1
|
Li J, Yu Z, Han M, Zeng Q, Zhang Y, Wei S, Wu L, Du J, Li J, Gao J, Li Y, Chen X. Biochemical component analysis of human myopic corneal stroma using the Raman spectrum. Int Ophthalmol 2024; 44:153. [PMID: 38509410 DOI: 10.1007/s10792-024-03034-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 01/12/2024] [Indexed: 03/22/2024]
Abstract
PURPOSE This study aimed to measure the Raman spectrum of the human corneal stroma lens obtained from small incision lenticule extraction surgery (SMILE) in Asian myopic eyes using a confocal Raman micro-spectrometer built in the laboratory. METHODS Forty-three myopic patients who underwent SMILE with equivalent diopters between - 4.00 and - 6.00 D were selected, and the right eye data were collected. Corneal stroma lenses were obtained during surgery, and the Raman spectra were measured after air drying. The complete Raman spectrum of human myopic corneal stroma lens tissue was obtained within the range of 700-4000 cm-1. RESULTS Thirteen characteristic peaks were found, with the stronger peaks appearing at 937 cm-1, corresponding to proline, valine, and the protein skeleton of the human myopic corneal stroma lens; 1243 cm-1, corresponding to collagen protein; 1448 cm-1, corresponding to the collagen protein and phospholipids; and 2940 cm-1, corresponding to the amino acid and lipids, which was the strongest Raman peak. CONCLUSION These results demonstrated that Raman spectroscopy has much potential as a fast, cost-effective, and reliable diagnostic tool in the diagnosis and treatment of eye diseases, including myopia, keratoconus, and corneal infection.
Collapse
Affiliation(s)
- Jing Li
- Shaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital, Affliated People's Hospital of Northwest University, No 4. Jiefang Road, Xin-Chen District, Xi'an, 710004, Shaanxi, China
| | - Zhe Yu
- Shaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital, Affliated People's Hospital of Northwest University, No 4. Jiefang Road, Xin-Chen District, Xi'an, 710004, Shaanxi, China
| | - Ming Han
- Xi'an Key Laboratory of Intelligent Sensing and Regulation of Trans-Scale Life Information, School of Life Science and Technology, Xidian University, Xi'an, 710126, Shaanxi, China
- Engineering Research Center of Molecular & Neuro Imaging of the Ministry of Education, Xidian University, Xi'an, 710126, Shaanxi, China
| | - Qi Zeng
- Xi'an Key Laboratory of Intelligent Sensing and Regulation of Trans-Scale Life Information, School of Life Science and Technology, Xidian University, Xi'an, 710126, Shaanxi, China
- Engineering Research Center of Molecular & Neuro Imaging of the Ministry of Education, Xidian University, Xi'an, 710126, Shaanxi, China
| | - Yaohua Zhang
- Shaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital, Affliated People's Hospital of Northwest University, No 4. Jiefang Road, Xin-Chen District, Xi'an, 710004, Shaanxi, China
| | - Shengsheng Wei
- Shaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital, Affliated People's Hospital of Northwest University, No 4. Jiefang Road, Xin-Chen District, Xi'an, 710004, Shaanxi, China
| | - Liping Wu
- Shaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital, Affliated People's Hospital of Northwest University, No 4. Jiefang Road, Xin-Chen District, Xi'an, 710004, Shaanxi, China
| | - Jing Du
- Shaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital, Affliated People's Hospital of Northwest University, No 4. Jiefang Road, Xin-Chen District, Xi'an, 710004, Shaanxi, China
| | - Juan Li
- Shaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital, Affliated People's Hospital of Northwest University, No 4. Jiefang Road, Xin-Chen District, Xi'an, 710004, Shaanxi, China
| | - Jinrong Gao
- Shaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital, Affliated People's Hospital of Northwest University, No 4. Jiefang Road, Xin-Chen District, Xi'an, 710004, Shaanxi, China
| | - Yong Li
- Shaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital, Affliated People's Hospital of Northwest University, No 4. Jiefang Road, Xin-Chen District, Xi'an, 710004, Shaanxi, China.
| | - Xueli Chen
- Xi'an Key Laboratory of Intelligent Sensing and Regulation of Trans-Scale Life Information, School of Life Science and Technology, Xidian University, Xi'an, 710126, Shaanxi, China.
- Engineering Research Center of Molecular & Neuro Imaging of the Ministry of Education, Xidian University, Xi'an, 710126, Shaanxi, China.
| |
Collapse
|
2
|
Zheng X, Duan X, Tu X, Jiang S, Song C. The Fusion of Microfluidics and Optics for On-Chip Detection and Characterization of Microalgae. Micromachines (Basel) 2021; 12:1137. [PMID: 34683188 PMCID: PMC8540680 DOI: 10.3390/mi12101137] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 09/17/2021] [Accepted: 09/18/2021] [Indexed: 01/21/2023]
Abstract
It has been demonstrated that microalgae play an important role in the food, agriculture and medicine industries. Additionally, the identification and counting of the microalgae are also a critical step in evaluating water quality, and some lipid-rich microalgae species even have the potential to be an alternative to fossil fuels. However, current technologies for the detection and analysis of microalgae are costly, labor-intensive, time-consuming and throughput limited. In the past few years, microfluidic chips integrating optical components have emerged as powerful tools that can be used for the analysis of microalgae with high specificity, sensitivity and throughput. In this paper, we review recent optofluidic lab-on-chip systems and techniques used for microalgal detection and characterization. We introduce three optofluidic technologies that are based on fluorescence, Raman spectroscopy and imaging-based flow cytometry, each of which can achieve the determination of cell viability, lipid content, metabolic heterogeneity and counting. We analyze and summarize the merits and drawbacks of these micro-systems and conclude the direction of the future development of the optofluidic platforms applied in microalgal research.
Collapse
Affiliation(s)
| | | | | | | | - Chaolong Song
- School of Mechanical Engineering and Electronic Information, China University of Geosciences, Wuhan 430074, China; (X.Z.); (X.D.); (X.T.); (S.J.)
| |
Collapse
|
3
|
Abstract
INTRODUCTION Raman and Infrared spectroscopic techniques are being used for the analysis of different types of cancers and other biological molecules. It is possible to identify cancers from normal tissues both in fresh and fixed tissues. These techniques can be used not only for the early diagnosis of cancer but also for monitoring the progression of the disease. Furthermore, chemical pathways to the progression of the disease process can be understood and followed. AREAS COVERED More recently, Artificial Intelligence (AI), Neural Network (NN), and Machine Learning are being combined with spectroscopy, which is making it easier to understand the chemical structural details of cancers and biological molecules more precisely and accurately. In this report, these aspects are being outlined by using breast cancer as a specific example. EXPERT OPINION A pathway showing to combine vibrational spectroscopy with AI and ML has immense potential in predicting various stages of different disease processes, in particular, in cancer diagnosis, staging, and designing treatment. This will result in improved patient care pathways.
Collapse
Affiliation(s)
- Ihtesham U Rehman
- Bioengineering │ Engineering Department, Faculty of Science and Technology, Lancaster University , Lancaster, UK
| | - Rabia Sannam Khan
- Bioengineering │ Engineering Department, Faculty of Science and Technology, Lancaster University , Lancaster, UK
| | - Shazza Rehman
- Department of Medical Oncology, Airedale NHS Foundation Trust, Airedale General Hospital, Steeton , West Yorkshire, UK
| |
Collapse
|
4
|
Bertens CJ, Gijs M, van den Biggelaar FJ, Nuijts RM. Topical drug delivery devices: A review. Exp Eye Res 2018; 168:149-160. [DOI: 10.1016/j.exer.2018.01.010] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 12/08/2017] [Accepted: 01/11/2018] [Indexed: 12/22/2022]
|
5
|
Tian Y, Su JW, Ju J, Liu Q. Efficiency enhancement of Raman spectroscopy at long working distance by parabolic reflector. Biomed Opt Express 2017; 8:5243-5252. [PMID: 29188117 PMCID: PMC5695967 DOI: 10.1364/boe.8.005243] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 10/04/2017] [Accepted: 10/18/2017] [Indexed: 06/07/2023]
Abstract
Raman spectroscopy is well suited for readily revealing information about bio-samples. As such, this technique has been applied to a wide range of areas, particularly in bio-medical diagnostics. Raman scattering in bio-samples typically has a low signal level due to the nature of inelastic scattering of photons. To achieve a high signal level, usually a high numerical aperture objective is employed. One drawback with these objectives is that their working distance is very short. However, in many cases of clinical diagnostics, a long working distance is preferable. We propose a practical solution to this problem by enhancing the Raman signal using a parabolic reflector. The high signal level is achieved through the large light collection solid angle of the parabolic reflector while the long working distance is ensured by the novel design of our microscope. The enhancement capability of the microscope was demonstrated on four types of samples. Among these samples, we find that this microscope design is most suitable for turbid samples.
Collapse
Affiliation(s)
- Yao Tian
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Dr. 637459,
Singapore
| | - Joshua Weiming Su
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Dr. 637459,
Singapore
| | - Jian Ju
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Dr. 637459,
Singapore
| | - Quan Liu
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Dr. 637459,
Singapore
| |
Collapse
|
6
|
Hu J, Wu F, Huang Z, Ma S, Zhang J, Yang J, Han X, Xu G. Raman Spectroscopy Analysis of the Biochemical Characteristics of Experimental Keratomycosis. Curr Eye Res 2016; 41:1408-1413. [PMID: 27158983 DOI: 10.3109/02713683.2015.1127393] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Jianzhang Hu
- From the Eye Center of the First Affiliated Hospital of Fujian Medical University, Fujian Eye Institute, Fu Zhou, China
| | - Fujin Wu
- From the Eye Center of the First Affiliated Hospital of Fujian Medical University, Fujian Eye Institute, Fu Zhou, China
| | - Zufang Huang
- From the Key Laboratory of Optoelectronic Science and Technology for Medicine, Ministry of Education, Fujian Provincial Key Laboratory of Photonic Technology, Fujian Normal University, Fu Zhou, China
| | - Shuting Ma
- From the Eye Center of the First Affiliated Hospital of Fujian Medical University, Fujian Eye Institute, Fu Zhou, China
| | - Jingjin Zhang
- From the Eye Center of the First Affiliated Hospital of Fujian Medical University, Fujian Eye Institute, Fu Zhou, China
| | - Juan Yang
- From the Eye Center of the First Affiliated Hospital of Fujian Medical University, Fujian Eye Institute, Fu Zhou, China
| | - Xiaoli Han
- From the Eye Center of the First Affiliated Hospital of Fujian Medical University, Fujian Eye Institute, Fu Zhou, China
| | - Guoxing Xu
- From the Eye Center of the First Affiliated Hospital of Fujian Medical University, Fujian Eye Institute, Fu Zhou, China
| |
Collapse
|
7
|
Taylor ZD, Garritano J, Sung S, Bajwa N, Bennett DB, Nowroozi B, Tewari P, Sayre J, Hubschman JP, Deng S, Brown ER, Grundfest WS. THz and mm-Wave Sensing of Corneal Tissue Water Content: Electromagnetic Modeling and Analysis. IEEE Trans Terahertz Sci Technol 2015; 5:170-183. [PMID: 26322247 PMCID: PMC4551413 DOI: 10.1109/tthz.2015.2392619] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Terahertz (THz) spectral properties of human cornea are explored as a function of central corneal thickness (CCT) and corneal water content, and the clinical utility of THz-based corneal water content sensing is discussed. Three candidate corneal tissue water content (CTWC) perturbations, based on corneal physiology, are investigated that affect the axial water distribution and total thickness. The THz frequency reflectivity properties of the three CTWC perturbations were simulated and explored with varying system center frequency and bandwidths (Q-factors). The modeling showed that at effective optical path lengths on the order of a wavelength the cornea presents a lossy etalon bordered by air at the anterior and the aqueous humor at the posterior. The simulated standing wave peak-to-valley ratio is pronounced at lower frequencies and its effect on acquired data can be modulated by adjusting the bandwidth of the sensing system. These observations are supported with experimental spectroscopic data. The results suggest that a priori knowledge of corneal thickness can be utilized for accurate assessments of corneal tissue water content. The physiologic variation of corneal thickness with respect to the wavelengths spanned by the THz band is extremely limited compared to all other structures in the body making CTWC sensing unique amongst all proposed applications of THz medical imaging.
Collapse
Affiliation(s)
- Zachary D. Taylor
- Department of Bioengineering, University of California (UCLA), Los Angeles, CA 90095 USA, and also with the Center for Advanced Surgical and Interventional Technology (CASIT), University of California (UCLA), Los Angeles, CA 90095 USA
| | - James Garritano
- Department of Bioengineering, University of California (UCLA), Los Angeles, CA 90095 USA, and also with the Center for Advanced Surgical and Interventional Technology (CASIT), University of California (UCLA), Los Angeles, CA 90095 USA
| | - Shijun Sung
- Department of Electrical Engineering, University of California (UCLA), Los Angeles, CA 90095 USA
| | - Neha Bajwa
- Department of Bioengineering, University of California (UCLA), Los Angeles, CA 90095 USA, and also with the Center for Advanced Surgical and Interventional Technology (CASIT), University of California (UCLA), Los Angeles, CA 90095 USA
| | - David B. Bennett
- Department of Electrical Engineering, University of California (UCLA), Los Angeles, CA 90095 USA. He is now with Fitbit, San Francisco, CA 94105 USA
| | - Bryan Nowroozi
- Department of Bioengineering, University of California (UCLA), Los Angeles, CA 90095 USA, and also with the Center for Advanced Surgical and Interventional Technology (CASIT), University of California (UCLA), Los Angeles, CA 90095 USA. He is now with Mimeo Labs Inc, Santa Monica, CA 90404 USA
| | - Priyamvada Tewari
- Department of Bioengineering, University of California (UCLA), Los Angeles, CA 90095 USA, and also with the Center for Advanced Surgical and Interventional Technology (CASIT), University of California (UCLA), Los Angeles, CA 90095 USA. She is now with Elsevier Life Science solutions, San Francisco, CA 94105 USA
| | - James Sayre
- Department of Biostatistics, University of California (UCLA), Los Angeles, CA 90095 USA
| | - Jean-Pierre Hubschman
- Department of Ophthalmology, University of California (UCLA), Los Angeles, CA 90095 USA
| | - Sophie Deng
- Department of Ophthalmology, University of California (UCLA), Los Angeles, CA 90095 USA
| | - Elliott R. Brown
- Department. of Electrical Engineering, Wright State University, Dayton, OH 45435 USA
| | - Warren S. Grundfest
- Department of Bioengineering, University of California (UCLA), Los Angeles, CA 90095 USA, and also with the Center for Advanced Surgical and Interventional Technology (CASIT), University of California (UCLA), Los Angeles, CA 90095 USA
| |
Collapse
|
8
|
Wang H, Lee AM, Lui H, McLean DI, Zeng H. A method for accurate in vivo micro-Raman spectroscopic measurements under guidance of advanced microscopy imaging. Sci Rep 2013; 3:1890. [PMID: 23712517 DOI: 10.1038/srep01890] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Accepted: 05/01/2013] [Indexed: 11/25/2022] Open
Abstract
The movement from the subjects during in vivo confocal Raman spectral measurements could change the measurement volume, leading to non-specific signals and inaccurate interpretation of the acquired spectrum. Here we introduce a generally applicable method that includes (1) developing a multimodal system to achieve real-time monitoring of every spectral measurement with reflectance confocal microscopy (RCM) and multiphoton microscopy (MPM) imaging; (2) performing region-of-interest measurement by scanning an area of the tissue during spectral acquisition. The developed method has been validated by measuring different micro-structures of in vivo human skin. Our results demonstrated great consistency between RCM images and confocal Raman spectra. The superior quality of the images and spectra allows us to derive blood flow velocity and blood glucose level. We believe this method is valuable for realizing accurate microscopic spectral measurement and have great potential to be adapted into clinic to achieve non-invasive measurement of important biological parameters.
Collapse
|
9
|
|
10
|
Patel S, Alió JL, Javaloy J, Perez-Santonja JJ, Artola A, Rodriguez-Prats J. Human Cornea Before and After Refractive Surgery Using a New Device: VCH-1. Cornea 2008; 27:1042-9. [DOI: 10.1097/ico.0b013e318172fc40] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
|
11
|
Bauer NJC, Motamedi M, Hendrikse F, Wicksted JP. Remote temperature monitoring in ocular tissue using confocal Raman spectroscopy. J Biomed Opt 2005; 10:031109. [PMID: 16229634 DOI: 10.1117/1.1911901] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
We demonstrated the feasibility of Raman spectroscopy for remote temperature monitoring within the aqueous humor of the rabbit eye in vivo. Using a confocal Raman spectroscopy system, Raman spectra from 2580 to 3800 cm(-1) were recorded in HPLC-grade water and in the aqueous humor of the rabbit eye under in vivo and ex vivo conditions within a temperature range of 14-34 degrees C. The ratio between the integrated Raman intensities of two temperature dependent OH-vibrational regions (OH2/OH1) in the spectra of water showed high linear dependence on temperature both in pure water [0.0049(+/-1.2%)T+0.4522(+/-0.5%), R2=0.99, n=50, p<0.05], as well as in the rabbit aqueous humor [0.0036(+/-2.8%)T+0.4966(+/-0.6%), R2=0.98, n=162, p<0.05] with a high degree of reproducibility and sensitivity ( approximately 0.2-0.7 degrees C). Raman spectroscopy can be used for high resolution and remote monitoring of temperature in the aqueous humor under in vivo conditions.
Collapse
Affiliation(s)
- Noel J C Bauer
- Department of Ophthalmology, Academic Hospital Maastricht, Maastricht, the Netherlands
| | | | | | | |
Collapse
|
12
|
Abstract
Epithelial ovarian cancer has the highest mortality rate among the gynecologic cancers and spreads beyond the ovary in 90% of the women diagnosed with ovarian cancer. Detection before the disease has spread beyond the ovary would significantly improve the survival from ovarian cancer, which is currently only 30% over 5 years, despite extensive efforts to improve the survival. This study describes initial investigation of the use of optical technologies to improve the outcome for this disease by detecting cancers at an earlier and more treatable stage. Women undergoing oophorectomy were recruited for this study. Ovaries were harvested for fluorescence spectroscopy, confocal microscopy, and optical coherence tomography. Fluorescence spectroscopy showed large diagnostic differences between normal and abnormal tissue at 270 and 340 nm excitation. Optical coherence tomography was able to image up to 2mm deep into the ovary with particular patterns of backscattered intensity observed in normal versus abnormal tissue. Fluorescence confocal microscopy was able to visualize sub-cellular structures of the surface epithelium and underlying cell layers. Optical imaging and/or spectroscopy has the potential to improve the diagnostic capability in the ovary, but extended systematic investigations are needed to identify the unique signatures of disease. The combination of optical technologies supported by modern molecular biology may lead to an instrument that can accurately detect early carcinogenesis.
Collapse
Affiliation(s)
- Molly A Brewer
- Biomedical Engineering Program, University of Arizona, 1515 N. Campbell Ave., Room 1968, Tucson, AZ 85724-5024, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Abstract
PURPOSE The degree of corneal hydration has been linked to excimer laser corneal ablation rates. Enhanced precision with excimer laser refractive surgery may result from a better understanding of the transient changes in corneal hydration. To better understand the dynamic nature of corneal hydration, bovine corneas were investigated under different surface treatments. METHODS Confocal micro-Raman spectroscopy was used to quantify corneal hydration. Water and acetone solutions were used to establish a quantitative response of the relative OH/CH Raman bands, which are consistent with the water and collagen protein bands in cornea, respectively. Intact bovine corneas were manually debrided (designated MD group) or lamellar flaps were created to expose stromal tissue (designated lamellar keratectomy or LK group). Raman spectra were recorded every 30 seconds for 6 minutes while the prepared cornea surfaces were exposed to quiescent air or to a forced nitrogen gas flow across the surface. RESULTS The OH and CH Raman bands yielded a linear response while the percentage of acetone was varied from 0% to 100%. For the bovine cornea under forced flow drying, the OH/CH Raman band ratio was found to decrease by 41% from the initial value for both the MD and LK treatment groups. These decreases were significantly more (p = 0.0051 and 0.054, respectively) than the 26% decrease in the OH/CH band ratio measured for the control corneas. In quiescent air, the control and MD groups exhibited a 7% and 6% decrease in the OH/CH ratio, respectively, while the LK treatment group revealed a 19% decrease in the OH/CH ratio. CONCLUSIONS The bovine eye experiments demonstrate that significant changes in corneal hydration are realized under different drying conditions and treatment methodologies. This study elucidates the nature of transient changes in corneal hydration in a bovine model and suggests the need for further study of the role of such variations in surgical outcome for excimer laser corneal refractive procedures.
Collapse
Affiliation(s)
- Brian T Fisher
- College of Engineering, University of Florida, Gainsville, Florida, USA
| | | | | | | |
Collapse
|
14
|
Abstract
PURPOSE To correlate the observed fluorescence spectrum with the depth of ablation during 193 nm argon-fluoride excimer laser ablation of chemically damaged corneas. SETTING Laser facility, Cedars-Sinai Medical Center, Los Angeles, California, USA. METHODS Three cadaver New Zealand white rabbit corneas were exposed to 1 N hydrogen chloride for 10 seconds. The resultant opaque corneas were ablated to perforation using the excimer laser. Laser-induced fluorescence was collected at 45 degrees from incidence and channeled into an ultraviolet-visible spectrometer coupled to an optical multichannel analyzer reading a diode array detector. The detector recorded single-shot fluorescence spectra. The data were examined by principal component analysis, and the evolution of eigenvectors and their weighting coefficients were used to compare data among corneas. The results were correlated with histopathological sections. RESULTS The eigenvalues of 3 principal components corresponded to 88.9%, 10.0%, and 0.4% of the data in acid-burned corneas. Compared to that in undamaged corneas, more information was stored in the first principal component and the third eigenvector was distinctly altered. Acid-scarred tissue blue shifted the dominant fluorescence peak compared to that in normal corneal tissue. CONCLUSIONS After severe hydrogen chloride burn to the rabbit corneal surface, monitoring the dominant peak wavelength shift of excimer-laser-induced fluorescence can detect the transition between severely acid-damaged and underlying tissue.
Collapse
Affiliation(s)
- Roy S Chuck
- Department of Ophthalmology, University of California, Irvine, California 92697-4375, USA.
| | | | | | | | | | | |
Collapse
|
15
|
Choo-Smith LP, Edwards HGM, Endtz HP, Kros JM, Heule F, Barr H, Robinson JS, Bruining HA, Puppels GJ. Medical applications of Raman spectroscopy: from proof of principle to clinical implementation. Biopolymers 2002; 67:1-9. [PMID: 11842408 DOI: 10.1002/bip.10064] [Citation(s) in RCA: 126] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Raman spectroscopy has recently been applied ex vivo and in vivo to address various biomedical issues such as the early detection of cancers, monitoring of the effect of various agents on the skin, determination of atherosclerotic plaque composition, and rapid identification of pathogenic microorganisms. This leap in the number of applications and the number of groups active in this field has been facilitated by several technological advancements in lasers, CCD detectors, and fiber-optic probes. However, most of the studies are still at the proof of concept stage. We present a discussion on the status of the field today, as well as the problems and issues that still need to be resolved to bring this technology to hospital settings (i.e., the medical laboratory, surgical suites, or clinics). Taken from the viewpoint of clinicians and medical analysts, the potential of Raman spectroscopic techniques as new tools for biomedical applications is discussed and a path is proposed for the clinical implementation of these techniques.
Collapse
Affiliation(s)
- L-P Choo-Smith
- Laboratory for Intensive Care Research and Optical Spectroscopy, Erasmus University Rotterdam, Rotterdam, The Netherlands. lin-p'
| | | | | | | | | | | | | | | | | |
Collapse
|