How to treat dry eyes. You may have been diagnosed with dry eye disease or you may just feel your eyes to be dry. This short guide will give you some information about dry eyes, its causes and what you can do.
Firstly, don’t be alarmed by the term dry eye disease or DED for short. There are a number of types and not all are related to disease. Some are simply due to environment and some can be due to disease processes in the body.
It is recommended to see an Optometrist who is experienced with dry eye to give you the best advise on the type you have and the best way to treat it. This will also allow you to know if there are any underlying causes that are not immediately obvious to you.
Symptoms of dry eyes can include gritty eyes, burning sensations, a prickly feeling, he need to rub the eyes, itchy eyes, a filmy eye and red eyes. A more strange symptoms for some is watery eyes. This can seem counter-intuitive but a dry eye can produce reactive tearing , making the eye feel watery. Other symptoms include difficulties in opening the eyes on waking up. Dry eye has often been described as walking around with a stone in your shoe.
So what is going on in the eyes when they are dry? If you image a layer of fluid, your tears, in between your closed eyelid and the surface of the eyeball, each time you open and close your eyes the eyelid is sliding on a “bed of tears” and spreading them around the surface of the eyes. If that “bed of tears” becomes too thin, to the point that your eyelid is rubbing on the eyeball without any lubricant in between, it will cause friction. If you scratch the skin of your arm, after a while it will become red, if you continue to scratch it will become inflamed. This is a simple way of understanding what is happening in your eyes when they are dry.
So why would the eye become watery? Because our eyes have mechanisms to protect the eyes from infection and foreign objects, if there’s anything unusual going on our eyes can tend to produce excess reactive tears to wash things out.
If my eyes are dry, should I be concerned enough to go to A&E? The answer to that is a most definitely no. Dry eyes are fortunately, not an emergency. If the dryness is severe you can be referred to a specialist. If your Optometrist suspects an underlying cause, they may refer you to a specialist.
What types of dry eye are there?
Environmental dry eye can be as a result of exposure of the eye to excessive heat, dust, air/wind, chemicals like solvents. Treating the dry eyes could require changes to the environment or adapting to the environment. Examples of this would be someone who works on a building site where there is lots of dust in the air. The tears will be overwhelmed by the dust causing a breakdown of the tear film.
Another example is of an office worker who spends a lot of time in front of a screen, in an air conditioned office. The effect of this is a combination of staring at a screen for long periods without a break and the dry air caused by the air conditioning coming together to cause the tears to evaporate too quickly.
From the above example you can see that some simple changes to the way one works in those cases will treat the dry eyes and relieve the symptoms.
Sometimes the environment can exacerbate an underlying cause which then becomes a problem. Examples of this could be contact lens use. A person with mild dry eye may become symptomatic only when they start wearing contact lenses. Their eye care professional would need to treat the dry eyes because having them resume contact lens wear.
So what are the underlying causes of dry eye?
Dry eye can be caused by
Local inflammation like blepharitis
Cosmetic laser vision correction; LASIK or LASEK
Other eye surgery
To understand how the above causes dry eye, let’s get to know about the way our tear film works.
We have three places from which the components of the tearfilm come from:
The glands in our eyelids called the meibomian glands.These produce meibum.
The glands in the bony part of the eyebrow called the lacrimal gland. These produce the lacrimal tears.
The cells on the surface of the cornea called the epithelial cells. These produce mucin.
As you can see our tear film is made up of 3 layers working together to moisten the eye surface, to defend the eye from pathogens, to repair and surface damage quickly and to create a nice “bed of tears” for our eyelids to ride on. An imbalance or deficiency in the layers will cause the 3 layers to work ineffectively. If we want to know how to treat dry eyes effectively we need to know which of the layers is responsible or deficient.
An important aim of treatment is to break the cycle of tear film instability and inflammation. The altered tear film causes a response by the body in the form of reflex tearing. These reflex tears contain components that cause inflammation, which leads to cell damage. The damaged cells bring about a nervous response that causes further inflammation, which causes further surface damage and tear film instability. The cycle is then repeated unless something is done to disrupt this cycle, by bringing the tear film back to its normal function.
The aim of treatment is to bring about a balance with a maintenance schedule that controls the tear film problem
Why do my eyes water?
Your tear gland is producing reflex tears in response to a problem on the surface of your eyes.
You may have a blockage in your drainage ducts
How do you control dry eye?
We use a combination of the the following :
Drops to supplement the tears
Drops to modify the tears
Procedures to conserve the tears
Procedures to stimulate the tears
Procedures to control disease processes that may be contributing
Advice to control risk factors
How to artificial tears/ lubricants work?
They increase the amount of tears
Reduce tear osmolarity.
Provide symptomatic relief
Hydrate the eye surface
Aid in healing.
Why use preservative free eye drops?
Preservatives vary in their side affects on the eye.
They can cause intolerance if used for long periods.
They have surfactant properties in that they dissolve the lipid layer of the tear film .
The can damage the surface epithelium of the eye over a long period of time.
They are used in glaucoma medication which means that people who need them will be sensitive to using dry eye drops that also contain preservative as this would mean they are exposing their eye to higher levels of the preservative agent.
Benzalkonium chloride (BAC) is a commonly used preservative that is well known for causing problems for dry eye sufferers.
Since there are now many non preserved drops on the market, the needs for using preserved drops is longer there.
Preservatives should not be avoided where the benefit of the drug outweighs the possible risks of the preservative, eg. glaucoma medication.
How do I know which drops are right for me?
Although we will recommend the type of eye drop you would benefit from based on the deficiency in your tear film, for those who have chronic dry eyes the right drop may change. The right drops can vary from person to person in the same way that different face creams suit different people.