Most people have experienced the feeling of dry eye at some time. The condition can range from mild irritation to a long-term condition associated with great discomfort or pain and can affect your vision. Dry eye is very common but people who suffer from it shouldn’t think they just have to live with it, as there are several treatment options.
Dry eye syndrome is caused by a disruption in the tear production process. Normally, a thin film of tears coats the eyes, providing sufficient lubrication and optimal vision. The tear film consists of three layers – an inner mucous layer, a middle aqueous layer, and an outer lipid layer. If an absence occurs in any of the three layers, dry eye symptoms will transpire. An imbalance between tear production, drainage and retention can be caused by a number of factors. Age is one factor with people over 65 years having 60% less oil in their bodies than younger adults. As well as being caused by the normal ageing of tear glands, dry eye syndrome can also occur due to Meibomian gland dysfunction, blepharitis, extended contact lens wear, medications, hormonal changes, immune disorders, eye surgery such as LASIK, environmental factors, air travel, computer-related eye strain and inadequate diet.
Dry Eye Causes
- Meibomian Gland Dysfunction
- Blepharitis
- Contact lens wear
- Diseases eg. Rheumatoid arthritis
- Medicines including antihistamines, diuretic, oral contraceptives, nasal decongestants
- Environmental factors such as low humidity
- Windy environments & air-conditioning
- Age
Meibomian Gland Dysfunction and Blepharitis
Meibomian gland dysfunction (MGD) is a leading cause of dry eye syndrome. MGD is a blockage or other abnormality of the meibomian glands which are located behind the eyelids. Chronic inflammation disturbs the production of the lipids emitted by the meibomian gland. Without enough oil-secreting into the tears, tears evaporate too quickly. MGD is also associated with the eyelid problem called blepharitis. Certain skin diseases, like rosacea and seborrheic dermatitis, or infection with staphylococcal bacteria, can also lead to blepharitis, which is characterised by inflammation of the eyelid margins and dry eye symptoms.
Blepharitis
Blepharitis is an inflammation of the eyelids. Although it is a very common external eye disorder, the exact cause of the condition is still unclear. Due to the close relationship between the eyelids and the eyes, many patients with blepharitis have associated tear film instability, which can lead to gritty and sore eyes. Unfortunately, there is no specific cure for blepharitis, and it can only be managed with ongoing treatment.
Common symptoms include redness of the eyelids, itchy or irritated eyes, crusting of the edge of the eyelids or lashes, a dry or scratchy feeling of the eyes, sensitivity to light, swollen eyelids, redness of the eye, fluctuating vision.
Contact Lens Wear
As contact lenses rest directly on the cornea, wearing contact lenses for extended periods can lead to a decrease in the amount of oxygen that reaches your eyes. Bacteria and other infection-causing agents can accumulate on contact lenses also, especially as lenses get older and deposits build upon their surfaces, contributing to inflammatory issues. Contact lens solutions that contain preservatives can also cause irritation to the corneal surface, causing dry eyes symptoms.
Medications
Dry eye can be a side effect of some medications, including antihistamines, nasal decongestants, sedatives, certain blood pressure medications, beta-blockers, certain antibiotics, certain psychiatric medications, Parkinson’s medications, birth control pills, diuretics, appetite suppressants, and antidepressants.
Hormonal Changes
Changes in tear production can cause dry eye in women who are pregnant, lactating, menstruating, peri-menopausal or menopausal. Women on hormone replacement therapy may also experience dry eye symptoms. Women taking estrogen are 70 per cent more likely to experience dry eyes, and those taking estrogen and progesterone have a 30 per cent increased risk of developing dry eyes. Before menopause, it is understood that the greater a woman’s testosterone, the fewer tears produced, and the greater their estrogen, the greater tears produced. During menopause, however, this reverses. Research is emerging about the role hormones play in the lubrication of eyes, but it is understood that dry eyes can result from a deficiency of estrogen, progesterone, or testosterone, or possibly from an imbalance of any of the three.
Immune Disorders
Dry eye syndrome can be associated with immune system disorders such as Sjogren’s Syndrome, Lupus, Rheumatoid Arthritis, Diabetes, and Thyroid disease. Sjogren’s Syndrome is most commonly associated with dryness of the eyes and mouth. It is a relatively common immune disorder, in which the body’s own cells attack the glands responsible for keeping the eye, mouth and other parts of the body moist and lubricated.
LASIK and other Eye Surgery
Dry eye is an extremely common complication of eye surgery such as LASIK, with more than half of patients experiencing dry eyes after the procedure. LASIK causes some nerves in the cornea to be cut, which reduces corneal sensitivity to some degree. In response, your eyes may not sense the need for lubrication, causing your body to produce fewer tears, leading to dry eye syndrome. Dry eyes after LASIK can cause both discomfort and less than optimal visual outcomes, with aqueous tear production reduced and wound healing delayed. The condition usually resolves after a few months; however, in some cases, dry eye symptoms can continue for several months.
Cataract surgery has also been found to exacerbate pre-existing dry eye and to induce dry eye in patients with healthy corneas. As with LASIK and other eye surgeries, postoperative dry eyes can affect visual outcomes and recovery time.
Environmental Factors
Dry eye can be a symptom of chronic inflammation of the conjunctiva, the membrane lining the eyelid and covering the front part of the eye or the lacrimal gland. Chronic conjunctivitis can be caused by exposure to certain irritants such as air pollution, drafts from air conditioning or heating, climate conditions or seasonal allergy.
Air Travel
Low relative humidity conditions such as those experienced in aeroplane cabins can cause an increase in aqueous tear evaporation that intensifies dry eye symptoms. Increases in evaporative rates during air travel are experienced both by people with existing dry eye issues and also by people with no previous history of dry eye syndrome. Duration and frequency of flying increase the likelihood of dry eye syndrome.
Computer-Related (Digital) Eye Strain
The infrequent blinking associated with staring at computers or video screens can lead to dry eye symptoms. The normal blink rate in human eyes is 16 to 22 blinks per minute. Studies have shown that the blink rate decreases to as low as 6 to 8 blinks per minute for persons working on computer screens. Also, the focusing effort required for extended periods of computer work puts strain on the ciliary muscles of the eye, further exacerbating inflammatory issues.
Assessments
There are many aspects to fully assessing whether a patient has dry eye disease, and if so what type of dry eye disease they have. The following are some of the investigations we will perform to help fully understand and manage your dry eye issues.
- Questionnaires
- Tear Break Up Time (TBUT)
- Conjunctival & corneal staining with vital dyes
- Tear film osmolarity
- Infra-red meibography
You can start the process by completing the OSDI questionnaire prior to your consultation.
Treatments
- Eye Drops
- Warm Compress Therapy
- Lid Scrubs
- Nutritional Supplements
Eye Drops (Tear Supplements)
If you have dry eyes, the first thing you probably reach for is a bottle of eye drops. But like so many health products, the sheer variety of eye drops available can be overwhelming. With all the different types out there, does it matter which you choose?
Yes, it definitely does. You use different types of drops to treat different problems, like allergies versus dry eyes. And the wrong ones may make your symptoms worse. Once we’ve assessed your eyes we will be able to recommend specific eye drops to help manage your dry eye issues.
Warm Compress Therapy
Your eyelids contain numerous tiny glands (meibomian glands) which secrete oils into the tear film. These oils help stabilise the tears and prevent them from evaporating too quickly. When these glands become blocked or infected the quality of the tear film suffers. This typically leads to dry eye symptoms (burning, stinging, grittiness, weeping eyes) and/or oily red eyelids margins.
The following procedure is aimed to unblock the meibomian glands and return them to normal health. You should perform this procedure at least once a day. One to two weeks is usually sufficient for mild blockages, a month or two for more severe problems.
Note: Remove contact lenses prior to this procedure.
1. Warm a Bruder or OptiSoothe mask in the microwave for 30 seconds or as directed.
2. Apply the mask for 5 minutes with your eyes closed the entire time.
3. Remove the mask and begin blink exercises to help move the blockages out of the glands, without damaging the delicate tissue. Squeeze your eyelids together without scrunching up the tissue surrounding your eyes. It will look like you’ve just closed your eyes. Hold for 10 seconds, then release. Repeat this 10 times.
Lid Scrubs
1. Wrap a moistened towelette (pre-soaked with lid cleansing solution) around your index finger and gently scrub your eyelid along the lash line. Alternatively, use a Sterile foaming cleanser.
2. Rinse closed eyes with water to remove all residue.
Extra care should be taken to remove any eye make-up before going to bed. The pre-moistened towelettes are particularly good for this.
This regime should be continued for at least 4 weeks. Some people find they need to continue indefinitely to control their symptoms.
Note: If after performing this procedure for a few days your eyes feel worse, stop the procedure and contact our practice.
Nutritional Supplements
Increasingly, research demonstrates the important role nutrition can play in providing systemic support and relief for dry eyes.
Supplements that include omega-3 can improve tear quality and reduce the symptoms of dry eye. These supplements take some time to make a difference and generally need to be used on an ongoing basis. Whilst Omega-3 supplements such as fish oil and flaxseed tablets are available from pharmacies and supermarkets, a range of dry eye-specific products such as Dry Eye Forte & Lacritec are now available. Speak to our optometrists to discuss this further.