Ischemic Optic NeuropathySightSaverNCT02643615
Safety and Efficacy of Using SightSaver Visual Evoked Potential (VEP) for VEP Monitoring in Prone Spine Surgery
A study testing VEP under TIVA, VEP under balanced anesth. and Propofol in people with Ischemic Optic Neuropathy, run by Ohio State University at 1 site in United States.
Trial summary
Post-operative visual loss (POVL) following non-ocular surgical procedures is an infrequent but severe complication. Little is understood about this complication, but most cases seem to result from loss of blood flow to the optic nerve. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Ischemic Optic Neuropathy
- What is being tested?
- VEP under TIVA, VEP under balanced anesth. and Propofol
- Type of treatment
- Injection or infusion, Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteUnited States
- Study dates
- Sep 2014to Mar 2016
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Male or Female older than 18 years of age
- American Society of Anesthesiologists (ASA) status of I to IV and scheduled to undergo elective spinal prone position procedures under general anesthesia or TIVA only with intraoperative neurophysiological monitoring with an expected duration of surgery to be at least 2 hours
- If female, have been surgically sterilized or are postmenopausal; if of child-bearing potential, must have a negative serum pregnancy test the day of surgery
- Ability and willingness to sign informed consent
- Literate in the English language
Who cannot join
- Prisoner status
- Women who are pregnant or lactating/breast feeding
- Patients with a history of contact allergies to foam and/or plastic devices
- Any condition, which, in the opinion of the investigator, would make the subject ineligible for participation in the study, such as a history of unstable cardiovascular, pulmonary, renal, hepatic, neurologic (seizures), hematologic or endocrine abnormality (hyperthyroidism, unstable Diabetes type I/II)
Trial locations and contacts
1 site in 1 country.
United States1 site
The Ohio State University Wexner Medical Center
Columbus, Ohio, 43210
About this study
Official title: A Pilot Study to Determine the Efficacy and Safety of Detecting Subtle Visual Changes During Visual Evoked Potential (VEP) Monitoring Using SightSaver ™ Flash Visual Evoked Potential Stimulator in Spine Prone Surgery
Post-operative visual loss (POVL) following non-ocular surgical procedures is an infrequent but severe complication. Little is understood about this complication, but most cases seem to result from loss of blood flow to the optic nerve. This is a pilot, single center, prospective, randomized, two-arm study involving 20 subjects at The Ohio State University Wexner Medical Center who are scheduled to undergo spine surgery that requires prone position and at least two hours of general anesthesia or total intravenous anesthesia (TIVA) and intraoperative neurophysiological monitoring. Patients will be randomized to either general anesthesia or TIVA, and wear the SightSaver device to monitor visual evoked potentials (VEPs) during surgery in order to detect possible changes in optic nerve function that may lead to POVL. We hypothesize that this new, flexible, disposable device will yield better results and more patient satisfaction than devices currently used for visual monitoring during prone spine surgeries.
Read the detailed description
The exact mechanism underlying POVL is poorly understood, but nearly all cases seem to involve ischemic optic neuropathy (ION). Posterior ION is more commonly the result of spinal procedures. The spine surgery associated risk factors include: prone position, Trendelenburg positioning, blood loss, prolonged procedure, use of vasoconstriction agents to correct blood pressure, direct ocular compression, and hypotension [1,2]. Given the fact that the suspected mechanism is a gradual infarction of the optic nerve, POVL could theoretically be prevented based on early detection of reversible optic nerve dysfunction. Visual evoked potentials (VEP) are a highly sensitive method for detecting optic nerve dysfunction, including ischemia.
During intraoperative neurophysiological monitoring (IONM), an emitted light passes through the lens, reaching the retina and causing hyperpolarization. The signal generated by the retina in response to a flash of light is known as the electroretinogram (ERG). This response may be recorded using conventional neurophysiological equipment and reflects overall retinal function. The VEP peaks are generated during the passage of electrical signal from the retina via the optic pathways to the primary visual cortex, and can also be registered during IONM. Measurements of VEP peaks under anesthesia can vary depending on type of anesthetic regimen, some producing more interference with the electrical impulses than others.
The problems encountered during VEP monitoring are numerous: a reusable device must be cleaned in between patients, tightly fitting goggles pose a risk of damaging the eyes, goggles may fall off or move intraoperatively and be difficult to reposition once the procedure is underway. Also, the light emitting diodes tend to be too weak to produce an adequate stimulus. This pilot study presents a new different approach from current methods. The SightSaverTM visual stimulator design consists of the following key advantages over the current technologies: hygienically superior to re-usable goggles, provides physical protection to the ocular region, use of higher intensity diodes and adhesive foam padding shaped to contours of periocular region.
This pilot, single center, prospective, randomized, two-arm study will involve 20 subjects at The Ohio State University Wexner Medical Center who are scheduled to undergo spine surgery that requires prone position and at least two hours of general anesthesia or TIVA and intraoperative neurophysiological monitoring. Eligible subjects that provide voluntary and written informed consent will be included in the study with a 1:1 randomization ratio of two arms, n=10 patients per each of two anesthesia regimen groups: general anesthesia and TIVA. All patients will wear the SightSaverTM visual stimulator. IONM of VEP with include insertion of half-inch needle electrodes placed just under the skin on either side of the eye, at the top of the forehead and three along the back of the head. Flashes of light, delivered at continuous intervals, will be emitted from diodes mounted in the SightSaverTM visual stimulator. After the baseline VEP is established for the patient, monitoring of VEP will occur at every 30 minutes during surgery. If during the monitoring process, a significant VEP waveform change has occurred, an alert will trigger the surgical staff to check four different parameters: technical issues with goggles, anesthetic changes, significant blood loss or a blood pressure change. Analysis of data collected will be used to evaluate the efficacy of SightSaverTM visual stimulator for intraoperative VEP-based detection of significant visual changes during prone spine surgeries.
- Conditions
- Ischemic Optic Neuropathy
- Being tested
- VEP under TIVA, VEP under balanced anesth., Propofol, Desflurane
- Keywords
- Visual Evoked Potentials
- Medical subject headings
- Optic Neuropathy, Ischemic
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
VEP under TIVADevice
Propofol will be administered for anesthesia maintenance in patients randomized to the TIVA arm of the study. In order to record the VEPs, standard half-inch sub-dermal needle electrodes will be inserted subcutaneously around the visual area and the SightSaverTM visual stimulator will be placed to monitor VEP during surgery.
VEP under balanced anesth.Device
Balanced general anesthesia with desflurane will be administered for anesthesia maintenance in patients randomized to the balanced general anesthesia arm of the study, In order to record the VEPs, standard half-inch sub-dermal needle electrodes will be inserted subcutaneously around the visual area and the SightSaverTM visual stimulator will be placed to monitor VEP during surgery.
PropofolDrug
Also called Diprivan
Propofol will be administered for anesthesia maintenance in patients randomized to the TIVA arm of the study. In order to record the VEPs, standard half-inch sub-dermal needle electrodes will be inserted subcutaneously around the visual area and the SightSaverTM visual stimulator will be placed to monitor VEP during surgery.
DesfluraneDrug
Also called Suprane
Balanced general anesthesia with desflurane will be administered for anesthesia maintenance in patients randomized to the balanced general anesthesia arm of the study, In order to record the VEPs, standard half-inch sub-dermal needle electrodes will be inserted subcutaneously around the visual area and the SightSaverTM visual stimulator will be placed to monitor VEP during surgery.
| Study group | Role | What they receive |
|---|---|---|
| VEP under TIVA | Experimental | Patients undergoing prone spine surgery will receive an anesthesia regimen using propofol (TIVA) for maintenance Receives: Device: VEP under TIVA; Drug: Propofol |
| VEP under balanced anesthesia | Experimental | Patients undergoing prone spine surgery will receive an anesthesia regimen using Desflurane as part of balanced general anesthesia Receives: Device: VEP under balanced anesth.; Drug: Desflurane |
What is being measured
The primary outcome is the main question the study is designed to answer.
Efficacy in Detecting Subtle Intraoperative VEP Changes Using SightSaver Visual Stimulator During Spine Prone Surgeries Under Balanced General Anesthesia Versus TIVA.
Number of Participants with Subtle Intraoperative VEP Changes Observed Using SightSaver Visual Stimulator During Spine Prone Surgeries Under Balanced General Anesthesia Versus TIVA
Measured: VEP waveforms recorded every 30 minutes during the entire procedure for up to 6 hours.
Secondary outcomes (3)
The Difference in VEP Changes in Amplitude Among Both Groups
VEP waveforms were evaluated using either present baseline - reproducible positive-negative-positive complex of substantial amplitude (≥2 µV) that appeared 100-200 ms after pulse stimulus onset; marginal Baseline - low amplitude (<2 µV) reproducible P100 waveform; or absent baseline - no repeatable response present. Any activity of <0.5 µV was not considered a response. Best derivation for each particular patient was used for monitoring electroretinogram (ERG) recording and confirming the stimulation.
Measured: Every 30 minutes during surgery for up to 6 hours
The Difference in VEP Changes in Amplitude Among Both Groups
The difference in VEP changes in amplitude with a single and double stimuli using the SightSaver visual stimulator under balanced general anesthesia versus TIVA.
Measured: every 30 minutes during the entire procedure for up to 6 hours
Safety of Using SightSaver Visual Stimulator During Spine Prone Surgeries Under Balanced General Anesthesia Versus TIVA
Number of participants experiencing adverse events related to the study procedures during prone surgery and 24 hours after surgery under balanced general anesthesia versus TIVA
Measured: From start of surgery up to 24 hours after surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted31 Dec 2015 (estimated)
- Study startSep 2014
- Primary completionMar 2016
- Study completionMar 2016
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Ischemic Optic NeuropathyStudies of the same condition, open and under way.
- More trials run by Ohio State UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 20 participants (actual)
Sponsor and investigators
- Lead sponsor
- Ohio State University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Sergio Bergese, Ohio State University
- Investigators
- Sergio D Bergese, MD, Principal investigator, Ohio State University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02643615
- Sponsor's protocol ID
- 2014H0208
- Acronym
- SightSaver
- Status last verified
- Jul 2017
- First submitted
- 11 Dec 2015
- Last updated
- 1 Aug 2017
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- No: Enrolled subjects will be assigned a subject identification number and we will not collect any identifiable data
Study at a glance
From the registry record, last updated by the sponsor on 1 Aug 2017. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Pilot Study to Determine the Efficacy and Safety of Detecting Subtle Visual Changes During Visual Evoked Potential (VEP) Monitoring Using SightSaver ™ Flash Visual Evoked Potential Stimulator in Spine Prone Surgery
- ClinicalTrials.gov ID
- NCT02643615
- Acronym / sponsor ID
- SightSaver / 2014H0208
- Conditions
- Ischemic Optic Neuropathy
- Keywords
- Visual Evoked Potentials
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 20 participants (actual)
- Lead sponsor
- Ohio State UniversityUniversity, hospital or other
- Study start
- Sep 2014
- Primary completion
- Mar 2016 (actual)
- Study completion
- Mar 2016 (actual)
- First posted
- 31 Dec 2015 (estimated)
- Results
- Posted 1 Aug 2017
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Post-operative visual loss (POVL) following non-ocular surgical procedures is an infrequent but severe complication. Little is understood about this complication, but most cases seem to result from loss of blood flow to the optic nerve. This is a pilot, single center, prospective, randomized, two-arm study involving 20 subjects at The Ohio State University Wexner Medical Center who are scheduled to undergo spine surgery that requires prone position and at least two hours of general anesthesia or total intravenous anesthesia (TIVA) and intraoperative neurophysiological monitoring. Patients will be randomized to either general anesthesia or TIVA, and wear the SightSaver device to monitor visual evoked potentials (VEPs) during surgery in order to detect possible changes in optic nerve function that may lead to POVL. We hypothesize that this new, flexible, disposable device will yield better results and more patient satisfaction than devices currently used for visual monitoring during prone spine surgeries.
Detailed description
The exact mechanism underlying POVL is poorly understood, but nearly all cases seem to involve ischemic optic neuropathy (ION). Posterior ION is more commonly the result of spinal procedures. The spine surgery associated risk factors include: prone position, Trendelenburg positioning, blood loss, prolonged procedure, use of vasoconstriction agents to correct blood pressure, direct ocular compression, and hypotension [1,2]. Given the fact that the suspected mechanism is a gradual infarction of the optic nerve, POVL could theoretically be prevented based on early detection of reversible optic nerve dysfunction. Visual evoked potentials (VEP) are a highly sensitive method for detecting optic nerve dysfunction, including ischemia.
During intraoperative neurophysiological monitoring (IONM), an emitted light passes through the lens, reaching the retina and causing hyperpolarization. The signal generated by the retina in response to a flash of light is known as the electroretinogram (ERG). This response may be recorded using conventional neurophysiological equipment and reflects overall retinal function. The VEP peaks are generated during the passage of electrical signal from the retina via the optic pathways to the primary visual cortex, and can also be registered during IONM. Measurements of VEP peaks under anesthesia can vary depending on type of anesthetic regimen, some producing more interference with the electrical impulses than others.
The problems encountered during VEP monitoring are numerous: a reusable device must be cleaned in between patients, tightly fitting goggles pose a risk of damaging the eyes, goggles may fall off or move intraoperatively and be difficult to reposition once the procedure is underway. Also, the light emitting diodes tend to be too weak to produce an adequate stimulus. This pilot study presents a new different approach from current methods. The SightSaverTM visual stimulator design consists of the following key advantages over the current technologies: hygienically superior to re-usable goggles, provides physical protection to the ocular region, use of higher intensity diodes and adhesive foam padding shaped to contours of periocular region.
This pilot, single center, prospective, randomized, two-arm study will involve 20 subjects at The Ohio State University Wexner Medical Center who are scheduled to undergo spine surgery that requires prone position and at least two hours of general anesthesia or TIVA and intraoperative neurophysiological monitoring. Eligible subjects that provide voluntary and written informed consent will be included in the study with a 1:1 randomization ratio of two arms, n=10 patients per each of two anesthesia regimen groups: general anesthesia and TIVA. All patients will wear the SightSaverTM visual stimulator. IONM of VEP with include insertion of half-inch needle electrodes placed just under the skin on either side of the eye, at the top of the forehead and three along the back of the head. Flashes of light, delivered at continuous intervals, will be emitted from diodes mounted in the SightSaverTM visual stimulator. After the baseline VEP is established for the patient, monitoring of VEP will occur at every 30 minutes during surgery. If during the monitoring process, a significant VEP waveform change has occurred, an alert will trigger the surgical staff to check four different parameters: technical issues with goggles, anesthetic changes, significant blood loss or a blood pressure change. Analysis of data collected will be used to evaluate the efficacy of SightSaverTM visual stimulator for intraoperative VEP-based detection of significant visual changes during prone spine surgeries.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| VEP under TIVA | Experimental | Device: VEP under TIVA, Drug: PropofolPatients undergoing prone spine surgery will receive an anesthesia regimen using propofol (TIVA) for maintenance |
| VEP under balanced anesthesia | Experimental | Device: VEP under balanced anesth., Drug: DesfluranePatients undergoing prone spine surgery will receive an anesthesia regimen using Desflurane as part of balanced general anesthesia |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Male or Female older than 18 years of age
- American Society of Anesthesiologists (ASA) status of I to IV and scheduled to undergo elective spinal prone position procedures under general anesthesia or TIVA only with intraoperative neurophysiological monitoring with an expected duration of surgery to be at least 2 hours
- If female, have been surgically sterilized or are postmenopausal; if of child-bearing potential, must have a negative serum pregnancy test the day of surgery
- Ability and willingness to sign informed consent
- Literate in the English language
Key exclusion criteria (4 listed)
- Prisoner status
- Women who are pregnant or lactating/breast feeding
- Patients with a history of contact allergies to foam and/or plastic devices
- Any condition, which, in the opinion of the investigator, would make the subject ineligible for participation in the study, such as a history of unstable cardiovascular, pulmonary, renal, hepatic, neurologic (seizures), hematologic or endocrine abnormality (hyperthyroidism, unstable Diabetes type I/II)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| VEP under TIVAPropofol will be administered for anesthesia maintenance in patients randomized to the TIVA arm of the study. In order to record the VEPs, standard half-inch sub-dermal needle electrodes will be inserted subcutaneously around the visual area and the SightSaverTM visual stimulator will be placed to monitor VEP during surgery. | Device | VEP under TIVA |
| VEP under balanced anesth.Balanced general anesthesia with desflurane will be administered for anesthesia maintenance in patients randomized to the balanced general anesthesia arm of the study, In order to record the VEPs, standard half-inch sub-dermal needle electrodes will be inserted subcutaneously around the visual area and the SightSaverTM visual stimulator will be placed to monitor VEP during surgery. | Device | VEP under balanced anesthesia |
| PropofolAlso: DiprivanPropofol will be administered for anesthesia maintenance in patients randomized to the TIVA arm of the study. In order to record the VEPs, standard half-inch sub-dermal needle electrodes will be inserted subcutaneously around the visual area and the SightSaverTM visual stimulator will be placed to monitor VEP during surgery. | Drug | VEP under TIVA |
| DesfluraneAlso: SupraneBalanced general anesthesia with desflurane will be administered for anesthesia maintenance in patients randomized to the balanced general anesthesia arm of the study, In order to record the VEPs, standard half-inch sub-dermal needle electrodes will be inserted subcutaneously around the visual area and the SightSaverTM visual stimulator will be placed to monitor VEP during surgery. | Drug | VEP under balanced anesthesia |
Primary outcome
Efficacy in Detecting Subtle Intraoperative VEP Changes Using SightSaver Visual Stimulator During Spine Prone Surgeries Under Balanced General Anesthesia Versus TIVA.
Time frame: VEP waveforms recorded every 30 minutes during the entire procedure for up to 6 hours.
Number of Participants with Subtle Intraoperative VEP Changes Observed Using SightSaver Visual Stimulator During Spine Prone Surgeries Under Balanced General Anesthesia Versus TIVA
3 secondary outcomes
The Difference in VEP Changes in Amplitude Among Both Groups
Time frame: Every 30 minutes during surgery for up to 6 hours
The Difference in VEP Changes in Amplitude Among Both Groups
Time frame: every 30 minutes during the entire procedure for up to 6 hours
Safety of Using SightSaver Visual Stimulator During Spine Prone Surgeries Under Balanced General Anesthesia Versus TIVA
Time frame: From start of surgery up to 24 hours after surgery
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 Aug 2017.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: No. Enrolled subjects will be assigned a subject identification number and we will not collect any identifiable data
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Sergio D Bergese, MD principal investigator
Ohio State University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing VEP under TIVA, VEP under balanced anesth. and Propofol in people with Ischemic Optic Neuropathy, run by Ohio State University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 1 Aug 2017. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Yes. Results are posted in the registry (first posted 1 Aug 2017). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Efficacy in Detecting Subtle Intraoperative VEP Changes Using SightSaver Visual Stimulator During Spine Prone Surgeries Under Balanced General Anesthesia Versus TIVA. (time frame: VEP waveforms recorded every 30 minutes during the entire procedure for up to 6 hours.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 1 Aug 2017.