Understanding Dry Eye Syndrome and what causes it is the first step towards treating this condition. We will walk you through everything you need to know.
What Are Tears Made Of?
Before we dive into the definition of Dry Eye Syndrome, let’s have a look at what tears are made up of.
Tears are composed of three different layers.
What Is Dry Eye Syndrome?
Dry Eye Syndrome (DES), also called dry eye or Keratoconjunctivitis sicca (KCS), is a common condition caused by a lack of moisture on the surface of your eyes that results from:
- decreased tear production,
- excessive tear evaporation,
- an abnormality in the production of mucus or lipids normally found in the tear layer,
- or a combination of these.
This condition may result in disruption of the ocular surface, causing a variety of symptoms and signs that interfere with a person’s quality of life.
Another term used for dry eye is Ocular Surface Disease.
What Causes Dry Eye Syndrome?
Aqueous (watery) tear deficiency is caused by either poor production of watery tears or excessive evaporation of the watery tear layer.
Let’s explore these causes further.
Poor production of tears by the tear glands may be a result of age, hormonal changes, or various autoimmune diseases, such as primary Sjögren’s syndrome, rheumatoid arthritis, or lupus.
Some medications, such as antihistamines, antidepressants, beta-blockers, and oral contraceptives, may also decrease tear production.
Abnormal production of mucin by the conjunctiva may occur. This can result from chemical (alkali) burns to the eye or because of different autoimmune diseases, such as Stevens-Johnson syndrome and cicatricial pemphigoid. This abnormal production leads to the poor spreading of tears over the surface of the eye. The surface of the eye can dry out and even become damaged, even though more than enough watery tears may be present.
Evaporative loss of the watery tear layer is usually a result of an insufficient overlying lipid layer.
These insufficient layers are the result of Meibomian Gland Dysfunction, rosacea, or can occur following oral isotretinoin medication (Roaccutane for acne). Meibomian glands are the oil glands in the eyelids that produce the lipid layer. If these glands become blocked or if the oil is too thick, there may not be enough oil to cover the watery tear layer to prevent its evaporation.
If blinking is decreased or if the eyelids cannot be closed, the eyes may dry out because of tear evaporation. While reading, watching TV or spending 5-8 hours a day on the computer performing a task that requires close attention with the eyes, a person may not blink as often. This is known as blanking. Decreased blinking allows excessive evaporation of the tears. Certain conditions, such as stroke or Bell’s palsy, make it difficult to close the eyes. As a result, the eyes may become dry from tear evaporation.
Also, if an infection is present along the eyelids or the eyelashes (called blepharitis) the bacteria may break down the oil, so there may not be enough. This may lead to evaporative loss of tears as well.
Exploring Meibomian Gland Dysfunction
Contact Lens Wear
“Between 50%-75% of contact lens wearers experience dry eyes at some point with many discontinuing or limiting lens wear because of this.”
For this reason, we advocate doing LASIK surgery to decrease your lifetime risk of dry eyes and Meibomian Gland Dysfunction associated with contact lens wear.
Discomfort and the irritation of dry eyes do not just affect your ocular health, but it can also cause deterioration of general wellbeing, emotional health, and social functioning.
Dry Eye Syndrome Symptoms and Signs
A person with Dry Eye Syndrome may experience:
- Dry, gritty/scratchy, or a filmy feeling, burning or itching, redness of the eyes (conjunctivitis)
- Blurred vision
- Foreign body sensation
- Light sensitivity
- Intermittent excessive tearing:
When the eyes become slightly dry and irritated, it may produce a large number of tears all at once to try to get moist and comfortable again. Unfortunately, the eyes can only handle so many tears at any one time; the rest pour over the eyelids and down the cheeks. Those tears that pour down the cheeks do not help the eyes and are wasted. A short time later, the eyes will become slightly dry and irritated again and the whole process may repeat itself.
Symptoms seem to worsen in dry or windy climates and with higher temperatures and lower humidity. Symptoms may also be worse with prolonged use of the eyes (e.g., while reading and watching TV), as well as toward the end of the day.
If autoimmune diseases or Sjögren’s syndrome are suspected as a cause of Dry Eye Syndrome, blood tests may be performed.
These blood tests check for the presence of different antibodies that may be associated with Dry Eye Syndrome. Rarely, a biopsy of the salivary glands will be performed. Certain diseases, such as Sjögren’s syndrome, affect both the salivary glands, which produce saliva in your mouth and the lacrimal glands, which produce tears.
Most people with Dry Eye Syndrome have nothing to worry about aside from an annoying inconvenience.
For those with more severe Dry Eye Syndrome, significant drying of the surface of the eye can lead to an increased risk of serious infections. Ultimately, scarring, thinning, and even perforation of the cornea may occur. As a result, vision, or even the eye itself, may be permanently lost.
What Are the Risk Factors of Dry Eye Syndrome?
Dry eye syndrome is more common with increasing age, female sex, and Asian ethnicity.
1. Menopause Can Increase the Risk of Dry Eye Syndrome
Postmenopausal women on hormone replacement therapy, especially oestrogens alone, have a higher prevalence of dry eyes than postmenopausal women taking no hormones.
2. Occupational and Environmental Factors
Low humidity, high room temperature, wind exposure, pollution, poor air quality, smoking, and decreased blink rates due to sustained computer use or reading.
3. Diseases Associated With Dry Eyes
Vitamin A deficiency, autoimmune/connective tissue disease, hepatitis C infection, HIV infection, Sjögren’s syndrome, sarcoidosis, diabetes mellitus, and androgen or oestrogen deficiency.
4. Wearing Contact Lenses
Contact lens wear increases the risk of Dry Eye Syndrome.
5. Poor Diet
A diet low in Omega-3 fatty acids or a diet with a relatively high amount of Omega-6 fatty acids relative to Omega-3 fatty acids can also increase the risk of Dry Eye Syndrome.
Various medications including systemic chemotherapy, diuretics, antidepressants, antihistamines and beta-adrenergic blockers may cause dry eyes as a side effect of the medication.
Irregularities of the conjunctival surface as seen with pingueculae or pterygia, can cause dry eye symptoms.
The Vicious Cycle of Dry Eye Disease
As you can see, dry eye may be caused by a host of both external and internal issues.
When the eyes become dry, the surface of the eye becomes irritated. This irritation releases a whole bunch of what we call inflammatory mediators, which in turn, worsens the dry eye.
Take a look below at the number of extrinsic and intrinsic factors responsible for dry eye, as well as how the ocular surface (eye) becomes irritated and more inflamed as this wheel keeps revolving.
The self-perpetuating vicious cycle is a tricky rhythm to break. Therefore, targeting the correct cause of the Dry Eye Syndrome is so vital, and not just the symptom.
Dry Eye Management and Treatment Options
There are various treatment options available, based on the type of dry eye issue you are experiencing.
You can use any drop that you prefer, but our only strong recommendation is that you use a preservative-free drop.
Type: There are many lubricant eye drops on the market such as Tears Naturale, Optive, Optive Fusion, Optive Plus, Xailin Hydrate, Xailin HA, Systane (SDU) and Systane Balance.
Directions, dosage and duration: We advise using the drops 4 times per day as a general guideline, but they can be used as often as required. There is no limit to the number of drops that can be used.
You can use lubricant gels every night to stabilise the tear film and your vision.
Type: Xailin Night gel and Liposic are the preferred night time gels since they contain oil that is required to protect the watery tear layer from evaporating.
Directions, dosage and duration: This gel needs to be warmed before use. If the gel is placed in the eye or along the lower lid at room temperature, it remains too rigid and often pops out onto the cheek.
Oral Omega 3
We recommend using Omega Eye. It is the only supplement to our knowledge that has shown, in published results, to have a beneficial effect on the tear film.
Omega 3 supplements need to contain EPA and DHA in the following amounts – 1 680 mg and 560 mg respectively – to have value. There are alternatives to Omega 3 like flaxseed or krill oil, but they need to contain the same amount of EPA and DHA as Omega Eye to be as effective.
There are several videos on YouTube that demonstrate how to do warm compresses with a hot cloth. It takes time and most people tend to give up on this method within a couple of weeks.
Type: We recommend the Opti-Therm microwavable eye mask.
How to do warm compresses:
- Place the Opti-Therm mask into the microwave, as per instructions on the bag.
- Once heated, check the temperature of the compress, making sure that it’s not too hot.
- Find a comfortable place to sit down, where you can recline your head.
- Place the compress over the eyes for at least 10 minutes.
The heat tends to make the Meibum secretions softer and dilate the glands slightly, thereby facilitating the expression of the oily Meibum. This should ideally be followed by Meibomian gland expression which is explained below.
Meibomian Gland Q-Tip Expression
Once the warm compress has been done, it is best to express the glands by massaging them with a Q-tip/cotton bud. This takes about one minute per eyelid.
It can be performed on both lids but is generally only performed on the lower lid. When this material is expressed into the tear film, it may be extremely uncomfortable as the material is old and possibly inflamed.
However, within a few days to weeks, the new healthy oils will start moving through the glands and the comfort levels will increase significantly.
Directions and Dosage summary
Additional drops may be beneficial for a select number of patients. Your doctor will discuss further with you if you may benefit from these and they are available on prescription only.
Prednisolone drops are cortisone drops that are very potent anti-inflammatory agents.
Directions, dosage and duration: The preservative-free drops are called Pred Minims and they are normally used 4 times per day. If they are used for a period longer than 7 days, they should not be stopped abruptly.
Instead, they should be tapered according to a schedule that will be given to you. This schedule would often be along the lines of going from 4 times per day to 3 times per day, then twice a day for a week and finally once per day for a week.
If they are stopped abruptly, a condition called “rebound” can occur whereby the eye becomes red and irritated again.
FML or Pred-Mild Drops
FML or Pred-Mild Drops are sometimes prescribed once the Pred Forte taper has been completed.
Directions, dosage and duration: These drops are 10 times less potent than Pred Forte. When the once per day schedule has been completed for Pred Forte, a 4x/day schedule can be initiated for FML or Pred-Mild.
Restasis or iKervis Drops
Restasis or iKervis are both anti-inflammatory drops (cyclosporine) that can help the tear gland produce more water for the tear layer.
Directions, dosage and duration: They are used either once or twice per day and both may first irritate the eye or cause redness before starting to demonstrate their beneficial effects. They can be used for 6 months and longer. Some patients remain on 1 drop per day lifelong. It is not uncommon to struggle to see the benefit of these drops within the first 3 months, but it is advised to push through this initial period.
Tacrolimus is also a potent anti-inflammatory drop that is only available on prescription and your doctor will use this as a second- or third-line medication in the treatment of dry eye.
Persistence is key with dry eye and most of the improvement is seen at home with your therapy! So, don’t give up on your eyes.
Surgery to Treat Dry Eye Syndrome
If the above treatment options proved to be futile, then surgery should be considered.
Different minor surgical procedures may help decrease Dry Eye Syndrome such as:
Near the inner corner of each eyelid are small openings, called punctae, that are the beginning of the normal tear drainage system.
Punctal occlusion decreases the normal drainage of the tears from the ocular surface and down the tear drainage system, into the back of the nose, and down the throat.
This occlusion is usually a remarkably simple office procedure and only takes a few minutes. It is completely painless and can either be temporary or permanent depending on the type of plug used.
Punctal Plugs or Lacrimal Canalicular Plugs
Different plugs can be placed at or just inside these openings to keep the tears from flowing down the tear drainage system. Therefore, the eyes stay moist and comfortable, even if one has fewer tears. These plugs can usually be removed very easily, if necessary.
Sometimes, in severe cases of Dry Eye Syndrome, these openings are permanently closed by cautery (burning) or laser. This accomplishes the same thing as the plugs, but it is difficult, if not impossible, to reverse.
If a person has difficulty closing the eyes for any reason, such as Bell’s palsy, the eyes may dry out because of tear evaporation. Lateral tarsorrhaphy is a procedure during which the lateral (outside) one-third of the eyelids are sewn together to decrease the ability of the eye to open widely and to help the eyes close more easily. If a stroke or nerve damage keeps the eyelids from closing properly, a small gold weight can be implanted into the upper eyelid to help it close.
Dr Joseph will discuss these options with you if the conservative routes of dry eye treatment are not working.