原发性开角型青光眼黄斑区视网膜内层结构和功能的关系

Central visual function and inner retinal structure in primary open-angle glaucoma

目的:探讨原发性开角型青光眼(POAG)患者黄斑区视网膜内层结构和功能的关系。创新点:POAG的潜在原因是视网膜神经节细胞(RGC)的丢失。虽然在传统上我们可以通过测量视网膜后极部约30°的结构和功能来评估青光眼性视神经损害,但是50%的RGC存在于黄斑区4.5 mm范围内。本研究关注黄斑区约10°范围视网膜结构和功能的关系,有助于更早地监测到青光眼性视神经损害。方法:本研究纳入了78例POAG患者及58例健康对照者,其中POAG分为早期青光眼(EG)和中晚期青光眼(AG)。所有受试者均进行了以下检测:分离格栅视觉诱发电位(icVEP)、标准自动视野计(SAP)及光学相干断层扫描(OCT)。icVEP检测时给予8%、14%、22%及32%对比度刺激,采集相应的信躁比(SNR)。黄斑区视野敏感度(mMS)通过计算黄斑中心12点的敏感度平均值获得。OCT扫描包括视网膜神经节细胞层+内丛状层的平均厚度(GCL+IPLT)及视盘周围神经纤维层平均厚度(pRNFLT)。我们比较了各组间SNR、mMS、GCL+IPLT及pRNFLT值,并分析了结构性指标和功能性指标之间的相关性。结论:POAG组患者的SNR、mMS、GCL+IPLT及pRNFLT均较正常对照组显著下降(所有P值<0.001)。在早期青光眼中,SNR及mMS均与视网膜内层厚度呈中度相关;而在中晚期青光眼中,mMS与视网膜内层厚度呈高度相关。

To investigate associations between central visual function and inner retinal structure in primary open-angle glaucoma(POAG). This study enrolled 78 POAG patients and 58 healthy controls. POAG was classified into early glaucoma and moderate to advanced glaucoma. The following tests were performed on all participants: isolated-check visual evoked potential(ic VEP) testing, 24-2 standard automated perimetry(SAP), and Cirrus optical coherence tomography(OCT) examinations. Signal-to-noise ratio(SNR) measures obtained from ic VEP responses to isolated checks presented at four depths of modulation(DOMs;8%, 14%, 22%, and 32%) were explored. Mean macular sensitivity(mMS) was assessed by calculating the mean sensitivities of central 12 SAP points. Ganglion cell layer+ inner plexiform layer thickness(GCL+IPLT) and peripapillary retinal nerve fiber layer thickness(pRNFLT) were measured by OCT scanning. For each group of subjects, linear relationships among the following measures were analyzed: SNR, mMS, GCL+IPLT, and pRNFLT. SNR, mMS, GCL+IPLT, and pRNFLT were all more significantly decreased in glaucoma than in controls(P<0.001). A significant positive association was found between SNR at 14% DOM and GCL+IPLT at the inferior sector in early glaucoma(r=0.465, P=0.004). In moderate to advanced glaucoma, significant correlations were found between SNR at 32% DOM and mean GCL+IPLT(r=0.364, P=0.023), superior GCL+IPLT(r=0.358, P=0.025), and mean p RNFLT(r=0.396, P=0.025). In addition, in moderate to advanced glaucoma, there were significant correlations between mMS and all relevant measures of retinal thickness(r=0.330–0.663, P< 0.010). In early glaucoma, significant correlations were found between mean mMS and minimum GCL+IPLT(r=0.373, P=0.023), and between inferior mMS and superior GCL+IPLT(r=0.470, P=0.003). Linear models provided a good explanation for the relationship between SNR and inner retinal thickness(IRT), whereas nonlinear models better explained the relationship between mMS and IRT. In early glaucoma, both SNR and mMS were related moderately and significantly to IRT, whereas in moderate to advanced glaucoma, mMS was more strongly correlated with IRT than SNR.