Weber Timothy D, Mertz Jerome
Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, Massachusetts 02215, USA.
Photonics Center, Boston University, 8 Saint Mary's Street, Boston, Massachusetts 02215, USA.
Biomed Opt Express. 2018 Jul 25;9(8):3867-3882. doi: 10.1364/BOE.9.003867. eCollection 2018 Aug 1.
The human retina is typically imaged in a reflection geometry, where light is delivered through the pupil and images are formed from the light reflected back from the retina. In this configuration, artifacts caused by retinal surface reflex are often encountered, which complicate quantitative interpretation of the reflection images. We present an alternative illumination method, which avoids these artifacts. The method uses deeply penetrating near-infrared (NIR) light delivered transcranially from the side of the head, and exploits multiple scattering to redirect a portion of the light towards the posterior eye. This unique transmission geometry simplifies absorption measurements and enables flash-free, non-mydriatic imaging as deep as the choroid. Images taken with this new transillumination approach are applied to retinal oximetry.
人类视网膜通常在反射几何结构中成像，即光线通过瞳孔传输，图像由从视网膜反射回来的光线形成。在这种配置下，经常会遇到由视网膜表面反射引起的伪像，这使得反射图像的定量解释变得复杂。我们提出了一种替代照明方法，可避免这些伪像。该方法使用从头部侧面经颅传输的深度穿透近红外（NIR）光，并利用多次散射将一部分光线重定向到眼球后部。这种独特的传输几何结构简化了吸收测量，并能够进行无闪光、不散瞳的成像，深度可达脉络膜。用这种新的透照方法拍摄的图像被应用于视网膜血氧测定。
