Design of 1300 nm spectral domain optical coherence tomography angiography system for iris microvascular imaging
Design of 1300 nm spectral domain optical coherence tomography angiography system for iris microvascular imaging
复制标题
虹膜微血管成像1300 nm谱域光学相干断层扫描血管造影系统设计
DOI：
10.1088/1361-6463/abf577
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发表时间：
2021-07-01
影响因子：
3.4
通讯作者：
Wei, Xunbin
中科院分区：
文献类型：
--
作者：
Lan, Gongpu;Xu, Jingjiang;Wei, Xunbin
开发一种高分辨率的无创光学相干断层血管成像（OCTA）方法用于虹膜血管成像对于诊断各种眼部病变至关重要。然而，目前的虹膜- octa设备在成像质量和穿透深度上仍然受到限制，对于棕色到深棕色的深色眼睛。本文提出了一种光谱域虹膜- octa系统，该系统包括一个1300 nm波长，用于更深的组织穿透，一个线性波数光谱仪，用于更好的检测灵敏度，以及一个虹膜扫描物镜，用于在12 × 12 mm2扫描场上更好地聚焦整个虹膜。−6db的衰减范围为~ 3mm，在6.94 mm处灵敏度最大衰减为−28.57 dB。轴向分辨率为15.1±3.2 μm。40 mm焦距虹膜扫描物镜是根据100名亚洲受试者左眼的眼参数进行优化设计的，其虹膜横向分辨率一般为衍射极限（14.14 μm）。根据平均眼参数校准OCT畸变，所有眼的横向和轴向最大残余畸变均<0.1 mm（2.0%）。一项关于瞳孔收缩的初步研究进行了演示，通过水平或垂直快速扫描协议在深棕色眼睛中进行高对比度，宽视场的面部虹膜微血管成像。虹膜血管呈放射状排列，每条血管相对于快速扫描方向的角度为~ 65°-90°时更明显。一种新的环形快速扫描协议可以提高图像质量，使虹膜特征更好地可视化，或者与图像配准算法和眼动补偿眼动跟踪系统集成。
Developing a high-resolution non-invasive optical coherence tomography angiography (OCTA) method for iris vasculature imaging is essential for diagnosing a wide range of ocular pathologies. However, the current iris-OCTA devices are still limited in imaging quality and penetration depth for dark-colored eyes ranging from brown to dark brown. A spectral domain iris-OCTA system is presented in this paper incorporating a 1300 nm wavelength for deeper tissue penetration, a linear-wavenumber spectrometer for better detection sensitivity, and an iris scan objective lens for better optical focusing across the entire iris over a 12 × 12 mm2 scan field. The −6 dB fall-off range is ∼3 mm, and the maximum sensitivity fall-off is −28.57 dB at 6.94 mm. The axial resolution is 15.1 ± 3.2 μm. The 40 mm focal-length iris scan objective is optimized based on the ocular parameters from 100 Asian participants’ left eyes, and it has a diffraction-limited lateral resolution (14.14 μm) for the iris, in general. OCT distortions were calibrated based on the average ocular parameters, and the maximum residual distortions in both the lateral and axial directions were <0.1 mm (2.0%) for all of the eyes. A pilot study on a constricted pupil was performed to demonstrate high-contrast, wide-field en face iris microvascular imaging by either a horizontal or vertical fast-scan protocol in a dark brown eye. The iris vessels are radially aligned, and each vessel is more visible when it has an angle of ∼65°–90° with respect to the fast-scan direction. A new circular fast-scan protocol could improve image quality for better visualization of the iris features or integration with image-registration algorithms and an eye-tracking system for eye-motion compensation.