{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,23]],"date-time":"2026-10-23T20:50:05Z","timestamp":1792788605451,"version":"4.5.0"},"reference-count":35,"publisher":"Public Library of Science (PLoS)","issue":"10","license":[{"start":{"date-parts":[[2023,10,5]],"date-time":"2023-10-05T00:00:00Z","timestamp":1696464000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000781","name":"European Research Council","doi-asserted-by":"publisher","award":["Synergy grant agreement no. 610110"],"award-info":[{"award-number":["Synergy grant agreement no. 610110"]}],"id":[{"id":"10.13039\/501100000781","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000781","name":"European Research Council","doi-asserted-by":"publisher","award":["Marie Sk\u0142odowska-Curie grant agreement no. 709104"],"award-info":[{"award-number":["Marie Sk\u0142odowska-Curie grant agreement no. 709104"]}],"id":[{"id":"10.13039\/501100000781","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100018875","name":"LabEx PALM","doi-asserted-by":"crossref","award":["ANR-10-LABX-0039-PALM"],"award-info":[{"award-number":["ANR-10-LABX-0039-PALM"]}],"id":[{"id":"10.13039\/501100018875","id-type":"DOI","asserted-by":"crossref"}]},{"name":"\u201cBanque Fran\u00e7aise des Yeux\u201d","award":["Prix BFY 2019"],"award-info":[{"award-number":["Prix BFY 2019"]}]},{"DOI":"10.13039\/501100001665","name":"Agence Nationale de la Recherche","doi-asserted-by":"publisher","award":["Investissements d\u2019Avenir"],"award-info":[{"award-number":["Investissements d\u2019Avenir"]}],"id":[{"id":"10.13039\/501100001665","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Institut Hospitalo-Universitaire","award":["FOReSIGHT (ANR-18-IAHU-0001)"],"award-info":[{"award-number":["FOReSIGHT (ANR-18-IAHU-0001)"]}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"<jats:p>\n                    Corneal transparency is essential to provide a clear view into and out of the eye, yet clinical means to assess such transparency are extremely limited and usually involve a subjective grading of visible opacities by means of slit-lamp biomicroscopy. Here, we describe an automated algorithm allowing extraction of quantitative corneal transparency parameters with standard clinical spectral-domain optical coherence tomography (SD-OCT). Our algorithm employs a novel pre-processing procedure to standardize SD-OCT image analysis and to numerically correct common instrumental artifacts before extracting mean intensity stromal-depth (\n                    <jats:italic>z<\/jats:italic>\n                    ) profiles over a 6-mm-wide corneal area. The\n                    <jats:italic>z<\/jats:italic>\n                    -profiles are analyzed using our previously developed objective method that derives quantitative transparency parameters directly related to the physics of light propagation in tissues. Tissular heterogeneity is quantified by the Birge ratio\n                    <jats:italic>B<\/jats:italic>\n                    <jats:sub>\n                      <jats:italic>r<\/jats:italic>\n                    <\/jats:sub>\n                    and the photon mean-free path (\n                    <jats:italic>l<\/jats:italic>\n                    <jats:sub>\n                      <jats:italic>s<\/jats:italic>\n                    <\/jats:sub>\n                    ) is determined for homogeneous tissues (i.e.,\n                    <jats:italic>B<\/jats:italic>\n                    <jats:sub>\n                      <jats:italic>r<\/jats:italic>\n                    <\/jats:sub>\n                    <jats:italic>~1<\/jats:italic>\n                    ). SD-OCT images of 83 normal corneas (ages 22\u201350 years) from a standard SD-OCT device (RTVue-XR Avanti, Optovue Inc.) were processed to establish a normative dataset of transparency values. After confirming stromal homogeneity (\n                    <jats:italic>B<\/jats:italic>\n                    <jats:sub>\n                      <jats:italic>r<\/jats:italic>\n                    <\/jats:sub>\n                    &lt;10), we measured a median\n                    <jats:italic>l<\/jats:italic>\n                    <jats:sub>\n                      <jats:italic>s<\/jats:italic>\n                    <\/jats:sub>\n                    of 570 \u03bcm (interdecile range: 270\u20132400 \u03bcm). By also considering corneal thicknesses, this may be translated into a median fraction of transmitted (coherent) light\n                    <jats:italic>T<\/jats:italic>\n                    <jats:sub>\n                      <jats:italic>coh(stroma)<\/jats:italic>\n                    <\/jats:sub>\n                    of 51% (interdecile range: 22\u201383%). Excluding images with central saturation artifact raised our median\n                    <jats:italic>T<\/jats:italic>\n                    <jats:sub>\n                      <jats:italic>coh(stroma)<\/jats:italic>\n                    <\/jats:sub>\n                    to 73% (interdecile range: 34\u201384%). These transparency values are slightly lower than those previously reported, which we attribute to the detection configuration of SD-OCT with a relatively small and selective acceptance angle. No statistically significant correlation between transparency and age or thickness was found. In conclusion, our algorithm provides robust and quantitative measurements of corneal transparency from standard SD-OCT images with sufficient quality (such as \u2018Line\u2019 and \u2018CrossLine\u2019 B-scan modes without central saturation artifact) and addresses the demand for such an objective means in the clinical setting.\n                  <\/jats:p>","DOI":"10.1371\/journal.pone.0291613","type":"journal-article","created":{"date-parts":[[2023,10,5]],"date-time":"2023-10-05T13:33:12Z","timestamp":1696512792000},"page":"e0291613","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":7,"title":["A new method for in vivo assessment of corneal transparency using spectral-domain OCT"],"prefix":"10.1371","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3380-290X","authenticated-orcid":true,"given":"Ma\u00eblle","family":"Vilbert","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Romain","family":"Bocheux","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cristina","family":"Georgeon","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vincent","family":"Borderie","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pascal","family":"Pernot","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2525-4288","authenticated-orcid":true,"given":"Kristina","family":"Irsch","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Karsten","family":"Plamann","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2023,10,5]]},"reference":[{"issue":"3","key":"pone.0291613.ref001","doi-asserted-by":"crossref","first-page":"439","DOI":"10.1016\/S0161-6420(96)30674-X","article-title":"Objective measurement of corneal light scattering after excimer laser keratectomy","volume":"103","author":"RE Braunstein","year":"1996","journal-title":"Ophthalmology"},{"issue":"5","key":"pone.0291613.ref002","doi-asserted-by":"crossref","first-page":"665","DOI":"10.1001\/archopht.1990.01070070051034","article-title":"Wound healing after excimer laser keratomileusis (photorefractive keratectomy) in monkeys","volume":"108","author":"FE Fantes","year":"1990","journal-title":"Arch Ophthalmol"},{"issue":"4","key":"pone.0291613.ref003","doi-asserted-by":"crossref","first-page":"161","DOI":"10.1016\/j.clae.2004.08.001","article-title":"Grading of corneal transparency","volume":"27","author":"C O\u2019Donnell","year":"2004","journal-title":"Cont Lens Anterior Eye"},{"issue":"2","key":"pone.0291613.ref004","doi-asserted-by":"crossref","first-page":"114","DOI":"10.3928\/1081-597X-19920301-03","article-title":"Corneal light scattering after excimer laser photorefractive keratectomy: the objective measurements of haze","volume":"8","author":"CP Lohmann","year":"1992","journal-title":"Refract Corneal Surg"},{"issue":"4","key":"pone.0291613.ref005","doi-asserted-by":"crossref","first-page":"584","DOI":"10.1038\/eye.1990.81","article-title":"Light scatter from the central human cornea","volume":"4","author":"GT Smith","year":"1990","journal-title":"Eye"},{"issue":"2","key":"pone.0291613.ref006","doi-asserted-by":"crossref","first-page":"204","DOI":"10.1016\/S0002-9394(01)01003-0","article-title":"Objective assessment of transient corneal haze and its relation to visual performance after photorefractive keratectomy","volume":"132","author":"C van de Pol","year":"2001","journal-title":"Am J Ophthalmol"},{"issue":"10","key":"pone.0291613.ref007","doi-asserted-by":"crossref","first-page":"1744","DOI":"10.1016\/S0161-6420(01)00771-0","article-title":"Evaluation of corneal stromal changes in vivo after laser in situ keratomileusis with confocal microscopy","volume":"108","author":"P-J Pisella","year":"2001","journal-title":"Ophthalmology"},{"issue":"10","key":"pone.0291613.ref008","doi-asserted-by":"crossref","first-page":"3493","DOI":"10.1167\/iovs.04-0096","article-title":"Objective measurements of corneal light-backscatter during corneal swelling, by optical coherence tomography","volume":"45","author":"J Wang","year":"2004","journal-title":"Invest Ophthalmol Vis Sci"},{"issue":"3","key":"pone.0291613.ref009","doi-asserted-by":"crossref","first-page":"501","DOI":"10.1016\/j.ophtha.2011.08.024","article-title":"Corneal densitometry as an indicator of corneal health","volume":"119","author":"AM Otri","year":"2012","journal-title":"Ophthalmology"},{"issue":"1","key":"pone.0291613.ref010","doi-asserted-by":"crossref","first-page":"162","DOI":"10.1167\/iovs.13-13236","article-title":"Normative values for corneal densitometry analysis by Scheimpflug optical assessment","volume":"55","author":"S N\u00ed Dhubhghaill","year":"2014","journal-title":"Invest Ophthalmol Vis Sci"},{"issue":"8","key":"pone.0291613.ref011","doi-asserted-by":"crossref","first-page":"e0221707","DOI":"10.1371\/journal.pone.0221707","article-title":"Quantitative measures of corneal transparency, derived from objective analysis of depth-resolved corneal images, demonstrated with full-field optical coherence tomographic microscopy","volume":"14","author":"R Bocheux","year":"2019","journal-title":"PLOS ONE"},{"issue":"2","key":"pone.0291613.ref012","doi-asserted-by":"crossref","first-page":"420","DOI":"10.1037\/0033-2909.86.2.420","article-title":"Intraclass correlations: Uses in assessing rater reliability","volume":"86","author":"PE Shrout","year":"1979","journal-title":"Psychol Bull"},{"issue":"31","key":"pone.0291613.ref013","doi-asserted-by":"crossref","first-page":"1026","DOI":"10.21105\/joss.01026","article-title":"Pingouin: statistics in Python","volume":"3","author":"R. Vallat","year":"2018","journal-title":"J Open Source Softw"},{"key":"pone.0291613.ref014","unstructured":"Vilbert M, Bocheux R. FitOCT-preprocessing: get OCT decays from raw corneal SD-OCT images. Version (1.0.0). 2021. available from: https:\/\/github.com\/maelle-v\/FitOCT-preprocessing"},{"issue":"6","key":"pone.0291613.ref015","doi-asserted-by":"crossref","first-page":"1524","DOI":"10.1364\/BOE.2.001524","article-title":"Robust automatic segmentation of corneal layer boundaries in SDOCT images using graph theory and dynamic programming","volume":"2","author":"F LaRocca","year":"2011","journal-title":"Biomed Opt Express"},{"key":"pone.0291613.ref016","article-title":"Enhance resolution on OCT profilometry measurements using harmonic artifacts","author":"MP Raele","year":"2015","journal-title":"Proc. SPIE 9312, Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XIX, 93123Q"},{"issue":"2","key":"pone.0291613.ref017","first-page":"333","article-title":"Normal human keratocyte density and corneal thickness measurement by using confocal microscopy in vivo","volume":"42","author":"SV Patel","year":"2001","journal-title":"Invest Ophthalmol Vis Sci"},{"key":"pone.0291613.ref018","unstructured":"Pernot P. FitOCT: Fit of OCT decays using R\/stan. Version (1.3.3). 2019. available from: https:\/\/doi.org\/10.5281\/zenodo.2579915"},{"key":"pone.0291613.ref019","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1117\/12.2527085","article-title":"Objective and quantitative analysis of corneal transparency with clinical spectral-domain optical coherence tomography","author":"R Bocheux","year":"2019","journal-title":"Proc. SPIE 11073, Clinical and Preclinical Optical Diagnostics II"},{"issue":"09","key":"pone.0291613.ref020","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1117\/1.JBO.24.9.090901","article-title":"Review of methods and applications of attenuation coefficient measurements with optical coherence tomography","volume":"24","author":"S Chang","year":"2019","journal-title":"J Biomed Opt"},{"issue":"04","key":"pone.0291613.ref021","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1117\/1.JBO.25.4.040901","article-title":"Parametric imaging of attenuation by optical coherence tomography: review of models, methods, and clinical translation","volume":"25","author":"P Gong","year":"2020","journal-title":"J Biomed Opt"},{"issue":"8","key":"pone.0291613.ref022","doi-asserted-by":"crossref","first-page":"590","DOI":"10.1364\/OL.19.000590","article-title":"Optical coherence microscopy in scattering media","volume":"19","author":"JA Izatt","year":"1994","journal-title":"Opt Lett"},{"issue":"2","key":"pone.0291613.ref023","doi-asserted-by":"crossref","first-page":"210","DOI":"10.1109\/JSTQE.2003.814194","article-title":"Accurate measurement of total attenuation coefficient of thin tissue with optical coherence tomography","volume":"9","author":"AI Kholodnykh","year":"2003","journal-title":"IEEE J Sel Top Quantum Electron"},{"issue":"19","key":"pone.0291613.ref024","doi-asserted-by":"crossref","first-page":"4353","DOI":"10.1364\/OPEX.12.004353","article-title":"Quantitative measurement of attenuation coefficients of weakly scattering media using optical coherence tomography","volume":"12","author":"DJ Faber","year":"2004","journal-title":"Opt Express"},{"issue":"3","key":"pone.0291613.ref025","doi-asserted-by":"crossref","first-page":"278","DOI":"10.1111\/cxo.12002","article-title":"Repeatability and reproducibility of corneal thickness using SOCT Copernicus HR: Corneal thickness using SOCT Copernicus HR","volume":"96","author":"S Vidal","year":"2013","journal-title":"Clin Exp Optom"},{"issue":"6","key":"pone.0291613.ref026","first-page":"776","article-title":"Transmission of the ocular media","volume":"1","author":"EA Boettner","year":"1962","journal-title":"Invest Ophthalmol Vis Sci"},{"issue":"1","key":"pone.0291613.ref027","doi-asserted-by":"crossref","first-page":"3","DOI":"10.3109\/02713688408997182","article-title":"Biophysical aspects of corneal and lenticular transparency","volume":"3","author":"S. Lerman","year":"1984","journal-title":"Curr Eye Res"},{"issue":"4","key":"pone.0291613.ref028","doi-asserted-by":"crossref","first-page":"393","DOI":"10.1016\/0014-4835(90)90140-P","article-title":"Light transmission of the cornea in whole human eyes","volume":"50","author":"EM Beems","year":"1990","journal-title":"Exp Eye Res"},{"issue":"11","key":"pone.0291613.ref029","doi-asserted-by":"crossref","first-page":"1453","DOI":"10.1016\/0042-6989(94)90146-5","article-title":"Light transmittance of the human cornea from 320 to 700 nm for different ages","volume":"34","author":"TJTP van den Berg","year":"1994","journal-title":"Vision Res"},{"issue":"10","key":"pone.0291613.ref030","doi-asserted-by":"crossref","first-page":"786","DOI":"10.3928\/1081597X-20100921-04","article-title":"Effect of incident light wavelength and corneal edema on light scattering and penetration: laboratory study of human corneas","volume":"26","author":"DA Peyrot","year":"2010","journal-title":"J Refract Surg"},{"issue":"5","key":"pone.0291613.ref031","doi-asserted-by":"crossref","first-page":"3340","DOI":"10.1167\/iovs.12-10694","article-title":"Wavelength optimization in femtosecond laser corneal surgery","volume":"54","author":"C Crotti","year":"2013","journal-title":"Invest Ophthalmol Vis Sci"},{"issue":"3","key":"pone.0291613.ref032","doi-asserted-by":"crossref","first-page":"335","DOI":"10.1007\/s10384-018-0584-7","article-title":"Assessment of corneal backward light scattering in the healthy cornea and factors affecting corneal transparency","volume":"62","author":"AB Cankaya","year":"2018","journal-title":"Jpn J Ophthalmol"},{"issue":"1","key":"pone.0291613.ref033","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1097\/01.ico.0000240095.95067.3f","article-title":"Age-related changes in central and peripheral corneal thickness: determination of normal values with the Orbscan II Topography System","volume":"26","author":"F R\u00fcfer","year":"2007","journal-title":"Cornea"},{"issue":"8","key":"pone.0291613.ref034","doi-asserted-by":"crossref","first-page":"086001","DOI":"10.1117\/1.JBO.17.8.086001","article-title":"Birefringence of the central cornea in children assessed with scanning laser polarimetry","volume":"17","author":"K Irsch","year":"2012","journal-title":"J Biomed Opt"},{"issue":"10","key":"pone.0291613.ref035","doi-asserted-by":"crossref","first-page":"3718","DOI":"10.1167\/iovs.04-1497","article-title":"Central corneal thickness is highly heritable: the twin eye studies","volume":"46","author":"T Toh","year":"2005","journal-title":"Invest Ophthalmol Vis Sci"}],"container-title":["PLOS ONE"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0291613","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,5]],"date-time":"2023-10-05T13:33:42Z","timestamp":1696512822000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0291613"}},"subtitle":[],"editor":[{"given":"Omnia","family":"Hamdy","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2023,10,5]]},"references-count":35,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2023,10,5]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0291613","relation":{},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,10,5]]}}}