全视网膜光凝术对视网膜黄斑部微循环状态的影响

目的　通过光学相干断层扫描血管成像技术（OCTA）观察全视网膜光凝术（PRP）后患者黄斑部血流状态改变以评估PRP术后患者黄斑部的血供变化。方法　选择重度非增生型糖尿病视网膜病变（NPDR）拟行PRP的患者，采用OCTA观察治疗前和治疗后3个月时患者黄斑部3 mm×3 mm范围内浅层和深层中心凹、旁中心凹、鼻侧、上方、颞侧、下方各区域视网膜血流密度（VD）和黄斑部视网膜厚度的变化，并分析黄斑部视网膜VD与血糖水平的关系。结果　共纳入重度NPDR患者24例（32眼），PRP术前患者空腹血糖为（11.38±5.38）mmol·L^-1，术后3个月时糖化血红蛋白为（8.75±3.18）%。治疗后3个月时患者黄斑中心凹视网膜深层总VD为（43.41±5.95）%、深层旁中心凹VD为（45.73±6.04）%，与治疗前相比均有提高（均为P<0.001）；浅层旁中心VD为（37.95±4.63）%，黄斑中心凹无血管区面积为（0.286±0.133）mm²，与治疗前相比均有下降，但差异均无统计学意义（P=0.107、0.165）；黄斑中心凹视网膜厚度为（362.50±63.51）μm，与治疗前相比明显下降（P<0.000 1）。相关性分析显示，患者治疗前和治疗后3个月患者视网膜黄斑部深层VD的改善程度与空腹血糖水平呈负相关（r=-0.675，P<0.001），与糖化血红蛋白水平呈负相关（r=-0.726，P<0.001）；多元回归分析显示，糖化血红蛋白水平为患者视网膜旁中心凹深层VD改善的独立危险因素（t=-2.400，P=0.027）。结论　重度NPDR患者在PRP术后视网膜黄斑部深层视网膜VD得到改善，这可能与血糖控制水平相关。

Effect of panretinal photocoagulation on macular microcirculation

Objective　To evaluate the changes in macular blood supply in patients after panretinal photocoagulation (PRP) through macular blood flow by optical coherence tomography angiography (OCTA). Methods　Patients with severe non-proliferative diabetic retinopathy (NPDR) who intended to receive PRP therapy were enrolled in this study. A 3 mm×3 mm macular OCTA scan was performed before and three months after PRP to evaluate changes in superficial and deep retinal vessel density (VD) in foveal, parafoveal, nasal, superior, temporal, and inferior areas and changes in macular retinal thickness. The correlation between macular VD and blood glucose level was analyzed. Results　A total of 24 patients (32 eyes) with severe NPDR were enrolled. Their fasting blood glucose (FBG) was (11.38±5.38) mmol·L^-1 before PRP, and HbAlc was (8.75±3.18)% three months after PRP. Three months after PRP, the deep retinal VD in the whole macular area and in the parafoveal area was (43.41±5.95)% and (45.73±6.04)%, respectively, improving significantly compared with before PRP (both P<0.001); the superficial retinal VD in the parafoveal area was (37.95±4.63)%, and the area of foveal avascular zone was (0.286±0.133) mm², both lower than those at baseline (P=0.107, 0.165); the macular retinal thickness was (362.50±63.51) μm, significantly lower than that at baseline (P<0.000 1). Correlation analysis results revealed that the improvement of deep retinal VD in the macular area was negatively correlated with FBG (r=-0.675, P<0.001) and HbAlc (r=-0.726, P<0.001). Multivariate regression analysis results showed that HbAlc level was an independent factor affecting the improvement of deep retinal VD in the parafoveal area (t=-2.400, P=0.027). Conclusion　In patients with severe NPDR, the deep macular VD can improve after PRP, which may correlate with the level of blood glucose.