This study aims to evaluate the effectiveness and safety of a device, iTEAR100 Neurostimulator (the device), which is designed to help people with Dry Eye Disease (DED) who are not satisfied with using artificial tears. The study will last three months and take place at one location. Thirty participants will use the iTEAR100 Neurostimulator, which stimulates the outside of the nose to help with dry eye symptoms.

Participants will have three main visits: one at the start (Day 0), one after 30 days (Day 30), and one at the end of the study (Day 90). For the first 30 days, they will use the device twice a day for 30 seconds on each side of the nose. After that, they will use it as needed for the next 60 days.

Before starting the treatment, participants will undergo tests to measure their initial eye condition. The effectiveness of the device will be checked by comparing these baseline measurements to those taken on Day 30 and Day 90. Participants will also fill out a questionnaire about their eye symptoms on Day 14.

The main measure of success is how much the participants' symptoms improve on the Ocular Surface Disease Index (OSDI) from Day 0 to Day 30. Other measures include changes in tear production, tear quality, and eye health from Day 0 to Days 30 and 90. Participants' safety will be monitored by tracking any adverse events (side effects) throughout the study.

This is a Phase IV, single-centre, open-label, single-arm study to evaluate the effectiveness and safety of extra nasal neurostimulation in relieving symptoms of patients with Dry Eye Disease (DED) who are dissatisfied with artificial tear treatment. The intervention product is the extranasal neurostimulator, branded iTEAR.

The study duration is three months, with visits on Days 0, 30 and 90. Participants will follow a treatment regimen to apply neurostimulation to each side of the nose for 30 seconds twice daily for 30 days. From Day 31 to Day 90, participants will use the device as needed. Screening tests to measure baseline levels will be performed on Visit 1, and efficacy measures will be performed on Day 30 and Day 90. The participants will be instructed to perform a questionnaire on the ocular surface disease index (OSDI) on Day 14. Primary efficacy measures include changes in OSDI from baseline to Day 30. Secondary efficacy measures include the change in Schirmer Test Score, tear lipid layer thickness, corneal/conjunctival staining, and non-invasive tear film break-up time (NIBUT) from baseline to Day 30 and Day 90. Adverse Event (AE) Query is used as a safety measure to report adverse events in the duration of the study. The estimation of subjects in this trial is 30, with a power of 0.8 and assuming a 20% dropout rate.

To be included in the study, participants must be able to provide informed consent to participate in the study. They must have reported dissatisfaction (OSDI ≥ 23) with the recent use of artificial tears for DED (within 30 days of Visit 1), and Schirmer Test Score ≤ 10 mm/5 min in at least one eye.

The study eye will be defined as the eye with a Schirmer Test Score ≤ 10 mm/5 min. If both eyes qualify, the eye with a lower Schirmer Test Score during screening will be chosen as the study eye. If there is no difference, the right eye will be selected as the study eye.

The participants are excluded from the study if they have used extranasal or intranasal neurostimulator within 30 days of Visit 1, or participated in any clinical trial with an investigational substance or device within 30 days of Visit 1. In the opinion of the investigator, any condition that could impair study participation/ocular evaluation, or the potential risks of participation outweigh the potential benefits will also lead to exclusion from the study.

The participants will be withdrawn from the study if they voluntarily withdraw their consent to study participation, develop any adverse event that prevents the study participation, persistently do not comply with the study protocol, are lost to follow-up, or when the investigator believes the risk of further subject participation outweighs the benefit.

Inclusion Criteria:

Each patient must meet all the following criteria to be enrolled in this study:

1. Provided informed consent, approved by the Institutional Review Board (IRB), to participate in the study.
2. Reported use of artificial tears for DED within 30 days of Visit 1.
3. Ocular Surface Disease Index (OSDI) ≥ 23 (with no more than 3 N/A in the answers).
4. Anesthetized Schirmer Test Score ≤ 10 mm/5 min in at least one eye.

Exclusion Criteria:

Patients who meet any of the following criteria will be excluded from the study:

1. Used extranasal or intranasal neurostimulator within 30 days of Visit 1.
2. Participation in any clinical trial with an investigational drug or device within 30 days of Visit 1.
3. In the opinion of the investigator, any condition that could impair study participation/ocular evaluation or the potential risks of participation outweigh the potential benefits.