Dry eye syndrome is an umbrella term for dry eyes caused by a lack of proper tear production and distribution. It is also known as dysfunctional tear syndrome, The medical term is keratoconjunctivitis sicca. It’s something I encounter daily in practice and something that affects me personally. It is a multifactorial disease and is more complex than one might first think. Therefore, this article covers the more common causes.
Symptoms Of Dry Eyes
Dry eyes give rise to a number of different symptoms and every individual is different. The commonest symptoms are as follows:
- Sore, gritty, sandy, uncomfortable eyes
- Photophobia (a dislike of bright light)
- Excessively watery eyes
- “Smeary,” blurred or fluctuating vision
- A hot or burning sensation
- A foreign body sensation, (like something is in the eyes)
- Difficulty opening the eyes in the morning because they feel like they are glued shut
- Uncomfortable contact lenses
Prevalence and Cause of Dry Eyes
Dry eye syndrome affects up to 33% of the population. It affects women more than men and its prevalence increases with age. The chances of developing dry eye increase for those that:
- Have ocular conditions blepharitis or meibomian gland dysfunction (MGD)
- Have medical conditions including Sjögren’s syndrome, diabetes, arthritis, thyroid disease and rheumatoid arthritis
- Take medication for allergies or depression
- Take the contraceptive pill or HRT
- Wear contact lenses
- Have had LASIK or laser eye surgery
- Look at a (computer) screen for long periods
- Frequently drive long distances
- Live or work in a dry, windy, air-conditioned or smoky environment
Dry eyes can be broadly categorised into two types: Those caused by tear deficiency and those caused by excessive evaporation of tears.
Tear Production, Composition and Function
Tears perform a number of important functions. Along with the eyelids, they cleanse, protect and nourish the eye. With every blink, the eyelids distribute tears over the eyes, flushing away dust, debris and bacteria. Tears transport proteins and important nutrients onto the eyes where they are absorbed by the cornea.
The layer of tears that coats the eyes is called the tear film. It is composed of three layers: the lipid layer, the aqueous layer and the mucin layer. A healthy tear film provides a smooth optical surface on the cornea. This ensures that a high-quality image is transmitted through the eye onto the retina. An irregular surface therefore, leads to blurred vision.
Tear Film Quality and Quantity
Anomalies in the quality and/or the quantity of tears will cause dry eyes.
- The lacrimal glands produce the aqueous (watery) part of the tear film. An insufficiency results is an aqueous deficient dry eye.
- The goblet cells of the conjunctiva produce mucin. If they don’t produce enough, the cornea becomes “unwettable.” As a consequence, the tears cannot adhere to the surface of the eye. Causes of goblet cell malfunction include inflammation, infection, burns and vitamin-A deficiency.
- Meibomian glands produce the lipid (oil) part of the tears. A lack of oil means the tears evaporate too quickly. This causes evaporative dry eye.
Broadly speaking, if the eyes get dry as the day goes on, it is an evaporative dry eye.
Interestingly, it is not uncommon for a patient’s only symptom to be excessive watering, (epiphora). This is known as the dry eye paradox. When tears evaporate, they become more concentrated and salty. This causes inflammation, so the eye and eyelids get hotter. Nature responds by flooding the eye with tears.
Treatment For Dry Eyes
The treatment or perhaps more accurately, the management, of dry eyes depends on the cause. I say this because it is hard to cure a dry eye, it is usually a case of managing, and keeping on top of the symptoms
Management Of Meibomian Gland Dysfunction
Meibomian gland dysfunction, (also known as posterior blepharitis), is a leading cause of dry eye. This itself is a complex disease. Typically it arises because the glands become inflamed due to a blockage, often because the oily secretions have become waxy. Another type of MGD occurs when too much lipid is secreted. All types result is an unstable tear film which causes evaporative dry eye.
A hot compress followed by digital massage will help to unblock the glands. A hot flannel is good, but a purpose-made eye mask is better. Some can be heated up in a microwave oven, or in a cup of hot water. Place the mask on closed eyes and lie down for ten minutes. Immediately afterwards, use the fingers to massage the upper and lower eyelids to dislodge any melted secretions. Your optometrist will be able to demonstrate this technique.
Management Of Dry Eyes In General
- Blink more! The blink rate drops during prolonged periods of concentration, for example, when staring at a computer screen or driving long distances.
- Make your environment more humid
- Avoid draughts, air-conditioning and central heating
- Keep hydrated, drink plenty of water
- Eat foods rich in Omega 3, for example, oily fish, chia seeds, berries. (Some clinical evidence suggests that Omega 3 improves the symptoms of dry eyes, other evidence refutes it. I believe it is beneficial. See “My Dry Eye Routine” below).
- Use ocular lubricants, eye drops and/or gels and/ointments). Ask your optometrist to recommend the best type for your particular type of dry eye.
How To Insert Eye Drops
It isn’t always easy to insert eye drops into one’s own eyes. The best way is to tilt the head back as far as possible, so the chin is pointing towards the ceiling. Pull the lower lid down to create a pocket. Squeeze the dropper gently taking care not to touch the eye or lashes with the dropper. Keep the head tilted back, release the eyelid and blink two or three times to distribute the drops. Use the same method to instil eye ointment.
My Dry Eye Routine
I started to get an increase in my dry eye symptoms towards the end of last year. My eyes felt gritty and my vision was “smeary.” It was at its worst at 100% Optical in January. I have mild MGD which I managed with hot compresses and occasional lubricating drops. However, dehydration from the Christmas period(!), increased time on my laptop, central heating and a hot train journey to London exacerbated it. My eyes were driving me to distraction. I went to my good friends at Bondeye Optical and begged for some lubricating drops. (Bondeye Optical is a one-stop optical shop. It sells everything from spectacle frames to contact lens solutions and lots of dry eye remedies. I’ve met a lot of the team over the last two years; they’re great.
They gave me a bottle of Systane eye drops which provided immediate relief. They also kindly gave me a selection of other products to try including Lagad Lacrima supplements. The supplements claim to promote the production of tears, improve the nutrition of the cornea and improve comfort. They contain gamma linolenic acid, Omega 3 oil, antioxidants, vitamins, minerals and essential fatty acids.
As I said above, there is no definitive answer regarding Omega 3 and dry eyes. I started taking the supplements in January and I noticed a significant improvement in my symptoms after about three months. (I eat a healthy diet full of tuna, nuts, seeds and berries too). My eyes don’t seem to dry out as readily as they did, regardless of my behaviour and environment. And just so you know, this isn’t a sponsored post and I have no association with Lagad. I believe the supplements have worked for me, so I highly recommend them. I use a hot compress several times a week, (for maintenance) and follow it with digital massage, then I use lubricating drops as and when I need to.
See Your Optometrist
If you think you have dry eyes, do visit your optometrist. Dry eye syndrome is a multifactorial disease which needs professional diagnosis and guidance. The optometrist will take a detailed history and will run a number of tests to look for the underlying cause. This will involve, at the very least, instilling a fluorescent yellow-orange dye. The dye, called fluorescein, helps assess the tear quality and quantity. It will also highlight any dry or damaged areas on the ocular surface. Based on findings, the optometrist will be able to say whether or not your symptoms are because of dry eyes and will advise on best management. If not, they know which fellow professional to refer you to, usually a GP or an ophthalmologist.
Please note: If you experience any sudden loss or deterioration of vision or severe/acute eye pain, you need an urgent appointment with an optometrist, doctor or eye-casualty department.
My last piece of advice is to be patient and be consistent. It can take several weeks to see an improvement.