Measurement of Intraocular Pressure in Patients Undergoing Laminectomy in the Prone Position

NCT07067008 | Not Yet Recruiting DMC

• 1 other identifier: FSCH-SB-2024/07
• Study Type: observational
• Target: 60
• Locations: 0 countries
• Sites: N/A

Brief Summary

Laminectomy surgeries, typically performed for lumbar disc herniation and spinal disorders, are often lengthy surgical procedures requiring patients to be in the prone position. While this position provides better visibility of the surgical field, it can lead to physiological changes in intraocular pressure (IOP) in anesthetized patients. An increase in IOP, though rare, has the potential to cause severe ocular complications such as postoperative vision loss (POVL), which is one of the most feared complications after spinal surgery. One of the main mechanisms of IOP elevation in the prone position is the impediment of venous return in the head and neck region due to gravity, leading to an increase in episcleral venous pressure. Additionally, direct mechanical pressure on the face and globe can also increase IOP. Anesthesia management can also play a role in IOP dynamics by affecting intrathoracic pressure and venous return. This complex interaction necessitates careful monitoring of eye health in anesthetized patients in the prone position. Non-contact tonometers offer a non-invasive, rapid, and reliable method for IOP measurement. They are particularly advantageous for repeated measurements in anesthetized patients. This clinical study aims to evaluate changes in IOP using a non-contact tonometer in patients undergoing laminectomy in the prone position and to identify anesthesia- and patient-related factors influencing these changes. The data obtained will contribute to the development of anesthesia and positioning strategies aimed at reducing the risk of ocular complications.

Conditions

Laminectomy; Intraocular Pressure; Prone Position

Keywords

Prone Position; Intraocular Pressure; Laminectomy

Outcome Measures

Primary Outcomes (1)

• Intraoperative IOP Measurement Schedule After Induction: Intraocular pressure (IOP) is measured non-contact using a tonometer. Intraoperative 1st Hour: After Prone Positioning:

  half an hour

Study Arms (2)

Group 1 will include those with a BMI of 40 kg/m2 and above.

Group 2 will include those with a BMI below 40 kg/m2.

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

Patients scheduled for laminectomy surgery under general anesthesia.

You may qualify if:

• Patients scheduled for laminectomy surgery under general anesthesia
• Patients with ASA physical status I-II-III
• Patients who can cooperate postoperatively
• Patients without eye diseases or conditions affecting eye physiology (such as glaucoma)
• Patients who have not undergone eye surgery
• Patients who consent to participate in the study

You may not qualify if:

• Patients scheduled for laminectomy surgery but not receiving general anesthesia
• Patients with ASA physical status IV-V
• Patients who do not consent to participate in the study
• Patients who cannot cooperate postoperatively
• Patients with eye diseases or conditions affecting eye physiology (such as glaucoma)
• Patients who have undergone eye surgery
• Patients from whom consent cannot be obtained

Sponsors & Collaborators

• Elazıg Fethi Sekin Sehir Hastanesi: lead

Related Publications (2)

• Kim YS, Seo KH, Jeon YS, In JH, Jung HS, Park YJ, Jun EH, Yu E. Effects of Positive End-Expiratory Pressure on Intraocular Pressure during One-Lung Ventilation in the Lateral Decubitus Position-A Prospective Randomized Trial. Medicina (Kaunas). 2022 Jul 15;58(7):940. doi: 10.3390/medicina58070940.

  PMID: 35888659 BACKGROUND

• Saoulidou EN, Giavi VD, Paidakakos NA, Papaconstantinou DS, Dimakopoulou AN, Matsota PK. Effect of Prone Position on Intraocular Pressure in Patients Undergoing Nonocular Surgery: A Systematic Review. Cureus. 2025 May 6;17(5):e83617. doi: 10.7759/cureus.83617. eCollection 2025 May.

  PMID: 40351490 BACKGROUND

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: OTHER
• Target Duration: 1 Day
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: July 4, 2025
• First Posted: July 15, 2025
• Study Start: August 15, 2025
• Primary Completion: October 15, 2025
• Study Completion: October 30, 2025
• Last Updated: July 18, 2025

Record last verified: 2025-07