<clinical_study>
  <!-- This xml conforms to an XML Schema at:
    https://clinicaltrials.gov/ct2/html/images/info/public.xsd -->
  <required_header>
    <download_date>ClinicalTrials.gov processed this data on September 20, 2023</download_date>
    <link_text>Link to the current ClinicalTrials.gov record.</link_text>
    <url>https://clinicaltrials.gov/ct2/show/NCT03299400</url>
  </required_header>
  <id_info>
    <org_study_id>UW 16-207</org_study_id>
    <nct_id>NCT03299400</nct_id>
  </id_info>
  <brief_title>Continuous Intraocular Pressure Patterns in Spine Surgery</brief_title>
  <official_title>Continuous Intraocular Pressure Patterns in Spine Surgery</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>The University of Hong Kong</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
  </sponsors>
  <source>The University of Hong Kong</source>
  <oversight_info>
    <has_dmc>No</has_dmc>
    <is_fda_regulated_drug>No</is_fda_regulated_drug>
    <is_fda_regulated_device>No</is_fda_regulated_device>
  </oversight_info>
  <brief_summary>
    <textblock>
      Post-operative visual loss is a rare but serious complication after surgery. It is most&#xD;
      significantly correlated with prone spinal surgery with a prolonged duration. The cause and&#xD;
      risk factors are not elucidated, but the majority of the cases are due posterior ischaemic&#xD;
      optic neuropathy (PION). This entity is directly related to the ocular perfusion pressure&#xD;
      (OPP), which is estimated as the difference between mean arterial blood pressure (MAP) and&#xD;
      intraocular pressure (IOP). Autoregulation is believed to maintain a constant perfusion to&#xD;
      the optic nerve despite fluctuations in the perfusion pressure.&#xD;
&#xD;
      IOP is known to increase in the prone position thus putting susceptible patients at risk for&#xD;
      inadequate ocular nerve perfusion. Most of the evidence comes from animal and healthy&#xD;
      volunteer studies and cannot give an accurate insight into the subtle changes of&#xD;
      intra-operative IOP. All the published studies employed the use of a tonometer, which may&#xD;
      have rooms for measurement errors due to inadvertent pressure on the globe while retracting&#xD;
      the eyelids, particularly when there is significant periorbital/conjunctival swelling in the&#xD;
      prone position. The majority of the studies recruited healthy volunteers in a simulated&#xD;
      surgical setting so other fluctuating parameters, which can affect intraoperative IOP, cannot&#xD;
      be measured. In the few reports where patients undergoing surgery in the prone position were&#xD;
      studies, IOP measurements were taken at non-continuous monitoring at time intervals, thus the&#xD;
      effects of changes in blood volume, MAP, central venous pressure (CVP) and PaCO 2 could not&#xD;
      be studied. Lastly, all the literature consists of case series only with no control group so&#xD;
      the effect of position cannot be evaluated independently of the other factors.&#xD;
&#xD;
      The investigators therefore propose to conduct a prospective study with continuous&#xD;
      intraoperative IOP monitoring to give us further insight into the physiological changes of&#xD;
      IOP in patients undergoing spine surgery, and identify the risk factors related to&#xD;
      fluctuations of IOP during prone spinal surgery.&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      Post-operative visual loss (POVL) is a rare but serious complication after surgery.&#xD;
&#xD;
      One of the known associations is prone spinal surgery with a prolonged duration.&#xD;
&#xD;
      The cause is not completely understood, but some of the risk factors for developing POVL&#xD;
      include anaemia, hypotension, the duration of surgery and patient factors such as age,&#xD;
      hypertension and atherosclerosis. There are also some unidentifiablerisk factors that may&#xD;
      predispose young healthy patients to POVL. Once the patient develops POVL, it is usually&#xD;
      irreversible, and the patient is left with a permanent disability.&#xD;
&#xD;
      The majority of POVL cases that occur with prone spinal surgery are due to posterior&#xD;
      ischaemic optic neuropathy (PION). PION is directly related to the ocular perfusion pressure&#xD;
      (OPP), which is estimated as the difference between mean arterial blood pressure (MAP) and&#xD;
      intraocular pressure (IOP). Autoregulation is believed to maintain a constant perfusion to&#xD;
      the optic nerve despite fluctuations in the perfusion pressure.&#xD;
&#xD;
      However, there is a knowledge gap in the physiological changes of IOP during prone surgery.&#xD;
      IOP is a highly dynamic parameter, and the most widely used method to measure it is using a&#xD;
      handheld tonometer. The main limitation of this technique is the isolated nature of its&#xD;
      measurements, as it can only be taken at regular intervals, and may not reflect the full&#xD;
      range of IOP changes. Studies on IOP during prone position in the current literature have all&#xD;
      used this technique. 1-5 Hence subtle changes of IOP can be undetected, as interval&#xD;
      measurements cannot reflect short-term variations that occur within seconds or minutes.&#xD;
      Furthermore, most of the studies are performed on animals or healthy volunteers 5,6 , which&#xD;
      further limit the interpretation of their results. For the few studies performed on&#xD;
      anaesthetised patients undergoing spinal surgeries, the duration of surgery is short or&#xD;
      mixed, so the critical time point may not have been studied. The American Society of&#xD;
      Anesthesiologists Postoperative Visual Loss Registry suggests that an anaesthetic duration of&#xD;
      greater than 6 hours is more correlated with POVL.&#xD;
&#xD;
      Using state of the art technology Over the past five years, advances in technology have led&#xD;
      to the development of devices that allow 24 hour continuous IOP monitoring. The new system&#xD;
      makes use of microelectromechanical systems, nanotechnology, and telemetry to allow&#xD;
      continuous monitoring. A disposable contact lens sensor, first proposed by Leonardi et al. 8&#xD;
      , is now commercially available (SENSIMED Triggerfish; Sensimed AG, Lausanne, Switzerland).&#xD;
      This technology can acquire data points over a 24 hour period corresponding to 30 seconds of&#xD;
      continuous measurements. It measures changes in the ocular dimensions at the corneoscleral&#xD;
      junction, which corresponds to changes to IOP and volume. The microprocessor within the lens&#xD;
      transmits data to an external antenna, and the profiles can be stored in a portable recorder.&#xD;
      9 Although this sensor does not measure IOP directly, it gives measurements with a composite&#xD;
      of IOP and volume changes, and it is most valuable in documenting relative changes of&#xD;
      IOP-related events and their timing. It is also well tolerated in real life patients, and&#xD;
      have been used to document IOP changes in patients with glaucoma and thyroid eye disease.&#xD;
      9-11 This is the only non-invasive temporary continuous monitoring in the system that can be&#xD;
      used in human beings. This new technology is therefore ideal in detecting subtle changes in&#xD;
      IOP pattern in prone spinal surgery. It will provide a continuous monitoring which can be&#xD;
      correlated with the patient's level of anaesthesia, arterial pressure fluctuations and volume&#xD;
      status, and can contribute to improved understanding of IOP changes during prone spinal&#xD;
      surgery, which may in turn bridge the knowledge gap of the causes of POVL.&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Completed</overall_status>
  <start_date type="Actual">May 9, 2016</start_date>
  <completion_date type="Actual">May 9, 2017</completion_date>
  <primary_completion_date type="Actual">May 9, 2017</primary_completion_date>
  <phase>N/A</phase>
  <study_type>Interventional</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <allocation>N/A</allocation>
    <intervention_model>Single Group Assignment</intervention_model>
    <intervention_model_description>All eligible patients who have given informed consent will attend the ophthalmology clinic for screening.&#xD;
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.&#xD;
Once positioned, the head is carefully placed on the GentleTouch prone positioning pillow of the appropriate size.&#xD;
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.</intervention_model_description>
    <primary_purpose>Diagnostic</primary_purpose>
    <masking>None (Open Label)</masking>
  </study_design_info>
  <primary_outcome>
    <measure>Report the physiological changes of IOP patterns during prone spinal surgery</measure>
    <time_frame>1 year</time_frame>
    <description>The outcome measure will be to report the physiological changes of IOP patterns during prone spinal surgery.</description>
  </primary_outcome>
  <secondary_outcome>
    <measure>Correlate any intraoperative risk factors that may cause IOP fluctuations</measure>
    <time_frame>1 year</time_frame>
    <description>To correlate any intraoperative risk factors that may cause IOP fluctuations</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Documentation of IOP changes after the surgery until the contact lens sensor is removed</measure>
    <time_frame>1 year</time_frame>
    <description>Documentation of IOP changes after the surgery until the contact lens sensor is removed</description>
  </secondary_outcome>
  <number_of_arms>1</number_of_arms>
  <enrollment type="Actual">10</enrollment>
  <condition>Intraocular Pressure</condition>
  <arm_group>
    <arm_group_label>Contact lens sensor</arm_group_label>
    <arm_group_type>Experimental</arm_group_type>
    <description>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.</description>
  </arm_group>
  <intervention>
    <intervention_type>Device</intervention_type>
    <intervention_name>Contact lens sensor</intervention_name>
    <description>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.</description>
    <arm_group_label>Contact lens sensor</arm_group_label>
  </intervention>
  <eligibility>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          -  Signed informed consent&#xD;
&#xD;
          -  Age 18 to 80 years inclusive&#xD;
&#xD;
          -  No pre-existing eye pathology (excluding refractive error), patients with glaucoma,&#xD;
             history of eye injury or ophthalmic surgery&#xD;
&#xD;
          -  No known allergy to contact lens material&#xD;
&#xD;
          -  Patients undergoing anterior cervical spine surgery and prone spine surgery for&#xD;
             duration of 3 hours or longer&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          -  Unable to comply with follow up or give informed consent&#xD;
&#xD;
          -  Cannot tolerate wearing contact lens&#xD;
&#xD;
          -  Has active eye infection&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>18 Years</minimum_age>
    <maximum_age>80 Years</maximum_age>
    <healthy_volunteers>No</healthy_volunteers>
  </eligibility>
  <overall_official>
    <last_name>Dr Kenny Kwan, BMBCh(Oxon)</last_name>
    <role>Principal Investigator</role>
    <affiliation>The University of Hong Kong</affiliation>
  </overall_official>
  <location>
    <facility>
      <name>Duchess of Kent Children's Hospital</name>
      <address>
        <city>Hong Kong</city>
        <country>Hong Kong</country>
      </address>
    </facility>
  </location>
  <location_countries>
    <country>Hong Kong</country>
  </location_countries>
  <reference>
    <citation>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.</citation>
    <PMID>24456677</PMID>
  </reference>
  <reference>
    <citation>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.</citation>
    <PMID>22274735</PMID>
  </reference>
  <reference>
    <citation>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.</citation>
    <PMID>25249431</PMID>
  </reference>
  <reference>
    <citation>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.</citation>
    <PMID>24565128</PMID>
  </reference>
  <reference>
    <citation>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.</citation>
    <PMID>17978659</PMID>
  </reference>
  <reference>
    <citation>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.</citation>
    <PMID>9538286</PMID>
  </reference>
  <reference>
    <citation>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.</citation>
    <PMID>22185873</PMID>
  </reference>
  <reference>
    <citation>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.</citation>
    <PMID>19016660</PMID>
  </reference>
  <reference>
    <citation>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.</citation>
    <PMID>22457163</PMID>
  </reference>
  <reference>
    <citation>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.</citation>
    <PMID>25132194</PMID>
  </reference>
  <reference>
    <citation>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.</citation>
    <PMID>21602707</PMID>
  </reference>
  <verification_date>May 2020</verification_date>
  <study_first_submitted>September 27, 2017</study_first_submitted>
  <study_first_submitted_qc>September 27, 2017</study_first_submitted_qc>
  <study_first_posted type="Actual">October 3, 2017</study_first_posted>
  <last_update_submitted>May 5, 2020</last_update_submitted>
  <last_update_submitted_qc>May 5, 2020</last_update_submitted_qc>
  <last_update_posted type="Actual">May 6, 2020</last_update_posted>
  <responsible_party>
    <responsible_party_type>Principal Investigator</responsible_party_type>
    <investigator_affiliation>The University of Hong Kong</investigator_affiliation>
    <investigator_full_name>Dr. Kenny Kwan</investigator_full_name>
    <investigator_title>Clinical Assistant Professor</investigator_title>
  </responsible_party>
  <keyword>IOP</keyword>
  <patient_data>
    <sharing_ipd>No</sharing_ipd>
  </patient_data>
  <!-- Results have not yet been posted for this study                                          -->
</clinical_study>


download date: ClinicalTrials.gov processed this data on September 20, 2023
link text: Link to the current ClinicalTrials.gov record.
url: https://clinicaltrials.gov/ct2/show/NCT03299400
org study id: UW 16-207
nct id: NCT03299400
lead sponsor: 
has dmc: No
is fda regulated drug: No
is fda regulated device: No
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.
Post-operative visual loss (POVL) is a rare but serious complication after surgery.

      One of the known associations is prone spinal surgery with a prolonged duration.

      The cause is not completely understood, but some of the risk factors for developing POVL
      include anaemia, hypotension, the duration of surgery and patient factors such as age,
      hypertension and atherosclerosis. There are also some unidentifiablerisk factors that may
      predispose young healthy patients to POVL. Once the patient develops POVL, it is usually
      irreversible, and the patient is left with a permanent disability.

      The majority of POVL cases that occur with prone spinal surgery are due to posterior
      ischaemic optic neuropathy (PION). PION 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.

      However, there is a knowledge gap in the physiological changes of IOP during prone surgery.
      IOP is a highly dynamic parameter, and the most widely used method to measure it is using a
      handheld tonometer. The main limitation of this technique is the isolated nature of its
      measurements, as it can only be taken at regular intervals, and may not reflect the full
      range of IOP changes. Studies on IOP during prone position in the current literature have all
      used this technique. 1-5 Hence subtle changes of IOP can be undetected, as interval
      measurements cannot reflect short-term variations that occur within seconds or minutes.
      Furthermore, most of the studies are performed on animals or healthy volunteers 5,6 , which
      further limit the interpretation of their results. For the few studies performed on
      anaesthetised patients undergoing spinal surgeries, the duration of surgery is short or
      mixed, so the critical time point may not have been studied. The American Society of
      Anesthesiologists Postoperative Visual Loss Registry suggests that an anaesthetic duration of
      greater than 6 hours is more correlated with POVL.

      Using state of the art technology Over the past five years, advances in technology have led
      to the development of devices that allow 24 hour continuous IOP monitoring. The new system
      makes use of microelectromechanical systems, nanotechnology, and telemetry to allow
      continuous monitoring. A disposable contact lens sensor, first proposed by Leonardi et al. 8
      , is now commercially available (SENSIMED Triggerfish; Sensimed AG, Lausanne, Switzerland).
      This technology can acquire data points over a 24 hour period corresponding to 30 seconds of
      continuous measurements. It measures changes in the ocular dimensions at the corneoscleral
      junction, which corresponds to changes to IOP and volume. The microprocessor within the lens
      transmits data to an external antenna, and the profiles can be stored in a portable recorder.
      9 Although this sensor does not measure IOP directly, it gives measurements with a composite
      of IOP and volume changes, and it is most valuable in documenting relative changes of
      IOP-related events and their timing. It is also well tolerated in real life patients, and
      have been used to document IOP changes in patients with glaucoma and thyroid eye disease.
      9-11 This is the only non-invasive temporary continuous monitoring in the system that can be
      used in human beings. This new technology is therefore ideal in detecting subtle changes in
      IOP pattern in prone spinal surgery. It will provide a continuous monitoring which can be
      correlated with the patient's level of anaesthesia, arterial pressure fluctuations and volume
      status, and can contribute to improved understanding of IOP changes during prone spinal
      surgery, which may in turn bridge the knowledge gap of the causes of POVL.
allocation: N/A
intervention model: Single Group Assignment
intervention model description: 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.
primary purpose: Diagnostic
masking: None (Open Label)
measure: Report the physiological changes of IOP patterns during prone spinal surgery
time frame: 1 year
description: The outcome measure will be to report the physiological changes of IOP patterns during prone spinal surgery.
measure: Correlate any intraoperative risk factors that may cause IOP fluctuations
time frame: 1 year
description: To correlate any intraoperative risk factors that may cause IOP fluctuations
measure: Documentation of IOP changes after the surgery until the contact lens sensor is removed
time frame: 1 year
description: Documentation of IOP changes after the surgery until the contact lens sensor is removed
arm group label: Contact lens sensor
arm group type: Experimental
description: 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.
intervention type: Device
intervention name: Contact lens sensor
description: 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.
arm group label: Contact lens sensor
criteria: 
gender: All
minimum age: 18 Years
maximum age: 80 Years
healthy volunteers: No
last name: Dr Kenny Kwan, BMBCh(Oxon)
role: Principal Investigator
affiliation: The University of Hong Kong
facility: 
country: Hong Kong
citation: 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
citation: 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
citation: 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
citation: 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
citation: 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
citation: 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
citation: 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
citation: 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
citation: 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
citation: 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
citation: 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
responsible party type: Principal Investigator
investigator affiliation: The University of Hong Kong
investigator full name: Dr. Kenny Kwan
investigator title: Clinical Assistant Professor
sharing ipd: No