Non-invasive estimation of cerebrospinal fluid pressure (CSFp) has been attempted by many investigators using different approaches; however, no satisfactory and practical methodology has yet been achieved. CSFp is generally measured using invasive methods by implanting catheters in the brain tissue, with associated risk of morbidity and infection. CSF flows in the subarachnoid space of the optic nerve and so can influence the ocular circulation through this anatomical connection. It has been shown that CSFp has a direct effect on retinal vasculature. Spontaneous retinal venous pulsatility (SRVP), a vascular phenomenon occurring in the eyes of the majority of individuals, has been reported to be associated with CSFp and intraocular pressure. The objective of this book is to characterize SRVP in normal and diseased states, with the aim to develop a novel approach for non-invasive estimation of CSFp. This was achieved by the combination of measurement of vessel pulsatility and intra-ocular pressure. Additionally, characteristics of retinal vasculature and retinal nerve fibre layer in abnormalities associated with CSFp (e.g. glaucoma) have also been investigated.