The Translaminar Pressure Gradient in Spaceflight Associated Neuro-ocular Syndrome: The Relationship between Intraocular and Intracranial Pressures and Its Role in Pathogenesis

Spaceflight associated neuro-ocular syndrome (SANS) refers to the unique clinical and imaging characteristics that can develop during or following long-duration spaceflights. A number of theories about the pathogenesis of SANS have been proposed, while there is continuous interest and research about the effect of these missions on human health. The ocular translaminar pressure gradient, which is generated by the difference between intraocular pressure and retrolaminar intracranial pressure at the level of the lamina cribrosa, has been considered an important factor in the development of glaucoma and papilledema. The objective of this work is to review the changes in intraocular pressure and intracranial pressure in microgravity conditions and further discuss the role of translaminar pressure gradient in the pathogenesis of SANS.