Last updated on August 23rd, 2023.
Having no tears left to cry may sound empowering, but it’s bad news for your eyes. It conjures up a condition called keratoconjunctivitis sicca—or, in layman’s terms, dry eye. It’s often associated with another condition we explore in this article What Exactly is Macular Degeneration? While there is overlap in the symptoms of eye blurriness, macular degeneration, and dry eye have little to do with each other.
Dry eye is a common condition that affects a significant number of people worldwide. Dry eye affects approximately 50 million people in the United States and only 35 million people have been officially diagnosed. However, it is worth noting that many cases of dry eye go undiagnosed or unreported, which means the actual number of people impacted by the condition may be higher.
Dry eye is more prevalent in certain populations, such as older individuals. It is estimated that over 6% of individuals aged 65 and older in the United States experience symptoms of dry eye. Globally, the prevalence of dry eye varies across different regions and populations. In some studies, the prevalence rates have ranged from 5% to 50% depending on the population studied and the diagnostic criteria used. Given the widespread nature of the condition and its impact on daily life and vision, dry eye is a significant health concern affecting millions of individuals worldwide.
History and Types of Dry Eye
A brief history. The fact that our eyes need tears to function properly was recognized as far back as Ancient Egypt. Here, the Ebers Papyrus, a collection of their medical knowledge, cited moisture as “the water within.” It recommended that deficiencies be treated with incense, myrrh, and lead. However, the condition only gained prominence around the 1970s when researchers began examining mucin, a protein layer covering wet epithelial surfaces on the body. From there, Western medicine began to deepen its understanding of dry eye as its own condition.
Aqueous tear-deficient dry eye. This type of dry eye occurs when your lacrimal gland, the tear-shaped gland in the corner of your eye, doesn’t produce enough moisture. It’s most common symptom is a lack of tears, but you may also experience eye itchiness, a burning sensation when you blink, and redness. There are several tests to diagnose this condition. For example, your doctor may conduct a simple blink frequency test—if you blink less than once every 30 seconds, you likely have the disease. They may also track your tear film breakup time or take a sample of your tears to check for blood or inflammation.
Evaporative dry eye. This condition involves your eyes’ meibomian or oil glands, which are found on your inner eyelids near your eyelashes. They can cause evaporative dry eye if they malfunction via either keratinization, which obstructs the opening of the oil gland, or because your meibum, the oil that provides tear film stability, is too thick to mix well with your tears. Evaporative dry eye is associated with a crusting around the eyes, swollen eyelids, or a blurriness that comes and goes. Doctors usually use Schirmer’s test to measure your eyes’ tear production volume, which involves placing a filter paper under your eye for five minutes. They may also use a slit lamp to detect any irregularities at the surface of your eye that could be the cause of blockages.
Mixed dry eye. It’s also possible to have a hybrid of the two conditions above. This results in eyes that cannot create enough tears to sustain the eyes’ moisture, with the tears that are created very rapidly drying up. Mixed dry eye’s similarities to aqueous deficient dry eye and evaporative dry eye thus make it difficult to diagnose. Your doctor may diagnose you by first ruling out if your symptoms are caused by eye allergies and evaluating other possible risk factors. Afterward, they may run tests that look at homeostasis markers and ocular surface staining to determine what’s aggravating your eyes.
Causes of Dry Eye
Environmental and lifestyle choices. One possible cause of dry eye is the environment you reside in. If you live in a particularly dry climate or are continually exposed to wind or smoke, your tear film is more likely to get damaged. Your habits also play a role. If you spend a lot of time gazing at screens without blinking, your eyes may become dry.
Medical conditions. One of the most common causes of aqueous deficient dry eye is Sjögren’s disease, an immune system disorder that affects your body’s ability to produce fluids. Meanwhile, dry eye conditions in general can develop as a complication of diabetes. Your weight may also predispose you to dry eye, as body fat is connected to the lipid metabolic changes that determine the functionality of your eye film.
Depression may have an impact. Another thing dry eye syndrome may find its roots in is mental conditions. Researchers from JAMA Opthalmology linked depression to dry eye. The connection between the two appears to be cyclical—those with depression are more likely to engage in behaviors that worsen dry eye, such as increased screen time, while dry eye often lowers the quality of life and puts one at greater risk of depression.
Medications and recovery processes. Some medications, like those for treating allergies and high blood pressure, can reduce tear production and cause dry eye. If you’re recovering from a refractive eye surgery like LASIK, your eyes may also experience a temporary decrease in the amount and quality of your tears.
Gender. Women are more likely to experience dry eye, especially when experiencing hormonal changes due to pregnancy or menopause. Testosterone, which women have less of, is one of the key regulators of meibomian glands, and shifts in hormone production can cause dry eye.
Treatment of Dry Eye
For a quick fix, dry eye can sometimes be treated with eye drops or nasal sprays. However, more severe cases will require professional advice. For example, your optometrist might suggest therapeutic contact lenses to lubricate your ocular surface. The Optometry Times cites scleral lenses as good options for dry eye patients who have complexities associated with their condition. Meanwhile, Bioinfinity contacts are ranked among the most breathable lenses for dry eye: they use Aquaform Technology to maintain optimal moisture needed for symptom relief. You can customize these according to your other visual needs, such as toric lenses for astigmatism. Finally, you may be recommended for intense pulsed light therapy. The FDA-approved Lipiflow device uses thermal pulsations to unclog stagnant oil in your eyelids. This soothes dry eye by better allowing tears to naturally flow into and better lubricate your eyes.
Dry eye is an aggravating eye ailment, but there are effective treatments out there. Visit your healthcare provider to heal your eyes as soon as possible.