Effects of prone and reverse trendelenburg positioning on ocular parameters

Geordie P. Grant, Bernard C. Szirth, Henry L. Bennett, Sophia S. Huang, Rajesh S. Thaker, Robert F. Heary, Roger E. Turbin

Research output: Contribution to journalArticlepeer-review

43 Scopus citations


Background: In a pilot study of awake volunteers, intraocular pressure (IOP), choroid layer thickness, and optic nerve diameter were shown to increase in the prone position over 5 h with a nonsignificant trend of attenuation using a 4-degree increase of table inclination. These effects have previously not been isolated from anesthetic and fluid administration over a prolonged period, using an adequate sample size. Methods: After institutional review board approval, 10 healthy volunteers underwent IOP measurement (Tono-Pen XL, Medtronic Solan, Jacksonville, FL) as well as choroidal thickness and optic nerve diameter assessment (Sonomed B-1000, Sonomed, Inc., Lake Success, NY, or the I System-ABD, Innovative Imaging, Inc., Sacramento, CA) on a Jackson table (Orthopedic Systems, Inc., Union City, CA), during 5 h horizontal prone and 5 h 4-degree reverse Trendelenburg positioning. Measurements were assessed as initial supine, initial prone, and hourly thereafter. Vital signs were recorded at each position and time point. Results: IOP, choroidal thickness, and optic nerve diameter were observed to increase with time in the prone position. A small degree of reverse Trendelenburg attenuated the increase in choroidal thickness but not IOP or optic nerve diameter. Conclusions: Prolonged prone positioning increases IOP, choroid layer thickness, and optic nerve diameter independent of anesthetics and intravenous fluid infusion and 4 degrees of table inclination (15 cm of head to foot vertical disparity) may not attenuate these effects.

Original languageEnglish (US)
Pages (from-to)57-65
Number of pages9
Issue number1
StatePublished - Jan 2010

All Science Journal Classification (ASJC) codes

  • Anesthesiology and Pain Medicine

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