Did you know there are two types of dry eye - and EDE? Knowing what type you have will help ensure you get the most effective relief
Before we tell you more about what type of dry eye you might have, you will need to understand more about the structure of your tears.
The tears or tear film has a vital function to protect and lubricate the surface of your eye. It is far more than just water, it actually contains more than 1500 different types of protein, and all these need to be continuously replenished by the lacrimal system – a series of small glands and special cells found around the eye and eyelids.
The tear film is more complex than you might think
The tear film is made up of three layers: the inner mucin, middle aqueous, and outer lipid layer. The latest thinking suggests that these layers are less distinct than first thought and in reality they mix together to some degree.
Inner mucin layer: this layer is secreted by cells on the surface of the eye. There is more than one type of mucin, together they provide lubrication and maintain hydration. Hydration is maintained by the mucin molecules anchoring the aqueous layer to the eye. The mucin layer is all about stability.
Middle aqueous layer: this layer makes up the bulk of the tear film thickness. Its’ main job is lubricating and protecting the surface of the eye. This layer is vital to the health of the eye suppling nutrients, essential electrolytes and oxygen. It also washes away debris and toxins
Outer lipid layer: this layer is essential for slowing the rate of evaporation from the aqueous layer but it is also a great lubricant. It is only thin but contains cholesterol, wax esters, fatty acids, and phospholipids which are produced by the meibomian glands found along the inner margin of the eyelid.
Read on to find out more about the two different types of dry eye:
The two main types of dry eye explained
Now you know a bit more about the tear film hopefully the following will make a lot more sense.
ADDE or Aqueous Deficient Dry Eyes – is simply defined as a reduction in the production of the watery AQUEOUS component of your tears .
EDE or Evaporative Dry Eyes – is the loss of the LIPID layer from the surface of the tear film and, as the name suggests it results in a faster than normal evaporation.
A world forum of dry eye experts got together to write a guide to the classification of dry eye and these different types. Things got a bit more complicated when they decided that quite a lot of people had both types – this was referred to as ‘mixed’ dry eye. A study published earlier this year looked at the prevalence of each type. These researchers, who studied a group of hospital patients, discovered that of those with dry eye EDE was the most common type (39.6%), followed by ADDE (34.7%) and then mixed (25.7% ). However, there are many estimates available which put the level of EDDE at a much higher level.
How does treatment differ?
If you have ADDE then the most important thing you can do is help support the middle aqueous layer of the tear film by regularly using dry eye drops such as HydraMed. HydraMed uses a unique bi-polymer which rapidly relieves dry gritty eye sensations. This patented bi-polymer provides comfort benefits that are greater than the sum of its two parts. And because it also mimics the mucin layer the bi-polymer, along with all its water, anchors itself in the eye – that means longer lasting symptom relief.
The experts at Dry Eye Zone would advise you to use your eye drops throughout the day, do not wait for symptoms to develop instead keep your aqueous layer topped up and your eyes comfortable. In more severe cases your eye care professional might suggest plugging your tear ducts to help retain your natural tears for longer. Dry Eye Zone explains this simple procedure here.
If your symptoms are due to an imperfect lipid layer, the most common cause being meibomian gland dysfunction (MGD), then just adding more to the aqueous layer will not do the trick. Instead, as well as supporting the aqueous layer, you also need think about helping your lipid layer. This is generally done by working with the meibomian glands to unblock them with cleansing, heat treatment and massage. New developments in heat compresses for eyes now make this far easier to do with much less hassle . This will help replenish your natural lipid layer and slow down the rate of evaporation.
You can get more tips on how to do this from Dry Eye Zone here.
But what type do you have?
There are certain signs which indicate the type of dry eye you have such as ‘sticky’ tired and red eyes in the morning might indicate EDE. But there is only one way to be sure and that is to see your independent optician and ask for a dry eye appointment. Their range of diagnostic tests will pin point the type of dry eye you are suffering with and recommend the most appropriate treatment plan. By taking this initiative you will be helping protect the future health of your eyes as dry eye is a progressive condition which if left untreated can lead to more serious problems.
If you are experiencing dry eye symptoms then you should ask the advice of your eye care professional. Why not book your next eye examination with an independent optician today.
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Don’t Overlook Aqueous-deficient Dry Eye
Familiarize yourself with this subset so that you’re better able to detect and manage it if it does present.
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