PDF(Pubmed)
Abstract：
Photoreceptors (PRs) and retinal pigment epithelial (RPE) cells form a functional unit called the PR-RPE complex. The PR-RPE complex plays a critical role in maintaining retinal homeostasis and function, and the quantification of its structure and topographical arrangement across the macula are important for understanding the etiology, mechanisms, and progression of many retinal diseases. However, the three-dimensional cellular morphology of the PR-RPE complex in living human eyes has not been completely described due to limitations in imaging techniques. We used the cellular resolution and depth-sectioning capabilities of a custom, high-speed Fourier domain mode-locked laser-based adaptive optics-optical coherence tomography (FDML-AO-OCT) platform to characterize human PR-RPE complex topography across the temporal macula from eleven healthy volunteers. With the aid of a deep learning algorithm, key metrics were extracted from the PR-RPE complex of averaged AO-OCT volumes including PR and RPE cell density, PR outer segment length (OSL), and PR/RPE ratio. We found a tight grouping among our cohort for PR density, with a mean (±SD) value of 53,329 (±8106) cells/mm2 at 1° decreasing to 8669 (±737) cells/mm2 at 12°. We observed a power function relationship between eccentricity and both PR density and PR/RPE ratio. We found similar variability in our RPE density measures, with a mean value of 7335 (±681) cells/mm2 at 1° decreasing to 5547 (±356) cells/mm2 at 12°, exhibiting a linear relationship with a negative slope of -123 cells/mm2 per degree. OSL monotonically decreased from 33.3 (±2.4) µm at 1° to 18.0 (±1.8) µm at 12°, following a second-order polynomial relationship. PR/RPE ratio decreased from 7.3 (±0.9) µm at 1° to 1.5 (±0.1) µm at 12°. The normative data from this investigation will help lay a foundation for future studies of retinal pathology.
摘要：
光感受器(PR)和视网膜色素上皮(RPE)细胞形成称为PR-RPE复合物的功能单元。PR-RPE复合物在维持视网膜稳态和功能方面发挥关键作用，对黄斑的结构和地形排列的量化对于理解病因很重要，机制,和许多视网膜疾病的进展。然而,由于成像技术的局限性，尚未完全描述活体人眼中PR-RPE复合物的三维细胞形态。我们使用了自定义的细胞分辨率和深度切片功能，基于高速傅里叶域锁模激光的自适应光学相干断层扫描（FDML-AO-OCT）平台，可表征来自11名健康志愿者的颞叶黄斑上的人类PR-RPE复杂形貌。借助深度学习算法，从平均AO-OCT体积的PR-RPE复合物中提取关键指标，包括PR和RPE细胞密度，PR外段长度(OSL),和PR/RPE比率。我们在我们的队列中发现了一个紧密的PR密度分组，在1°时的平均（±SD）值为53,329（±8106）个细胞/mm2，在12°时降低到8669（±737）个细胞/mm2。我们观察到偏心率与PR密度和PR/RPE比之间的幂函数关系。我们在RPE密度测量中发现了类似的可变性，1°时的平均值为7335（±681）个细胞/mm2，12°时的平均值为5547（±356）个细胞/mm2，表现出线性关系，负斜率为-123个细胞/mm2/度。OSL从1°时的33.3(±2.4)µm单调下降到12°时的18.0(±1.8)µm,遵循二阶多项式关系。PR/RPE比从1°的7.3（±0.9）µm下降到12°的1.5（±0.1）µm。这项调查的规范数据将有助于为未来的视网膜病理学研究奠定基础。
