Dynamic changes in optic disc morphology, choroidal thickness, anterior chamber parameters, and intraocular pressure during Valsalva maneuver.

Abstract

Purpose: To investigate the effects of the Valsalva maneuver (VM) on optic disc morphology, choroidal thickness, and anterior chamber parameters. Methods: This prospective observational study included 60 eyes of 60 healthy subjects. The anterior chamber parameters, including central corneal thick-ness (CCT), anterior chamber depth (ACD), anterior chamber angle (ACA), anterior chamber volume (ACV), pupil diameter (PD), axial length (AL), subfoveal and pe-ripapillary choroidal thickness, optic disc parameters, and intraocular pressure (IOP), were measured at rest and during VM. Results: VM did not have any significant influence on AL, subfoveal and peripapillary choroidal thickness, optic disc area, rim area, cup area, cup-to-disc area ratio, vertical cup-to-disc ratio, rim volume, cup volume, and nerve head volume measurements (for all; p > 0.05). IOP and PD significantly increased during VM (for both; p < 0.001). VM significantly decreased CCT, ACD, ACA, and ACV values (for all; p < 0.001). Moreover, the optic nerve cup volume decreased and the horizontal cup-to-disc ratio significantly increased during VM (for both; p < 0.05). Conclusions: VM may cause transient changes in IOP, optic disc morphology, and anterior chamber parameters.