Physiology and clinical relevance of this parameter

Summary Ocular Pulse Amplitude (OPA) refers to a fluctuation in pressure with the cardiac cycle. It has been widely used as a surrogate endpoint for ocular circulation with a number of studies inferring which ocular tissue, structural characteristics and vascular beds are responsible for this fluctuation. Accordingly, a number of ocular and conditions have been consistently associated with extreme OPA values (either high or low). Ranging from glaucoma to carotid stenosis, these conditions will be reviewed, thus providing the audience with a glimpse of the state of the art in the clinical implications of this parameter.