Dry eyes occur when your tears aren't able to provide adequate moisture for your eyes. Tears can be inadequate for many reasons. For example, dry eyes may occur if you don't produce enough tears or if you produce poor-quality tears.
Dry eye is caused by insufficient natural tear production by a variety of lacrimal glands present around the eyes. The tear layer protecting the front surface of the eye is constituted from 3 different fluid layers. It has a number of functions, including optical, anti-bacterial, lubricating and wetting properties.
| • A stinging, burning or scratchy sensation in your eyes. |
| • Stringy mucus in or around your eyes. |
| • Increased eye irritation from smoke or wind. |
| • Eye fatigue |
| • Sensitivity to light. |
| • Eye redness. |
| • A sensation of having something in your eyes. |
| • Difficulty wearing contact lenses |
| • Periods of excessive tearing. |
| • Blurred vision, often worsening at the end of the day or after focusing for a prolonged period. |
These symptoms are common and are present because you are most likely exposed to a climate that is hot and dry, an air conditioned environment, air pollution or windy and dusty conditions. Smoke and contact lens wear may also contribute to the discomfort of dry eyes.
What are the risk factors for dry eye syndrome?| • Are older than 50 |
| • Are a postmenopausal woman |
| • Have a medical condition that reduces your tear production such as diabetes, rheumatoid arthritis, lupus, scleroderma, Sjogren's syndrome, thyroid disorders, vitamin A deficiency, hepatitis C infection, HIV infection, sarcoidosis, and androgen or oestrogen deficiency. |
| • Have had laser eye surgery. Refractive eye surgeries such as laser-assisted in-situ keratomileusis (LASIK) may cause decreased tear production and dry eyes. Symptoms of dry eyes related to these procedures are usually temporary. |
| • Have tear gland damage. Damage to the tear glands from inflammation or radiation can hamper tear production. |
Blinking spreads a continuous thin film of tears across the surface of your eyes. If you have an eyelid problem that makes it difficult to blink, tears may not be spread across your eye adequately or your tears may evaporate too quickly, causing dry eyes. Eyelid problems can include an out-turning of the lids (ectropion) or an in-turning of the lids (entropion).
4. Medications that cause dry eyes| • Some drugs used to treat high blood pressure |
| • Antihistamines and decongestants |
| • Hormone replacement therapy |
| • Certain antidepressants |
| • Isotretinoin-type drugs for treatment of acne |
| • Wind |
| • Dry air |
| • Tasks that require enough concentration that you blink less often, such as working at a computer, driving or reading |
TREATMENT OPTIONS
ARTIFICIAL TEAR SUPPLEMENTATION
A variety of tear supplementations are available on the market. These range from preparations that have a watery constitute to more viscous substances. These medications may be presented in a multidose bottle, implicating that a preservative has to be added to the substance, or it may be packed as small single dose vials, which are unpreserved. From a clinical standpoint, the use of single dose vials hold preference over the multidose packages, as the unwanted effect of preservatives are negated, and the chances for causing an eye infection through the use of a contaminated bottle is limited.
Recently, the use of omega 3 oils have gained popularity in the treatment of dry eye. These supplements may also be used with great benefit.
PUNCTAL OCCLUSION
This may either be done as a semi-permanent procedure via the use of artificial punctal plugs, or it may be done by permanent surgical closure of the puncta.
The puncta are the minute orifices of the tear drainage system to the nose, and are located on the nasal aspect of the upper and lower eyelid margins. The function of the punctum in the normal state is to collect and drain excess amounts of tears into the nose via the lacrimal drainage system. In some cases this mechanism is too efficient, leading to a dry eye.
A punctum plug is a tiny device made of thermodynamic hydrophobic acrylic material which is placed into the punctum. This prevents the tears from draining into the nose, with the result that the eyes are kept moist. Patients are routinely fitted with a temporary collagen dissolvable punctum plug in each punctum for a trial period of 3 to 5 days before permanent plugs are inserted. This trial period enables the patient to determine whether the proposed occlusion will yield the desired effect. It is also done to ensure that no excessive tearing will occur, with tears spilling over the eyelids, once the semi-permanent punctum plugs are inserted.
For patients who have worn punctal plugs successfully over an extended period of time, the option of permanent surgical closure may also be considered.
AUTOLOGOUS SERUM
In extremely resistant and difficult cases, the use of autologous serum is advocated. These eye drops are prepared on special request. Blood is donated by the individual, from which eye drops are manufactured containing natural proteins and antibodies unique to the specific patient. These specially prepared eye drops are to be kept in the freezer at home. A supply that lasts for approximately 6 months is usually provided from each donation.
PROTECTIVE EYE WEAR
Special protective goggles and 'bandage' contact lenses may also be used in extreme cases to restrict the evaporation of tears from the eyes.
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