Dry Eye Syndrome
What is Dry Eye Syndrome (DES): Symptoms, Causes and Treatments
Dry eye syndrome (DES) is a condition that affects the tear film of the eye – the thin layer of tears that coats the eye’s surface. When we blink, the tear film spreads over the ocular surface and lubricates the eye, which is essential for proper light refraction (clear vision), nourishes it, and keeps it free of debris.
The tear film is made up of three distinct layers: an oily layer, called the lipid layer, which helps to slow down tear evaporation, a watery later, called the aqueous later, which contains water, electrolytes, and enzymes, and a mucous layer, which helps to spread the tears evenly over the eye’s surface. If any one of these layers does not produce enough tears, or if it doesn’t produce good quality tears, it can lead to DES.
Dry eye syndrome affects millions of people around the globe. The American Academy of Ophthalmology estimates that 16 million people in U.S. alone have DES.[i] It affects more women than men and tends to increase in prevalence with age.[ii]
What are the symptoms of dry eye syndrome?
Symptoms of DES can vary from person to person, but some of the most common symptoms include:
- A gritty or scratchy sensation in the eye
- A feeling like something is in the eye
- A burning or stinging sensation
- Redness of the eyes
- Blurred vision
- Sensitivity to light
- Difficulty wearing contact lenses
- Excessive tearing (This may seem counterintuitive, but the eyes can actually produce more tears to overcompensate for dryness.)
What causes dry eye syndrome?
There are many possible causes of dry eye syndrome, from lifestyle factors to medical conditions. One common symptom is spending extended periods of time looking at screens. When we are engrossed in digital content, our blink rate decreases, and blinking is essential for spreading tears and lubricating the ocular surface. Less blinking leads to less tear distribution, increased tear evaporation, and ultimately dry eyes.
Environmental factors may also contribute to DES. Wind, smoke, pollution, and low humidity can all lead to dry eyes. Air conditioning and airplane travel both cause low humidity conditions, which can exacerbate eye dryness.
Certain medical conditions, such as Sjogren’s syndrome and some autoimmune diseases, as well as certain medications, such as antihistamines and decongestants can also be sources of dry eyes.
Temporary dryness can also occur after ocular surgeries, such as cataract or refractive surgery. In fact, the Refractive Surgery Alliance coined a term to describe this temporary effect – Surgical Temporary Ocular Discomfort Syndrome or STODS. To varying degrees, all patients who undergo ocular surgery experience STODS.
How is dry eye syndrome treated?
While there is no cure for DES, there are a number of treatments that can help relieve dry eye symptoms. Treatments include:
- Artificial tears – Artificial tears can supplement naturally created tears and help to keep the eyes lubricated.
- Punctal plugs – Punctal plugs are tiny inserts – about the size of a grain of rice – placed inside the tear ducts by an eye care professional. They help prevent tears from draining too quickly.
- Lid wipes – Lid wipes can help keep debris away from the edges of the eyelids, which can sometimes improve the quality of tears.
- Lifestyle changes – Making deliberate changes to avoid dry air, such as using a humidifier indoors, and taking regular breaks from staring at computer screens may improve dry eye symptoms.
- Prescription medications – In some cases, eye doctors may prescribe medications to help increase tear production or decrease inflammation in the eye, which is one reason for poor quality tears.
There are other treatments currently in development that hold the potential to improve dry eye symptoms, particularly when it comes to the temporary dryness experienced after eye surgery – STODS. The future looks bright when it comes to improving patient comfort and satisfaction associated with dry eyes.
Resources for more information on dry eye:
https://www.aao.org/eye-health/diseases/what-is-dry-eye
https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/dry-eye
https://www.mayoclinic.org/diseases-conditions/dry-eyes/symptoms-causes/syc-20371863
https://www.ncbi.nlm.nih.gov/books/NBK572136/