Abstract
Purpose :
Neuropathic corneal pain (NCP) is a debilitating disease with limited treatment options. Neuromodulation has been evolving for the treatment of chronic pain syndromes. This study aimed to investigate the efficacy of intranasal neurostimulation (ITNS) in ameliorating pain among NCP patients.
Methods :
A total of 21 patients diagnosed with peripheral or mixed NCP were enrolled. Patients were instructed to use the ITNS device for three minutes each day, documenting alterations in pain intensity and changes in quality-of-life scores (QoL) through the Ocular Pain Assessment Survey daily. The clinical visits were scheduled at baseline, 30-days, and 90-days, and the clinical results along with the reasons for treatment discontinuation and the patterns of pain intensity changes (scale 0-10) were analyzed.
Results :
The median age was 53.05±3.23 years and female/male ratio was 18/3. The pain intensities before ITNS showed a reduction of 18.15% at 30 days and 46.24% at 90 days compared to the baseline (p=0.11 and 0.16, respectively). Pain scores after ITNS changed from 5.73±0.45 to 1.92±0.36 (p <0.001) at baseline, 4.69±0.61 to 2.76±0.70 (p=0.005) at 30 days and 3.08±0.93 to 2.33±0.76 (p=0.41) at 90 days. Mean QoL scores gradually decreased with 6.46±0.55, 4.90±0.74 and 3.98±1.07 at baseline, 30-days, and 90-days, respectively (p=0.19). Seven (33.33%) out of 21 patients discontinued ITNS due to loss of effectiveness (n=3), induction of migraine attacks (n=2), increased pain intensity (n=1), and sinus infection (n=1). The changes in pain scores following ITNS stratified patients as responders (78.57%; continuous =28.57%, waning effect=28.57%, cyclic =21.43%) and non-responders (21.43%). Group of responders and non-responders demonstrated that burning sensation were reported as 86.81±3.58% and 30±10% for responder and non-responder groups respectively (p=0.009). Other factors did not demonstrate significant differences between groups.
Conclusions :
ITNS can be effective in relieving pain symptoms in most patients with peripheral and mixed NCP, in particular in patients with burning. However, within responders, there seem to be variable patterns, with some patients potentially developing tolerance to ITNS. Neurostimulation presents a promising adjunct treatment for NCP and future prospective randomized trials are warranted.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.