Dry eye is a general term used to describe abnormalities in the tear film which normally protects the cornea and allows clear vision.
Dry eyes occur when your tears do not provide adequate lubrication for your eyes
It may be due to low production of tears due to age, connective tissue disorders, medication use (Anti-histamines, decongestants), tear gland damage.
It may be also be due to increased evaporation of tears such as windy environments, air-conditioning, abnormal eyelid positions.
In some cases, it is the quality of the tears that is inadequate.
It may sound counter-intuitive but having dry eyes does not mean that your eyes are always lacking tears. Some patients experience the opposite with persistently watery eyes. This is because dry eye occurs due to an abnormality with the tear film. The tear film is a complex layer with which has oil, water and mucus. If any component is not rightly balanced, it leads to dry eyes.
Dry eyes can cause a variety of symptoms including:
- Burning, gritty sensation in the eyes
- Feeling like there is a foreign object in the eye
- Eyes that get tired easily
- Fluctuating vision that gets better with rest or blinking
- Watery eyes
- Blurred vision
Dry eye can easily be seen by an ophthalmologist using a special microscope called the slit lamp. Some signs that are seen include the presence of multiple dry spots on the cornea, tears that “breaks up” too quickly, abnormal blood vessel growth onto the cornea. Specialised tests can also be done to objectively measure tear production as well as tear quality. This include the schirmer test as well as measuring the “lipid layer thickness”
While there is no permanent cure for dry eyes, there are multiple dry eye treatment options that should be tailored according to your specific condition and severity.
Dry eye treatment includes:
- Controlling environmental factors e.g. avoiding prolonged stay in air conditioned rooms
- Controlling underlying disease e.g. autoimmune conditions
- Lubricating eye drops, eye gels and eye ointments
- Proper lid hygiene
- Warm compresses
- Pluctal plugs
- Steroid eye drops
- Immune modulating eye drops
- Autologous serum eye drops
- Scleral contact lenses
- Oral supplements like omega 3 fish oil
The health of the cornea and its ability to transmit light effectively is related to the ability of the corneal surface to be lubricated. Dry eyes compromise this health and creates a rough surface which may lead to severe complications including infections and poor vision. Lubricating eye drops, gels and ointments work synergistically to ensure a constantly wet corneal surface, protecting it from injury and minimising discomfort.
Tears drain from the surface of the eye via through the 2 “puncta” located at the inner portion of the upper and lower eyelids. From here, tears drain to the nose and ends up at the back of your throat. This explains the bitter taste you may have experienced if you have used antibiotic eye drops before. Punctal plugs stop this drainage of tears, ensuring the tears last longer and serves its function of lubricating the eyes.
For many patients with dry eyes, a contributing factor is that the oil glands of the eyelids are blocked. This is also known as MGD (Meibomian Gland Dysfunction). Tears have different components in them and one of the layers is the oil layer which reduces the rate of evaporation of tears from the corneal surface. If the oil glands are blocked, this oil layer in tears is compromised and results in dry eyes. Proper lid hygiene ensures that the oil glands of the eyelids are functioning well and helps with dry eye symptoms.
Foreign body sensation is a common symptom patients with dry eyes complain about. With dry eyes, the surface of the eye can become damaged with many dry spots appearing. This is easily seen and visualised with a special fluorescein stain and blue light. Think of it as having many small abrasions in the eye. You know how painful skin abrasions can be, let alone abrasions of the eye!
Dry eyes can present anywhere on the spectrum from mild to severe and even blinding. In patients with mild to moderate dry eye disease, simple measures like lubricating eye drops and lid hygiene can be sufficient for treatment. In patients with severe dry eyes, more aggressive treatment may be needed including steroid and immune modulating eye drops. Leaving dry eyes untreated can result in further complications including infections, compromised vision and even blindness.
Lubricating eye drops are a mainstay in treating dry eyes. While there are many brands generally available over the counter, they are not all the same. One factor which should be taken into consideration is the presence of preservatives. Here are some pros and cons regarding preservatives in eye drops.
|– They last longer||– They can cause eye irritation|
|– They are more affordable||– They cannot be used as frequently|
|– They inhibit bacterial growth|
Overall, use of preservative free eye drops is recommended where possible.
Without the right building blocks, our tears may not function as efficiently as it should. Fish oil supplements are helpful in the treatment of dry eyes. These supplements contain omega-3 fatty acid including DHA (docosahexaenoic acid) and EPA (eicosapentaenoic). These fatty acids help the oil glands in the eyelids (the meibomian glands) to improve the eye’s oil film and reduce dry eyes. Dietary sources of omega-3 fatty acids include salmon, sea bass, hailbut and tuna.
Ciclosporin eye drops are an effective alternative to common dry eye treatment options, especially in patients who have persistent dry eye symptoms despite multiple lubricants. Ciclosporin eye drops have an anti-inflammatory effect which helps dry eye symptoms but it does take a period of consistent use before the effects fully kick in. A common experience is eye stinging, eye irritation and redness upon instilling the eye drops. These symptoms tend to get better with time, along with the dry eye symptoms. Some examples of ciclosporin eye drops are Restasis and Ikervis.
With activities like computer use and reading, the content can be quite engaging and unknowingly, we blink less as result and this results in dry eyes. Blinking is essential to maintaining eye health and a simple reminder to yourself to blink can make a significant difference. Blinking not only helps spread the tears to wet the eye, it also aids in the secretion of oil from the oil glands present; this layer of oil prevents the tears from evaporating too quickly and reduces dry eyes.
LipiFlow by Johnson and Johnson is a vectored thermal pulsation system used in the management of meibomian gland disease (MGD) and dry eyes. In this treatment, heat is applied to the eyelids to “melt” the oil that often clogs up the oil glands and together with a massaging action of the device clears up the passage for the oil to flow as it normally should. This oil film is an essential component of tears and helps reduce dry eye symptoms.
In Singapore alone, dry eyes have been estimated to cause symptoms in about 12% of the population. That works out to more than 650’000 people in Singapore so you are not alone in this struggle against dry eyes.
Some simple tips to reduce dry eye symptoms include:
- Drink plenty of water
- Modify your diet to include food rich in omega-3 fatty acids
- Take frequent eye breaks when working long hours on the computer
- Remind yourself to blink
- Practice good lid hygiene habits
- Avoid long term use of eye drops with preservatives
- Avoid windy environments
- Avoid prolonged stay in air-conditioned environments