青光眼患者视网膜结构与功能损害的关系

A pilot study of the relationship between retinal structural and functional damage in primary open-angle glaucoma

背景 应用有效的技术手段和客观指标对青光眼进行早期诊断、病情监测和疗效评估有重要的临床意义,目前关于青光眼视网膜结构和功能损害的研究已不少见,但早期青光眼患者视网膜结构损伤与功能损害的关系研究鲜有报道. 目的 探讨早期原发性开角型青光眼（POAG）视网膜结构损害与功能损害之间的关系. 方法 采用前瞻性研究方法,纳入2011年1月至2013年6月在深圳市眼科医院确诊的POAG患者95例95眼,同期收集41位正常人的41眼作为对照.分别采用RTVue-100光学相干断层扫描（OCT）和Cirrus HD-OCT测量仪测量受检眼视网膜结构变化,包括视盘全周平均视网膜神经纤维层（RNFL-Avg）厚度和黄斑区平均视网膜神经节细胞复合体（GCC-Avg）厚度;采用Humphrey视野平均偏差（MD）和闪光视网膜电图（F-ERG）明视负波反应（PhNR）评估受检眼视网膜的功能变化.通过曲线拟合、建立回归模型的方法分析POAG患者视网膜结构变化值和功能变化值的关系. 结果 POAG组患眼MD值、GCC-Avg、RNFL-Avg和PhNR振幅值分别为（-10.82±9.87）dB、（75.07±12.29） μm、（69.09±12.96） μm和（28.38±11.52） μV,均明显低于正常对照组的（-0.68±1.72）dB、（97.17±4.82）μm、（102.51±8.74） μm和（49.61±11.01）μV,差异均有统计学意义（t=6.549、11.118、-15.061、9.956,均P=0.001）.受检者GCC-Avg厚度与MD值间呈二次曲线变化关系,其回归模型的R2值为0.595（F=97.089,P＜0.001）;GCC-Avg厚度与PhNR振幅间呈直线变化关系,回归模型的R2值为0.437（F=103.413,P＜0.001）;RNFL-Avg厚度与MD值、PhNR振幅分别呈二次曲线和直线相关关系,R2值分别是0.606（F=101.666,P＜0.001）和0.454（F=54.983,P＜0.001）. 结论 POAG患眼GCC厚度和RNFL厚度与MD值均呈曲线变化关系,而与PhNR振幅呈直线变化关系,RNFL厚度与MD值和PhNR振幅回归模型的拟合优度略高于GCC厚度与MD值和PhNR振幅的回归模型.

Background Application of available technology and objective indexes are very important for the early diagnosis,monitoring and therapeutic evaluation of primary open angle glaucoma （POAG）.Many studies have determined retinal damage in structure and function in POAG.However,the study on the association of structural damage and functional abnormality in early POAG is still lack.Objective This study was to evaluate the relationship between structural and functional changes of retina in early stage of POAG.Methods A prospectively pilot study was performed under the approval of Ethic Committee of Shenzhen Eye Hospital from January 2011 to June 2013.Based on Helsinki Declaration,written informed consent was obtained from subject prior to entering the cohort.Ninety-five eyes of 95 POAG patients were included as the study group,and 41 eyes of 41 non-glaucoma subjects were enrolled at the same period as controls.The structural parameters of retinas were measured using RTVue-100 OCT and Cirrus HD-OCT respectively,including macular ganglion cell complex （GCC）-Avg thickness and peripapillary retinal neural fibril layer （RNFL）-Avg thickness;and the functional parameters of retinas were obtained by Humphrey visual filed analyzer and RETI scan 3.15 system respectively,including MD of visual field and PhNR of flash electroretinogram （F-ERG）.The associations between the GCC or RNFL thickness and M D or amplitude of PhNR were evaluated by linear and curvilinear regression models.Results The MD,GCC-Avg,RNFL-Avg and PhNR amplitude were （-0.68±1.72）dB,（97.17± 4.82）μm,（102.51±8.74） μm and （49.61±11.01）μV respectively in the control subjects,and those in the POAG patients were （-10.82±9.87） dB,（75.07±12.29） μm,（69.09±12.96） μm and （28.38± 11.52） μV,showing significant differences between them （t =6.549,11.118,-15.061,9.956,all at P=0.001）.The curvilinear regression model appeared to better describe the relationship between GCC thickness and MD （R2 =0.595,F=97.089,P＜0.001） ;while a linear regression model seemed to be better fit for the relationship between GCC thickness and amplitude of PhNR （R2=0.437,F=103.413,P＜0.001）.RNFL thickness analysis showed the similar regression models with MD and amplitude of PhNR as GCC thickness,but R2 values were higher between the RNFL thickness and MD （R2 =0.606,F =101.666,P＜0.001） or amplitude of PhNR （R2 =0.454,F=54.983,P＜0.001）.Conclusions Both GCC thickness and RNFL thickness show a curvilinear relationship with MD and a linear relationship with amplitude of PhNR.Goodness-of-fit of RNFL thickness is superior to GCC thickness.