Efficacy of Extranasal Neurostimulation for Patients With Neuropathic Corneal Pain: A Pilot Study

Purpose: Neuropathic corneal pain (NCP) has been recognized as a distinct disease, yet treatment options remain limited. The aim of this pilot study was to explore the effectiveness of extranasal neurostimulation (EXNS) as a potential pain relief strategy for individuals with the peripheral component of NCP. Methods: A retrospective study was performed to identify patients who were diagnosed with refractory peripheral or mixed NCP and subsequently underwent a single session of EXNS. Visual analog scale (VAS) was used to evaluate pain intensities in the office before and after 60 seconds of EXNS. Demographic information, changes in pain scores, and comorbidities were recorded, and their correlations with pain score changes were analyzed. Results: Twenty-two patients with a mean age of 48.91 ± 3.32 years were included. The average VAS score before EXNS was 5.59 ± 0.41, which was reduced to 2.59 ± 0.43 after EXNS, indicating a 54.88% reduction ( P < 0.001). EXNS reduced VAS scores from 4.90 ± 0.72 to 1.60 ± 0.42 (68.40%) for 10 patients with peripheral NCP and from 6.17 ± 0.42 to 3.42 ± 0.62 (43.61%) for 12 patients with mixed (peripheral and central) NCP ( P = 0.005 for both groups). Fourteen patients (63.63%) experienced an improvement of at least 50% in their pain scores, 2 patients (9.09%) showed an improvement between 30% and 49.9%, while 6 patients (27.27%) experienced an improvement of less than 30%. No correlations between the change in pain scores and patient demographics, as well as comorbidities were detected. Conclusions: EXNS may be used as an adjuvant therapy to ameliorate pain among patients with NCP with the peripheral pain component.