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CorneaINSTANTNCT03674892

Intranasal Neurostimulation in Ameliorating Symptoms of Neuropathic Corneal Pain

A study testing TrueTear™ intranasal neurostimulator (ITN) in people with Cornea, run by Tufts Medical Center at 1 site in United States.

Terminated

Stopped early. The study ended before it was planned to and will not resume.

Official record
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Trial summary

This study is a prospective, interventional, open-label, single arm, non-randomized trial treating 30 patients with peripheral or mixed neuropathic corneal pain at their baseline exam and following 45 days and 90 days of daily use with the TrueTear™ ITN device. Read more about this study

Who is it for?
Ages 22 years and older
Conditions the study is for
Cornea
What is being tested?
TrueTear™ intranasal neurostimulator (ITN)
Type of treatment
Medical device
Could I receive a placebo?
No, everyone receives an active treatment
How many people
21 participants
Where
1 siteUnited States
Study dates
28 Sep 2018to 9 Sep 2023
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 22 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Age >22
  • Ability to consent to study.
  • Symptoms of neuropathic corneal pain for at least 3 months, such as burning, stinging, light sensitivity, discomfort or pain.
  • Positive in vivo confocal microscopy (IVCM) findings for NCP such as presence of microneuromas and decreased nerve density.
  • Fifty percent or more relief of pain or discomfort after instillation of Proparacaine eye drops as measured by the Visual Analogue Scale (VAS).

Who cannot join

  • Clinically significant acute ocular surface diseases, such as active infectious keratitis or recent ocular surgery in the past 3 months.
  • Chronic or recurrent epistaxis, coagulation disorders.
  • Nasal or sinus surgery or significant trauma to the nose.
  • Severe nasal airway obstruction or vascularized nasal polyps.
  • Cardiac demand pacemaker, implanted defibrillator, or other implanted electronic device in the head or neck.
  • Chronic or recurrent nosebleeds
Show all 9Show fewer
  • Bleeding disorder
  • Known hypersensitivity (allergy) to the hydrogel material
  • Disabling arthritis, neuropathy, or limited motor coordination affecting self-handling of the device.

Trial locations and contacts

1 site in 1 country.

United States1 site
  • Tufts Medical Center

    Boston, Massachusetts, 02111

Other trials in United States

About this study

Official title: Assessing the Efficacy of Intranasal Neurostimulation in Ameliorating Symptoms of Neuropathic Corneal Pain

This study is a prospective, interventional, open-label, single arm, non-randomized trial treating 30 patients with peripheral or mixed neuropathic corneal pain at their baseline exam and following 45 days and 90 days of daily use with the TrueTear™ ITN device.

Read the detailed description

The investigators hypothesize that the stimulation through the ethmoidal nerve in the nasal cavity may have an inhibitory effect on the primary TG interneurons and block the ocular pain signaling to the brain.

The investigators propose a non-randomized, open-label, single arm pilot trial for treatment of neuropathic corneal pain (NCP) with ITN with the following specific aims:

Specific Aims:

  1. To elucidate the efficacy of ITN in ameliorating pain among neuropathic corneal pain patients.
  2. To elucidate the safety, efficacy, longevity of ITN in ameliorating pain among neuropathic corneal pain patients during a 90-day period with daily use.
  3. To assess quality of life changes by treating neuropathic corneal pain with ITN during a 90-day period with daily use.
Conditions
Cornea
Being tested
TrueTear™ intranasal neurostimulator (ITN)
Keywords
Intranasal Neurostimulation
Medical subject headings
Corneal Diseases

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • TrueTear™ intranasal neurostimulator (ITN)Device

    TrueTear™ intranasal neurostimulator (ITN)

Study groups in NCT03674892
Study groupRoleWhat they receive
TrueTear™ intranasal neurostimulator (ITN)ExperimentalTrueTear™ intranasal neurostimulator (ITN)
Receives: Device: TrueTear™ intranasal neurostimulator (ITN)

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change to Overall Pain by the Visual Analogue Scale (VAS) After Intranasal Neurostimulator (ITN) Stimulation at Baseline

    The Visual Analogue Scale (VAS) is a 10 cm line, with one end labeled 'no pain' (which is equivalent to a score of 0 on the numerical scale) and the other end labeled 'worst pain imaginable' (which is equivalent to a score of 10 on the numerical scale). The patient is asked to mark the scale according to the intensity of their eye pain, and the examiner measures the distance in centimeters from the 'no pain' end of the line to score the VAS. The level of discomfort/pain before and after ITN was assessed using the VAS questionnaire (0-10). The changes in overall eye pain after ITN were recorded. Higher scores on the VAS indicate more intense pain and a worse outcome.

    Measured: immediately before and after ITN on Day 1 (baseline)

Secondary outcomes (12)
  1. Change to Overall Pain by the Visual Analogue Scale (VAS) After Daily Intranasal Neurostimulator (ITN) Stimulation Over 45-day Period

    The VAS is a 10 cm line, with one end labeled 'no pain' (which is equivalent to a score of 0 on the numerical scale) and the other end labeled 'worst pain imaginable' (which is equivalent to a score of 10 on the numerical scale). The patient is asked to mark the scale according to the intensity of their eye pain, and the examiner measures the distance in centimeters or millimeters from the 'no pain' end of the line to score the VAS. The level of discomfort/pain before and after ITN was assessed using the VAS questionnaire (0-10). The changes in overall eye pain after ITN were recorded. Higher scores on the VAS indicate more intense pain and a worse outcome.

    Measured: immediately before and after ITN on Day 45

  2. Change to Overall Pain by the Visual Analogue Scale (VAS) After Daily Intranasal Neurostimulator (ITN) Stimulation Over 90-day Period

    The Visual Analogue Scale (VAS) is a 10 cm line, with one end labeled 'no pain' (which is equivalent to a score of 0 on the numerical scale) and the other end labeled 'worst pain imaginable' (which is equivalent to a score of 10 on the numerical scale). The patient is asked to mark the scale according to the intensity of their eye pain, and the examiner measures the distance in centimeters or millimeters from the 'no pain' end of the line to score the VAS. The level of discomfort/pain before and after ITN was assessed using the VAS questionnaire (0-10). The changes in overall eye pain after ITN were recorded. Higher scores on the VAS indicate more intense pain and a worse outcome.

    Measured: immediately before and after ITN on Day 90

  3. Quality of Life as Measured With OPAS at Baseline

    The Ocular Pain Assessment Survey (OPAS) is a multidimensional questionnaire that assesses eye pain, non-eye pain, quality of life (QoL), aggravating factors, and associated factors. The QoL section evaluates seven dimensions, with the first six graded using numerical rating scales (0-10) and the final question expressed as a percentage (0-100). Higher scores indicate severe pain and lower QoL in the QoL section of OPAS questionnaire. Ranges: 0-10 for the "Reading and/or computer use", "Driving and/or watching TV", "General Activity", "Mood", "Sleep", "Enjoying Life/ Relationship. "Time spent thinking about pain" dimensions and 0-100. Higher scores indicate worse QoL.

    Measured: Day 1 (Baseline)

  4. Quality of Life as Measured Daily With OPAS at 45 Days

    The Ocular Pain Assessment Survey (OPAS) is a multidimensional questionnaire that assesses eye pain, non-eye pain, quality of life (QoL), aggravating factors, and associated factors. The QoL section evaluates seven dimensions, with the first six graded using numerical rating scales (0-10) and the final question expressed as a percentage (0-100). Higher scores indicate severe pain and lower QoL in the QoL section of OPAS questionnaire. Ranges: 0-10 for the "Reading and/or computer use", "Driving and/or watching TV", "General Activity", "Mood", "Sleep", "Enjoying Life/ Relationship. "Time spent thinking about pain" dimensions and 0-100. Higher scores indicate worse QoL.

    Measured: 45 days

  5. Quality of Life as Measured Daily With OPAS at 90 Days

    The Ocular Pain Assessment Survey (OPAS) is a multidimensional questionnaire that assesses eye pain, non-eye pain, quality of life (QoL), aggravating factors, and associated factors. The QoL section evaluates seven dimensions, with the first six graded using numerical rating scales (0-10) and the final question expressed as a percentage (0-100). Higher scores indicate severe pain and lower QoL in the QoL section of OPAS questionnaire. Ranges: 0-10 for the "Reading and/or computer use", "Driving and/or watching TV", "General Activity", "Mood", "Sleep", "Enjoying Life/ Relationship. "Time spent thinking about pain" dimensions and 0-100. Higher scores indicate worse QoL.

    Measured: 90 days

  6. Overall Change in Quality of Life as Measured Daily With OPAS

    The Ocular Pain Assessment Survey (OPAS) is a multidimensional questionnaire that assesses eye pain, non-eye pain, quality of life (QoL), aggravating factors, and associated factors. The QoL section evaluates seven dimensions, with the first six graded using numerical rating scales (0-10) and the final question expressed as a percentage (0-100). Higher scores indicate severe pain and lower QoL in the QoL section of OPAS questionnaire.

    Percentage changes in the scores between baseline vs 45-day visit and baseline vs 90-day visit after daily intranasal neurostimulation are given below.

    Measured: Baseline vs day 45 visit and Baseline vs day 90 visit

  7. Percent Change From Pain Level Dimension Questions of the Ocular Pain Assessment Survey (OPAS)

    The Ocular Pain Assessment Survey (OPAS) is a multidimensional questionnaire that assesses eye pain, non-eye pain, quality of life (QoL), aggravating factors, and associated factors. Eye pain intensity was assessed using a numerical scale (0-10) for the most, least, and average pain in the past 24 hours and 2 weeks. Higher scores indicate severe pain of OPAS questionnaire. The percent changes in pain intensity between baseline vs 45-day and baseline vs 90-day are provided below.

    Measured: Baseline vs day 45 visit and Baseline vs day 90 visit

  8. Overall Percent Change on Impact of Dry Eye in Everyday Life (IDEEL)

    IDEEL Quality of Life Questionnaire is a 27-item questionnaire, designed specifically for DED and is divided into three parts. It assesses the quality of life in three aspects of life for the previous 2 weeks: daily activities, work and feelings. The quality of life is assessed on a scale of 0-5, with zero being inability to do the activity. The score is calculated between 0 - 100 with higher scores indicating a better quality of life. Percentage change in IDEEL questionnaire subheading between baseline and day 45 and baseline and day 90 were given below.

    Measured: Baseline vs day 45 visit and Baseline vs day 90 visit

  9. Change in the Intraocular Pressure (IOP) Measured in Each Visit.

    Intraocular pressure will be measured by an applanation tonometer used on slit lamp (Goldmann) in mmHg. Change in IOP values between baseline and 90-day is provided below. A healthy eye pressure is between 10 and 21 millimeters of mercury. The differences in intraocular pressure between the baseline and day 45 visits, as well as between the baseline and day 90 visits, are presented below.

    Measured: Baseline vs day 45 visit and Baseline vs day 90 visit

  10. Number of Participants With Adverse Events (Safety)

    For safety analyses during the study, patient-reported adverse events that developed after intranasal neurostimulation were recorded.

    Measured: 90 days

  11. Number of Participants With Adverse Events (Tolerability)

    Tolerability of Intranasal Neurostimulator (ITN) was evaluated by using Ocular Tolerability and Compliance Questionnaire. It assesses symptoms of discomfort in each eye after ITN use.

    Measured: 90 days

  12. Reduction on Other Concomitant Pain Therapy

    After daily intranasal neurostimulation, the change in the number of systemic pain medication between baseline vs 45-day visit and Baseline vs 90-day visit was evaluated.

    Measured: Baseline vs 45 Day Visit and baseline vs 90 Day Visit

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted18 Sep 2018
  2. Study start28 Sep 2018
  3. Primary completion9 Sep 2022
  4. Study completion9 Sep 2023

Why it stopped: Original device is now discontinued; we are changing the study device shortly

Resources

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
Diagnosis
Allocation
Not applicable
Intervention model
Single group
Model description
non-randomized, open-label, single arm pilot trial
Masking
None (open label)
Enrolment
21 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT03674892
Sponsor's protocol ID
12978
Acronym
INSTANT
Status last verified
Aug 2025
First submitted
12 Sep 2018
Last updated
24 Aug 2025
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
Yes
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A study testing TrueTear™ intranasal neurostimulator (ITN) in people with Cornea, run by Tufts Medical Center 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 9 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: stopped early, as of the sponsor's last update on 24 Aug 2025. 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 24 Aug 2025). 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?

Change to Overall Pain by the Visual Analogue Scale (VAS) After Intranasal Neurostimulator (ITN) Stimulation at Baseline (time frame: immediately before and after ITN on Day 1 (baseline)). 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 24 Aug 2025.

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