Med Device Monday: Triggerfish

Glaucoma is a term used to describe a group of diseases of the eye and optic nerve which, if left untreated, can lead to blindness or loss of vision. Once vision loss sets in, it cannot be recovered. While there is no cure for glaucoma, with early detection and treatment it can be managed and these side effects can be mitigated, delayed, or even avoided.

Managing the disease has to do with managing or alleviating pressure in the eye. 

Photo from nei.nih.gov.

Photo from nei.nih.gov.

The National Eye Institute explains, "Several large studies have shown that eye pressure is a major risk factor for optic nerve damage. In the front of the eye is a space called the anterior chamber. A clear fluid flows continuously in and out of the chamber and nourishes nearby tissues. The fluid leaves the chamber at the open angle where the cornea and iris meet. (See diagram below.) When the fluid reaches the angle, it flows through a spongy meshwork, like a drain, and leaves the eye.

In open-angle glaucoma, even though the drainage angle is “open”, the fluid passes too slowly through the meshwork drain. Since the fluid builds up, the pressure inside the eye rises to a level that may damage the optic nerve. When the optic nerve is damaged from increased pressure, open-angle glaucoma-and vision loss—may result. That’s why controlling pressure inside the eye is important."

Photo from nei.nih.gov.

Photo from nei.nih.gov.

So if managing pressure is key, then so must be monitoring it. 

Enter the Triggerfish "smart" contact lens. (If looking at this doesn't make you feel like you're living in the future, I don't know what will.)

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Photos from sensimed.ch.

Photos from sensimed.ch.

While traditional methods of monitoring pressure in the eye meant taking a measurement during a visit to your eye doctor, Triggerfish is a soft contact lens that monitors pressure in the eye over a 24-hour period, providing insight into changes and peaks in pressure throughout the day. The type, timing, and dose of medication (like pressure-mitigating eye drops) can then be more precisely prescribed for the patient. Personalizing and targeting precise treatment in this way is then of course more likely to lead to a better outcome.

Photo from sensimed.ch.

Photo from sensimed.ch.

An article from VisionAware (part of the American Foundation for the Blind) explains, "The Triggerfish® lens is a sensor that monitors changes in the curvature of the cornea, the transparent dome-shaped tissue that forms the front part of the eye. According to Sensimed, these changes in the cornea correspond directly to fluctuations in intraocular pressure, which is characteristic of certain types of glaucoma.

Eye pressure data from the Triggerfish® lens is transmitted wirelessly to a small adhesive antenna placed on the face near the eye. The antenna then transmits the data to a portable recorder worn by the patient. The lens can be worn continuously for one 24-hour period...When the patient returns to his or her eye doctor, the data is transferred from the recorder to the doctor's computer via Bluetooth technology for immediate analysis."

The article's editor then goes on to note that recent studies have shown that pressure is often lowest during waking hours, when patients are most likely to see their doctors, and highest at night–thus making this information that much more valuable in crafting a treatment plan.

I absolutely love this type of personalized medicine: it's a win for patients and healthcare providers alike. Being able to tailor a care plan to a patient's specific experience and needs not only means that their vision is more likely to be preserved, but it is also more efficient by cutting back on the number of doctor's appointments for evaluation and treatment adjustments. Triggerfish is one more reason I'm excited to be living in the medical future!

 

Further reading:

FDA's Triggerfish Classification Order

FDA's Triggerfish Decision Summary