Intranasal Neurostimulation in Ameliorating Symptoms of Neuropathic Corneal Pain

Study Overview
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Brief Summary
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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.

Detailed Description
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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: To elucidate the efficacy of ITN in ameliorating pain among neuropathic corneal pain patients. To elucidate the safety, efficacy, longevity of ITN in ameliorating pain among neuropathic corneal pain patients during a 90-day period with daily use. To assess quality of life changes by treating neuropathic corneal pain with ITN during a 90-day period with daily use.

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

Conditions
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Cornea

Intervention / Treatment
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* Device: TrueTear™ intranasal neurostimulator (ITN)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 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). Exclusion Criteria: 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 Bleeding disorder Known hypersensitivity (allergy) to the hydrogel material Disabling arthritis, neuropathy, or limited motor coordination affecting self-handling of the device.

Ages Eligible for Study
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Minimum Age: 22 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Interventional Model Description: non-randomized, open-label, single arm pilot trial
Masking: None (Open Label)


Arms and Interventions

| Intervention/Treatment |
| --- |
|Device: TrueTear™ intranasal neurostimulator (ITN)|Subject will place the tips of the ITN into both nostrils simultaneously. Subject will be asked to apply it for 3 minutes [could be modified if need be], daily.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in pain score measured by the Visual Analogue Scale (VAS) after intranasal neurostimulator (ITN) stimulation | Visual Analogue Scale (VAS) questionnaire is single-item scale for pain intensity, the scale is most commonly anchored by no pain (score of 0) and pain as bad as it could be or worst imaginable pain (score of 100 [100-mm scale]) | 90 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Corneal nerve density measured by laser in vivo confocal microscopy (IVCM) in mm/mm2 | IVCM is a non-invasive, high-resolution, real-time imaging technique that allows the study of corneal nerve morphology. | 90 days | 
| Response to proparacaine drops based on Visual Analogue Scale (VAS) scores | The level of pain will be measured on a visual analogue faces scale before and after application of a proparacaine drop. Visual Analogue Scale (VAS) questionnaire is single-item scale for pain intensity, the scale is most commonly anchored by no pain (score of 0) and pain as bad as it could be or worst imaginable pain (score of 100 [100-mm scale]) | 90 days | 
| Quality of Life (QoL) based on the multidimensional ocular pain questionnaire | Ocular Pain Assessment Survey (OPAS) is a multidimensional 32-questions, 8-domain questionnaire using numerical rating scales to assess eye pain intensity (worse eye) in the past 24 hours and 2 weeks (worst, least and average pain intensity), frequency of eye and non-eye pain (past 24 hours and 2 weeks), non-eye pain intensity (past 24 hours and 2 weeks), impact on QoL, pre-occupation with eye and non-eye pain, aggravating factors and associated factors. | 90 days | 
| Change in quality of life as measured daily with Impact of Dry Eye on 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. | 90 days | 
| Micro-neuroma density measured by laser in vivo confocal microscopy (IVCM) in unit/ mm2 | IVCM is a non-invasive, high-resolution, real-time imaging technique that allows the study of corneal nerve morphology. | 90 days | 
| Change in the intraocular pressure (IOP) measured in mmHg | Intraocular pressure will be measured by an applanation tonometer used on slit lamp (Goldmann) in mmHg. | 90 days | 
| Tolerability of ITN | Directed questioning about itching, burning sensation, and foreign body sensation will be done to assess tolerability | 90 days | 
| Changes in the current systemic medications | Questionnaires regarding changes or reduction in the current systemic medications will be applied and used as a clinical effective parameter. | 90 days | 
| Response to hyperosmolar drops based on Visual Analogue Scale (VAS) scores | The hypersensitivity to hyperosmolarity will be examined by applying a 5% sodium chloride drop on the conjunctival fornix of both eyes. The level of pain will be measured on a visual analogue faces scale before and after application of a 5% sodium chloride drop.Visual Analogue Scale (VAS) questionnaire is single-item scale for pain intensity, the scale is most commonly anchored by no pain (score of 0) and pain as bad as it could be or worst imaginable pain (score of 100 [100-mm scale]) | 90 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Intranasal Neurostimulation