What is Dry Eye Syndrome?
Understand the causes & newer treatments
Understand the causes & newer treatments
Dry eye Syndrome is a very common condition that affects more than 2 million people in the UK, its incidence increasing with age, and affects more women than men. Dry eye occurs when people don’t have either enough tears, or the proper composition of tears.
The tear film is composed of three layers, which are co- dependent on the other for proper function. The outermost oily layer of the tear film is produced by the meibomian glands (which are in the eyelids), and helps reduces evaporation of the tears. The middle, watery layer is made by the lacrimal gland and washes away irritants. The inner, mucus layer is secreted by the goblet cells in the conjunctiva (mucous lining) of the eye and helps the tear film stick to the cornea.
However ALL patients with dry eye can have an inflammatory component.
Dry eye does not frequently cause blindness, but as it is such an uncomfortable condition, it is a common reason for seeking assistance. Furthermore, dry eye syndrome is associated with a decreased ability to perform activities that require visual attention, such as reading, computer work and driving a car.
Patients with the most severe disease are at increased risk of developing corneal infection, scarring or ulceration. These conditions can cause permanent vision loss, misdirected eyelashes or loss of eyelashes and entropion (chronic blepharitis), so it is important to seek urgent professional help if you have severe symptoms of dry eye.
Severe dry eye is sometimes caused by Sjögren’s syndrome, which is an uncommon autoimmune disorder that also results in dry mouth and often arthritis.
There are many tests that indicate you may be suffering with dry eye. Not all tests are always performed, but include:
Tear Meniscus: the height of the tear film along the lower lid border (reduced in dry eye).
Tear Break Up Time (TBUT) – The speed at which tears break up reflects evaporation (<5 seconds indicates dry eye)
Schirmer’s Test – A test to measure quantity of tear production where strips of sterile blotting paper are placed at the outer corner of the eye for 5 minutes and the length of wetting is measured. However it is not a very reliable test, as it does not comment on tear quality.
Tear Osmolarity – A test to measure the osmolarity of tears (high & variable in dry eye). This is an extremely reliable test, but does not help differentiate between the different types of dry eye.
Blink – An assessment of whether the blink is partial or reduced.
Ocular surface staining –with the help of topical drops, to evaluate the tear film and study ocular surface damage.
Assessment of Meibum expressibility (meibomian gland secretions), which indicates function of the oil glands.
Assessment of the Meibomian glands – with Meibography, to assess the drop out of meibomian glands
Avoid anything that can aggravate dryness, such as:
HRT can aggravate dry eye. There is some evidence that, in older women, hormone replacement therapy makes dry eye worse; if you are using HRT, talk to your doctor about this.
First line of treatment is the use of artificial teardrops or gels, which can be bought over the counter. You may need to try out different types to see what combination relieves your symptoms of dry eye. Preservatives in eye drops can aggravate your eye, and if you are using them more than 4 times/day, I recommend using non-preserved drops instead. Some newer lubricating drops try to replicate the tear film, thus have been shown to be of benefit and newer preparations are being researched.
Our modern diet is sadly lacking in sufficient quantities of Omega 3 and there is an overbalance of Omega 6, which contributes to inflammation. Omega 3 supplementation has been shown to be very useful for improving the function of Meibomian glands in blepharitis. It is mportant that the correct preparation be used, as not all Omega 3 preparations are biocompatible. While recent long-term studies indicate a somewhat better bioavailability for omega 3 fatty acids in triglyceride versus ethyl ester form, the cost of high-omega-3 concentrates is generally much greater for the triglyceride forms versus equal amounts of omega-3 in the concentrated ethyl ester form.
In more severe cases of dry eye, the eye might become inflamed and anti-inflammatory medications including steroid eye drops may be prescribed for short-term use.
This is an ophthalmic preparation of Cyclosporine, which is useful in decreasing inflammation and in Sjogren’s syndrome.
Punctal Occlusion (temporary or permanent) may be an option offered by your ophthalmologist in severe cases. This involves blocking ducts within your eyelid. Used incorrectly punctal occlusion can sometimes cause more problems especially in inflammatory dry eye.
Mainstay to treat anterior & posterior blepharitis. The Meibomian glands in the eyelids get blocked and as a result lead to evaporative dry eye.
This is an effective and simple option to provide warmth to the eyelids without the fuss of hot water etc. The EyeBag is placed in a microwave oven for 30 seconds, and then placed on the closed eyelids for about 10 minutes following which massage/scrubs can be performed.
An electrical pair of goggles that provides warmth and steam to treat MGD. Many patients prefer using this device although it is a slightly more expensive option, as it offers moist heat.
A highly sophisticated treatment option that warms the lids and squeezes them to evacuate meibum within the oil glands. Excellent for kick starting treatment in selected cases, the use of regular lid hygiene is recommended to maintain the health and function of the glands.