Kocaoglu Omer P, Lee Sangyeol, Jonnal Ravi S, Wang Qiang, Herde Ashley E, Derby Jack C, Gao Weihua, Miller Donald T
School of Optometry, Indiana University, 800 East Atwater Avenue, Bloomington, IN 47405, USA.
Biomed Opt Express. 2011 Mar 1;2(4):748-63. doi: 10.1364/BOE.2.000748.
Cone photoreceptors in the living human eye have recently been imaged with micron-scale resolution in all three spatial dimensions using adaptive optics optical coherence tomography. While these advances have allowed non-invasive study of the three-dimensional structure of living human cones, studies of their function and physiology are still hampered by the difficulties to monitor the same cells over time. The purpose of this study is to demonstrate the feasibility of cone monitoring using ultrahigh-resolution adaptive optics optical coherence tomography. Critical to this is incorporation of a high speed CMOS camera (125 KHz) and a novel feature-based, image registration/dewarping algorithm for reducing the deleterious effects of eye motion on volume images. Volume movies were acquired on three healthy subjects at retinal eccentricities from 0.5° to 6°. Image registration/dewarping reduced motion artifacts in the movies from 15 μm to 1.3 μm root mean square, the latter sufficient for identifying and tracking cones. Cone row-to-row spacing and outer segment lengths were consistent with that reported in the literature. Cone length analysis demonstrates that UHR-AO-OCT is sufficiently sensitive to measure real length differences between cones in the same 0.5° retinal patch, and requires no more than five measurements of OS length to achieve 95% confidence. We know of no other imaging modality that can monitor foveal or parafoveal cones over time with comparable resolution in all three dimensions.
最近，利用自适应光学光学相干断层扫描技术，已在三个空间维度上以微米级分辨率对活人眼中的视锥光感受器进行了成像。虽然这些进展使得对活人视锥细胞的三维结构进行非侵入性研究成为可能，但对视锥细胞功能和生理学的研究仍因难以长时间监测同一细胞而受到阻碍。本研究的目的是证明使用超高分辨率自适应光学光学相干断层扫描技术监测视锥细胞的可行性。对此至关重要的是采用高速CMOS相机（125千赫兹）和一种基于特征的新型图像配准/去扭曲算法，以减少眼球运动对体图像的有害影响。在三名健康受试者的视网膜偏心度为0.5°至6°的区域采集了体视电影。图像配准/去扭曲将电影中的运动伪影从均方根15微米减少到1.3微米，后者足以识别和跟踪视锥细胞。视锥细胞的行间距和外段长度与文献报道一致。视锥细胞长度分析表明，超高分辨率自适应光学光学相干断层扫描技术足够灵敏，能够测量同一0.5°视网膜区域内视锥细胞之间的实际长度差异，并且测量视锥细胞外段长度不超过五次就能达到95%的置信度。我们所知的其他成像方式，都无法在所有三个维度上以可比的分辨率长时间监测中央凹或中央凹旁的视锥细胞。
