{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,6]],"date-time":"2026-10-06T01:09:09Z","timestamp":1791248949495,"version":"4.1.0"},"reference-count":41,"publisher":"Springer Science and Business Media LLC","issue":"2","license":[{"start":{"date-parts":[[2021,12,16]],"date-time":"2021-12-16T00:00:00Z","timestamp":1639612800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Ophthalmic Physiologic Optic"],"published-print":{"date-parts":[[2022,3]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Purpose<\/jats:title>\n                    <jats:p>To evaluate the effects of the Valsalva manoeuvre (VM) on the choroidal vascularity index (CVI) in healthy volunteers.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>This prospective, cross\u2010sectional study included 60 eyes of 30\u00a0healthy volunteers. Enhanced depth imaging\u2010optical coherence tomography scans of both eyes involving the fovea were taken, and a 1500\u00a0\u03bcm subfoveal choroidal area was selected for image binarization with open\u2010access Fiji software. The binarized image was segmented into the stromal area (SA) and luminal area (LA), and CVI was calculated as the ratio (%) of LA to the total choroidal area (TCA). CVI, subfoveal choroidal thickness (SFCT), IOP, systolic and diastolic blood pressure were evaluated at rest and during the VM.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      During the VM, a mean\u00a0\u00b1\u00a0standard deviation increase in LA (0.02\u00a0\u00b1\u00a00.05\u00a0mm\n                      <jats:sup>2<\/jats:sup>\n                      ,\n                      <jats:italic>p\u00a0<\/jats:italic>\n                      &lt;\u00a00.001) and CVI (1.72\u00a0\u00b1\u00a02.83%,\n                      <jats:italic>p\u00a0<\/jats:italic>\n                      &lt;\u00a00.001) was observed, whereas SA (\u22120.02\u00a0\u00b1\u00a00.05\u00a0mm\n                      <jats:sup>2<\/jats:sup>\n                      ,\n                      <jats:italic>p\u00a0<\/jats:italic>\n                      &lt;\u00a00.001) decreased. There was no significant change in TCA (0.00\u00a0\u00b1\u00a00.03\u00a0mm\n                      <jats:sup>2<\/jats:sup>\n                      ,\n                      <jats:italic>p\u00a0<\/jats:italic>\n                      =\u00a00.55) or SFCT (1.05\u00a0\u00b1\u00a010.92\u00a0\u03bcm,\n                      <jats:italic>p\u00a0<\/jats:italic>\n                      =\u00a00.46). There was a moderate positive correlation between the spherical equivalent refractive error (SE) and SFCT both at rest and during VM (r\n                      <jats:sub>58<\/jats:sub>\n                      \u00a0=\u00a00.49,\n                      <jats:italic>p\u00a0<\/jats:italic>\n                      &lt;\u00a00.0005 and r\n                      <jats:sub>58<\/jats:sub>\n                      \u00a0=\u00a00.49,\n                      <jats:italic>p<\/jats:italic>\n                      \u00a0&lt;\u00a00.0005, respectively). However, there was no significant correlation between SE and CVI either at rest or during VM (\n                      <jats:italic>p<\/jats:italic>\n                      \u00a0=\u00a00.11 and 0.06, respectively). In a multiple linear regression analysis, CVI was only associated with SFCT; however, SFCT was also associated with SE, both at rest and during VM (\n                      <jats:italic>p<\/jats:italic>\n                      \u00a0&lt;\u00a00.001).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>Valsalva manoeuvre increases CVI by choroidal vascular dilation as demonstrated by an increase in LA and a decrease in SA. Researchers should be careful about unintentional VM during examinations.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1111\/opo.12935","type":"journal-article","created":{"date-parts":[[2021,12,16]],"date-time":"2021-12-16T07:28:06Z","timestamp":1639639686000},"page":"367-375","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["Choroidal vascularity index changes during the Valsalva manoeuvre in healthy volunteers"],"prefix":"10.1007","volume":"42","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7130-4798","authenticated-orcid":false,"given":"Mehmet Orkun","family":"Sevik","sequence":"first","affiliation":[{"name":"Department of Ophthalmology Marmara University School of Medicine  Istanbul 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