VanNasdale Dean A, Elsner Ann E, Peabody Todd D, Kohne Kimberly D, Malinovsky Victor E, Haggerty Bryan P, Weber Anke, Clark Christopher A, Burns Stephen A
The Ohio State University College of Optometry, Columbus, Ohio, United States.
Indiana University School of Optometry, Bloomington, Indiana, United States.
Invest Ophthalmol Vis Sci. 2014 Dec 18;56(1):284-90. doi: 10.1167/iovs.14-14459.
To quantify and compare phase retardation amplitude and regularity associated with the Henle fiber layer (HFL) between nonexudative AMD patients and age-matched controls using scanning laser polarimetry (SLP) imaging.
A scanning laser polarimeter was used to collect 15 × 15° macular-centered images in 25 patients with nonexudative AMD and 25 age-matched controls. Raw image data were used to compute macular phase retardation maps associated with the HFL. Consecutive, annular regions of interest from 0.5 to 3.0° eccentricity, centered on the fovea, were used to generate intensity profiles from phase retardation data and analyzed with two complementary techniques: a normalized second harmonic frequency (2f) of the fast Fourier Transform (FFT) analysis and a curve fitting analysis using a 2f sine function. Paired t-tests were used to compare the normalized 2f FFT magnitude at each eccentricity between the two groups, the eccentricity that yielded the maximum normalized 2f FFT between paired individuals across the two groups, and curve fitting RMS error at each eccentricity between the two groups.
Normalized 2f FFT components were lower in the AMD group at each eccentricity, with no difference between the two groups in the maximum normalized 2f FFT component eccentricity. The root-mean-square (RMS) error from curve fitting was significantly higher in the AMD group.
Phase retardation changes in the central macula indicate loss and/or structural alterations to central cone photoreceptors in nonexudative AMD patients. Scanning laser polarimetry imaging is a noninvasive method for quantifying cone photoreceptor changes associated with central macular disease.
使用扫描激光偏振仪（SLP）成像技术，对非渗出性年龄相关性黄斑变性（AMD）患者与年龄匹配的对照组之间与Henle纤维层（HFL）相关的相位延迟幅度和规律性进行量化和比较。
使用扫描激光偏振仪收集25例非渗出性AMD患者和25例年龄匹配的对照组以黄斑为中心的15×15°图像。原始图像数据用于计算与HFL相关的黄斑相位延迟图。以中央凹为中心，从0.5至3.0°偏心度的连续环形感兴趣区域用于从相位延迟数据生成强度分布图，并采用两种互补技术进行分析：快速傅里叶变换（FFT）分析的归一化二次谐波频率（2f）和使用2f正弦函数的曲线拟合分析。采用配对t检验比较两组之间每个偏心度下的归一化2f FFT幅度、两组配对个体之间产生最大归一化2f FFT的偏心度以及两组之间每个偏心度下的曲线拟合均方根（RMS）误差。
AMD组在每个偏心度下的归一化2f FFT分量均较低，两组之间最大归一化2f FFT分量偏心度无差异。AMD组曲线拟合的均方根（RMS）误差显著更高。
黄斑中心的相位延迟变化表明非渗出性AMD患者中央视锥光感受器的丢失和/或结构改变。扫描激光偏振仪成像是一种用于量化与黄斑中心疾病相关的视锥光感受器变化的非侵入性方法。
