EnglishArabicBulgarianChinese (Simplified)CzechGreekHindiJapanesePersianPolishRomanianRussianSpanish
<< Go back to Cornea and eye surface


Basic Facts: Understanding The Tear Film

The eye and eyelids are lined by a fluid layer called the tear film. This is so fine as to be nearly invisible. It can just be seen as a ‘sheen’ on the eye surface and of course is more obvious when a person weeps. A healthy tear film is essential to the eye – it lubricates it, contains antibacterial agents and provides oxygen and nourishment. The tear film is not a simple layer of water but a complex mixture of water, lipids (oils), mucous and proteins. The lacrimal glands (located behind the eye) produce the water and antibacterial agents, the meibomium glands (located in the eyelids) produce the lipids and numerous cells distributed on the eye surface produce the mucous. The tear film is not static. In fact it is constantly being renewed, spread around the eye surface by the action of blinking and discharged into the tear ducts. The opening of the tear ducts are on the inner corner of the eyelids (the same side as the nose) and can just be seen as minute dots.

What Is Blepharitis?

Blepharitis is a disorder of the meibomium glands of the eyelids. Both upper and lower eyelids contain 30-40 glands, located beneath the skin. Their pores open just behind the base of the eyelashes on the eyelid margin. In blepharitis the glands become inflamed and their pores become blocked. Although blepharitis is primarily an eyelid problem, the eye is directly affected. This is because the function of the meibomium glands is to produce the lipid (oil) component of the tear film. Because blepharitis reduces production of one of the essential components of the tear film, it is in fact a type of ‘Dry Eye’. However the term dry eye is usually used to refer to a specific reduction in the water component of the tear film and blepharitis is generally considered as a separate entity. Many patients will suffer from a combination of water-deficient dry eye and blepharitis.

What Are The Symptoms Of Blepharitis?

The common symptoms of blepharitis are eye irritation, soreness and redness and the accumulation of matter on the eyelids. Less common symptoms are intermittent blurred vision, tearing, a feeling that the eyes are constantly ‘tired’ and the formation of visible eyelid cysts called ‘chalazia’. Many of these symptoms are similar to those associated with water-deficient dry eye. This is to be expected since both blepharitis and water-deficient dry eye cause symptoms by disrupting the tear film.

Blepharitis is a very common disorder in fact it is probably the most common eye disorder. It is especially common in older (ie: 50+) individuals, but it occurs at all ages, including children. It is a long-term condition which tends to come and go, for no apparent reason and may be occasionally so severe as to be misdiagnosed as an eye infection.

Blepharitis 1

1. A normal eyelid margin. You can see the base of the eyelashes and behind them the pores of the eyelid glands. 2. A case of blepharitis. The pores of the eyelid glands are blocked and inflamed. 3. A case of blepharitis showing redness and inflammation of the eyelid margin and mattering of the eyelashes.

What Is The Cause?

In older individuals, it is believed that the problem is the same deficiency of Androgen sex hormones that is responsible for many cases of dry eye. The hormone deficiency is ‘local’ ie: within the eyelid, rather than throughout the entire body. This explains why blepharitis and water-deficient dry eye co-exist in many patients. Some cases of blepharitis may be caused or exacerbated by the presence of bacteria on the eyelid margin or within the meibomium glands.

Understanding The Treatment Of Blepharitis

Successful treatment requires you to appreciate several principles. Firstly, blepharitis is a long term condition which can be controlled but unfortunately never cured. Long term treatment is often needed, although the condition tends naturally to come and go. Secondly the main purpose of treatment is to unblock the meibomium glands to enable them to produce the lipid component of the tear film. This is why you will perform regular eyelid cleaning (see below). Thirdly antibiotics may be needed to reduce the bacterial component of blepharitis and anti-inflammatory agents to control inflammation (see below).

Eyelid Cleaning

The most important aspect of treatment is regular and frequent (once or preferably twice daily) eyelid cleaning. This releases the lipid trapped in the meibomium glands of the eyelids and so normalises the tear film. There are three stages to eyelid cleaning -

First soak a flannel in warm tap water as warm as you can comfortably bear. Apply the compress to your closed eyelids for 5-10 minutes. You will need to re-warm the flannel repeatedly. This loosens the lipids stuck in the meibomium glands.

The second stage is to clean the eyelid margins. This is intended to unblock the pores of the meibomium glands. Do this by dipping a clean cotton wool bud in a solution containing either a few drops of baby shampoo or bicarbonate of soda in a cup of water. A bicarbonate solution is made by dissolving one teaspoon of bicarbonate of soda in a pint of water that has been boiled and then allowed to cool. This solution can be kept in the fridge in a clean, sealed container for a few days after which a new solution should be made. Some people find bicarbonate more soothing than baby shampoo. Use a well-illuminated magnifying mirror or better, have someone do this for you. With your eye open, gently slide the moist bud along the margin of both the upper and lower eyelids, taking care not to accidentally touch the eye. If you find using a cotton bud difficult, the next best thing is to soak some cotton wool in the same solution and gently rub it along the eyelid margin with your eye closed.

There is a commercial preparation called ‘Lid-Care’. This is a proprietary cleaning solution which you may obtain from any chemist and many opticians. It is not available as an NHS prescription. Many people find Lid-Care easier and more convenient to use than home-made solutions. It should be used once or preferably twice each day.

Blepharitis 2

Eyelid cleaning using a cotton wool bud soaked in cleaning solution as described above. Gently rub in a side-to-side motion along the eyelid margin. This opens the blocked pores of the eyelid glands, reducing the inflammation of the glands and therefore the symptons of blepharitis.

The third stage is eyelid massage. Its purpose is to express the lipid caught in the meibomium glands. Do this by applying gentle pressure on your top and bottom eyelids with either your finger or a cotton wool bud. Do not press hard. Move the finger/bud from one side of the eyelid to the other so that all the meibomium glands are compressed. This stage is essential as otherwise the lipid will remain in the meibomium gland.

Please note that you must not do any upper eyelid massage or cleaning if you have had trabeculectomy surgery for glaucoma as this might damage the delicate valve created on the surface of the eye. Also refrain from eyelid cleaning for a month after cataract surgery.

Tear Supplements

These are available as artificial (eg: Hypromellose, Tears Naturale, Liquifilm Tears, Celluvisc) and more Viscous gels (Gel Tears, ViscoTears). These agents are available with or without preservative the latter are more expensive. Tear Supplements will reduce symptoms of burning, grittiness etc. They are non-medicated and may be used as frequently as you choose, whenever you have symptoms.

Antibiotic Ointment

Prolonged courses of antibiotic eye ointment such as Fucithalmic may be required. Apply it after eyelid cleaning. Place a small amount of ointment on your finger, close your eye and gently rub the ointment into the crack between your closed eyelids. This is a convenient method of placing the ointment on to the eyelid margins but not the eye itself.

Antibiotic Tablets

If these are required, I usually prescribe Doxycycline 100mg per day for six to twelve weeks. Because it is impossible to completely eradicate eyelid infection, repeated courses of Doxycycline may be required on a long term basis. It works by reducing bacterial eyelid infection and also by having beneficial affects on meibomium gland performance which are unrelated to infection. Doxycycline is an extremely safe antibiotic. For example it is frequently used for long periods by dermatologists to treat skin acne. However it is essential that you do not become pregnant whilst taking it as it stains the teeth of babies permanently brown. It occasionally also causes sensitivity to sunlight. Avoid food and milk for an hour after taking the tablet since this will reduce absorption.

Anti-Inflammatory Agents: Steroid Eye-Drops And Cyclosporine Eye Drops

These may be required to reduce the inflammation associated with blepharitis (and water-deficient dry-eye). Steroid eye-drops (eg: Predsol, Dexamethasone, Maxidex) may be prescribed with or without preservatives. They are best used in short courses eg: of one month duration. It is important that your eyes are examined whilst using steroids as they very occasionally cause complications eg: an increase in intraocular pressure. This increase is reversed almost immediately when they are no longer used. Cyclosporine eye-drops are a new treatment. They are applied in a very dilute form and very little is absorbed into the body, so that it is not necessary to monitor levels of Cyclosporine in the blood and they do not normally cause any eye or body side affects.

How Soon Will The Condition Improve?

The response varies from patient to patient but generally symptoms will improve between 2 and 8 weeks after starting treatment. When this has happened it may be possible to reduce the treatment, for example by stopping antibiotics. You should appreciate that it is often necessary to continue eyelid cleaning indefinitely in order to reduce your symptoms to an acceptable level.


Conjunctivochalasis is the presence of microscopic folds on the surface of the white part of the eye. They are not usually visible to the naked eye. The folds are age related and/or due to the inflammation of the eye surface caused by blepharitis. The folds are typically located along the lower eyelid margin. During blinking the folds are crushed between the upper and lower eyelids and so become inflamed. Conjunctivochalasis typically causes eye irritation, watering and difficulty with prolonged reading. It usually co-exists with blepharitis. Treatment is lubricating eye-drops, steroid eye-drops to reduce inflammation and if necessary, surgery. The folds are removed and replaced by a small amniotic membrane transplant. This tissue is removed from human placenta after birth, and prepared and supplied by United Kingdom Transplant. It has powerful healing properties and the surgery is often highly successful in treating conjunctivochalasis.

blepharitis example of conjuncivochalasis

Examples of conjunctivochalasis. An abnormal fold of tissue is present between the eye and the lower eyelid. A red dye (Rose Bengal) has been applied to make the folds more visible.