Impact of Valsalva Maneuver on Corneal Morphology and Anterior Chamber Parameters

Abstract

Our aim was to examine the influence of the Valsalva maneuver (VM) on corneal morphology and anterior chamber parameters. This prospective observational study included 35 eyes of 35 healthy volunteers. One of the eyes of each subject was selected randomly. The keratometry (K), pachymetry, corneal volume, iridocorneal angle, anterior chamber depth, anterior chamber volume, and corneal wave front measurements (high-order aberration, low-order aberration, total root mean square) were performed with the Pentacam HR (Oculus, Wetzlar, Germany). The subjects were aged between 22 and 41 years. There were 24 men (69%) and 11 women (31%). The VM did not have any significant influence on K-flat and K-average values (P > 0.05), but it decreased K-steep values significantly (P = 0.006). The VM did not have any significant impact on low-order aberrations and total root mean square parameters (P > 0.05), but it increased high-order aberrations significantly (P = 0.008). The central corneal thickness and corneal volume decreased significantly during the VM (P < 0.05). The iridocorneal angle, anterior chamber depth, and anterior chamber volume decreased markedly during the VM (P < 0.001). The VM has some influence on corneal morphology and anterior chamber parameters, so that it should be considered during anterior segment examinations and operations.