Eye-dropper bottle evolves

September 25, 2013
An older male patient demonstrates use of the Whisper eyedrop device.

An older male patient demonstrates use of the Whisper eyedrop device.

By Geoffrey W. Goodfellow, O.D., and Dominick M. Maino, O.D.

The instillation of ocular pharmaceuticals has been around for more than 100 years. From diagnostic agents we instill in the office, to prescription pharmaceuticals patients administer themselves, very little has changed about the delivery mechanism over the years.

Most optometrists are familiar with the limitations of the traditional dropper bottle. It can be difficult to control the exact size of the drop that gets into the eye, and patients often blink at just the wrong moment. The challenges are increased when the bottle is in the hand of the patient at home – who knows exactly how much medication is getting in the eye or if they have been taking their medications regularly.

Sean Ianchulev, M.D., MPH, associate clinical professor of ophthalmology at the University of California San Francisco, and Mark Packer, M.D., clinical associate professor of ophthalmology at Oregon Health & Science University in Portland, are working with Corinthian Ophthalmic, Inc. to upgrade the technology used to instill ocular pharmaceuticals.

The new microdroplet fluid ejection device “Whisper” is built to  dramatically improve  the way  eyedrops are administered.

The new microdroplet fluid ejection device “Whisper” is built to
dramatically improve
the way
eyedrops are administered.

Although not yet commercially available, the new microdroplet fluid ejection device named “Whisper” is built to address the above challenges as well as drastically improve the way eyedrops are administered.

The piezoelectric fluid ejection system is able to control the exact dose and droplet size. A no-touch LED alignment system eliminates the need for patients to tilt their heads, and the medication is delivered about a third faster than the human blink rate.

The system also stands apart from the old-fashioned bottle in that it delivers the drug in a parallel stream of similarly sized droplets traveling at the same velocity. Because there isn’t much turbulence, nearly all of the pharmaceutical agent gets to the target tissue, allowing the amount of drug needed to be considerably less.

To put that into perspective, the traditional dropper bottle uses about 30 microliters of liquid, whereas the Whisper device was able to get the same medication effect using about 6 microliters. That’s less liquid for the patient to feel, less stinging, and less tearing.

Drs. Ianchulev and Packer describe the proof-of-concept study where pupil dilation was measured after administration of 2.5 percent phenylephrine and 1 percent tropicamide in various dose volumes. Some eyes received the medication via a 30-microliter eyedrop while others received delivery from the Whisper device at either 1.5 microliters, 2 x 3 microliters, or 6 microliters. The initial findings were that 6 microliters of drug delivered with the Whisper created about the same dilation effect as with the traditional eyedrop. They’ve also been successful delivering countless other ophthalmic medications.

The designers of the device want it to be comfortable for the patient, inexpensive, and use a cartridge mechanism so that different pharmaceuticals can be snapped into the device. Because the device has multiple seals, Corinthian believes there may be no need for preservatives in medications delivered with the Whisper device.

In the future, using a more technologically enhanced method of delivering ocular drugs could enable other improvements too. In general, technology like the Whisper could:

  • Provide more independence for the elderly or others with limited dexterity to self-administer eyedrops.
  • Add an alarm to remind patients to instill their drops.
  • Build in a recording system where the device could report back to the doctor when the drops were taken.
  • Eliminate preservatives in certain ocular pharmaceuticals.
  • Deliver multiple individual drugs simultaneously to provide a combined effect without the drugs needing to exist as combinations.
  • Design an auto-mix system to ensure suspensions are shaken well before delivery.

There are likely many other benefits that could be derived from devices like the Whisper. Although technologies like automated visual fields, optical coherence tomography, and Heidelberg Retina Tomograph have revolutionized eye care, optometrists may also have much to gain by exploring improvements to our simple plastic dropper bottles.

Dr. Goodfellow is an associate professor of optometry at ICO and the college’s assistant dean for curriculum and assessment. He can be contacted at ggoodfel@ ico.edu. Dr. Maino is a professor at the Illinois College of Optometry (ICO), a Distinguished Practitioner of the National Academies of Practice, and the newest member of the Lyons Family Eye Care team. He can be contacted at dmaino@ico.edu.

The views expressed are those of the authors and do not necessarily reflect the views of the AOA.

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