Mehmet Orkun Sevik, Furkan Çam, Aslan Aykut, Volkan Dericioğlu, Özlem Şahin
{"title":"Choroidal vascularity index changes during the Valsalva manoeuvre in healthy volunteers.","authors":"Mehmet Orkun Sevik, Furkan Çam, Aslan Aykut, Volkan Dericioğlu, Özlem Şahin","doi":"10.1111/opo.12935","DOIUrl":null,"url":null,"abstract":"<p><strong>Purpose: </strong>To evaluate the effects of the Valsalva manoeuvre (VM) on the choroidal vascularity index (CVI) in healthy volunteers.</p><p><strong>Methods: </strong>This prospective, cross-sectional study included 60 eyes of 30 healthy volunteers. Enhanced depth imaging-optical coherence tomography scans of both eyes involving the fovea were taken, and a 1500 μm subfoveal choroidal area was selected for image binarization with open-access 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.</p><p><strong>Results: </strong>During the VM, a mean ± standard deviation increase in LA (0.02 ± 0.05 mm<sup>2</sup> , p < 0.001) and CVI (1.72 ± 2.83%, p < 0.001) was observed, whereas SA (-0.02 ± 0.05 mm<sup>2</sup> , p < 0.001) decreased. There was no significant change in TCA (0.00 ± 0.03 mm<sup>2</sup> , p = 0.55) or SFCT (1.05 ± 10.92 μm, p = 0.46). There was a moderate positive correlation between the spherical equivalent refractive error (SE) and SFCT both at rest and during VM (r<sub>58</sub> = 0.49, p < 0.0005 and r<sub>58</sub> = 0.49, p < 0.0005, respectively). However, there was no significant correlation between SE and CVI either at rest or during VM (p = 0.11 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 (p < 0.001).</p><p><strong>Conclusion: </strong>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.</p>","PeriodicalId":520731,"journal":{"name":"Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists)","volume":" ","pages":"367-375"},"PeriodicalIF":0.0000,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"5","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists)","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1111/opo.12935","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2021/12/16 0:00:00","PubModel":"Epub","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 5
Abstract
Purpose: To evaluate the effects of the Valsalva manoeuvre (VM) on the choroidal vascularity index (CVI) in healthy volunteers.
Methods: This prospective, cross-sectional study included 60 eyes of 30 healthy volunteers. Enhanced depth imaging-optical coherence tomography scans of both eyes involving the fovea were taken, and a 1500 μm subfoveal choroidal area was selected for image binarization with open-access 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.
Results: During the VM, a mean ± standard deviation increase in LA (0.02 ± 0.05 mm2 , p < 0.001) and CVI (1.72 ± 2.83%, p < 0.001) was observed, whereas SA (-0.02 ± 0.05 mm2 , p < 0.001) decreased. There was no significant change in TCA (0.00 ± 0.03 mm2 , p = 0.55) or SFCT (1.05 ± 10.92 μm, p = 0.46). There was a moderate positive correlation between the spherical equivalent refractive error (SE) and SFCT both at rest and during VM (r58 = 0.49, p < 0.0005 and r58 = 0.49, p < 0.0005, respectively). However, there was no significant correlation between SE and CVI either at rest or during VM (p = 0.11 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 (p < 0.001).
Conclusion: 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.