{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,25]],"date-time":"2026-04-25T02:39:28Z","timestamp":1777084768928,"version":"3.51.4"},"reference-count":22,"publisher":"Aerospace Medical Association","issue":"2","license":[{"start":{"date-parts":[[2026,2,1]],"date-time":"2026-02-01T00:00:00Z","timestamp":1769904000000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,2]]},"abstract":"\n INTRODUCTION:<\/jats:bold>\n Acute hypoxia poses a serious risk in military aviation because it can lead to impaired performance of safety-critical tasks. Early detection of hypoxia is therefore critical. Oxygen saturation (S\n p<\/jats:sub>\n o<\/jats:sc>\n 2<\/jats:sub>\n ) of the retinal blood vessels may serve as a surrogate biomarker for brain hypoxia. This study investigates the feasibility of detecting hypoxia through retinal imaging in the near-infrared (NIR) spectrum, which does not interfere with the pilot\u2019s vision.\n <\/jats:p>\n \n METHODS:<\/jats:bold>\n There were 12 subjects who participated in a hypobaric flight simulation to lower systemic S\n p<\/jats:sub>\n o<\/jats:sc>\n 2<\/jats:sub>\n . Retinal images were captured using a dual-wavelength NIR fundus camera, while S\n p<\/jats:sub>\n o<\/jats:sc>\n 2<\/jats:sub>\n was measured via fingertip pulse oximetry. The optical density (OD) of retinal blood vessels was extracted from the images at both wavelengths. It was hypothesized that the ratio of vessel OD between the two wavelengths increases with rising S\n p<\/jats:sub>\n o<\/jats:sc>\n 2<\/jats:sub>\n .\n <\/jats:p>\n \n RESULTS:<\/jats:bold>\n Measured S\n p<\/jats:sub>\n o<\/jats:sc>\n 2<\/jats:sub>\n was compared with the calculated OD ratio. No correlation was found between the OD ratio and S\n p<\/jats:sub>\n o<\/jats:sc>\n 2<\/jats:sub>\n .\n <\/jats:p>\n \n DISCUSSION:<\/jats:bold>\n NIR retinal imaging appears to be unsuitable for accurate hypoxia detection within an acceptable \u00b14% error margin using our imaging protocol. This is mainly due to the low contrast of blood vessels in the NIR wavelength region, along with limited imaging repeatability resulting from realignment and refocusing steps in the imaging protocol. These factors have a larger distorting effect on the images than the subtle OD ratio changes related to varying S\n p<\/jats:sub>\n o<\/jats:sc>\n 2<\/jats:sub>\n .\n <\/jats:p>\n \n \n Bekkers A, Zoutenbier V, Bussink P, Groen E, Kuijf H, Amelink A.\n Using near infrared light to detect hypoxia in retinal images<\/jats:italic>\n . Aerosp Med Hum Perform. 2026; 97(2):111\u2013115.\n <\/jats:bold>\n <\/jats:p>","DOI":"10.3357\/amhp.6789.2026","type":"journal-article","created":{"date-parts":[[2026,2,10]],"date-time":"2026-02-10T13:44:32Z","timestamp":1770731072000},"page":"111-115","source":"Crossref","is-referenced-by-count":0,"title":["Using Near Infrared Light to Detect Hypoxia in Retinal Images"],"prefix":"10.3357","volume":"97","author":[{"given":"Amerens","family":"Bekkers","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Vincent","family":"Zoutenbier","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Peter","family":"Bussink","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Eric","family":"Groen","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hugo","family":"Kuijf","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Arjen","family":"Amelink","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1911","reference":[{"key":"B1","series-title":"Front Physiol.","first-page":"665821","article-title":"Hypoxic hypoxia and brain function in military aviation: basic physiology and applied perspectives","volume":"12","author":"Shaw DM","year":"2021","unstructured":"Shaw DM, Cabre G, Gant N. Hypoxic hypoxia and brain function in military aviation: basic physiology and applied perspectives. Front Physiol. 2021 May 17; 12:665821."},{"issue":"1","key":"B2","series-title":"PLoS One.","first-page":"e0190612","article-title":"Non-invasive assessment of cerebral oxygenation: a comparison of retinal and transcranial oximetry","volume":"13","author":"Van Keer K","year":"2018","unstructured":"Van Keer K, Van Keer J, Barbosa Breda J, Nassiri V, De Deyne C, Non-invasive assessment of cerebral oxygenation: a comparison of retinal and transcranial oximetry. PLoS One. 2018 Jan 5; 13(1):e0190612."},{"issue":"2","key":"B3","series-title":"Transl Vis Sci Technol.","first-page":"5","article-title":"Advances in retinal oximetry","volume":"10","author":"Garg AK","year":"2021","unstructured":"Garg AK, Knight D, Lando L, Chao DL. Advances in retinal oximetry. Transl Vis Sci Technol. 2021 Feb 5; 10(2):5."},{"issue":"3","key":"B4","series-title":"Exp Eye Res.","first-page":"473","article-title":"Oxygen-dependent diseases in the retina: role of hypoxia-inducible factors","volume":"83","author":"Arjamaa O","year":"2006","unstructured":"Arjamaa O, Nikinmaa M. Oxygen-dependent diseases in the retina: role of hypoxia-inducible factors. Exp Eye Res. 2006 Sep; 83(3):473\u201383."},{"issue":"2","key":"B5","series-title":"J Appl Physiol (1985).","first-page":"748","article-title":"Oximetry of retinal vessels by dual-wavelength imaging: calibration and influence of pigmentation","volume":"86","author":"Beach JM","year":"1999","unstructured":"Beach JM, Schwenzer KJ, Srinivas S, Kim D, Tiedeman JS. Oximetry of retinal vessels by dual-wavelength imaging: calibration and influence of pigmentation. J Appl Physiol (1985). 1999 Feb; 86(2):748\u201358."},{"issue":"12","key":"B6","series-title":"Graefes Arch Clin Exp Ophthalmol.","first-page":"2373","article-title":"In vivo retinal and choroidal hypoxia imaging using a novel activatable hypoxia-selective near-infrared fluorescent probe","volume":"254","author":"Fukuda S","year":"2016","unstructured":"Fukuda S, Okuda K, Kishino G, Hoshi S, Kawano I, In vivo retinal and choroidal hypoxia imaging using a novel activatable hypoxia-selective near-infrared fluorescent probe. Graefes Arch Clin Exp Ophthalmol. 2016 Dec; 254(12):2373\u201385."},{"issue":"4","key":"B7","series-title":"ACS Med Chem Lett.","first-page":"445","article-title":"Applications of azo-based probes for imaging retinal hypoxia","volume":"6","author":"Uddin MI","year":"2015","unstructured":"Uddin MI, Evans SM, Craft JR, Marnett LJ, Uddin MJ, Jayagopal A. Applications of azo-based probes for imaging retinal hypoxia. 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