What is Dry eye syndrome?
Dry eyes or dry eye syndrome is a common eye condition, caused by low production or low quality of tears. Tears are continuously produced by lacrimal gland and accessory glands in the eyes. Tears help keep the cornea moist and wash away debris and irritants. Tears also contain anti-bacterial substances to prevent infections. Some eye or health conditions and environmental factors affect the production or quality of tears leading to dry eye syndrome. When you have dry eyes, you start to have dry eye symptoms such as burning eyes, tearing or watering, sensation of foreign object in the eye, sharp pain, redness etc. Dry eye symptoms can also be severe that untreated chronic dry eyes can cause keratitis, redness and blurred vision.
What causes dry eyes?
The production or the quality of tear film diminishes with the increased age.
2. Environmental factors
Exposure to low humidity, smoke and wind can cause dry eyes.
Medicines that are used to treat glaucoma, allergy, high blood pressure etc. can also cause dry eyes.
4. Health conditions
Dry eye syndrome is also caused by certain health conditions such as Diabetes, Rheumatoid arthritis, Parkinson’s disease, Rosacea, Sjogren’s syndrome, Thyroid disease, Lupus etc.
5. Eye conditions
Impaired eye lids in patients with Bell’s palsy, exposure keratitis, ectropion, Pterygium, Lagophthalmos etc. and disorders of the surface of the cornea can also affect the stability of tear film.
6. Previous eye surgeries
7. Hormonal changes
Hormonal changes from menopause can also cause dry eyes.
8. Activities that reduce blinking
Looking at a computer screen for a long time and other activities that reduce blinking.
Symptoms of dry eyes?
-Burning and scratchy
-Redness (Pink eye)
How is dry eye diagnosed?
Dry eye is diagnosed during a comprehensive eye exam. Your eye doctor performs tests such as tear film break-up time (TBUT), schirmer’s test, fluorescein, rose bengal and lissamine green test, corneal topography etc. to evaluate the quality of tear film and how your eyes are producing it.
What is tear film?
Tear film is produced by lacrimal gland and other accessory glands on the conjunctiva and eyelids. It has three layers.
This is the inner most layer of the tear film. Mucin is produced on the conjunctiva. It helps spread tears over the cornea to make the surface smooth for clear vision. The deficiency of this layer is seen in Stevens-Johnson syndrome, chemical burns, radiations.
Aqueous or watery layer
This is the middle layer which makes up most of the tear film. This watery layer is produced by lacrimal gland and eye lid glands. The main function of this layer is to protect the surface of the eyes from foreign objects, dusts, smoke etc. Aqueous layer deficiency is also known as Keratoconjunctivitis sicca. The deficiency of this layer is caused by Sjorgren’s syndrome, congenital alacrimia, paralytic hyposecretion etc.
Lipid or oily layer
This is the outer most layer of the tear film, which is produced by meibomian glands. This layer protects tears from evaporation and drying up too quickly. Inflammation of the eyelids decrease the production of this layer.
Prevention and treatment of dry eyes
Over-the-counter artificial tears
If you are diagnosed with dry eyes, your eye doctor may recommend over-the-counter lubricating eye drops as one of the choices for dry eye treatment. You can find several brands of artificial tears. Some are in gel forms and some in liquid. Preservative-free artificial tears are also available and is a good option if you have chronic dry eyes.
Prescription eye drops
You may choose prescription eye drop such as Restasis. Instead of just relieving dry eye symptoms, it actually helps produce natural tears in the eyes. When you use Restasis, you can not see its result immediately and should wait a few months to experience the full benefit.
Preserving existing tears
You can also reduce dry eye symptoms by preserving tears which your eyes have produced. Evaporation of tears can be prevented by using sunglasses or being less exposed to dry heat and smoky environment. If you have severe dry eyes, your eye doctor may also recommend punctal occlusion (blocking the tear ducts) to decrease drainage of tear film. Punctal plugs are commonly used medical devices and used to block drainage of tears. You might also chose surgical method or laser or electrocauterization as an option to preserve tears.
Dry eye complications:
Untreated chronic dry eye condition can cause damage to the eyes. It can cause inflammation on the cornea and conjunctiva. Depending on the severity, it can be mild or severe. Severe complications can be corneal ulcer, scarring on the cornea, pain, light sensitivity, decreased vision etc.