Author Affiliations
Abstract
1 Department of Biomedical Engineering Yonsei University Wonju-si, Gangwon-do 26493 Republic of Korea
2 Research Center for Science and Technology in Medicine Tehran University of Medical Sciences Tehran 14185-615, Iran
3 Institute of Metabolism and Systems Research University of Birmingham Edgbaston Birmingham B15 2TT, UK
Typical fundus photography produces a two-dimensional image. This makes it difficult to observe the microvascular and neural abnormalities, because the depth of the image is missing. To provide depth appreciation, we develop a single-channel stereoscopic fundus video imaging system based on a rotating refractor. With respect to the pupil center, the rotating refractor laterally displaces the optical path and the illumination. This allows standard monocular fundus cameras to generate stereo-parallax and image disparity through sequential image acquisition. We optimize our imaging system, characterize the stereo-base, and image an eyeball model and a rabbit eye. When virtual realities are considered, our imaging system can be a simple yet efficient technique to provide depth perception in a virtual space that allows users to perceive abnormalities in the eye fundus.
Imaging systems ophthalmic optics and devices refraction vision — binocular and stereopsis ophthalmic optics and devices Journal of Innovative Optical Health Sciences
2021, 14(3): 2150012
1 中国科学院自适应光学重点实验室, 四川 成都 610209
2 中国科学院光电技术研究所, 四川 成都 610209
3 中国科学院大学, 北京 100049
光学相干层析血管造影(OCTA)是一种无需注射染料和无创的新兴影像学检查方法,它能以极高的分辨率和灵敏度来显示眼底血管网络,其高达微米级的纵向分辨能力能够定位病变在视网膜和脉络膜中的原发位置。OCTA可以提供与当前金标准相当甚至更好的血管观察效果,尤其是在没有副作用的情况下重复检查。因此,自从OCTA技术问世后,就获得了快速发展,商用化产品已经在临床实践中获得了应用。为了帮助相关人员快速了解这一技术,本文对OCTA技术的原理方法、在眼科学中的应用、产品和临床使用现状、存在不足与展望等进行了介绍。
医用光学 光学相干层析血管造影术 光学相干层析成像术 血管造影术 眼底血管疾病 眼科光学与仪器 激光与光电子学进展
2020, 57(18): 180002
1 加州大学戴维斯分校医学院, 加利福尼亚州, 戴维斯 95616, 美国
2 加州大学戴维斯分校生物医学工程学院, 加利福尼亚州, 戴维斯 95616, 美国
3 波士顿大学医学院, 马萨诸塞州, 波士顿 02118, 美国
4 伊利诺伊大学芝加哥分校生物工程学院, 伊利诺斯州, 芝加哥 60612, 美国
5 俄勒冈健康与科学大学生物医学工程学院, 俄勒冈州, 波特兰 97239, 美国
鉴于动物研究在基础研究中的重要作用,近年来几种在人眼视网膜成像中广泛应用的光学成像技术也在动物视网膜中得到了成功应用,无需组织学切片即可实现对动物视网膜的高精度细胞级别成像,这为使用动物视网膜进行基础研究的科研工作者提供了强有力的工具。与之相应的是,动物视网膜的研究工作中也开发了一些新型的、可以应用于人眼的成像技术,或者增强了对人眼视网膜功能机理的理解。结合自身在小鼠视网膜多种活体成像方式上的技术积累和研究经历,从若干方面阐述了近年来在小鼠和人眼视网膜高精度光学成像领域出现的技术突破,侧重于展示当前技术所能达到的成像水平,希望能起到抛砖引玉的效果,为促进动物视网膜影像和人眼视网膜影像之间的相互交流和相互促进起到积极的作用。
医用光学 眼科 成像系统 眼科光学与设备
Author Affiliations
Abstract
1 School of Electrical Engineering, Yanshan University, Qinhuangdao 066004, China
2 School of Control Engineering, Northeastern University at Qinhuangdao, Qinhuangdao 066004, China
3 Experiment Education Center, Northeastern University at Qinhuangdao, Qinhuangdao 066004, China
We demonstrated a method for measurement of central corneal thickness (CCT) with a sub-micrometer sensitivity using a spectral domain optical coherence tomography system without needing a super broad bandwidth light source. By combining the frequency and phase components of Fourier transform, the method is capable of measurement of a large dynamic range with a high sensitivity. Absolute phases are retrieved by comparing the correlations between the detected and simulated interference fringes. The phase unwrapping ability of the present method was quantitatively tested by measuring the displacement of a piezo linear stage. The human CCTs of six volunteers were measured to verify its clinical application. It provides a potential tool for clinical diagnosis and research applications in ophthalmology.
170.4500 Optical coherence tomography 170.4460 Ophthalmic optics and devices Chinese Optics Letters
2019, 17(4): 041701
Author Affiliations
Abstract
1 Key Laboratory on Adaptive Optics, Chinese Academy of Sciences, Chengdu 610209, China
2 Laboratory on Adaptive Optics, Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu 610209, China
3 University of Chinese Academy of Sciences, Beijing 100049, China
4 School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China
An objective visual performance evaluation with visual evoked potential (VEP) measurements was first integrated into an adaptive optics (AO) system. The optical and neural limits to vision can be bypassed through this system. Visual performance can be measured electrophysiologically with VEP, which reflects the objective function from the retina to the primary visual cortex. The VEP measurements without and with AO correction were preliminarily carried out using this system, demonstrating the great potential of this system in the objective visual performance evaluation. The new system will provide the necessary technique and equipment support for the further study of human visual function.
330.4460 Ophthalmic optics and devices 220.1080 Active or adoptive optics 330.4300 Vision system - noninvasive assessment 330.1070 Vision - acuity Chinese Optics Letters
2018, 16(5): 053301
Author Affiliations
Abstract
1 School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou 325027, China
2 The Eye Hospital of Wenzhou Medical University, Wenzhou 325027, China
Astigmatism is inevitable and inherent to progressive addition lenses (PALs), which are typically distributed in the lateral areas on both sides of the progressive corridor. In this study, we took into account the spectacle frame for the customized freeform PAL design with the variational-difference numerical approach. The PAL surface with minimized astigmatism, approximately equal to 84% of the added power, was numerically resolved without expending the zone for clear vision. We validated our approach by experimentally demonstrating the procedure from tool path generation to surface power measurement, thus providing an efficient solution to the personalization of astigmatism-minimized PAL design and manufacture.
330.4460 Ophthalmic optics and devices 080.4225 Nonspherical lens design Chinese Optics Letters
2018, 16(11): 113302
Author Affiliations
Abstract
1 Key Laboratory on Adaptive Optics, Chinese Academy of Sciences, Chengdu 610209, China
2 Laboratory on Adaptive Optics, Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu 610209, China
3 University of Chinese Academy of Sciences, Beijing 100049, China
A simple and straightforward method to objectively measure the transverse chromatic aberration (TCA) at horizontal field angles out to ±10° from the visual axis of the human eye was proposed. Longitudinal chromatic aberration (LCA) was also measured across the visual field. The TCA of a human eye was obtained by deviation of the point spread function (PSF) images. LCA was calculated from the Zernike defocus. The average TCA changing with eccentricity was 0.162 arcmin/degree between 639 nm and 795 nm wavelengths. Near the optic axis of the eye, the average LCA was 0.37 ± 0.02 D, and it increased slightly with eccentricity (up to 0.54 ± 0.02 D).
330.4460 Ophthalmic optics and devices 170.4460 Ophthalmic optics and devices 330.7327 Visual optics, ophthalmic instrumentation Chinese Optics Letters
2018, 16(11): 113301
Author Affiliations
Abstract
Institute of Modern Optics, Nankai University, Tianjin 300350, China
A double-zone aspheric diffractive intraocular lens (IOL) was designed and manufactured aiming to regain a continuous range of clear vision for pseudophakic presbyopia. After obtaining the IOL structure parameters through optimization based on an aphakic model eye, its imaging performances were analyzed in the model eye. The modulation transfer function at 50 cycles/mm remained above 0.29 within ±5° field of view for object distance ranging from 6 to 0.66 m. In addition, the imaging qualities are robust for pupil changes, polychromatic light, and different corneal asphericities. The manufactured IOL exhibits the ability to extend depth of focus.
330.4460 Ophthalmic optics and devices 220.2740 Geometric optical design 330.7323 Visual optics, aging changes Chinese Optics Letters
2018, 16(9): 093301
Author Affiliations
Abstract
1 School of Control Engineering, Northeastern University at Qinhuangdao, Qinhuangdao 066004, China
2 School of Electrical Engineering, Yanshan University, Qinhuangdao 066004, China
We demonstrate a system for measuring the ocular axial length (AL) with high sensitivity and high speed using spectral-domain low-coherence interferometry (SD-LCI). To address the limit in measuring such a large range by using SD-LCI, we propose a full-range method to recognize the positive and negative depths. The reference arm length is changed synchronously with the shift of the focal point of the probing beam. The system provides a composite depth range that is sufficient to cover the whole eye. We demonstrate the performance of the presented system by measuring the ALs of five volunteers. This system can provide the A-scan ocular biometric assessment of the corneal thickness and AL in 0.1 s.
170.4500 Optical coherence tomography 170.4460 Ophthalmic optics and devices Chinese Optics Letters
2018, 16(3): 031701
Author Affiliations
Abstract
1 Department of Biomedical Engineering, Peking University, Beijing 100871, China
2 Department of Anatomy, School of Basic Medical Sciences, Peking University, Beijing 100191, China
3 Laboratory Animal Center, Peking University, Beijing 100871, China
4 School of Public Health, Jilin University, Changchun 130012, China
Since significant ocular differences in both anatomical structure and optical properties exist between rodents and humans, clinical imaging devices for human use are not suitable for use on rodents. In this study, we develop a contact probe with a flexible surface that can closely fit the rodent cornea for fundus imaging with a confocal scanning laser ophthalmoscope. Both Zemax simulation and in vivo fundus imaging demonstrate that this contact probe can significantly improve both the imaging quality and the operational convenience.
170.0170 Medical optics and biotechnology 170.4460 Ophthalmic optics and devices 170.5755 Retina scanning 170.2520 Fluorescence microscopy Chinese Optics Letters
2016, 14(3): 031701
