Intranasal Neurostimulation in Ameliorating Symptoms of Neuropathic Corneal Pain

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.