正常人黄斑区视网膜神经纤维层OCT光学特征与年龄的关系

Correlations between optical parameters of retinal nerve fiber layer measured by optical coherence tomography and age in normal population

背景 Cirrus光学相干断层扫描（OCT）测量视网膜神经纤维层（RNFL）已广泛用于眼科临床,基于OCT的光学特征,其在某些眼科疾病的检测中可以弥补空间测量的不足,但目前相关研究较少. 目的 观察正常人RNFL的OCT光学特征,研究其与年龄的关系. 方法 纳入2011年6月至2012年6月在上海市北医院体检的健康者406人,年龄40 ～ 83岁,平均58.6岁,均纳入一侧眼统计.采用Cirrus OCT的5线扫描模式测量黄斑区RNFL,使用图像处理软件分析RNFL的光学特征,包括吸光度（A）值和吸光系数,比较不同年龄层次不同性别间的测量结果,对RNFL的A值和吸光系数与受试者年龄的关系进行分析. 结果 共纳入353名受试者,受试者RNFL厚度、A值和吸光系数的平均值分别为（35.1±4.4） μm、121.6±5.3和2.06±0.25.RNFL厚度、A值与受试者年龄均呈线性负相关（r=-0.487、-0.571,均P＜0.01）,回归方程分别为Y=-0.17 X＋45.23、Y=-0.24 X＋135.82,而RNFL吸光系数则与受试者年龄呈正相关（rs=0.368,P＜0.01）,一元回归方程为Y=0.01 X＋1.63.受检眼RNFL厚度和RNFL A值与OCT信号强度间均呈微弱正相关（rs=0.128,P=0.016;rs=0.284,P＜0.01）,而RNFL吸光系数与OCT信号强度间无明显相关关系（rs=-0.053,P=0.319）.结论 正常人RNFL的OCT光学特征参数受年龄的影响,在研究RNFL的光学特征变化时,应考虑年龄因素.

Background The measurement of retinal nerve fiber layer （RNFL） by Cirrus optical coherence tomography （OCT） has been applied widely in ophthalmology.However,previous assessment of RNFL is based on spatial measurement,while the evaluation based on optical characteristics of OCT can offset the shortcomings of spatial measurement in some eye diseases.Objective This study was to analyze the optical characters of RNFL measured by OCT and its correlation with age in healthy Chinese individuals.Methods Four hundred and six normal healthy subjects were collected in Shanghai Shibei Hospital from June 2011 to June 2012,with the age of 40-83 years old.Macular RNFL was unilateral imaged using a Cirrus OCT device with 5 line raster macular scan mode under the approval of Ethic Committee of Shanghai Shibei Hospital and informed consent of subjects.A customized software was used to measure RNFL optical characters,including absorbance （A value） and attenuate coefficient.The difference of the measured parameters in different genders was compared.The correlations between RNFL optical characters and age were analyzed by linear regression analysis.Results The data of 353 eyes were included in the final outcomes.The RNFL thickness,A value and attenuate coefficient were （35.1 ±4.4） μm,121.6 ±5.3 and 2.06 ±0.25,respectively.RNFL thickness and A value showed significantly negative correlations with age （r=-0.487,-0.571,both at P〈0.01） with the regression equation Y=-0.17 X＋45.23 and Y=-0.24 X＋ 135.82,while a positive correlation was found between the attenuate coefficient and age （r=0.368,P〈0.01） with the regression equation Y=0.01 X＋1.63.RNFL thickness and A value showed weaker positive correlations with OCT signal intensity （rs =0.128,P =0.016;rs =0.284,P〈0.01）,but no remarked correlation was seen between the attenuate coefficient and OCT signal intensity （rs =-0.053,P=0.319）.Conclusions Age of subjects affects the parameters of OCT optical characteristics in normal populaition.Age-related RNFL change in optical characters of OCT should be considered before concluding optical parameters.