背景 目前临床上已广泛使用海德堡视网膜断层扫描仪(HRT)诊断青光眼引起的视神经病变,有研究表明近视会影响HRT视盘参数测量结果,探索不同屈光状态和眼轴长度对HRT视盘结构参数的影响具有重要意义. 目的 评估屈光不正和眼轴长度对视盘结构参数的影响. 方法 采用前瞻性描述性系列病例观察研究方法.选取2006年7月至2011年8月参加“广州双生子研究”的家长作为研究对象.所有受检者行视力、裂隙灯显微镜和90 D前置镜眼底检查,并用电脑自动验光仪采集受检眼的屈光度,采用人工晶状体(IOL) Master测量眼轴长度,视盘结构参数的测量借助HRT-Ⅲ.对所有受检者右眼的自动验光、HRT和IOLMaster测量数据进行分析,采用Pearson直线相关分析法和多重线性回归分析对HRT测量的视盘结构参数与等效球镜度(SE)及眼轴长度间的关系进行评估.结果 共1748名健康成人纳入研究.高度近视组的视盘面积(DA) (P=0.021)、盘沿面积(RA) (P<0.001)、盘沿容积(RV) (P<0.001)、平均视网膜神经纤维层厚度(mRNFLt)(P<0.001)和RNFL横断面积(RNFLcsa)(P<0.001)明显大于正视组,差异均有统计学意义,而视杯面积(CA) (P=0.004)、杯盘面积比(C/DAR) (P<0.001)和视杯容积(CV) (P<0.001)则小于正视组,差异均有统计学意义;在中低度近视组,其RV(P<0.001)、mRNFLt(P<0.001)和RNFLcsa (P<0.001)明显大于正视组,而DA (P=0.038)、CA (P<0.001)、C/DAR(P<0.001)和CV (P=0.001)则明显小于正视组;远视组受检者视盘结构参数与正视组比较差异均无统计学意义(P>0.05).受检者DA值与SE间无明显相关性(r=-0.032,P=0.186),但CA、C/DAR、CV、平均视杯深度(MCD)和最大视杯深度(MxCD)与SE间均呈正相关(r=0.139、0.163、0.130、0.004、0.054,P<0.05),RA、RV、mRNFLt和RNFLcsa则与SE间均呈负相关(r=-0.178、-0.331、-0.241、-0.239,P<0.001).眼轴越长,DA、RA、RV、视杯形态测量(CSM)、mRNFLt和RNFLcsa越大,而CV则越小.随着CA的增大,RA、C/DAR、CV、RV、MCD、MxCD、CSM和RNFLcsa均增大,而mRNFLt则变小. 结论 屈光不正与DA无相关性,但不同屈光组的部分视盘结构参数测量值存在差异,随着眼轴长度的增长DA逐渐增大,眼轴长度和DA会影响HRT视盘结构参数的测量结果.
Background Heidelberg Retinal Tomograph (HRT) has been widely used in clinical diagnosis of glaucomatous optic neuropathy,importantly,the measurement results of HRT may be affected by myopia.Therefore,studying the effect of different refractive status and axial length on structural parameters of the optic disc is important.Objective This study was to evaluate the influence of refractive error and axial length to optic nerve head parameter measured by HRT.Methods The parents who participate in Guangzhou Twin Study were enrolled in this investigation from July 2006 to August 2011.The regular eye examinations,including visual acuity,slit lamp,fundus,auto-refraction,HRT-Ⅲ and intraocular lens (IOL) Master,were performed on all the subjects.Thc data from right eyes of subjects were collected and analyzed.The linear correlation analysis and multiple linear regression analysis were applied to analyze the correlation between HRT optic papilla configuration parameter and equivalent sphere and ocular axis length.Results A pilot prospective series cases observational study was designed.1748subjects were enrolled in this study.The disc area (DA) (P=0.021),rim area (RA) (P<0.001),rim volume (RV) (P<0.001),mean retinal nerve fiber layer thickness (mRNFLt) (P<0.001) and retinal nerve fiber layer cross section area (RNFLcsa) in the high myopia were greater than those of the emmetropic group,with significant difference between the two groups (P<0.001).However,the cup area (CA),cup/disk area ratio (C/DAR) and cup volume (CV) were less in the high myopic group than those of the emmetropic group (P=0.004,P<0.001 and P<O.001),respectively.In the mild-moderatc myopic group,the RV,mRNFLt and RNFLcsa were greater than those of the emmetropic group (all of the P value less than 0.001),but the numbers of DA,CA,C/DAR,and CV were less than those of the emmetropic group,the differences were significant and their P valuables were 0.038,< 0.001,<0.001 and 0.001 respectively.The differences of structure parameters between the hyperopia group and the emmetropic group were not statistically significant (P>0.05).The DA,CA,RA,C/DAR,CV,RV,mean cup depth (MCD),maximum cup depth (MxCD),cup shape measure (CSM),mRNFLt and RNTLcsa were (2.04±0.43) mm2,(0.49±0.34) mm2,(1.55 ± 0.34) mm2,0.23-0.13,(0.11 ± 0.12) mm3,(0.45 ± 0.19) mm3,(0.21 ± 0.09) mm,(0.60±0.21) mm,-0.21 ± 0.07,(0.29 ± 0.07) mm and (1.46 ± 0.36)mm2,respectively,in the 1748 eyes of 1748 subjects.No significant correlation was found between the DA value with SE (r=-0.032,P =0.186).However,weaker positive correlations were seen between the CA,C/DAR,CV,MCD,MxCD with SE (r=0.139,0.163,0.130,0.004,0.054,P< 0.05) and negative correlation between RA,RV,mRNFLt and RNFLcsa with SE (r =-0.178,-0.331,0.241,-0.239,P<0.001).With the increase of the ocular axial length,the DA,RA,RV,mRNFLt and RNFLcsa values were enlarged,and the CV value was smaller.With the increase of CA,the RA,C/DAR,CV,RV,MCD,MxCD,CSM and RNFLcsa values elevated,but mRNFLt value was decreased.Conclusions Refractive error is not associated with DA,but the measuring results are different among various refractive groups.Refractive error,ocular axial length and DA affect the measuring result of HRT.