Lacrimal gland courtesy of Shutterstock
As more Americans enter their "golden" years there's a concomitant increase in the number who suffer from a condition known as "dry eyes." Most frequently seen in people over 50, dry eyes can be caused by a variety of factors, including wind, several diseases and inadequate tear production. Untreated, dry eyes may lead to several complications such as difficulty reading, sore or itchy eyes, trouble seeing at night and a "foreign body" sensation in the eyes.
The watery layer of tears (they also include a layers of lipid and mucus) is produced by a small gland under the upper, outer corner of the eyelid called the lacrimal gland (see above image).
Tears produced by this gland sweep down across the surface of the eye and exit through a small duct that empties into the nasal passage (that's why your nose runs when you cry). To treat dry eyes there are many products eye drops, gels, and ointments on the market to soothe and compensate for a lack of tears. But those can be inconvenient to use and typically offer only temporary relief. Recent research, however, might point to a new way to alleviate the condition neural stimulation of the lacrimal gland.
A new report just published in the Journal of Neural Engineering describes a technique that involves inserting a tiny electrode under the lacrimal gland, which can be stimulated remotely (say by your smart phone with the appropriate app). This electrical stimulation causes the lacrimal gland to produce tears and should alleviate dry-eye discomfort.
Led by Dr. Mark Brinton from Stanford University, the international team included scientists from Korea. They found that the electrical stimulation of the afferent neural pathway (nerves leading from the lacrimal gland to the brain) resulted in even more tear production than did stimulation of the gland itself. When tested in anesthetized rabbits, the researchers found that the stimulation increased tear production by close to 60 percent.
The hope is that the method will be on the market as early as 2016, but first the makeup of the tears produced by this method must be evaluated, and clinical trials in humans will likely be the next step after that, so that goal may not be attained.
