- Dry eye disease is a chronic condition that afflicts 30 million Americans and 300 million people worldwide.
- In addition to debilitating symptoms, dry eye disease can affect your physical and mental wellbeing.
- Dry eye disease is chronic, but treatable.
Artificial tears, dry eye disease (DED), meibomian gland dysfunction, tear film
Taking the First Step
If you’re reading this article, either you or someone you know has dry eye disease (DED). It is a chronic condition that affects millions of people worldwide, and can impact you on multiple levels. In addition to your eye health, DED can influence your physical and mental wellbeing. Once you have DED, your symptoms may come and go, but you will typically have it for the rest of your life. We know this seems daunting, but with a good treatment plan you can take control of your DED!
What is Dry Eye Disease
Dry eye disease (DED) is also known as dry eye syndrome, keratoconjunctivitis sicca and ocular surface disease. DED is a chronic condition caused by unstable tears and inflammation, and leads to symptoms such as redness, burning, irritation, gritty sensation and blurry vision. Our goal in this article is to briefly review the different components of DED.
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The Tear Film & Ocular Surface Society Dry Eye Workshop II defines DED as “a symptomatic disease, characterized by a vicious cycle of tear film instability and hyperosmolarity, which leads to increased ocular surface inflammation, damage and neurosensory abnormalities.”1
So let’s break this down into readable and relatable language. Your tear film coats the front part of your eye, called the cornea, and it plays a crucial role in protecting the eyes, making your eyes feel comfortable, and in helping you see clearly. In DED, your tear film malfunctions, which sets off a cascade of inflammation, leading to symptoms.
Who Gets Dry Eye Disease
Literally everyone. If you’re reading this, chances are that you or someone you know has DED. Approximately 30 million Americans, and over 300 million people worldwide are affected by it.1 But the actual number is probably much higher. In fact, one in every three eye care clinic visits is related to symptoms of dry eyes.2 Think about it, anyone looking at a computer or phone screen (basically all of us these days!), or doing tasks that require long focus without blinking, or driving, or living in high pollution and low humidity areas, will invariably get dry eye symptoms. When these symptoms become persistent and get in the way of your life, that’s when you have DED.
The Impact of Dry Eye Disease
We get it. DED is tough for everyone involved. While it does not cause blindness, DED puts you at risk for vision-threatening complications, such as corneal infections and scarring. DED has a significant impact on a person’s life, leading to social, emotional and economic burdens.3 Most people with DED suffer from symptoms for months, try several different over-the-counter treatments, and spend a considerable amount of time, energy and money before seeking professional help.
Even after seeking help, a patient commonly sees multiple eye specialists (ophthalmologists and optometrists) because they feel that their eye specialist is not taking them seriously, or not spending enough time listening to them. This is not the eye doctor’s fault. Taking care of DED requires more time with the patient, which is not always feasible in a busy practice with overhead expenses. As you can imagine, this leads to frustration, hopelessness and treatment failure.4 You can learn more about the impact of DED here.
DED is chronic, but it is manageable and treatable, just like other chronic conditions that affect the body, such as diabetes and high blood pressure. That’s what we are here for! To get you the best treatment and support from the start as soon as you have symptoms. All we do here at CorneaCare is DED and we have honed our craft and our workflow so we can spend the much-needed time to listen, support, and provide you personalized eye care.
Having DED should not prevent you from doing anything you love or need to do. In fact, we’re here to tell you that with consistent effort on your part and support from us, you can protect and preserve your eyes, and live a healthy, fun and prosperous life.
What Are the Symptoms of Dry Eye
Everyone experiences dry eye symptoms differently. Your own experience with DED is very important to us, but the typical symptoms are:5
- Gritty sensation, or foreign body sensation
- Blurred vision
- Tearing or watery eyes
- Burning sensation or stinging of the eyes
- Light sensitivity
- Eye fatigue
What Are the Causes of Dry Eye Disease
Let us start by saying that DED is not your fault! The best way to think about what causes DED is to divide it up into decreased production of tears (aqueous deficient) or rapid evaporation of tears (evaporative).1
Your natural tears are produced by the lacrimal gland. Infection and inflammation may cause the lacrimal gland to malfunction, leading to decreased tear production.
One cause of inflammation of the lacrimal gland is Sjögren’s syndrome, an autoimmune condition, which is typically associated with severe dry eyes. Another cause of decreased tear production is a disruption in the link between the cornea and the lacrimal gland. When the cornea is dry, it naturally alerts the lacrimal gland to produce more tears. If this feedback loop is disrupted, tear production may decrease. This is commonly seen in people who have had eye injuries, infections or surgeries that decrease the sensitivity of the cornea.
In addition to decreased tear production, you could have increased tear evaporation, which also leads to dry eyes.
Your tear film is made up of three layers: the mucin layer, the aqueous layer and the lipid layer. The mucin layer is made up of molecules that allow it to bind to the surface of the cornea. The aqueous layer then sits on top of the mucin layer, and the lipid layer sits on top of the aqueous layer.
All three of these layers work collectively to stabilize the tear film, and prevent tear evaporation.
So you can imagine if the surface of the cornea is damaged, it may not bind to the mucin layer well. Or if there is a decrease in the oil production for the lipid layer, such as in meibomian gland dysfunction, your tear film may not be stable.
Contact lens use is another common cause of DED. This is because contact lenses may directly lead to changes on the cornea or decrease the sensitivity of the cornea, predisposing it to symptoms of chronic dry eye. Eye surgery, specifically refractive surgery (LASIK), and preexisting eye conditions, such as corneal diseases and glaucoma, are other risk factors for DED. Some systemic risk factors (with examples in parenthesis) are listed here for your reference: age (>50 years old), female gender, systemic medication side effects (oral antihistamines, antidepressants, decongestants, diuretics or birth control pills), hormonal changes (menopause), autoimmune diseases (thyroid eye disease and rheumatoid arthritis), medical conditions (cancer and diabetes), poor nutrition (low vitamin A), environmental factors (low humidity), and occupational factors (computer screens).6
You can learn more about the different causes of DED here.
How to Diagnose Dry Eye Disease
There are several ways to diagnose DED, but it all starts with listening to you, the patient.6 In fact, there are instances in DED when a patient has classic symptoms without any abnormal exam findings.7
Several questionnaires can be used to assess the patient’s symptoms. For example, the Ocular Surface Disease Index (OSDI), the Standard Patient Evaluation of Dry Eye Questionnaire (SPEED), or the Dry Eye Questionnaire (DEQ). These questionnaires attempt to capture the patient’s subjective experience with dry eye disease as objective, measurable data.8
Next is the exam, where we want to look at the skin around your eye, eyelids, eyelashes, how you blink, the surface of the cornea, the tear film, and the conjunctiva (a thin membrane that lines the inner part of your eyelids and covers the white part of your eye, the sclera). We look at several key exam findings. For example, if the skin around your eye is red, it cues us that you may have rosacea and so we are on the lookout for blepharitis (inflammation of the eyelids). On your eyelids, we look at your eyelid margin to see if you have meibomian gland dysfunction. We also pay attention to your blinking. If you close your eyes, and part of your eye is still exposed to the environment (incomplete blink), we worry about eyelid function.
On the surface of the cornea, the common things we check are corneal sensation, corneal staining, tear film break-up time (TBUT), and tear production over 5 minutes. Corneal sensation is typically checked with a cotton tip application (q-tip), and you know from above that a decrease in corneal sensation can lead to decreased tear production. Remember that yellow stuff your eye specialists put in your eyes? Well, that stuff is called fluorescein, and it can stain the surface of your cornea and conjunctiva, highlighting areas where the surface is loose, not as strong, or broken off, which are signs of DED. Fluorescein also helps us measure TBUT, which is an indicator of tear film stability. The faster your tear film breaks up, the quicker your tears evaporate. Finally, we may perform the Schirmer’s test, where we use a strip, placed gently on the inside of your eyelid, and we measure how many tears you produce over 5 minutes.
There are other molecular tests, such as detecting matrix metalloproteinases-9 (MMP-9), which is a marker of inflammation, and tear osmolarity measurement, which tells us the concentration of various molecules in your tears. High-quality imaging of the eye also allows for measuring the height of the tear meniscus, an indicator of your tear production. Novel imaging methods can also assess tear film quality and thickness of the lipid layer, something called tear film interferometry. More on all of this later!
How to Treat Dry Eye Disease
And so we get to the question you care most about! Unlike what you may have heard, dry eye treatment is not as simple as putting in eye drops. Remember DED is chronic, and therefore treating DED requires continued effort on your part.9 But no worries, we’re here to support you at each step! Treatment options for DED can be divided into five components:
- Education, implementation, and consistency
- Tear replacement
- Prevent tear evaporation
- Reduce inflammation
- Promote healthy nerve function and growth
By far, the most important aspect of treatment, and one that often goes unaddressed, is learning about DED and then implementing a treatment plan and staying consistent. Knowledge is power, and learning about DED is the first step to mastering your DED. Once you have a treatment plan, you have to implement it so that it integrates into your daily routine, and becomes habitual. Lastly, you have to stay consistent. You can have the best treatment, but if you do not adhere to it consistently, it will not work.10
To treat the aqueous deficient type of DED (not making enough tears), we can replace the deficiency with artificial tears to improve lubrication on the surface of the eye. There are over 50 different types of artificial tears. They can contain preservatives or be preservative-free, with different viscosities (thickness) and come in bottles or individual vials. You can also do tear replacement therapy with gels and ointments, which are typically used at bedtime.
To treat the evaporative type of DED, we can prevent tear evaporation. To accomplish this, we implement an eyelid hygiene routine with warm compresses and eyelid massages or scrubs. The goal of this is to optimize meibomian gland function, and produce a good lipid layer to prevent your tears from evaporating. There are many in-office procedures that heat and massage the meibomian glands. Other in-office procedures deal with the tear ducts, such as punctal plugs, which block the tear ducts to allow tears to stay in your eyes longer. Several prescription eye drops are coming to market that address the eyelid hygiene component.
Most individuals typically will have features of both aqueous deficient and evaporative DED. Therefore, a treatment regimen often consists of lubrication and eyelid hygiene.
We know inflammation plays a vital role in DED pathology. Therefore, reducing inflammation is an important part of treatment. We typically do this with anti-inflammatory prescription eye drops, such as steroids, cyclosporine (Restasis and Cequa) and lifitegrast (Xiidra). Another approach is to eat food rich in anti-inflammatory compounds and antioxidants, such as Omega-3 fatty acids.
Here at CorneaCare, we really stress the importance of your diet, because eating a well-balanced diet, with anti-inflammatory and antioxidant properties, is not only good for your eyes, but also foundational for your mind and body.
Promoting healthy nerve function and nerve growth in the cornea is not well understood, but we know it is important. The nerves in your cornea help with sensation (temperature, touch, pressure and pain), and also help in stimulating your lacrimal gland to produce tears. Inflammation and changes in tear osmolarity (concentration) can cause damage to the nerves in the cornea. If the nerves get damaged, they may not be able to communicate with the lacrimal gland, and alert it to produce tears. Alternatively, the nerves can become hypersensitive, causing them to activate randomly, or become overactive to mild stimuli. Meaning that a patient with seemingly “normal” eyes during an exam may still experience severe symptoms because the corneal nerves are hypersensitive.
Remember what we said – your experience with DED is just as important as the clinical exam. You can learn more about the treatment options for DED here.
Putting It All Together
CorneaCare is here to give you a voice and listen to you. DED is physically and emotionally exhausting, and we know you have been through difficult times searching for answers and trying to find treatments that work. We do not believe in creating one-sided physician-to-patient treatment plans, because that would just perpetuate what is already wrong with DED treatment. These are your eyes we are talking about, and you should be in the driver’s seat for making treatment decisions, with our support. We want to empower you to take control of your DED.
Receive exclusive offers about dry eye health and wellness, courses, and more!
Let’s dive into the different types of DED.