Intraocular pressure and ocular pulse amplitude variations during the Valsalva maneuver

To evaluate the effect of the Valsalva maneuver (VM) on short-term variations of intraocular pressure (IOP) and ocular pulse amplitude (OPA) values in healthy, young, male subjects. IOP and OPA values were measured before and during VM by Pascal dynamic contour tonometer (DCT) in 55 eyes of 55 healthy male volunteers aged 20 through 27 years. Mean IOP before VM was 17.2 +/- 2.9 mmHg and during the VM was 19.8 +/- 4 mmHg. The increase in mean IOP during the VM was found to be statistically significant (p = 0.001). The IOP increased in 46 (83.6%) of 55 eyes. However, in nine eyes (16.4%), IOP decreased during the VM. Mean OPA value before VM was 3.6 +/- 1.4 mmHg and during the VM was 3.6 +/- 1.3 mmHg. The change in mean OPA value was found to be statistically insignificant (p = 0.9). The IOP significantly increases during VM, whereas OPA remains stable. Strong autoregulatory mechanisms may provide consistent ocular perfusion in healthy subjects during VM.