Do you have dry eyes?
This is a common problem as you might not think and there are many causes to this including medications and doing certain activities.
BY: Dr Jovina See
In this age of mobile phones, electronic tablets and computers, dryness of the eyes is one of the most common eye problems faced by many today. A thin tear film coats our eyes, allowing us to see clearly and comfortably. This tear film consists of several layers – an outermost oily layer, which slows down evaporation of our tears; an intermediate watery layer, which lubricates our eyes; and an innermost mucous layer, which helps the film adhere to our eye surface.
A disruption or deficiency in any of these layers will result in dryness of the eyes. This is associated with discomfort, tiredness, grittiness/stinging/burning sensation, itch, headaches and fluctuating blurring of vision. In a situation of very dry eyes, the eyes may appear red, with increased mucus discharge at the inner corners. Occasionally, there may be a sudden reflex tearing, where tears may suddenly roll down the cheeks. In even more severe cases, recurrent corneal erosion (or abrasion) may occur. This is often characterised by a sharp pain in the eye followed by blurring of vision, especially upon waking up. If left untreated, it may result in corneal scarring.
Causes of dry eyes
- Dehydration – This can result in dry eyes. This could be simply due to drinking inadequate amounts of water, especially after excessive perspiration or drinking alcohol.
- Certain activities – Prolonged computer usage, reading, watching TV or travelling on an airplane can also exacerbate dry eyes. Our blink rate decreases to as little as a third of the normal rate during such activities, and results in less tear production. Engaging in such activities in a cold air-conditioned room or with the electric fan blowing directly into our eyes can further worsen the problem.
- Contact lenses – Wearing contact lens over many years can lead to de-sensitisation of the cornea and result in reduced tear production. Hence, wearers are more prone to developing dry eye symptoms from a younger age.
- Smokers – Smoking has also been associated with an increased incidence of dry eyes. In fact, it has been reported that smokers are twice as likely to have dry eye symptoms compared to non-smokers. Even exposure to secondhand smoke can alter the tear film and lead to dryness of the eyes.
- Age – This is also another factor, and dryness worsens, as we get older. Due to changes in our hormonal balance as we age, there is a gradual decrease in the amount of tear production starting from about the age of 40 and is more pronounced in women who are peri-menopausal.
- Medicines – Medications such as isotretinoin used in the treatment of acne, antihistamines and decongestants used for runny nose and allergies, and some medicines used to treat high blood pressure are associated with increased dry eyes. Some antidepressants and hormone replacement therapy can also cause dry eyes.
- Other causes – Rarer causes of dry eyes include damaged tear glands secondary to inflammation or radiation, as well as medical conditions such as diabetes, thyroid disease, rheumatoid arthritis, lupus, Sjogren’s syndrome (an autoimmune disorder), scleroderma and Vitamin A deficiency.
What can we do?
Drinking adequate amounts of water and consuming a diet rich in Omega-3 and Omega-6 fatty acids (such as found in certain types of oily fish, flaxseed oil and chia seeds) can help to increase our tear production. Health supplements with these fatty acids can also help to alleviate the symptoms.
Making lifestyle changes such as taking frequent vision breaks and decreasing our time spent staring at electronic gadgets will help prevent dry eyes. Reminding ourselves to blink regularly instead of staring, and keeping our books, computers or TV below eye level will help reduce dryness. The latter allows our eyelids to reduce the rate of evaporation of our tears.
Computer glasses can reduce glare, allowing us to work more comfortably, and can also help reduce dryness by blocking air currents from the air-conditioner blowing directly onto the eyes. Keeping air-conditioner vents and electric fans directed away from our eyes will also greatly reduce discomfort due to dry eyes.
Contact lens wearers should decrease the duration of contact lens wear and use daily disposable silicone hydrogel contact lenses that have higher wettability and oxygen permeability. Quitting smoking can greatly relieve dry eye symptoms.
Dryness of the eyes can be treated with eye lubricants. These help to alleviate eye fatigue and help maintain a stable sharp vision. They are available in drop or gel form, and range from non-viscous to viscous. Dryer eyes, in general, benefit from the more viscous lubricants as well as those with sodium hyaluronate, as they tend to be longer-lasting. Some lubricants restore the outermost oily layer of the tear film and thus are better able to more specifically target those who suffer from a disruption of this layer. Others may target the watery layer of the tear film and will work better for patients with a deficiency of this layer. Your eye doctor will be able to tell you which lubricant may be better suited for you. Preservative-free lubricants are particularly useful if frequent instillation is required or in the presence of allergies.
In cases of more severe dry eyes, anti-inflammatory eye medications may be necessary. Often, other co-existing eye conditions such as meibomitis (inflammation of the oil glands on the eyelid margins) and blepharitis (infection of the eyelids) can worsen dry eyes, and if present, these eye conditions should be treated simultaneously. If symptoms are severe, punctal plugs (tear duct plugs) may be used to decrease tear outflow from the eyes. The plug is a small medical device that is inserted into the tear duct of an eye to block the duct, preventing the drainage of liquid from the eye.
Dr Jovina See is a clinical director at Shinagawa Eye Centre.
(** Photos were provided by the doctor.)