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Richard P Stodtmeister, Maria Heyde, Sylvana Ventzke, Eberhard Spoerl, Lutz E Pillunat; During the Valsalva Maneuver the Retinal Venous Pressure Is Higher than the Airway Pressure and the Intraocular Pressure. Invest. Ophthalmol. Vis. Sci. 2015;56(7 ):2742.
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© ARVO (1962-2015); The Authors (2016-present)
The increase of the intraocular pressure (∆IOP) during the Valsalva maneuver (VM) has been ascribed to the assumed increase in venous pressure in the literature. In this study we simultaneously measured the airway pressure (AirP) and the retinal vein pressure (RVP) during VM in order to investigate the quantitative relation of these two parameters. ∆IOP during VM was measured for comparison.
31 healthy young volunteers were investigated (table 1). Left eyes were examined in mydriasis. Intraocular pressure was measured by Dynamic contour tonometry (DCT), the AirP by a pressure transducer (Foehr Medical Instruments, Seeheim-Jugenheim, Germany) the output of which was connected with a y-t plotter. The RVP was measured by Contact Lens Dynamometry (CLD) (Imedos, Jena, Germany). The following measurements were successively done: DCT, RVP, repeated simultaneous measurement of AirP and RVP during VM, DCT, DCT during VM. The pressures (AirP, RVP) during VM were determined at the timepoints 10s, 20s, and 30s after the onset of the VM by linear interpolation. The distribution was judged by P-P diagrams. ANOVA for repeated measurements, student one sample t-test and paired t-test were used with Bonferroni correction (significance level 0.05).
Table 2 shows the pressures measured. The standard deviation of the AirP increases with duration of the VM. The mean values of AirP do not differ significantly (ANOVA, P=0.7). During the VM RVP was significantly higher than AirP at the three time points (TP) (P<0.001). The increase in RVP (∆RVP) was at TP 10s: 8.5 (6.1-10.9) mmHg (mean and 95% confidence interval), at TP 20s: 7.8 (5.7-10.0) mmHg, at TP 30s: 5.6 (1,4- 9.9) mmHg. ∆RVP was statistically significantly higher than 5 mmHg at TP 10s (P<0,01) and at TP 20s (P<0.05). At TP 30s ∆RVP was higher than 1 mmHg (P<0.05). The ∆IOP during VM was 0.47 (-0.02-1,00) and statistically not different from zero (P=0.06). The ∆RVP was statistically significantly higher than the ∆IOP: TP 10s and 20s: P<0.001, TP 30: P<0.05.
The RVP during VM was higher than the AirP. The ∆RVP was significantly higher than the ∆IOP. During VM the retinal perfusion pressure and the perfusion pressure in the optic nerve head may be more decreased by ∆RVP than by the significantly lower ∆IOP. These properties may influence the retinal and optic nerve head pathophysiology.
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