Continuous Intraocular Pressure Patterns in Spine Surgery

NCT03299400 | Completed

• 1 other identifier: UW 16-207
• Study Type: interventional
• Target: 10
• Locations: 1 country
• Sites: 1

Brief Summary

Post-operative visual loss is a rare but serious complication after surgery. It is most significantly correlated with prone spinal surgery with a prolonged duration. The cause and risk factors are not elucidated, but the majority of the cases are due posterior ischaemic optic neuropathy (PION). This entity is directly related to the ocular perfusion pressure (OPP), which is estimated as the difference between mean arterial blood pressure (MAP) and intraocular pressure (IOP). Autoregulation is believed to maintain a constant perfusion to the optic nerve despite fluctuations in the perfusion pressure. IOP is known to increase in the prone position thus putting susceptible patients at risk for inadequate ocular nerve perfusion. Most of the evidence comes from animal and healthy volunteer studies and cannot give an accurate insight into the subtle changes of intra-operative IOP. All the published studies employed the use of a tonometer, which may have rooms for measurement errors due to inadvertent pressure on the globe while retracting the eyelids, particularly when there is significant periorbital/conjunctival swelling in the prone position. The majority of the studies recruited healthy volunteers in a simulated surgical setting so other fluctuating parameters, which can affect intraoperative IOP, cannot be measured. In the few reports where patients undergoing surgery in the prone position were studies, IOP measurements were taken at non-continuous monitoring at time intervals, thus the effects of changes in blood volume, MAP, central venous pressure (CVP) and PaCO 2 could not be studied. Lastly, all the literature consists of case series only with no control group so the effect of position cannot be evaluated independently of the other factors. The investigators therefore propose to conduct a prospective study with continuous intraoperative IOP monitoring to give us further insight into the physiological changes of IOP in patients undergoing spine surgery, and identify the risk factors related to fluctuations of IOP during prone spinal surgery.

Conditions

Intraocular Pressure

Keywords

IOP

Outcome Measures

Primary Outcomes (1)

• Report the physiological changes of IOP patterns during prone spinal surgery

  The outcome measure will be to report the physiological changes of IOP patterns during prone spinal surgery.

  1 year

Secondary Outcomes (2)

• Correlate any intraoperative risk factors that may cause IOP fluctuations

  1 year

• Documentation of IOP changes after the surgery until the contact lens sensor is removed

  1 year

Study Arms (1)

Contact lens sensor

EXPERIMENTAL

Patient will continue to wear the contact lens postoperatively for a total of 24 hours or until the patient cannot tolerate the contact lens. After removal of the contact lens sensor, the recorded profiles will be collected and visualized graphically on a computer interface.

Device: Contact lens sensor

Interventions

Contact lens sensor DEVICE

Patient will continue to wear the contact lens postoperatively for a total of 24 hours or until the patient cannot tolerate the contact lens. After removal of the contact lens sensor, the recorded profiles will be collected and visualized graphically on a computer interface.

Contact lens sensor

Eligibility Criteria

• Age: 18 Years - 80 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Signed informed consent
• Age 18 to 80 years inclusive
• No pre-existing eye pathology (excluding refractive error), patients with glaucoma, history of eye injury or ophthalmic surgery
• No known allergy to contact lens material
• Patients undergoing anterior cervical spine surgery and prone spine surgery for duration of 3 hours or longer

You may not qualify if:

• Unable to comply with follow up or give informed consent
• Cannot tolerate wearing contact lens
• Has active eye infection

Sponsors & Collaborators

• The University of Hong Kong: lead

Study Sites (1)

Duchess of Kent Children's Hospital

Hong Kong, Hong Kong

Location

Related Publications (11)

• Carey TW, Shaw KA, Weber ML, DeVine JG. Effect of the degree of reverse Trendelenburg position on intraocular pressure during prone spine surgery: a randomized controlled trial. Spine J. 2014 Sep 1;14(9):2118-26. doi: 10.1016/j.spinee.2013.12.025. Epub 2014 Jan 20.

  PMID: 24456677 BACKGROUND

• Sugata A, Hayashi H, Kawaguchi M, Hasuwa K, Nomura Y, Furuya H. Changes in intraocular pressure during prone spine surgery under propofol and sevoflurane anesthesia. J Neurosurg Anesthesiol. 2012 Apr;24(2):152-6. doi: 10.1097/ANA.0b013e31823fe822.

  PMID: 22274735 BACKGROUND

• Yoshimura K, Hayashi H, Tanaka Y, Nomura Y, Kawaguchi M. Evaluation of predictive factors associated with increased intraocular pressure during prone position spine surgery. J Anesth. 2015 Apr;29(2):170-4. doi: 10.1007/s00540-014-1921-8. Epub 2014 Sep 24.

  PMID: 25249431 BACKGROUND

• Deniz MN, Erakgun A, Sertoz N, Yilmaz SG, Ates H, Erhan E. The effect of head rotation on intraocular pressure in prone position: a randomized trial. Braz J Anesthesiol. 2013 Mar-Apr;63(2):209-12. doi: 10.1016/j.bjane.2012.03.008. Epub 2013 Aug 13.

  PMID: 24565128 BACKGROUND

• Walick KS, Kragh JE Jr, Ward JA, Crawford JJ. Changes in intraocular pressure due to surgical positioning: studying potential risk for postoperative vision loss. Spine (Phila Pa 1976). 2007 Nov 1;32(23):2591-5. doi: 10.1097/BRS.0b013e318158cc23.

  PMID: 17978659 BACKGROUND

• Setogawa A, Kawai. Measurement of intraocular pressure by both invasive and noninvasive techniques in rabbits exposed to head-down tilt. Jpn J Physiol. 1998 Feb;48(1):25-31. doi: 10.2170/jjphysiol.48.25.

  PMID: 9538286 BACKGROUND

• Postoperative Visual Loss Study Group. Risk factors associated with ischemic optic neuropathy after spinal fusion surgery. Anesthesiology. 2012 Jan;116(1):15-24. doi: 10.1097/ALN.0b013e31823d012a.

  PMID: 22185873 BACKGROUND

• Leonardi M, Pitchon EM, Bertsch A, Renaud P, Mermoud A. Wireless contact lens sensor for intraocular pressure monitoring: assessment on enucleated pig eyes. Acta Ophthalmol. 2009 Jun;87(4):433-7. doi: 10.1111/j.1755-3768.2008.01404.x. Epub 2008 Nov 12.

  PMID: 19016660 BACKGROUND

• Mansouri K, Weinreb R. Continuous 24-hour intraocular pressure monitoring for glaucoma--time for a paradigm change. Swiss Med Wkly. 2012 Mar 28;142:w13545. doi: 10.4414/smw.2012.13545. eCollection 2012.

  PMID: 22457163 BACKGROUND

• Parekh AS, Mansouri K, Weinreb RN, Tafreshi A, Korn BS, Kikkawa DO. Twenty-four-hour intraocular pressure patterns in patients with thyroid eye disease. Clin Exp Ophthalmol. 2015 Mar;43(2):108-14. doi: 10.1111/ceo.12400. Epub 2014 Sep 29.

  PMID: 25132194 BACKGROUND

• De Smedt S, Mermoud A, Schnyder C. 24-hour intraocular pressure fluctuation monitoring using an ocular telemetry Sensor: tolerability and functionality in healthy subjects. J Glaucoma. 2012 Oct-Nov;21(8):539-44. doi: 10.1097/IJG.0b013e31821dac43.

  PMID: 21602707 BACKGROUND

Study Officials

• Dr Kenny Kwan, BMBCh(Oxon)

  The University of Hong Kong

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Clinical Assistant Professor

Model Details: All eligible patients who have given informed consent will attend the ophthalmology clinic for screening. Patient will undergo general anaesthesia for prone spinal surgery. The degree of inclination was set prior to the start of the case and independently confirmed using a goniometer. Patients will be placed in the prone position on a Jackson Spine table. Once positioned, the head is carefully placed on the GentleTouch prone positioning pillow of the appropriate size. Patient will continue to wear the contact lens postoperatively for a total of 24 hours or until the patient cannot tolerate the contact lens. After removal of the contact lens sensor, the recorded profiles will be collected and visualized graphically on a computer interface. The output of the sensor expressed in voltage, and can be analysed in real time points corresponding to the intraoperative events.

Study Record Dates

• First Submitted: September 27, 2017
• First Posted: October 3, 2017
• Study Start: May 9, 2016
• Primary Completion: May 9, 2017
• Study Completion: May 9, 2017
• Last Updated: May 6, 2020

Record last verified: 2020-05

Data Sharing

• IPD Sharing: Will not share

Locations

HK (1)