Sarunic Marinko V, Yazdanpanah Azadeh, Gibson Eli, Xu Jing, Bai Yujing, Lee Sieun, Saragovi H Uri, Beg Mirza Faisal
School of Engineering Science, Simon Fraser University, BC, Canada.
Opt Express. 2010 Oct 25;18(22):23435-41. doi: 10.1364/OE.18.023435.
Rodent models of retinal degenerative diseases are used by vision scientists to develop therapies and to understand mechanisms of disease progression. Measurement of changes to the thickness of the various retinal layers provides an objective metric to evaluate the performance of the therapy. Because invasive histology is terminal and provides only a single data point, non-invasive imaging modalities are required to better study progression, and to reduce the number of animals used in research. Optical Coherence Tomography (OCT) has emerged as a dominant imaging modality for human ophthalmic imaging, but has only recently gained significant attention for rodent retinal imaging. OCT provides cross section images of retina with micron-scale resolution which permits measurement of the retinal layer thickness. However, in order to be useful to vision scientists, a significant fraction of the retinal surface needs to be measured. In addition, because the retinal thickness normally varies as a function of distance from optic nerve head, it is critical to sample all regions of the retina in a systematic fashion. We present a longitudinal study of OCT to measure retinal degeneration in rats which have undergone optic nerve axotomy, a well characterized form of rapid retinal degeneration. Volumetric images of the retina acquired with OCT in a time course study were segmented in 2D using a semi-automatic segmentation algorithm. Then, using a 3D algorithm, thickness measurements were quantified across the surface of the retina for all volume segmentations. The resulting maps of the changes to retinal thickness over time represent the progression of degeneration across the surface of the retina during injury. The computational tools complement OCT retinal volumetric acquisition, resulting in a powerful tool for vision scientists working with rodents.
视网膜退行性疾病的啮齿动物模型被视觉科学家用于开发治疗方法和理解疾病进展机制。测量视网膜各层厚度的变化提供了一个客观指标来评估治疗效果。由于侵入性组织学是一种终端方法且只能提供单个数据点，因此需要非侵入性成像方式来更好地研究疾病进展，并减少研究中使用的动物数量。光学相干断层扫描（OCT）已成为人类眼科成像的主导成像方式，但直到最近才在啮齿动物视网膜成像中受到广泛关注。OCT以微米级分辨率提供视网膜的横截面图像，从而能够测量视网膜层厚度。然而，为了对视觉科学家有用，需要测量相当一部分的视网膜表面。此外，由于视网膜厚度通常会随着与视神经乳头距离的变化而变化，因此以系统的方式对视网膜的所有区域进行采样至关重要。我们进行了一项纵向研究，利用OCT测量视神经切断术后大鼠的视网膜变性情况，视神经切断术是一种特征明确的快速视网膜变性形式。在一项时间进程研究中，通过OCT获取的视网膜体积图像使用半自动分割算法进行二维分割。然后，使用三维算法，对所有体积分割的视网膜表面进行厚度测量量化。随时间变化的视网膜厚度变化图代表了损伤过程中视网膜表面变性的进展情况。这些计算工具补充了OCT视网膜体积采集功能，为研究啮齿动物的视觉科学家提供了一个强大的工具。
