Changes in Intraocular Pressure due to Surgical Positioning Studying Potential Risk for Postoperative Vision Loss

Abstract

Compare the intraocular pressure responses in the prone flat versus prone Trendelenburg's position. Summary of Background Data. Postoperative vision loss (PVL) complicates approximately 0.05% of spine surgeries. Prone positioning is considered a risk factor because it increases intraocular pressure, which may decrease perfusion pressure to the optic nerve (perfusion pressure mean arterial pressure intraocular pressure [IOP]). The prone Trendelenburg's position is often used during spine surgery; however, its effect on optic nerve perfusion is unknown. The purpose of this study is to compare the IOP responses in the prone flat versus prone Trendelenburg s positions to determine if prone Trendelenburg's position also risks PVL. Methods. Twenty subjects randomized into 2 groups. Group 1 lay in the prone flat position (0 Degrees). Group 2 lay in the prone Trendelenburg's position (- 7 Degrees ). IOPs were measured with a hand-held applanation tonometer while seated, 1 minute after assuming the group's position (Time 0), and at 10-minute intervals for 60 minutes. Results. The differences in mean IOPs with respect to positions and time were significant ( P = 0.0001, P = 0.000). There was a significant difference between sitting and all other times for both groups. In Group 1, there was a significant difference in IOP between Time 0 and all other times prone flat P less than 0.05). In Group 2, there was a significant difference in IOP between Time 0 all other times prone Trendelenburg (P less than 0.05). Conclusion. IOP increases in the prone Trendelenburg's position, and when combined with other factors, may be a risk factor for PVL. The pathophysiology is discussed and suggestions for clinicians are made.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2007
Accession Number
ADA627820

Entities

People

  • John A. Ward
  • John E. Kragh Jr.
  • John J. Crawford
  • Kristina S. Walick

Organizations

  • United States Army Institute of Surgical Research

Tags

Communities of Interest

  • Biomedical

DTIC Thesaurus Topics

  • Analysis Of Variance
  • Anesthesia
  • Blood Flow
  • Cardiovascular System
  • Data Science
  • Hypotension
  • Information Science
  • Intervals
  • Measurement
  • Medical Personnel
  • Optic Nerve
  • Perfusion
  • Physicians
  • Pressure Measurement
  • Risk Factors
  • Statistical Analysis
  • Vascular Diseases

Fields of Study

  • Medicine

Readers

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