Measurement of Intraocular Pressure in Patients Undergoing Laminectomy in the Prone Position
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- This is an observational study: the protocol does not assign a study treatment.
- Who it may be relevant to
- Registry conditions: Laminectomy, Intraocular Pressure, Prone Position. Basic parameters: 18 years — 65 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Center list to be confirmed — check the primary protocol.
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
Measurement of Intraocular Pressure (With Non-contact Tonometer) in Patients Undergoing Laminectomy in the Prone Position: A Clinical Study
Overview
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.
Primary outcome measures
- Intraoperative IOP Measurement Schedule After Induction: Intraocular pressure (IOP) is measured non-contact using a tonometer. Intraoperative 1st Hour: After Prone Positioning: [Time frame: half an hour]
Eligibility criteria
Inclusion criteria
- 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
Exclusion criteria
- 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
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Observational model
- Cohort
Study locations
Center list to be confirmed — check the primary protocol.
Publications
- 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
- 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
Identifiers
NCT: NCT07067008 · FSCH-SB-2024/07