿近视眼黄斑区上方SCP及中心凹DCP呈代偿性血流密度升高状态； 除中心凹以外，黄斑区全层视网膜厚度显著降低。AL延长与黄斑区内层视网膜厚度增加，上方、鼻侧及下方外层视网膜厚度变薄相关。

AIM: To observe the macular retinal microvascular density and thickness of each retinal layer in children with monocular myopia by optical coherence tomography angiography(OCTA). Meanwhile, the correlation with the above-mentioned retinal parameters and axial length(AL)were analyzed.

METHODS: A cross-sectional study. A total of 32 children(64 eyes)with monocular myopia who were treated at the Affiliated Eye Hospital of Nanjing Medical University from November 2020 to April 2021 were selected,with an average age of 10.88±2.34 years old. According to the spherical equivalent refraction(SER)of the children, SER≤-0.75D was included in the myopia group, with an average SER of -2.15±1.10D; The contralateral healthy eye was included in the non-myopia group, with an average SER of 0.01±0.48D. All participants underwent general ophthalmic examination and OCTA was performed to measure the blood flow density of superficial retinal capillaries(SCP), deep retinal capillaries(DCP)blood flow density and the thickness of each retinal layer in the macular region.

RESULTS: The uncorrected visual acuity(UCVA)of the myopia group was lower than that of the non-myopia group, the SER and AL were higher than those of the non-myopia group(all P<0.01), and there was no difference in intraocular pressure and corneal flatness K value(all P>0.05). The blood flow density of SCP above the macular area and the DCP blood flow density of the fovea in the myopia group were significantly higher than those in the non-myopia group(P=0.029, 0.010), and there was no difference in the blood flow density of retinal capillaries in other regions(all P>0.05). Except for the fovea, the whole retinal thickness of myopia group in temporal, superior, nasal and inferior regions was significantly lower than those in the control group(all P<0.01). The temporal inner retinal thickness of the macular region in the myopia group was slightly lower than that in the non-myopia group(P=0.043). The macular fovea and the outer retinal thickness of the temporal, superior, nasal and inferior macular areas in the myopia group were significantly smaller than those in the non-myopia group(all P<0.05). Pearson correlation analysis showed that foveal SCP and DCP blood flow density were positively correlated with AL(r=0.432, 0.541, all P<0.01). AL was significantly positive correlated with inner retinal thickness in macular central, temporal, superior, nasal and inferior regions(r=0.452, 0.389, 0.313, 0.401,0.445, all P<0.05). AL was negative correlated with outer retinal thickness in superior, nasal and inferior regions(r=-0.308, -0.309, -0.330, all P<0.05).

CONCLUSION: There was a compensated increase of blood flow density in superior SCP and macular central DCP of the myopic eyes in unilateral myopic children. The full-thickness retinal thickness was significantly reduced in the macular region, except for the fovea. The AL elongation was related to the thickening of the inner retina, as well as the thinning in the superior, nasal, and inferior regions of outer retina.

国家自然科学基金资助项目(No.82070983); 南京医科大学科技发展基金项目(No.NMUB20210344)