Neurostimulation with the iTear 100 Device to Increase Tear Production
Dry eye disease is a multifactorial condition, meaning that there are many potential causes and contributing factors. This makes this condition incredibly hard to deal with as a patient, but it’s also just as challenging as a clinician. To properly treat dry eye disease, it’s important for both the patient and clinician to understand the many potential causes so that a proper treatment regimen can be chosen.
A treatment path which has come to the forefront in recent months is neurostimulation. In this interview, we’re going to discuss what this is, how it can benefit you, and how you can go about trying it out.
What is Neurostimulation?
This is a concept that’s been in medicine for a long time - cardiac pacemakers and cochlear implants are examples of neurostimulation. Basically, it is an intentional modulation of the nervous system’s activity using a variety of different devices. Depending on the device and therapy, neurostimulation may be invasive or noninvasive. Two neurostimulation devices have been released in eye care, and these are the TrueTear device (which has since been removed from the market) and the new iTEAR 100.
The Role of the Lacrimal Functional Unit in Dry Eye Disease
The Lacrimal Functional Unit (LFU) consists of the ocular surface (cornea, conjunctiva, accessory lacrimal glands, and meibomian glands), the main lacrimal gland and the interconnecting innervation between them. Each part of this system is of importance when we discuss dry eye disease, and neurosensory compromise is a part of the TFOS dry eye definition. This compromise can explain so much of what’s happening in dry eye disease.
For example, picture driving on a salty road in the wintertime in the Midwest. Eventually, your car is going to begin to rust and deteriorate due to the high salt situation. The same occurs on the ocular surface. Hyperosmolarity is an increase in salty tears due to either an increase in evaporation of the tears or loss of fresh tear input. This begins to corrode the front of the eyes, leading to dry patches and compromised corneal nerves.
Corneal Nerve Compromise in Dry Eye
The corneal nerves are there to consistently assess the quality and composition of your tears, and they adjust to take homeostatic control of the eye when needed. However, in dry eye disease, you lose that ability for the corneal nerves to adjust in real time. This means that environmental insults can be much more severe because your eyes are unable to compensate. This can be exacerbated by contact lens wear, refractive surgery, cataract surgery, and even severe autoimmune disease.
Now, there’s a way to bypass the damaged corneal nerves. In a healthy individual, the corneal nerves send signals to the brain which in turn send signals back to the lacrimal glands, meibomian glands and goblet cells of the conjunctiva. Each of these is under neural control from the central nervous system, yet even in those with corneal nerve damage you can now bypass these disrupted signals using neurostimulation devices such as the iTEAR 100.
By applying energy to peripheral nerves on the sides of the nose, you’re able to send a signal back to the brain and tell the lacrimal gland to produce tears, the meibomian glands to secrete meibum, and the goblet cells to produce mucin.
As you improve the entire LFU by decreasing hyperosmolarity and getting those corneal nerves to sensitize again, it is possible to reverse some of this corneal nerve compromise and truly heal the system.
How Do Ocular Surgeries Impede the Corneal Nerves?
We hear all the time from patients who have had LASIK that dry eye is their number one complaint. This is because LASIK, PRK, and other ocular surgeries physically cut the corneal nerves and impede this neurosensory feedback to the brain.
No longer are your corneal nerves able to send signals to the brain, and then to the lacrimal or meibomian glands. The same thing can happen when the corneal nerves begin to shrink down and dysregulate due to chronic inflammation in dry eye disease.
In addition to the effects above, you can also have a hyperstimulation of the corneal nerves in some cases. This is mitigated by osmoreceptors that detect salt load on the eyes, thermoreceptors that detect temperature changes, mechanoreceptors detecting pressure, and inflammation induced pain receptors. All of this may result in eyes that are overproducing tears, yet the quality may not be there.
The iTEAR ®100 Device and Dry Eye
How is it that a device that acts on the outside of your nose provides such relief for dry eye? The iTEAR 100 is an FDA approved, drug-free approach to increasing tear production in those with dry eye disease. This device provides a safe amount of mechanical stimulation to the outside of the nose, stimulating the external nasal nerve.
We know that neurostimulation has major impacts in medicine, and this is true for dry eye disease as well. As we’ve mentioned, early neurostimulation successes include the cardiac pacemaker, implantable devices for pain, and external electromagnetic stimulation for the treatment of depression. Neurostimulation applications in eye care are now emerging, and we’re bound to see more of this in the future.
The iTEAR ®100 device uses neurostimulation via a small oscillating tip which is applied to the outside of the nose. This stimulates the external branch of the anterior ethmoidal (or nasal) nerve, which is located on each side of the nose. When this happens, the adjacent lacrimal gland is stimulated to produce natural tears.
Studies on the iTEAR ®100 device
So far, clinical studies do show some efficacy and in-office observation by Dr. Periman and others has shown much promise for dry eye treatment using this modality. Recent studies were performed using the device twice per day, 30 seconds each side, and these studies have shown an increase in tear production immediately after stimulation. An increase was also seen in Schirmer scores at each visit, measured at day 14 and day 30. As with anything, there were adverse events, but they were minimal and included a 1-2% rate of lightheadedness and/or dizziness.
In other studies, it was found that baseline tear production greatly improved over time when using this device. That’s truthfully one of the most important things we’re looking for. Although some people may feel that it stops working after two weeks, this is not the case. It is merely the sensation of the tickle on the side of the nose that wanes a bit. However, you can be sure that your baseline tear production is still increasing during this time. In addition, the quality of the meibum, or oil, production goes from insippated to liquid and free-flowing during this time. Some people even noticed a drastic improvement in their visual acuity after a few months of use, which makes sense due to the robust tear film that’s being produced.
Who Can Use iTEAR 100?
Phase 3 FDA trials looked at severe dry eye patients, but it can be used earlier and often in many different types of dry eye patients. Anyone with any history of refractory dry eye - someone who has tried everything without relief - would be a candidate. Also, those with dry eye after refractive surgery, long term contact lens wearers, and those with autoimmune disease would also greatly benefit. Neurostimulation can be incredibly beneficial for these patients, and it may even help the neurosensory pathway regenerate and function normally again.
Contraindications for iTEAR 100
While there aren’t many contraindications, there are a few:
Significant nasal bleeding history
Implants such as pacemakers
Any metal in the nasal area
How to Use the iTEAR ®100 device
After turning the device on, you’ll hear a mosquito-like buzzing sound which means that the vibration is on. The device is to be used 30 seconds per side of the nose, twice per day. In severe situations or in cases where the patient may have a limited response to the device, Dr. Periman will prescribe up to 60 seconds, four times per day. The device can also be used as needed if you know you’ll be in an environment that is less dry eye friendly (such as on an airplane or out for a snowy hike).
You may notice that, when you find the right spot on your nose, it will tickle a bit. This is normal and to be expected. There is usually less sneezing noticed with this device versus the TrueTear intranasal device, although sneezing is possible during this procedure as well. Used properly, you should notice an almost immediate increase in the tear volume on your eyes. In fact, the better hydrated you are in general, the better tear production you’ll have from this device. This shows the importance of all of the self-care methods we teach, including hydration!
If you’re interested in this device, speak with your doctor. They can stock and dispense them in their clinic or they can order one for you directly through Olympic Ophthalmics. The device does require a prescription. There is no insurance coverage at this time, but you should be able to use your HSA dollars toward the device. At this time in early 2021, the cost of the initial device for 30 days is around $150 and refills each month are $50.
If you’d like to visit Dr. Periman in her new practice, The Periman Eye Institute, head to her websiteto schedule an appointment.