Towards a Regenerative Therapy for the Lacrimal Gland and Dry Eyes

The lacrimal gland provides moisture for the eyes, and like all parts of our physiology is prone to decline and failure in old age. Dry eye conditions, some of which are painful and debilitating, are common in old people. Researchers here demonstrate a cell therapy to spur regeneration of the lacrimal gland in an animal study, a step along the road to achieving the same thing in humans:

The eye's lacrimal gland is small but mighty. This gland produces moisture needed to heal eye injuries and clear out harmful dust, bacteria and other invaders. If the lacrimal gland is injured or damaged by aging, pollution or even certain pharmaceutical drugs, a person can experience a debilitating condition called aqueous deficiency dry eye (ADDE) - sometimes called "painful blindness." If injured, a healthy lacrimal gland naturally regenerates itself in about seven days. When diseased and chronically inflamed, however, regeneration stops - and scientists are not sure why.

Researchers looked at whether they could kick start regeneration by injecting progenitor cells into the lobes that make up the lacrimal gland. Progenitor cells are similar to stem cells in their ability to differentiate into different kinds of tissue. In this study, the researchers used progenitor cells that were poised to become epithelial tissue, a key component of the lacrimal gland. The researchers knew they faced a major challenge: sorting and separating "sticky" epithelial cell progenitors without destroying them. "We had to figure out how to dissociate the tissue into single cells without completely obliterating everything." The researchers solved this problem by developing markers to label the cells of interest and then testing different enzymes and other reagents to draw them out of tissues.

With these cells in hand, the researchers injected them into the lacrimal glands of mouse models of Sjogren's syndrome, an autoimmune disease that results in ADDE, dry mouth and other symptoms. The team used only older, female mice because ADDE most commonly strikes that demographic in humans. The treated mice showed a significant increase in tear production, indicating - for the first time - that epithelial cell progenitors could repair the lacrimal gland. Further tests suggested that epithelial cell progenitors helped by restoring the connection between cells called myoepithelial contractile cells and the lacrimal gland's secretory cells, which produce tears. The next step in this research will be to study how long the improvement in the lacrimal gland lasts after progenitor cell injections.



This is of interest to me because I have this condition. I read the full published study and it does look promising. But the authors fail to mention that the treatment will not cure the Sjogrens syndrome, it will just provide a temporary localized increase in lacrimal gland output, eventually the systemic Sjogrens will start to chip away at the lacrimal gland again and the dry eye will return. Sjogrens is responsible for the majority of dry eye symptoms. This is no doubt a decade away from FDA approval since it requires allogenic cells but I could imagine that the treatment could be done in office for $2,000 every couple of years by an occuloplastic surgeon if it were approved.

Posted by: JohnD at August 22nd, 2016 10:27 PM

Well, I certainly hope they make fast progress on this. I have dry eyes and it just gets worse.

Posted by: bmack500 at August 23rd, 2016 12:47 AM

I've read a story about people afflicted with dry eyes, and I didn't know just how debilitating it could be. I definitely support this kind of research, and hope more monetary and human efforts will pour in.

Even if they don't yet come up with a permanent solution, any form of proper relief would be welcome. And I bet that having to perform another surgery every few years will be peanuts compared to the huge gains in quality of life.

Posted by: Spede at August 23rd, 2016 8:58 AM

While a few cases of chronic dry eye are caused by exposure (lax eyelids), most emanate from evaporation due to a failure of the oil glands of Krause & Wolfing in the eyelids to secrete oil, which is the outermost clear coating over the cornea. The oral consumption of gamma-linolenic (GLA) oils from borage, evening primrose or black currant seed remedy most cases. Some cases of dry eye emanate from a lack of mucin which is the inner coating over the cornea. Mucin helps spread the tear film. Mucin is generated from vitamin A. Fat-soluble vitamins (vitamin D, E, K) compete for storage in the liver and my personal experience is that taking high-dose vitamin D fostered a shortage of vitamin A and I develop two bouts of eye infections before I realized the problem and now take vitamin A & D supplements. If the eye is dry, it will compensate by dumping more watery tears from the lacrimal gland over the brow and the eyes will appear watery as a protective reaction to the dry condition. Excess watery tears often flow into the drain in the eyelids (punctum) and make their way to the back of the throat where they induce post-nasal drip and a tickling cough. Computer users often fail to blink often enough. Blinking squeezes more oils out of the glands in the eyelids. The glands in the eyelids can be milked by placing thumb and forefingers over the lids and squeezing them to the edge. Then blink to clear up the vision obscured by the oils. Works better than eye drops. If this doesn't work, use OASIS brand viscous eye drops made from hyaluronic acid.

Posted by: Bill Sardi at August 28th, 2016 10:09 AM
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