What is Dry Eye Disease
Dry eye disease is a chronic issue that’s actually a common term used to describe the symptoms of many different issues that make your eyes feel uncomfortable. (It’s a misnomer like “pink eye” is.) It refers to an issue where your oil glands and tears don’t work correctly, and your eyes don’t get enough lubrication. The 2 main types stem from poor oil production called evaporative dry eye, or from not producing enough water called aqueous deficient dry eye. A panel of 150 experts created the definition below:
Both types can cause an unstable tear film. Initially symptoms are mild and intermittent, but if left untreated, it will gradually worsen. It increases your risk of eye infection and damages the eye slowly over time. Eventually, symptoms can make you so uncomfortable that you have to factor them into your daily routine and accommodate your life around the discomfort. Thankfully this is the exception, but the more advanced this disease, as with anything else (i.e. diabetes, heart disease, etc), the harder it is to treat and the less effective treatments are. Treatments range from simply life style tweaks like drinking more water to prescription drops to lid and skin procedures.
What causes Dry Eye Disease
Dry eye can be caused by a multitude of things but they all lead to a poor quality tear film. There are 3 layers to the tear film: a water layer, an oil layer and a mucous layer. Mucous allows the tears to adhere to the eye; oil called meibum keeps the water layer from evaporating; the water or aqueous layer makes up about 90% of the tear volume and is sandwiched between the other two and is home to all the proteins, electrolytes and dissolved oxygen that supports the ocular surface.
During a blink, the tears are spread from the tear lake (where tears pool on the lower lid) across the eye; when your eyelids close, meibum is squeezed from the oil glands into the tear film and it is spread across the ocular surface as you reopen the eye. The aqueous allows for proteins, lipids and nutrients to flow freely to and from the cells on the ocular surface; when the eye closes for the next blink, debris and waste in the aqueous is swept into the tear duct and draining into the nose.
If any of these components aren’t working properly, it leads to instability and inflammation. Inflammation is like fire to tissue; it destroys both poorly working cells and healthy ones, leading to damage than can be irreversible. For example, not enough water or excessive evaporation from poor meibum, and you get mucous clumping together and debris sticking against the lower lid. The debris plaques chemically change the meibum secretions into a soap like substance and a frothy tear lab along the lower lid margin. As anyone who ever got shampoo in their eye knows, soap burns! (Why would the eye make soap? The jury is out at this time, but its a common finding we see during eye exams.)
This is not a happy environment, so the eye stimulates the reflex tearing cascade. The excess tearing dilutes the soap until it’s not irritating anymore, but in the process rinsing out everything that’s helpful too. This is the beginning of terrible cycle where any good oil is rinsed out with the bad saponified oil, along with all the electrolytes that support the tissue. That leads to more irritation and stimulates more reflex tearing.
For people in the early stages of this, it might be counterintuitive, but adding some artificial tears that have both an oil and water component (they are typically cloudy and milky color) helps to reestablish homeostasis and stops your eyes from watering. People in this stage also benefit a lot from cleaning the lids to remove the plaques; some times a doctor with a microscope is required for this. This is just one of a dozen issues that leads down the path to poor comfort.
Although dry eye can happen to anyone and for a lot of reasons, it’s more common in those over 50, as we all just create less aqueous tears over time; this effect also happens to long term contact lens wears. Also, changes in hormones affect post menopausal women significantly, but similar results can occur from pregnancy or the use of hormonal birth control. A poor diet (low in Omega 3s), dehydration and screen time of 6+ hours a day also makes this disease more likely. Below are the most common causes of both types of dry eye:
- Not enough aqueous reduces tear lake volume & ability for waste removal (increases osmolarity)
- Poor blink habits (not closing your eye all the way – happens frequently when looking at screens for a while, or with Bell’s palsy and Parkinson’s disease)
- Poor quality meibum (thick or cloudy oil and no longer able to spread over the eye, think cold butter vs olive oil)
- Low volume of meibum which is clear and oily but not enough to prevent quick evaporation
- Inflammation of the eyelids (blepharitis or poor make up removal)
- Reduced ocular surface sensitivity from refractive surgery or contact lens wear
- Ocular allergies and irritation from preservative in eyedrops
- Pulling mucous strands from the eye (I know it satisfying, but fingers rubbing on your eye irritates the tissue and leads to more mucous production creating a viscous cycle)
- Cigarette smoke and other airborne irritants (like vent blowing on you in a car or plane, or exhaling through a mask all day)
- Vitamin A deficiency (rare in the US, unable to to create tears properly)
- Overgrowth of Demodex, a mite that lives on the lashes and causes irritation
- Eyes don’t close completely when sleeping (lagophthalmos, floppy eyelid syndrome)
- Systemic inflammatory diseases like Sjorgen’s syndrome, graft verses host disease, lupus, rheumatoid arthritis
- Rosacea or other inflammatory skin issues (superficial blood vessels are leaky and leach irritants into surrounding tissue making meibomian glands work poorly)
- Aging and hormones (we produce about 60% less volume by age 60)
- Medications that dehydrate the mucous membranes like antihistamine (1st generation like Benadryl), hormone replacement and birth control, antidepressants and meds for a plethora of issues including acne and hypertension
Common Symptoms of Dry Eye
Those with dry eye don’t always experience symptoms all the time, some patients only notice them in certain situations, like in a air-conditioned car, on an airplane or after looking at a computer for a while. Most patients will have physiological changes to their tear film after only 2 hours of screen time daily. Common symptoms include:
- Intermittent blurred vision or light sensitivity (trouble driving at night)
- Stinging, gritty, burning or foreign body sensation (discomfort can be mild to severe)
- Lots of Watering! If you don’t make enough tears, the body throws water at it, often making symptoms worse
- Tired eyes or eye fatigue
- Discomfort with contact lens wear
- Eye redness or itching
- Discomfort/eye pain after prolonged screen time
- Debris (gunk) in your lashes of the corner of your eye when you wake up
If you have any of these symptoms, we recommend you come in and see one of our dry eye specialists (Drs. Alyssa Sherwood, Melanie Deitch & Laura Nennig) for an evaluation, as chronic issues like this only get worse with time. Make an online appointment or text our office at 816-524-8900. They will take the time to educate you about what is going on and what treatment is recommended and why. Dry eye disease is a medical condition; most testing and some treatments can be billed through your medical insurance, and some will be out of pocket. Details can be reviewed at your initial visit.
How is dry eye disease diagnosed and what to expect?
We have a few tools to help us evaluate the extent of your dry eye, the most important is the slit lamp or the microscope we use to look at the ocular surface in high magnification. We can see if there is swelling on the conjunctiva or inside of the eyelid, how much redness you have, as well as view debris on lashes that can indicate Demodex. We can also see if there is corneal inflammation present or debris such as make up floating in your tear film.
There are some dyes we use in the eye that will stain where tissue is missing (fluorescein dye) or will get absorbed into devitalized cells (lissamine green dye); both are harmless and are instilled into the tear film with a saline wetted strip of paper containing the dye. They help establish how much inflammation and irritation is present on the cornea, conjunctiva and eyelids. Fluorescein dye will also allow us to figure out how long it takes for your tear film to evaporate, an important metric with meibomian gland dysfunction. There are some other “toys” optometrist can use to get some very specific metrics like inflammatory markers in the tear film or the exact osmolarity but those aren’t required to pin down what type of dry eye you have or how severe it is.
Likely, at each evaluation, there will be a questionnaire that evaluates your level of symptoms over time. This is one of the best ways to establish both how much dry eye is bothering you in the first place and to track how well treatment is working. The SPEED (Standard patient evaluation of eye dryness) questionnaire is the most commonly used due to it reproducible results when monitoring meibomian gland dysfunction; OSDI (Ocular surface disease index) is another commonly used choice.
How is this chronic disease managed and treated?
Over 80 % of dry eye suffers have meibomian gland dysfunction and treatment really focuses on improving gland function. Our dry eye program works on managing this chronic disease for the long term; this disease didn’t occur overnight and it won’t resolve overnight.
We create individualized treatment plans for each patient depending on what issues are affecting their tear film. Sadly a lot of over the counter treatments only help symptoms but don’t really treat the problem. We’ve found that treating the inflammation using intense pulse light (IPL) therapy, anti-inflammatory eye drops like Cyclosporine or Lifitegrast and meibomian gland expression (or evacuation) are the most helpful ways to reverse the disease and improve symptoms. Most patients will need treatment for many years to keep dry eye symptoms from returning. The sooner we start treatment the less invasive the treatments tend to be.
Common treatment options, most conservative are listed first:
- Artificial tears (both preserved and non-preserved)
- Hot Compresses (gel pack microwaved ~30s, place on eyes for 10 mins daily)
- Lid cleaners/lid scrubs (i.e. Blephadex, Sterilid, Ocusoft, Claridex foam)
- Sprays to reduce bacteria on skin (i.e. Avenoa, Hypochlore)
- Plunctal plugs (keeps more fluid against the eye, only works well if inflammation is well controlled)
- Short term anti inflammatory medications (i.e. Steroid drops for a few weeks)
- Long term anti inflammatory medications (i.e. Cyclosporine or Lifitegrast)
- Amniotic Membranes (stem cells help heal corneal damage)
- Debride lid margin of debris and plaques (i.e. BelphaEx)
- Autologous serum tears (takes your blood, spins out the blood cells, the remaining serum is bottled w/ a preservative or antibiotic; used daily, it helps heal ocular surface damage using your own immune system)
- Meibomian gland expression (i.e. iLux, LipiFlow – evacuates clogged glands by melting thick meibum)
- Scleral lenses (custom contact lenses that hold fluid against the eye to reduce ocular discomfort)
- IPL therapy (Intense pulse light – treats superficial leaky blood vessels around eye to lower meibomian gland and lid inflammation)
Your life style choices affect dry eye
There are lots of things we can control in our daily lives that can make dry eye worse or better, here are the highlights.
- Stay hydrated: aqueous volume can’t be at a normal level if you don’t have enough fluid in your body to create it
- Give your eyes a break: follow the 20-20-20 rule. Look 20 feet away for 20 seconds for every 20 minutes of screen time; do a few full blinks and squeeze your lids together to get the meibomian glands flowing again
- Exercise: Good blood flow isn’t just good for your heart and brain, it keeps all your mucous membranes healthy too
- Omega 3’s: DHA is a building block for meibum, and without it, you can’t expect to produce very good oil
Control your Environment
- Increased humidity in your home or work space can make for significantly reduced symptoms (i.e. add a humidifier)
- Place your computer screens below eye level so your eyes are open less as well as a more natural position
- Avoid sitting near vents which blow into your eyes
- Stop smoking; comfortable eyes is one more reason to quit
- Airplane and other dry environments (think deserts like Arizona) speed up how quickly your tear film evaporates
- Wear wrap around glasses when in windy situation to reduce air movement around your eyes
If you think you might have dry eye or ocular surface disease, we are happy to evaluate you in our clinic. Drs. Alyssa Sherwood and Laura Nennig offer appointments just for this; call or text 816-524-8900 or make an appointment online anytime.
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