WHAT IS DRY EYE SYNDROME?
Dry eye syndrome is an extremely common condition especially as we age. It is characterised by symptoms of varying severity ranging from mild intermittent irritation, foreign body sensation and redness to severe constant pain and even visual blurring. Ironically, it is also a common cause of the feeling of ‘watering’ in the eyes as well!
Dry eyes occur when the tear film fails to provide adequate lubrication and nurturing of the exposed surface of the eye. This in turn is caused by insufficient production of tears or the quality of tears produced is poor. Environmental factors also come into play. Air-conditioning, windy environments and activities that reduce frequency of blinking (e.g. reading, watching TV or using the computer for a prolonged duration) all accelerate evaporation of tears and exacerbate dry eye.
Other causes of dry eyes include certain medical conditions (e.g. diabetes, rheumatoid arthritis, Sjogren’s syndrome), medications (e.g. antidepressants, antihistamines) and eye related conditions such as blepharitis, contact lens wear, previous LASIK, eyelid malposition and damage to tear producing glands from previous inflammation or scarring.
WHAT ARE THE TYPES OF DRY EYE SYNDROME?
Our tear film is comprised of 3 different layers
- Outermost, oil layer produced by glands in the eye lid (Meibomian glands)
- Middle, watery layer that forms the bulk of the thickness of the tear film produced by the lacrimal gland
- Inner, mucous layer produced by ‘goblet cells’ in the thin membrane that covers the white of the eye (the conjunctiva)
Correct balance and composition of each layer is required for optimal function of the tear film in protecting and nourishing the eye surface. Inadequacy in any of the layers will result in dry eye. This can be classified into the following types:
- Aqueous tear deficiency: insufficient production of the watery component
- Evaporative tear dysfunction: deficiency in the oil component from failure of Meibomian glands or poor eyelid closure causing excessive exposure of the eye surface.
Treatment of dry eye should, therefore, be individualised and target the component that is most contributory in causing the dry eye symptoms in each patient. Often, however, it is a mixture of both to a varying degree.
HOW IS DRY EYE SYNDROME TREATED?
Unfortunately, there is no ‘cure’ as such for dry eye. It is a chronic condition that requires ongoing treatment to keep it under control. With effort, however, most people can bring their symptoms to a manageable level and reduce its effect on quality of life.
Depending on the cause of dry eye, various combination of treatments can be given to help:
- Lubricating eye drops / gel: Most people will experience significant temporary relief of their symptoms with lubrication drops alone. It does, however, need to be used regularly throughout the day (e.g. 3-4 times / day). There are many different types readily available from any chemist. Some aim to replace the water component as well as the oil layer, others have a thicker gel-like consistency to last longer in the eye. We recommend trying different types to see which gives the best relief to your symptoms. Many of these drops also come in ‘preservative-free’ preparations as well. Those requiring drops more than 4-6 times/day should use preservative-free drops.
- Lubricating ointments: These are thick ointments that have prolonged lubricating effects but cause significant blurring. As such, they are recommended just before bed to lubricate the eye during sleep.
- Eyelid oil sprays: to replenish oil on the eye surface.
- Hot compresses and eyelid massage / scrubs: this is especially helpful for those with oil gland (Meibomian) dysfunction. Heating the eye lid up (e.g. hot flannel or wheat bag for 1 minute) opens the pores of the glands and warms up the oil in the oil glands; massaging action helps get the oil out of the glands; lid scrubs reduce number of bacteria that break down the oil.
- Certain types of laser (Intensive Pulsed Light) treatment can help with treating specific types of dry eye syndrome by promoting meibomian oil gland secretion.
- Taking fish oil and flax seed oil orally (rich in omega-3 fatty acid) daily have been shown to help with meibomian gland function.
- Punctal plug / cautery: obstruction of the small holes in the eyelid that normally drain tears away from the eye. This allows tears to hang around in the eye for longer.
- Prescription medications such as anti-inflammatory eye drops and a course of certain antibiotic treatments can also help.
Remember, apart from the abovementioned treatments, it is just as important to avoid factors that increase drying of your eyes (e.g. redirect air-conditioning / heater vents, use of humidifiers, limit the hours of contact lens wear, take frequent breaks when in front of the computer and reading and wearing of well fitted eye-wear when outdoors to reduce wind draught).
If you would like to discuss about dry eye further, please consult one of our doctors at Applecross Eye Clinic.