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True Tears Prospective

Title Assessing the Efficacy of Intranasal Neurostimulation in Ameliorating Symptoms of Neuropathic Corneal Pain 
Therapeutic Area Corneal Pain, Corneal Disorders
Principal Investigator Pedram Hamrah, MD
Min Age 18 Years
Gender All
Contact Michael Dixon
More Information


Patients that suffered from neuropathic pain or photoallodynia, reported immediate relief of pain after use of TrueTear® intranasal neurostimulator (ITN). We propose a pilot study for treatment of neuropathic corneal pain (NCP) with ITN with the following specific aims: 

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

Study Details

Inclusion Criteria

  • 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. The presence of positive IVCM findings serves in lieu of skin biopsies as proof of nerve injury.
  • Fifty percent or more relief of neuropathic symptom 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. 

Study Requirements

1 screening visit; 3 additional study visits over 90 days. Most study visits take about 2 hours to complete. Patient will be trained to use an intranasal neurostimulator daily. Includes eye exam, questionnaires about symptoms, quality of life, and safety and tolerability. Patient will complete short daily diary about pain symptoms.