糖尿病患者视网膜神经节细胞复合体和神经纤维层厚度的变化

The thickness variation of ganglion cell complex and retinal nerve fiber layer thickness in patients with diabetes mellitus

摘要:

目的 观察2型糖尿病(T2DM)患者中视网膜神经纤维层(RNFL)和神经节细胞复合体(GCC)厚度的变化,分析其神经结构与微循环之间的相关关系。方法 采用横断面回顾性研究,入选2型糖尿病患者45例71眼、健康受试者36例68眼。采用光学相干断层扫描血管成像技术(OCTA)检测黄斑部的GCC厚度、视盘周围RNFL厚度、视网膜脉络膜毛细血管丛的微血管密度。观察不同分期糖尿病视网膜病变(DR)患眼中RNFL和GCC厚度变化,分析它们与微血管密度的相关关系。结果 与对照组相比,NDR组(无DR的糖尿病患者)GCC中局部丢失体积(FLV,P＝0.00)、整体丢失体积(GLV,P＝0.00)显著升高,可能是视网膜神经结构损伤的早期敏感指标。与对照组相比,轻中度非增殖性糖尿病视网膜病变(NPDR)组的下侧和鼻侧象限RNFL显著变薄(P＝0.00),可能是RNFL丢失的敏感区域。重度NPDR组中鼻侧象限RNFL仍然显著变薄,但下侧、颞侧象限RNFL显著增厚(P＝0.00)。增殖性糖尿病视网膜病变(PDR)组中 RNFL和GCC大部分参数普遍增厚(P＝0.00),可能与视网膜水肿导致的视网膜增厚有关。Spearman分析显示GCC、RNFL厚度与视网膜厚度呈正相关。此外,GCC及RNFL厚度与视网膜脉络膜毛细血管包括浅层毛细血管丛(SCP)、深层毛细血管丛(DCP)和脉络膜层毛细血管丛(CCP)的密度呈负相关。结论 GCC的FLV和GLV局限性丢失,可能是评价早期视网膜神经结构损伤的敏感指标。随DR的进展,RNFL厚度呈现先变薄后增厚的趋势,还需要扩大样本量进一步研究。

关键词:糖尿病视网膜病变;光学相干断层扫描血管成像技术;神经节细胞复合体;视网膜神经纤维层;脉络膜毛细血管密度

Abstract:

Aim To observe the thickness variation of retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) in type 2 diabetes mellitus (T2DM) patients. To analyze the correlation of retinal neural structure parameters and microcirculation parameters. Methods This was a cross-sectional retrospective study including 45 T2DM patients (71 eyes) and 36 healthy controls (68 eyes). The optical coherence tomography angiography (OCTA) was used to examine GCC thickness, RNFL thickness, microvascular density of retinal superior capillary plexus, retinal deep capillary plexus and choroidal capillary plexus. Then the RNFL and GCC thickness changes were observed in the diabetic retinopathy (DR) patients of different stages, furthermore, the correlation was analyzed between these parameters and microvascular density. Results Compared with the control group, the focal loss volume (FLV, P＝0.00) and global loss volume (GLV, P＝0.00) of GCC thickness increased significantly in NDR group (DM patients without DR), so FLV and GLV might be the potential sensitive parameters to assess early loss of retinal ganglion cell (RGC) in NDR patients. Compared with the control group, the RNFL thickness decreased initially in the inferior and nasal quadrant in the patients with mild non-proliferative DR (NPDR) and moderate NPDR (P＝0.00), implying the more susceptibility regions for RNFL loss. In the severe NPDR group, the nasal RNFL thickness were still thinner (P＝0.00), whereas the inferior and temporal RNFL thickness went up significantly, compared with the control group (P＝0.00). In the PDR group, RNFL and GCC thickness in most regions were thicker than the control group, which might be relevant to retina thickening caused by the edema of retina. This might be supported by the positive correlation between the GCC/RNFL thickness and the retinal thickness revealed by the Spearman correlation analysis. In addition, the GCC and RNFL thickness were negatively correlated with retinal superficial capillary plexus(SCP) density, the deep capillary plexus (DCP) density and choroidal capillary plexus (CCP) density. Conclusion Local loss of GCC occurred in advance of the presence of DR, FLV and GLV in GCC thickness might be the potential sensitive parameters to assess early loss of RGC. With the development and progress of DR, the RNFL thickness tends to drop down influentially, then goes up finally. Therefore, further prospective and longitudinal clinical researches are needed.

Key words:diabetic retinopathy; optical coherence tomography angiography; ganglion cell complex; retinal nerve fiber layer; choroidal capillary plexus density