Measurement of Acute Changes in Choroid Thickness in Healthy Eyes During Posture Change Using Optical Coherence TomographyThe Visual Impairment and Intracranial Pressure (VIIP) syndrome affects 60% of astronauts returning from long-duration missions and is characterized by structural and functional changes of the eye (3). Upon entry into weightlessness, approximately two liters of fluid translocates from the lower body to the thorax and cephalad regions, potentially contributing to elevated intracranial and intraocular pressures. The choroid is the vasculature that supplies blood flow to the posterior part of the retina and has limited autoregulation. As a consequence these vessels may engorge during a cephalad fluid shift, contributing to structural changes in the retina. The purpose of this experiment was to quantify changes in choroid thickness during a fluid shift. In order to fulfill this objective, it was also necessary to improve the measurement technique for assessing choroid thickness.
Document ID
20150016959
Acquisition Source
Johnson Space Center
Document Type
Conference Paper
Authors
Ferguson, Connor R. (Universities Space Research Association Houston, TX, United States)
Lee, Stuart M. C. (Wyle Science, Technology and Engineering Group Houston, TX, United States)
Stenger, Michael B. (Wyle Science, Technology and Engineering Group Houston, TX, United States)
Laurie, Steven S. (Wyle Science, Technology and Engineering Group Houston, TX, United States)