Intranasal Stimulator Improves Dry Eye Symptoms

Laird Harrison

October 31, 2018

CHICAGO — A device that zaps nerves inside the nasal cavity can significantly reduce symptoms of dry eye disease, a multifactorial disease that can be difficult to treat, researchers report.

"Oil, water, and mucous, or some combination of the three, can have deficiencies," said Gary Jerkins, MD, from Nashville Vision Associates in Tennessee. And none of the treatments currently available, including artificial tears and anti-inflammatories, work consistently in all patients.

But the TrueTear intranasal tear neurostimulator from Allergan — intended for patients with aqueous deficiency, not meibomian gland deficiency — works, he told Medscape Medical News.

The neurostimulator consists of a reusable base that produces microcurrents, a disposable tip that inserts in to the nasal cavity, and a battery charger. When the tip is attached to the base, microcurrents are delivered to the trigeminal nerve in the nasal cavity, which induces endogenous tear production through the nasolacrimal pathway, Jerkins explained here at American Academy of Ophthalmology 2018 Annual Meeting.

Pivotal trials have shown that the device can increase tear production. To determine whether it also improves symptoms, Jerkins and his colleagues conducted two studies.

In both, most of the participants were women and mean age was about 60 years. Mean basal Schirmer test scores ranged from 6.0 mm to 7.2 mm in 5 minutes for all eyes. Cotton swab-stimulated Schirmer scores ranged from 25.7 mm to 31.2 mm in 5 minutes.

At baseline, mean total scores on the Ocular Discomfort Scale ranged from 2.6 to 2.8 on a scale of 0 to 4. Mean rating on the 100 mm visual analogue scale for the Eye Dryness Score was 60 mm. In both studies, patients were exposed to a controlled adverse environment to exacerbate the symptoms and signs of dry eye.

In study 1 (NCT02910713), 185 patients used the device twice in a 2-hour period and rated eye dryness and eye discomfort every 5 minutes. Participants used the stimulator when their discomfort ratings exceeded 3 at two consecutive time points in the same eye. And they used it a second time after the next two consecutive ratings above 3.

For active treatment, the stimulator was placed inside the nasal cavity; for the control procedure, it was placed outside the nasal cavity. The order of active and control use of the stimulator was randomized.

Relief of symptoms was significantly greater in the active treatment group, when the device was used inside the nasal cavity, as intended, than in the control group.

Table. Decrease in Scores From Baseline After Device Use in Study 1

Measure Active Treatment Group Control Group P Value
Eye Dryness Score –16.5 –3.1 <.0001
Ocular Discomfort Scale –0.93 –0.34 <.0001

There was only one adverse event in study 1. A patient developed mild bilateral epistaxis that lasted about 30 seconds, but blood loss was minimal.

In study 2 (NCT03097614), 57 participants used the device 2 to 10 times a day for 45 days, and got just as much relief on day 45 as they did on day 1.

Table. Decreases in Scores From Baseline on the First and Last Days of Study 2
Measure Day 1 P Value Day 45 P Value
Eye Dryness Score –15.9 <.0001 –15.2 <.0001
Ocular Discomfort Scale –1.3 <.0001 –1.3 <.0001

In study 2, there were eight device-related adverse events, including sinus infections, transient electrical discomfort, worsening tinnitus, headache, common cold, and mild epistaxis. Three people discontinued their use of the device because of adverse events.

"I'm always going to try drops first," Jerkins said. "But this is close second." He gives patients 4 to 6 weeks to see if artificial tears provide adequate relief before suggesting the stimulator.

Patients are sometimes hesitant, he explained. "The hurdle to get over is that you're doing something in your nose to make your eyes water."

The treatment does not cure dry eye, but it does add to a growing set of treatments that are effective for at least some patients at least some of the time. "I don't think we have found the silver bullet," Jerkins said, but "it's another arrow in the quiver."

The devices shows "great potential," said Chris Rapuano, MD, from Wills Eye Hospital in Philadelphia.

"We're just beginning to use this, and so far it seems pretty good," he told Medscape Medical News.

Previous research suggests that the tears produced are of good quality. "Anybody can stick a cue tip up their nose and cause themselves to sneeze, which will cause tearing," he pointed out. But "this seems to be a different mechanism."

Jerkins has disclosed no relevant financial relationships. Rapuano reports a relationship with Allergan.

American Academy of Ophthalmology (AAO) 2018 Annual Meeting: Abstract PO044. Presented October 29, 2018.

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