Medeiros Felipe A, Zangwill Linda M, Bowd Christopher, Bernd Antje S, Weinreb Robert N
Department of Ophthalmology, University of California, San Diego, California 92093-0946, USA.
Invest Ophthalmol Vis Sci. 2003 Jun;44(6):2606-12. doi: 10.1167/iovs.02-0814.
To apply Fourier analysis to the retinal nerve fiber layer (RNFL) thickness measurements obtained with scanning laser polarimetry (SLP), by using variable corneal compensation, and to evaluate the ability of this method to discriminate glaucomatous from normal eyes.
The study included one eye each of 55 patients with glaucoma and 52 healthy subjects. RNFL thickness measurements were obtained with a modified commercial scanning laser polarimeter (GDx Nerve Fiber Analyzer; Laser Diagnostic Technologies, Inc., San Diego, CA) so that corneal birefringence could be corrected on a subject-specific variable basis. The shape of the RNFL thickness double-hump pattern was analyzed by Fourier analysis of polarimetry data. Fourier coefficients and GDx parameters were compared between the two groups. A linear discriminant function was developed to identify and combine the most useful Fourier coefficients to separate the two groups. Receiver operating characteristic (ROC) curves were obtained for each measurement, and sensitivity values (at fixed specificities) were calculated.
The Fourier-based linear discriminant function (LDF Fourier) resulted in a sensitivity of 84% for a specificity set at 92%. For similar specificity, the GDx software-provided parameters had sensitivities ranging from 24% to 69%. The area under ROC curve for the LDF Fourier was 0.949, significantly larger than the ROC curve area for the single best GDx software-provided parameter, superior average (0.870).
The combination of Fourier RNFL thickness measures in an LDF, obtained using SLP with variable corneal compensation, improved the ability to discriminate glaucomatous from healthy eyes, compared with the GDx software-provided parameters.
通过使用可变角膜补偿，将傅里叶分析应用于扫描激光偏振仪（SLP）获得的视网膜神经纤维层（RNFL）厚度测量，并评估该方法区分青光眼患者和正常眼睛的能力。
该研究纳入了55例青光眼患者和52名健康受试者的单眼。使用改良的商用扫描激光偏振仪（GDx神经纤维分析仪；Laser Diagnostic Technologies, Inc., 圣地亚哥，加利福尼亚州）获得RNFL厚度测量值，以便可以根据受试者的具体情况对角膜双折射进行校正。通过对偏振测量数据进行傅里叶分析来分析RNFL厚度双峰模式的形状。比较两组之间的傅里叶系数和GDx参数。开发了一种线性判别函数，以识别和组合最有用的傅里叶系数来区分两组。为每次测量获得受试者操作特征（ROC）曲线，并计算灵敏度值（在固定特异性下）。
基于傅里叶的线性判别函数（LDF Fourier）在特异性设定为92%时灵敏度为8:4%。对于相似的特异性，GDx软件提供的参数灵敏度范围为24%至69%。LDF Fourier的ROC曲线下面积为0.949，明显大于单个最佳GDx软件提供的参数“ superior average”的ROC曲线面积（0.870）。
与GDx软件提供的参数相比，使用可变角膜补偿的SLP获得的LDF中傅里叶RNFL厚度测量的组合提高了区分青光眼患者和健康眼睛的能力。
