{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,17]],"date-time":"2026-03-17T22:51:49Z","timestamp":1773787909005,"version":"3.50.1"},"reference-count":44,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2024,11,7]],"date-time":"2024-11-07T00:00:00Z","timestamp":1730937600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Background\/Objectives: Retinal vascular occlusions are a significant cause of visual impairment in older adults, resulting in ischemic retinal damage and sudden vision loss. This study evaluates the retinal, optic nerve head (ONH), and choroidal capillary networks in chronic and acute-on-chronic hypoxia compared to normal controls using optical coherence tomography angiography (OCT-A). Methods: We evaluated a prospective study including twenty patients in the hypoxic group (mean age 61.2 \u00b1 10.2) in two phases, chronic hypoxia and acute-on-chronic hypoxia, and 21 control subjects (mean age 59 \u00b1 9.4 years). All patients underwent a comprehensive eye examination, OCT, and OCT-A imaging. The data were analyzed using OCT-A analysis software (Zeiss OCT-A software 2.1.0.55513) and Fiji software (1.51a). Vascular density of the retina and ONH, choriocapillaries, and foveal avascular zone (FAZ) size were measured. Results: The superficial peripapillary vascular density was higher for the control group (0.387 \u00b1 0.03) compared to the hypoxic patients with (0.383 \u00b1 0.03) and without O2 supplementation (0.383 \u00b1 0.03; p = 0.018). No retinal angiographic differences were identified between the two study groups. The ganglion cell layer (GCL) was thinner in the hypoxic group. Both hypoxic subgroups demonstrated denser choriocapillaries (mean 13,073 \u00b1 1812 and 12,689 \u00b1 1815, with and without O2 supplementation, respectively) compared to the control group (mean 9749 \u00b1 2881, p &lt; 0.001 for both groups). Hypoxic patients demonstrated increased area size of choriocapillaries (+O2 supplementation\u2014mean 44,347 \u00b1 10,563; \u2212O2 supplementation\u2014mean 46,984 \u00b1 12,822) compared to the control group (mean 30,979 \u00b1 9635; p &lt; 0.01 and p &lt; 0.001, respectively). Conclusions: Chronic and acute-on-chronic hypoxia did not affect the retinal vascular network, most probably due to the strong autoregulation of vascular function of the retina. However, compared to the control group, GCL, ONH vasculature density, and most choriocapillaries indices were significantly altered among hypoxic patients.<\/jats:p>","DOI":"10.3390\/jcm13226680","type":"journal-article","created":{"date-parts":[[2024,11,7]],"date-time":"2024-11-07T07:47:16Z","timestamp":1730965636000},"page":"6680","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Evaluation of Retinal and Posterior Segment Vascular Changes Due to Systemic Hypoxia Using Optical Coherence Tomography Angiography"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3682-0225","authenticated-orcid":false,"given":"Nadav","family":"Levinger","sequence":"first","affiliation":[{"name":"Department of Ophthalmology, Hadassah University Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3327-0173","authenticated-orcid":false,"given":"Nir","family":"Erdinest","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Hadassah University Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1245-6844","authenticated-orcid":false,"given":"Ayman","family":"Abu Rmeileh","sequence":"additional","affiliation":[{"name":"Institute of Pulmonary Medicine, Hadassah University Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Eisa","family":"Mouallem","sequence":"additional","affiliation":[{"name":"Internal Medical Daycare, Hadassah University Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shadi","family":"Zahran","sequence":"additional","affiliation":[{"name":"Department of Medicine B, Hadassah University Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sheer","family":"Shabat","sequence":"additional","affiliation":[{"name":"Department of Physical & Medical Rehabilitation, Hadassah University Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yotam","family":"Kolben","sequence":"additional","affiliation":[{"name":"Department of Medicine A, Hadassah University Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Talmon","family":"Aviv","sequence":"additional","affiliation":[{"name":"Department of Medicine C, Hadassah University Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5191-5962","authenticated-orcid":false,"given":"Rottem","family":"Kuint","sequence":"additional","affiliation":[{"name":"Institute of Pulmonary Medicine, Hadassah University Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Liran","family":"Tiosano","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Hadassah University Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Samer","family":"Khateb","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Hadassah University Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,11,7]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"511","DOI":"10.1016\/j.ajo.2003.12.035","article-title":"Ophthalmic fundus imaging: Today and beyond","volume":"137","author":"Yannuzzi","year":"2004","journal-title":"Am. J. Ophthalmol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2163","DOI":"10.1097\/IAE.0000000000000765","article-title":"Image artifacts in optical coherence angiography","volume":"35","author":"Spaide","year":"2015","journal-title":"Retina"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Liu, T., Lin, W., Shi, G., Wang, W., Feng, M., Xie, X., Liu, T., and Zhou, Q. (2022). Retinal and Choroidal Vascular Perfusion and Thickness Measurement in Diabetic Retinopathy Patients by the Swept-Source Optical Coherence Tomography Angiography. Front. Med., 9.","DOI":"10.3389\/fmed.2022.786708"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"275","DOI":"10.1159\/000522503","article-title":"Optical Coherence Tomography Angiography In Central Retinal Vein Occlusion: Macular Changes And Their Correlation With Peripheral Nonperfusion At Ultra-Widefield Fluorescein Angiography","volume":"245","author":"Cavalleri","year":"2022","journal-title":"Ophthalmologica"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"3605","DOI":"10.1007\/s00417-021-05253-6","article-title":"Ocular perfusion in patients with reduced left ventricular ejection fraction measured by optical coherence tomography angiography","volume":"259","author":"Alnawaiseh","year":"2021","journal-title":"Graefe\u2019s Arch. Clin. Exp. Ophthalmol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"456","DOI":"10.1016\/j.ajo.2012.09.015","article-title":"Peripapillary retinal nerve fiber layer thickness in sickle-cell hemoglobinopathies using spectral-domain optical coherence tomography","volume":"155","author":"Chow","year":"2013","journal-title":"Am. J. Ophthalmol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"116","DOI":"10.1080\/02713683.2017.1373824","article-title":"The evaluation of retinal and choroidal structural changes by optical coherence tomography in patients with chronic obstructive pulmonary disease","volume":"43","author":"Gok","year":"2018","journal-title":"Curr. Eye Res."},{"key":"ref_8","first-page":"68","article-title":"Evaluation of choroidal thickness, retinal vascular caliber, and nerve fiber layer thickness in idiopathic interstitial pneumonia","volume":"34","author":"Ugurlu","year":"2017","journal-title":"Sarcoidosis Vasc. Diffus. Lung Dis."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"355","DOI":"10.1080\/02713683.2020.1801757","article-title":"OCT-angiography comparison between obstructive sleep apnea children and normal subjects in China","volume":"46","author":"Ye","year":"2021","journal-title":"Curr. Eye Res."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Heinonen, I.H., Boushel, R., and Kalliokoski, K.K. (2016). The circulatory and metabolic responses to hypoxia in humans\u2013with special reference to adipose tissue physiology and obesity. Front. Endocrinol., 7.","DOI":"10.3389\/fendo.2016.00116"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"S46","DOI":"10.1111\/j.1523-1755.2005.09909.x","article-title":"Role of hypoxia in the pathogenesis of renal disease","volume":"68","author":"Eckardt","year":"2005","journal-title":"Kidney Int."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"284","DOI":"10.1111\/crj.13478","article-title":"The alterations of retinal vasculature detected on optical coherence tomography angiography associated with chronic obstructive pulmonary disease","volume":"16","author":"Songur","year":"2022","journal-title":"Clin. Respir. J."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"247","DOI":"10.1111\/crj.12523","article-title":"New aspect for systemic effects of COPD: Eye findings","volume":"12","author":"Ugurlu","year":"2018","journal-title":"Clin. Respir. J."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"683","DOI":"10.1111\/crj.13349","article-title":"Peripapillary vascular density and retinal nerve fibre layer changes in patients with chronic obstructive pulmonary disease","volume":"15","author":"Alkan","year":"2021","journal-title":"Clin. Respir. J."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"944","DOI":"10.1016\/j.ophtha.2017.02.006","article-title":"Impact of multiple en face image averaging on quantitative assessment from optical coherence tomography angiography images","volume":"124","author":"Uji","year":"2017","journal-title":"Ophthalmology"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"397","DOI":"10.1016\/j.ajo.2019.08.026","article-title":"Impact of slab selection on quantification of choriocapillaris flow deficits by optical coherence tomography angiography","volume":"208","author":"Byon","year":"2019","journal-title":"Am. J. Ophthalmol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"203","DOI":"10.1167\/iovs.17-22953","article-title":"A novel strategy for quantifying choriocapillaris flow voids using swept-source OCT angiography","volume":"59","author":"Zhang","year":"2018","journal-title":"Investig. Ophthalmol. Vis. Sci."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1197","DOI":"10.1001\/jamaophthalmol.2017.3904","article-title":"Choriocapillaris imaging using multiple en face optical coherence tomography angiography image averaging","volume":"135","author":"Uji","year":"2017","journal-title":"JAMA Ophthalmol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"79","DOI":"10.1097\/IAE.0000000000001517","article-title":"Ising model of choriocapillaris flow","volume":"38","author":"Spaide","year":"2018","journal-title":"Retina"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"110","DOI":"10.1016\/j.ajo.2018.12.025","article-title":"Age-dependent changes in the macular choriocapillaris of normal eyes imaged with swept-source optical coherence tomography angiography","volume":"200","author":"Zheng","year":"2019","journal-title":"Am. J. Ophthalmol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1016\/j.ajo.2019.07.003","article-title":"Quantification of choriocapillaris with optical coherence tomography angiography: A comparison study","volume":"208","author":"Chu","year":"2019","journal-title":"Am. J. Ophthalmol."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Nassisi, M., Baghdasaryan, E., Tepelus, T., Asanad, S., Borrelli, E., and Sadda, S.R. (2018). Topographic distribution of choriocapillaris flow deficits in healthy eyes. PLoS ONE, 13.","DOI":"10.1371\/journal.pone.0207638"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1435","DOI":"10.2147\/COPD.S107424","article-title":"Morphological changes in small pulmonary vessels are associated with severe acute exacerbation in chronic obstructive pulmonary disease","volume":"11","author":"Yoshimura","year":"2016","journal-title":"Int. J. Chronic Obstr. Pulm. Dis."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"661","DOI":"10.1016\/j.redox.2014.04.006","article-title":"Oxygen delivery, consumption, and conversion to reactive oxygen species in experimental models of diabetic retinopathy","volume":"2","author":"Eshaq","year":"2014","journal-title":"Redox Biol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"43603","DOI":"10.1155\/2007\/43603","article-title":"Oxidative stress and diabetic retinopathy","volume":"2007","author":"Kowluru","year":"2007","journal-title":"Exp. Diabetes Res."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"175","DOI":"10.1016\/S1350-9462(00)00027-6","article-title":"Oxygen distribution and consumption within the retina in vascularised and avascular retinas and in animal models of retinal disease","volume":"20","author":"Yu","year":"2001","journal-title":"Prog. Retin. Eye Res."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"701","DOI":"10.1016\/S0161-6420(85)33978-7","article-title":"Retinal vascular autoregulation in conditions of hyperoxia and hypoxia using the blue field entoptic phenomenon","volume":"92","author":"Fallon","year":"1985","journal-title":"Ophthalmology"},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Sun, L., Chen, W., Chen, Z., Xiang, Y., Guo, J., Hu, T., Xu, Q., Zhang, H., and Wang, J. (2020). Dual effect of the Valsalva maneuver on autonomic nervous system activity, intraocular pressure, Schlemm\u2019s canal, and iridocorneal angle morphology. BMC Ophthalmol., 20.","DOI":"10.1186\/s12886-019-1275-y"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Zhang, C., Cheng, S., Chen, H., Yang, J., and Chen, Y. (2024). New findings on retinal microvascular changes in patients with primary COVID-19 infection: A longitudinal study. Front. Immunol., 15.","DOI":"10.3389\/fimmu.2024.1404785"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"103556","DOI":"10.1016\/j.pdpdt.2023.103556","article-title":"Retinal microvascular changes in patients recovered from COVID-19 compared to healthy controls: A meta-analysis","volume":"42","author":"Kazantzis","year":"2023","journal-title":"Photodiagnosis Photodyn. Ther."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1016\/j.ejrad.2005.06.010","article-title":"Color Doppler evaluation of the ocular arterial flow changes in chronic obstructive pulmonary disease","volume":"57","author":"Ozer","year":"2006","journal-title":"Eur. J. Radiol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1186\/s43168-021-00092-9","article-title":"Evaluation of the impact of COPD severity grading and oxygen saturation on the retinal nerve fiber layer thickness and subfoveal choroidal thickness in COPD patients","volume":"15","author":"Ahmed","year":"2021","journal-title":"Egypt. J. Bronchol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"334","DOI":"10.3928\/23258160-20240220-01","article-title":"Retinal Nerve Fiber Layer Changes in Patients With Chronic Obstructive Pulmonary Disease Compared to Healthy Controls: A Meta-analysis","volume":"55","author":"Kazantzis","year":"2024","journal-title":"Ophthalmic Surg. Lasers Imaging Retin."},{"key":"ref_34","first-page":"1201976","article-title":"Choroid and retinal nerve fiber layer thickness in patients with chronic obstructive pulmonary disease exacerbation","volume":"2018","author":"Zorlu","year":"2018","journal-title":"J. Ophthalmol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"9268364","DOI":"10.1155\/2020\/9268364","article-title":"Retinal Nerve Fibre Layer Thinning in Patients with Thalassaemia, Iron Deficiency Anaemia, and Anaemia of Chronic Diseases","volume":"2020","author":"Datta","year":"2020","journal-title":"J. Ophthalmol."},{"key":"ref_36","first-page":"704","article-title":"Retinal nerve fiber layer thickness changes in obstructive sleep apnea syndrome: One year follow-up results","volume":"7","author":"Zengin","year":"2014","journal-title":"Int. J. Ophthalmol."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Ekinci, M., Ceylan, E., Cagatay, H.H., Keles, S., Huseyinoglu, N., Tanyildiz, B., Cakici, O., and Kartal, B. (2014). Retinal nerve fibre layer, ganglion cell layer and choroid thinning in migraine with aura. BMC Ophthalmol., 14.","DOI":"10.1186\/1471-2415-14-75"},{"key":"ref_38","first-page":"e25517","article-title":"Role of Optical Coherence Tomography to Measure Retinal Nerve Fiber Layer Thickness in Patient With Chronic Obstructive Pulmonary Disease","volume":"14","author":"Wagh","year":"2022","journal-title":"Cureus"},{"key":"ref_39","unstructured":"Bron, A.J., Tripathi, R.C., and Tripathi, B.J. (1997). Wolff\u2019s Anatomy of the Eye and Orbit, Hodder Education."},{"key":"ref_40","first-page":"e98","article-title":"A review of the vascular anatomy of the optic nerve head and its clinical implications","volume":"5","author":"McAllister","year":"2013","journal-title":"Cureus"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"302","DOI":"10.1136\/bmj.1.4857.302","article-title":"Raised intracranial pressure in emphysema","volume":"1","author":"Westlake","year":"1954","journal-title":"Br. Med. J."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1186\/s40662-018-0118-x","article-title":"Choriocapillaris changes in dry age-related macular degeneration and geographic atrophy: A review","volume":"5","author":"Arya","year":"2018","journal-title":"Eye Vis."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Chua, J., Le, T.-T., Tan, B., Ke, M., Li, C., Wong, D.W.K., Tan, A., Lamoureux, E., Wong, T.Y., and Chin, C.W.L. (2021). Choriocapillaris microvasculature dysfunction in systemic hypertension. Sci. Rep., 11.","DOI":"10.1038\/s41598-021-84136-6"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"2991","DOI":"10.1038\/s41433-020-01298-9","article-title":"Progression of choriocapillaris flow deficits in clinically stable intermediate age-related macular degeneration","volume":"35","author":"Tiosano","year":"2021","journal-title":"Eye"}],"container-title":["Journal of Clinical Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2077-0383\/13\/22\/6680\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T16:27:56Z","timestamp":1760113676000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2077-0383\/13\/22\/6680"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,11,7]]},"references-count":44,"journal-issue":{"issue":"22","published-online":{"date-parts":[[2024,11]]}},"alternative-id":["jcm13226680"],"URL":"https:\/\/doi.org\/10.3390\/jcm13226680","relation":{},"ISSN":["2077-0383"],"issn-type":[{"value":"2077-0383","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,11,7]]}}}