Dry eye syndrome

Dry eye syndrome

Introduction

Dry eye syndrome, or dry eye disease, is a common condition that occurs when the eyes do not make enough tears or the tears evaporate too quickly.

This leads to the eyes drying out and becoming inflamed (red and swollen) and irritated.

Dry eye syndrome is also known as keratoconjunctivitis sicca, or simply ‘dry eyes’.

Symptoms of dry eye syndrome

The symptoms of dry eye syndrome usually affect both eyes and often include:

  • feelings of dryness, grittiness or soreness that get worse throughout the day
  • red eyes
  • eyelids that stick together when you wake up
  • temporarily blurred vision, which usually improves when you blink

See your GP if you experience persistent symptoms of dry eye syndrome. They may examine you to check if the problem is caused by an underlying condition or may refer you to an eye specialist called an optometrist or ophthalmologist for further tests.

Read more about the symptoms of dry eye syndrome and diagnosing dry eye syndrome.

What causes dry eye syndrome?

Dry eye syndrome can occur when the complex tear production process is disrupted in some way. There are many different reasons why this can happen, although a single identifiable cause is not often found.

Common causes include:

  • being in a hot or windy climate
  • wearing contact lenses
  • certain underlying medical conditions, such as blepharitis (inflammation of the eyelids)
  • side effects of certain medications
  • hormonal changes, such as during the menopause (when a woman’s periods stop)

Although the condition can affect people of any age, your chances of developing dry eye syndrome increase as you get older. It’s estimated that up to one in every three people over the age of 65 experiences problems with dry eyes.

Dry eye syndrome is also more common in women than men.

Read more about the causes of dry eye syndrome.

How dry eye syndrome is treated

Dry eye syndrome is not usually a serious condition.

Treatments are available to help relieve the symptoms, which include eye drops to lubricate the eyes, medications to reduce any inflammation, and (if necessary) surgery to prevent tears from draining away easily.

If dry eye syndrome is caused by an underlying condition, treating this condition will usually help relieve the symptoms. 

Read more about treating dry eye syndrome.

Caring for your eyes

As well as medical treatments, there are some things you can do yourself to help prevent dry eye syndrome or reduce the symptoms.

These include: 

  • keeping your eyes and eyelids clean and protecting them from dusty, smoky, windy and dry environments
  • using your computer or laptop correctly to avoid eye strain
  • using a humidifier to moisten the air
  • eating a healthy diet that includes omega-3 fats

Read more self-help tips for dry eye syndrome.

Further problems

Dry eye syndrome may be uncomfortable, but does not usually cause any serious problems. In rare cases, severe untreated dry eye syndrome can cause scarring of the eye’s surface, leading to visual impairment.

Contact your GP or visit your nearest accident and emergency (A&E) department immediately if you have any of the following symptoms, as they could be a sign of a more serious condition:

  • extreme sensitivity to light (photophobia)
  • very red or painful eyes
  • a deterioration in your vision

Read more about the complications of dry eye syndrome.

Symptoms of dry eye syndrome

The symptoms of dry eye syndrome are mild for most people, although more severe cases can be painful and lead to complications.

Symptoms usually affect both eyes and often include:

  • feelings of dryness, grittiness or soreness that get worse throughout the day
  • red eyes
  • eyelids that stick together when you wake up
  • temporarily blurred vision, which usually improves when you blink

Some people may also have episodes of watering eyes, which can occur if the eye tries to relieve the irritation by producing more tears.

More severe symptoms of dry eye syndrome include:

  • extreme sensitivity to light (photophobia)
  • very red and painful eyes
  • a deterioration in your vision

These severe symptoms can be a sign of a serious complication of dry eye syndrome, such as scarring of your cornea (the transparent layer at the front of the eye), that could affect your sight permanently if not treated.

When to seek medical advice

See your GP if you have persistent but mild symptoms of dry eye syndrome. They can examine your eyes and refer you to an eye specialist called an optometrist or ophthalmologist for further tests if necessary.

Contact your GP immediately if you have any severe symptoms. If this is not possible, visit your nearest accident and emergency (A&E) department.

Read more about diagnosing dry eye syndrome and treating dry eye syndrome.

Causes of dry eye syndrome

Dry eye syndrome can occur if your eyes do not produce enough tears or your tears evaporate too quickly.

There are many different reasons why this can happen, although a single identifiable cause is not often found.

About tears

You probably only notice your tears when you laugh or cry. However, the surface of your eye is always covered by a thin layer of liquid known as the tear film that helps to lubricate your eyes, keep them clean and free of dust, and protect them against infection.

The tear film is made up of water, salts, oils, proteins and mucus, which are produced by a number of different glands and cells situated in and around the eyes.

Dry eye syndrome can occur if any part of the tear production process becomes disrupted and the quantity or quality of your tears is affected.

Increased risk

Some of the things that can interfere with the tear production process are described below.

Hormonal changes

Hormones (powerful chemicals produced by the body) and the nervous system play an important part in tear production.

Hormones stimulate the production of tears. Changes in hormone levels in women (for example during the menopause or pregnancy or while using the contraceptive pill) can increase their risk of dry eye syndrome.

Ageing

Dry eye syndrome is more common in older people, possibly because you produce fewer tears as you get older and your eyelids become less effective at spreading tears over your eyes.

Environment and activities

Environmental factors can have a drying effect on your eyes, causing your tears to evaporate. These include:

  • sun
  • wind
  • dry climate
  • hot blowing air
  • high altitude

Certain activities that require visual concentration – such as reading, writing or working with a computer – can also contribute to dry eye syndrome. This is because people tend to blink less frequently during these activities, which means the tear film evaporates or drains away more quickly than it is replenished.

Certain medications

Several medicines are thought to cause dry eye syndrome as a side effect in some people.

These include antihistamines, antidepressants, beta-blockers and diuretics.

Laser eye surgery

Some people who have had certain types of laser eye surgery find they have dry eye syndrome in the weeks after surgery. The symptoms usually clear up after a few months, but in some cases may continue.

Contact lenses

Sometimes, contact lenses irritate the eye and cause dry eye syndrome. Changing to a different type of lens or limiting their use usually helps resolve the symptoms.

Medical conditions

There are a number of medical conditions that increase your risk of developing dry eye syndrome.

Many people with dry eye syndrome also have blepharitis. This is where the rims of the eyelids become inflamed, which can block the glands that produce oils for the tear film.

Blepharitis can occur at any age and in otherwise healthy people, although it sometimes occurs as the result of a bacterial infection or another condition such as rosacea (a skin condition that causes the face to appear red and blotchy).

Other medical conditions that can increase your risk of dry eye syndrome include:

  • allergic conjunctivitis  inflammation of the conjunctiva (the transparent layer of cells that covers the white part of the eyeball and the inner surfaces of the eyelids) caused by an allergy
  • contact dermatitis  a type of eczema that causes inflammation of the skin when you come into contact with a particular substance
  • Sjögren’s syndrome a condition that can cause excessive dryness of the eyes, mouth and vagina
  • rheumatoid arthritis  a condition that causes pain, swelling and inflammation in the joints and can affect any part of the body, including the glands around the eyes
  • lupus  a condition where the immune system attacks healthy body tissue, particularly blood vessels
  • scleroderma  a condition that causes areas of skin to become hard and thickened
  • previous trauma (serious injury) to the eyes  such as burns or exposure to radiation
  • Bell’s palsy  a condition that causes weakness or paralysis to the muscles of one side of the face
  • HIV  a virus that attacks the body’s immune system

Diagnosing dry eye syndrome

Your GP should be able to diagnose dry eye syndrome based on your symptoms and medical history. They may also examine you to check for other conditions and complications.

Your GP may want to know about:

  • any medicines that you are taking
  • what activities you do regularly – for example, if you work on a computer all day
  • whether you have any other symptoms (that may not be affecting your eyes)

These may help your GP identify a possible cause of your dry eye syndrome.

Referral to a specialist

Your GP may refer you to an optometrist for a check-up. Optometrists are trained to recognise sight defects and eye conditions. Although your GP may refer you to an optometrist, they are private practitioners and charge for their services.

Your optometrist can examine your eye and confirm whether you have dry eye syndrome and any other associated conditions and complications. They will also advise about treatment.

If the diagnosis is uncertain or specialist tests and treatment are needed, your GP or optometrist may refer you to an ophthalmologist. Ophthalmologists are surgeons who specialise in eye conditions. Like optometrists, they use special equipment and techniques to examine the eye. 

Two of the main tests carried out to check for signs of dry eye syndrome are described below.

Fluorescein dye test

During a fluorescein dye test, eye drops containing a special yellow-orange dye are used so your specialist can see your tears more clearly. This helps them find out how long it takes for your eye to start drying out. The dye is only temporary and will not change the colour of your eye.

Once the drops are in your eye, you’ll be asked to blink a few times and then keep your eyes open without blinking. Your specialist then uses a special light to see the dye and times how long it takes for a dry patch to appear.

If the patches begin to appear in less than ten seconds, this usually means you have dry eye syndrome.

If there is damage to the surface of the eye, the fluorescein dye test may also highlight the affected areas.

The Schirmer’s test

During the Schirmer’s test, small strips of blotting paper are hooked over your lower eyelid. After five minutes, the strips are removed and studied to determine how wet the paper is. If the paper has wetted less than 10mm in five minutes, this indicates dry eye syndrome.

Treating dry eye syndrome

There is no cure for dry eye syndrome and some people have recurring episodes for the rest of their lives, but there are treatments to help control the symptoms.

The exact treatment for dry eye syndrome depends on whether symptoms are caused by the decreased production of tears, tears that evaporate too quickly, or an underlying condition.

The first thing to consider is whether there are any obvious factors that could be changed, such as altering any medication that is causing symptoms.

If your dry eye syndrome is caused by an underlying medical condition, your GP will prescribe treatment for it or will refer you to an appropriate specialist.

You may also be able to help prevent dry eye syndrome or ease your symptoms by adjusting your environment, keeping your eyes clean and improving your diet. Read more about self-treating and preventing dry eye syndrome.

Lubricant treatments

Mild to moderate cases of dry eye syndrome can usually be treated using lubricant eye treatments that consist of a range of drops, gels and ointments. 

These lubricants are often called ‘artificial tears’ because they replace the missing water in the tear film. However, they do not contain the antibodies, vitamins and nutrients found in normal tears that are essential for eye health.

Some lubricants are available without a prescription over the counter from a pharmacy, whereas others are only available on prescription.

There are many different types of eye drops and gels, and it is often worth trying a number of different ones to find one that suits you. However, it is important you discuss any changes you wish to make to your treatment with your doctor.

Preservative-free drops

Some eye drops contain preservatives to prevent harmful bacteria from growing inside the medicine bottle. If your symptoms mean you need to use these eye drops more than six times a day, it’s better to use preservative-free eye drops. 

This is particularly important if your ophthalmologist has told you that you have severe dry eye disease because preservatives used in large quantities or over a prolonged period of time (months or years) may damage the delicate cells on the surface of the eye or cause inflammation.

If you wear soft contact lenses, you may also need to use a lubricant that is preservative-free, as preservatives attach to the contact lens and damage the eye. These types of eye drops may be more expensive.

If you have any difficulty putting in your drops, please discuss this with your doctor.

‘Oily’ tear eye drops

Eye drops that replenish the oily part of the tear film and reduce evaporation from the surface of the eye are also increasingly used. These preparations include synthetic guar gums or liposomal sprays.

Liposomal sprays are over-the-counter medications and do not require a prescription. They are sprayed onto the edges of your eyelids when your eyes are closed. When you open your eyes, the solution spreads across the surface of the eye, creating a new oily film.

Oily tear drops are particularly useful if you have blepharitis (inflammation of the rims of the eyelids) or dry eye syndrome caused by your tears evaporating too quickly. 

Eye ointments

Eye ointments can also be used to help lubricate your eyes and help keep them moist overnight because your tears can evaporate while you sleep if your eyes are not fully closed.

These ointments tend to be used overnight because they can cause blurred vision.

If you wear contact lenses, do not use eye ointments while wearing them. Ask your pharmacist or GP for advice about alternative treatments that may be suitable for you.

Anti-inflammatory treatments

The underlying problem with long-term dry eye syndrome is inflammation in and around the eye. Therefore, one of the anti-inflammatory treatments mentioned below may also be recommended.

Corticosteroid eye drops and ointments

Corticosteroids are powerful anti-inflammatory medications that can be given as eye drops or ointments in severe cases of dry eye syndrome. They have side effects such as cataract formation and raising the pressure within the eye in about one in every three people. This group of treatments should only be used if you are being supervised by an ophthalmologist in an eye clinic.

Oral tetracyclines

Low doses of medications called tetracyclines can be used as anti-inflammatory agents for a minimum of three to four months, sometimes much longer.

The most common tetracycline used is doxycycline, but others such as oxytetracycline and lymecycline are sometimes prescribed.

Ciclosporin eye drops

Ciclosporin is a medication that suppresses the activity of your immune system and is sometimes used in the treatment of dry eye syndrome.

However, this treatment is only available through a hospital eye department.

Autologous serum eye drops

In very rare cases, where all other medications have not worked, autologous serum eye drops may be required.

Special eye drops are made using components of your own blood. It is only available from the National Blood Service through an ophthalmologist and after funding is approved.

To make autologous serum eye drops, one unit of blood is taken under sterile conditions (as for regular blood donation). The blood cells are then removed and the remaining serum is put into eye drop bottles. Because of quality standards, this process can take several months before the treatment is finally available to use.

Surgery

If your dry eyes are severe and fail to respond to other forms of treatment, surgery may be an option. Two types of surgery sometimes used to treat dry eye syndrome are described below.

Punctal occlusion

Punctal occlusion involves using small plugs called punctal plugs to seal your tear ducts. This means your tears will not drain into the tear ducts and your eyes should remain moist. 

Temporary plugs made of silicone are normally used first to determine whether the operation has a positive effect. If it does, more permanent plugs can replace the silicone ones.

In more severe cases, the tear ducts are cauterised (sealed using heat). This permanently seals the drainage hole to increase the amount of tears on the surface.

Salivary gland autotransplantation

Salivary gland autotransplantation is an uncommon procedure that is usually only recommended after all other treatment options have been tried.

This procedure involves removing some of the glands that produce saliva from your lower lip and placing them under the skin around your eyes. The saliva produced by the glands acts as a substitute for tears.

Self-help advice for dry eye syndrome

There are a number of things you can do to prevent dry eye syndrome or ease your symptoms. 

Environmental factors

Certain environments can irritate your eyes. Keep your eyes protected from:

  • wind
  • hot air
  • smoke
  • dust

Wrap-around glasses may provide good protection. Avoid smoky environments, and if you smoke you should try to stop.

Avoid using eye makeup. Eyeliner and mascara can block the glands in the eyelids and cause the area around your eyes to become inflamed.

Specialised eyewear

Some cases of dry eye disease can be treated using specialised eyewear. These include specially made glasses called moisture chamber spectacles. These wrap around your eyes like goggles, helping to retain moisture and protecting your eyes from irritants.

If your previous contact lenses were causing dry eye disease, special contact lenses are also available. You should discuss various options with your high street optometrist.

Adjust your computer

If you regularly use a computer, make sure your computer workstation is set up correctly to minimise eye strain. Your monitor (screen) should stand at eye level or just below it.

If you are using a computer at work, most employers have a health and safety officer or an occupational health representative who can advise you about this.

You should also make sure that you take breaks away from your computer screen every hour and blink your eyes regularly.

Read more about workplace health and how to sit correctly.

Use a humidifier or air filter

A humidifier at work and home will moisten the surrounding air and can help reduce symptoms of dry eye syndrome. Opening windows for a few minutes on cold days and longer in spring and summer will also help keep air moist and prevent a build-up of mould.

If you work or live in a particularly dusty environment, you may also find it useful to use an air filter.

Keep your eyes clean

Good hygiene will help improve dry eye syndrome, particularly if you have blepharitis (inflammation of the eyelids).

There are three main steps to eyelid hygiene that should be performed once or twice a day:

  • using a warm compress to make the oil produced by the glands around your eyes more runny
  • gently massaging your eyelids to push the oil in your tears around the eye
  • cleaning your eyelids to wipe away any excess oil and remove any crusts, bacteria, dust or grime that might have accumulated

How you can carry out these steps is described below.

Warm compresses

  • boil water and leave it to cool to a warm temperature
  • soak a clean flannel or eye pad in the warm water and gently place this over the eyes for around 10 minutes
  • reheat the compress periodically by soaking it in warm water, ensuring that the flannel does not become cold

Some people find compression with a special microwavable ‘eyebag’ useful for dry eye syndrome. If you use one of these products, make sure you clean the bag before and after use.

Eyelid massage

  • gently massage your closed eyes by rolling your little finger in a circular motion
  • take a cotton wool bud and, with your eyes shut, gently roll the cotton bud downwards on the upper eyelid towards the lashes and edges of the eyelids
  • repeat this process along the whole width of the upper and lower eyelids

This process may cause your eyes to become slightly irritated at first, a bit like getting soap in your eyes, but this is normal and should get better with time.

Lid margin hygiene

Various eyelid-cleaning solutions are available commercially, or you can try making one at home.

For a home-made solution, fill a bowl with boiled water and allow it to cool to a warm temperature. Then add either a few drops of baby shampoo or tea tree shampoo, or a teaspoon of bicarbonate of soda.

Once you have made a cleaning solution:

  • soak some clean cotton wool in the solution and remove crustiness from around the eyelids, paying special attention to the eyelashes
  • repeat this process if necessary using a clean piece of cotton wool
  • dip a clean cotton bud into the solution and gently clean the edges of the eyelids by wiping the cotton bud along the bases and lengths of the lashes

Diet

There is some evidence to suggest that a diet high in omega-3 fats can help improve dry eye syndrome.

The best sources of omega-3s are oily fish, such as:

  • mackerel
  • salmon
  • sardines
  • herring
  • fresh or frozen tuna (not canned, as the canning process sometimes removes the beneficial oils)

Aim to eat at least two portions of fish a week, one of which should be oily fish. 

You can also get omega-3s from various nuts and seeds, vegetable oils, soya and soya products, and green leafy vegetables.

Read more about eating a healthy diet.

Complications of dry eye syndrome

Although most people only experience mild symptoms, severe cases of dry eye syndrome may cause complications.

The two main complications associated with dry eye syndrome are conjunctivitis and ulceration of the cornea.

Conjunctivitis

Conjunctivitis is inflammation of the conjunctiva (the transparent layer of cells that covers the white part of the eyeball and the inner surfaces of the eyelids).

Symptoms of conjunctivitis are similar to dry eye syndrome – including red eyes, a feeling of grit in your eyes, a burning sensation in your eyes and eyelids that stick together when you wake up.

Most cases of conjunctivitis caused by dry eye syndrome are mild and do not need specific treatment. However, if you have conjunctivitis that becomes severe and long-term (chronic), you may be referred to a specialist for treatment.

Inflammation of the cornea

In severe cases of untreated dry eye syndrome or cases that do not respond well to treatment, the associated inflammation can damage the surface of the cornea (the transparent layer at the front of the eye). This is called keratitis.

This damage can make the cornea vulnerable to ulceration and infection, which could potentially threaten your sight. 

Symptoms of serious problems with your corneas include eye pain, sensitivity to light and a deterioration in your vision.

Contact your GP immediately if you think you may have any problems with your corneas. If this is not possible, visit your nearest accident and emergency (A&E) department.