Akademik Veri Yönetim Sistemi
OPHTHALMIC AND PHYSIOLOGICAL OPTICS, cilt.42, sa.2, ss.367-375, 2022 (SCI-Expanded)
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 mu m 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 mm(2), p < 0.001) and CVI (1.72 +/- 2.83%, p < 0.001) was observed, whereas SA (-0.02 +/- 0.05 mm(2), p < 0.001) decreased. There was no significant change in TCA (0.00 +/- 0.03 mm(2), p = 0.55) or SFCT (1.05 +/- 10.92 mu m, 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(58) = 0.49, p < 0.0005 and r(58) = 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.