Dry Eye Syndrome

Description

Dry eye is a common condition that occurs when your tears are not able to produce adequate lubrication for your eyes. This can be for a number of reasons including; an individual might simply not produce enough tears, or the tears produced are of poor quality. Individuals with dry eyes describe feeling uncomfortable and eyes may sting or burn, in extreme circumstances significant inflammation and even scarring of the front of the can occur. Some individuals only experience dry eyes in certain situations such as in an air-conditioned room, on a plane, or following several hours of looking at a screen.

Symptoms

The symptoms of dry eyes can vary from person to person but are usually found to affect both eyes. These may include;
  • A burning, stinging or scratching sensation in your eyes.
  • Presence of string-like mucous in or around the eye
  • Sensitivity to light
  • Eye redness
  • A sensation of having something in your eye
  • Difficulty wearing contact lenses
  • Difficulty with driving at night
  • Blurred vision or eye fatigue
As a way to compensate for dry eyes, some people may also experience watery eyes. It is recommended that you see your eye doctor is symptoms of dry eye such as prolonged irritation, redness or painful eyes persist.

Causes

Dry eyes are caused by a lack of adequate tears, either due to poor quality of tears produced or poor quantity of tears produced. Tears are a mixture of water, oils and mucous that are required to lubricate and protect the eye. A problem with any of the sources for each component can result in tear instability and dry eyes. The medical terms dry eye are keratitis sicca, keratoconjunctivitis sicca, and dysfunctional tear syndrome. Common causes of decreased tear production are;
  • Ageing
  • Certain medical conditions including diabetes, rheumatoid arthritis, lupus, Sjogren’s syndrome, thyroid disorders and vitamin A deficiency.
  • Certain medications can also cause decreased tear production such as antihistamines, decongestants, hormone replacement therapies, antidepressants, and drugs required for high blood pressure or acne.
  • Laser eye surgery, however dry eyes related to this procedure are usually temporary
  • Tear gland damage caused by inflammation or radiation
There are different categories of dry eyes, depending on which component is affected. For example, meibomian glands, small glands on the edge of the eyelid, are responsible for tear oil production. If these glands don’t produce or release enough oil, the tear film can evaporate too quickly- a condition called “evaporative dry eye”. The condition, meibomian gland dysfunction, is currently recognised as a significant factor in many cases of dry eye. In other instances, the primary cause of dry eye is a failure of the lacrimal glands (tear glands) to produce enough water-like fluid to keep eyes moisturised. This condition is called “aqueous deficiency dry eye”. The specific cause of dry eye will determine the type of treatment your eye doctor recommends to provide relief from dry eye symptoms. There are a number of risk factors associated with development of dry eyes which are outlined below;
  • Being older than 50. Tear production naturally decreases as you get older
  • Females are more likely to develop dry eyes than males. This is especially true if they experience hormonal changes due to pregnancy, use of birth control pills or menopause.
  • Eating a diet that is low in vitamin A or low in omega-3 fatty acids increases individuals chances of developing dry eyes
  • Contact lens wearers are also at a higher risk of developing dry eye following long periods of wearing lenses.

Diagnosis

Chronic dry eye syndrome is best diagnosed by having your doctor perform more than one dry eye examination during an eye test. Symptoms can vary from person to person in number and severity. Tests you may have include; The Schirmer test: This involves your eye doctor assessing tear production through measuring absorbance of tears on to filter paper. If the paper takes longer than average to soak up tears it might be due to reduced tear production. Epithelial staining: This process involves the use of special eye drops that contain a dye which enables your eye doctor to observe the rate of tear film evaporation as well as assess whether there is any damage on the surface of the eye. The dye binds to damaged cells on the eye and it can also be useful in identifying areas of the eye that do not have a protective oil layer. Meibomian gland evaluation: Doctors can evaluate oil production by pressing on the meibomian glands, located on around the edge of the eyelid, and assessing whether oil is produced. The eye doctor will ask about a person’s medical history, including any family history of eye conditions. Individuals will receive a clinical eye examination where they may be asked to read letters off a chart (Snellen chart). They may also check intraocular pressure and examine visual field and visual acuity.

Treatment

Unfortunately there is no cure for this condition however there are a number treatments available for chronic dry eye syndrome. In the majority of cases, routine use of artificial tears and changes in behaviour (for example, taking breaks during long periods of computer use), can significantly reduce dry eye symptoms. If symptoms are persistent and more serious other avenues might be explored. The type of treatment you receive will be subject to specific dry eye diagnoses, i.e, what it is exactly that is causing your dry eyes. Underlying conditions might be responsible for some cases of dry eye. In this instance, treatment of the underlying condition such as cessation or changing of medications that may be causing dry eye. Examples of treatment options for meibomian gland dysfunction include administration of antibiotics to reduce eyelid inflammation, or manual unblocking or the glands using a warm compress. General eye check-ups are important for people living with dry eyes, as these individuals may still be at risk of developing other kinds of eye problems that affect the general population, some of which may be treatable. No matter what level of vision a person may have, it is important to look after the eyes. To find out more about what can be done to take care of the eyes on a daily basis, please visit our Tips for Good Eye Health. For further information, please contact the Research Department on 01 6789004 or email research@fightingblindness.ie.

Research

Researchers continue to actively search for novel ways to treat chronic dry eye syndrome. There are clinical trials on-going which are examining enzyme-based treatments for severe dry eye syndrome. Current eye drops do not contain the enzyme DNase. Current trials in phase II are evaluating the addition of DNase to conventional eye drops with the aim to reduce discomfort of users. A clinical trial is also underway which investigates a new type of eye drop containing antibodies. These antibodies aim to target foreign items on the eye surface and aid their destruction. Another clinical trial is examining the benefits of hyaluronic acid (salt-like solution) in the form of an eye drop for the treatment of the condition. This clinical trial is at an advanced stage of examination and completion is expected in 2020. There are multiple new treatment approaches being investigated in clinical trials for dry eye syndrome also. One approach involves the use of a laser acupuncture treatment used frequently over a 12 week treatment period for the relief of dry eye. Another option under investigation involves the use of a device to apply a small electrical current through the nasal cavity to stimulate the natural development of tears. Information about clinical trials that are on-going and completed can be found on the clinical trials website and can be searched by both condition and location.

Support

Receiving a diagnosis can be overwhelming for anyone, but this is not a journey that you have to make alone. There are many groups and resources available to provide support for people living with Stargardt Disease. Fighting Blindness offers a free and confidential counselling service (Insight Counselling). For further information please contact insight@fightingblindness.ie or call 01 6746496. We also offer support groups for people with a visual impairment to share their feelings and experiences with others facing the same challenges. Please consult the support groups section of our website here to access the latest timings and days for the various support groups we offer. For further information please contact insightgroups@fightingblindness.ie or call 01 6746496.

Resources

Féach provides support for parents of children living with sight loss in Ireland. ChildVision is the national education centre for children with sight loss in Ireland. Vision Ireland, formerly NCBI (National Council for the Blind in Ireland) provides support and services for people living with sight loss in Ireland. Irish Guide Dogs for the blind helps individuals and their families to achieve improved mobility and independence.