Burns Stephen A, Elsner Ann E, Mellem-Kairala Mariane B, Simmons Ruthanne B
The Schepens Eye Research Institute, Boston, Massachusetts 02114, USA.
Invest Ophthalmol Vis Sci. 2003 Sep;44(9):4061-8. doi: 10.1167/iovs.03-0124.
To improve the ability to detect and quantify the early retinal changes associated with aging, age-related maculopathy, and age-related macular degeneration.
A computational approach was implemented for analyzing images using a readily available polarimeter that is used for glaucoma diagnosis. This device, the GDx Nerve Fiber Analyzer (Laser Diagnostic Technologies, Inc., San Diego, CA), takes a series of images as a function of the polarization angle of the illuminating light. For each of 20 input polarizations, pairs of retinal images are digitized. One image is made of the light returning from the eye that is polarized parallel to the input light, and the other image is made of the light that is rotated by 90 degrees from the input polarization. Using the raw data from these 40 images, and a simplified model of the polarization properties of the eye, we calculated the amount of light that returns in a parallel polarized state, and the amount of light that is depolarized by multiple scattering. Measurements were made in seven subjects with small drusen.
The depolarized light image produced a 3.4 times higher contrast of drusen and subretinal changes than the parallel polarized light images.
Polarization-sensitive imaging combined with a simple computational approach allows the measurement of the retinal distribution of multiply scattered light. With this technique, retinal imaging of age-related changes in retinal and subretinal tissue can be improved.
提高检测和量化与衰老、年龄相关性黄斑病变及年龄相关性黄斑变性相关的早期视网膜变化的能力。
采用一种计算方法，利用一种常用于青光眼诊断的现成偏振仪来分析图像。该设备为GDx神经纤维分析仪（激光诊断技术公司，加利福尼亚州圣地亚哥），它根据照明光的偏振角拍摄一系列图像。对于20种输入偏振中的每一种，将一对视网膜图像数字化。一幅图像由与输入光平行偏振的从眼睛返回的光构成，另一幅图像由相对于输入偏振旋转90度的光构成。利用来自这40幅图像的原始数据以及眼睛偏振特性的简化模型，我们计算了以平行偏振状态返回的光量以及因多次散射而退偏振的光量。对7名患有小玻璃膜疣的受试者进行了测量。
与平行偏振光图像相比，退偏振光图像产生的玻璃膜疣和视网膜下变化的对比度高3.4倍。
偏振敏感成像结合简单的计算方法能够测量多次散射光的视网膜分布。利用这项技术，可以改善对视网膜和视网膜下组织中与年龄相关变化的视网膜成像。
