Do you know people who always carry eye drops in their bag? People who rub their eyes at every change of seasons or after spending time in air conditioning? They, and many other people, are dealing with dry eye syndrome. Dr. Eyal Cohen, an expert in eye diseases and director of the cornea bank and the dry eye center at Ichilov Hospital in Tel Aviv spoke on the podcast "Expert Clinic" to explain why this happens, how to treat the phenomenon and what one can do to improve the situation and make their eyes feel better.
"Dry eye is a syndrome that is very, very common, we hear about it a lot," said Cohen. He added that its prevalence stands at 10% of the entire population, with 25% of the adult population suffering from this syndrome. Doctors see it often. There are seasons where it’s more common, and there are reasons which cause it to be more prevalent.
This may sound like an insignificant problem, compared to other diseases, but the truth is that people who deal with dry eyes suffer greatly. "It often feels like a small grain of sand in the eye, or like cleaning the windshield on a car, and the visors are a bit dry and you hear squeaks and see that the windshield isn’t clean - that's how it feels," Cohen explained. "In a more serious condition, you can get vision damage, a daily burn complaint. It feels like a certain scratch."
He added that when ophthalmologists look at a dry eye, it looks like there’s sand scattered on the cornea. It's not really sand, but cells that aren’t transparent, abnormal, which can impair vision. Luckily, this is reversible, since the outer layer of the cornea is a regenerating layer, so once the moisture is returned to the eye, the smoothness of the surface returns and vision improves.
Why do our eyes dry out?
When asked why dry eye happens, Cohen explained that the syndrome has several causes. He explained that there are two major categories. One is the absence of tears, when the eye is unable to secrete enough tears. And the other side is that the eye secretes enough tears, but the evaporation of the tears happens in an increased way. There are numerous causes for each circumstance; one is laser eyeglass removal surgery.
Cohen explained that in eyeglass removal (laser) surgery the structure of the cornea is altered, and is the one that tells the tear gland to secrete tears. After surgery, there is dryness due to the lack of positive feedback that the eye gives to secrete more and more tears but in most cases, 99%, there is full recovery. He added that: "Because the nerve endings that are damaged during the surgery are regenerated, and the feedback for the secretion of tears returns, the eye becomes moist again and feels good again."
Contact lenses can also cause the absence of tears. "Because you put them on for hours, you hurt that positive feedback that the eye gives to the tear ducts, and when that feedback is damaged there’s less production of tears," Cohen explained. When someone wears lenses for more than 12 hours, for example, the eyes will get irritated, so learn your ‘tipping point’ and remove contacts after 10 or 12 hours, before your eyes become irritated.
In the case of increased evaporation of tears, the feeling is different as people feel like they are constantly in tears. Cohen says that multiple tears is a sign of a dry eye, but a reversal of the feeling of dry eye, as the lacrimal gland constantly secretes the aqueous fluid of the tears, but doesn’t secrete the fatty part that is supposed to trap the tears over the eye. "Then the tears flow down, flooding the face, but the eye dries," he added.
"The solutions are many, with the most common being drops, tear substitutes," said Cohen, adding that there are many types available. "There are tear substitutes with a preservative so that the bottle doesn’t become contaminated, but preservatives can damage the eye area, so there’s a limit of up to 4 times a day, a maximum of 6 times a day,
"When the condition is severe, we prefer to give tear substitutes without preservatives," he added. "They usually come in small ampoules or in special bottles that don’t allow pollutants to penetrate so there’s no preservative and they can be used frequently, even every half hour or hour."
But sometimes that's not enough either. Cohen says that it's important to note that dry eye is a chronic disease that we have all our lives, so the treatment is chronic, daily, routine maintenance adding that like one brushes teeth daily one should take care of their eyes when suffering from dry eye syndrome.
"In Israel and around the world, dry eye care centers are being established. In Ichilov, too, we have opened a center whose goal is to correctly diagnose patients, understand the exact cause of the dry eye, and give them the best treatment and significantly alleviate the problem," said Cohen."Tear substitutes are a band-aid. Advanced treatments improve the ability to secrete the fatty layer of tears, in order to moisturize the eye." For this purpose, there are several developments like heating masks that dissolve the fat that blocks the glands, special devices that heat the glands to equipment that works on the vibration that helps the gland function, and oral medications.
Preventing dry eye
"Because it gets worse as we get older, there are things that can be done as a preventative treatment. Just as a dental hygienist checks the oral cavity once a year, so does ophthalmology, as well as eye surface maintenance," said Cohen. The glands that secrete adipose tissue can improve their function as a preventative process. He recommends drinking a glass of water when you get up in the morning, since "fluid balance in the body is also significant in the maintenance of dry eyes." Before going to bed he recommends doing a strong blink of the eyelids, to release fat that is trapped and accumulates in the glands.
If you spend a lot of hours in front of screens it’s important to know how it affects the eyes and behave accordingly. We usually blink 20 times a minute, when we stare at the screen we blink 4 times a minute. This decrease in the amount of blinking, due to glare, causes the fluids to evaporate faster and the eye to be dry. He recommends looking at the distance every 20 minutes, disconnecting from the screen for a moment. "Blink hard, let the glands secrete fat, and return to work," he explained. "A lot of times beyond not blinking in terms of frequency, we also don't blink in full blink, so it's important to note that you close your eyelids to the end."
Another recommendation from Dr. Cohen: "Squeeze glands" at the end of the day. "It's very simple and anyone can do it at home. Close your eyes partially and simply push the fat from the bottom towards the lash border, and from the top towards the lash border. Cohen added that his eyes feel better after he does this daily routine.