The surface of the eye is coated with a film of tears. This film is made of three layers--an oily outer layer, a watery middle layer and an inner layer made of mucus. Abnormalities in any of these layers may deprive the eyes of protection and nourishment and may also cause dry eye. Dry eye is a condition in which the eyes do not produce enough tears or produce tears of poor quality. This condition can be treated with several medicines.
Considerations
Conditions like eyelid inflammation and age--over 50 years old--may cause dry eye. Also, a deficiency in the watery or oily part of the tear film may lead to dry eye. Several other factors, such as exposure to smoke, long-term use of contact lens and certain medications, could also cause dry eye. Drugs for dry eye treatment are selected based on the cause of the condition. The goal of treatment is to address the underlying cause or ensure that tears are present in the eyes.
Types
Several classes of drugs are used to treat dry eye; they include artificial tears, ophthalmic lubricants, antibiotics and anti-inflammatory drugs. Tetracycline, cyclosporine, hydroxypropyl methylcellulose and hydroxypropyl cellulose are all medicines used in dry eye treatment.
How They Work
Cyclosporine is an anti-inflammatory drug. According to the National Eye Institute, it treats dry eye by increasing tear production. Hydroxypropyl methylcellulose in gel form is an ophthalmic lubricant while hydroxypropyl cellulose is a form of artificial tears. They both treat dry eye by keeping the eyes lubricated. Inflammation of the eyelids can cause dry eye when production of oils in the eye is inhibited. This problem can be treated with antibiotics such as tetracycline, which has anti-inflammatory properties and treats dry eye by reducing inflammation in the eyelids.
Side Effects
A side effect of cyclosporine eye drops is a burning sensation that occurs when it is applied to the eye. "Dry Eye: A Practical Guide To Ocular Surface Disorders and Stem Cell Surgery," by Amar Agarwal states that the addition of a corticosteroid medication to dry eye treatment with cyclosporine may reduce this effect. Artificial tears that have preservatives may irritate the eyes. Also, a number of dry eye patients may have allergic reactions to some artificial tears.
Recommendations
The American Optometric Association recommends the use of artificial tears that are additive-free in dry eye treatment. This could prevent eye irritation. Also, the National Eye Institute suggests that evaporation of tears could be prevented by wearing glasses that fit closely around the eyes, as well as staying in humid environments.
References
- Mayo Clinic: Dry Eye- Treatments and Drugs
- "The Aging Eye"; Sandra Gordon, Harvard Medical School; 2001.
- "Dry Eye: A Practical Guide To Ocular Surface Disorders and Stem Cell Surgery"; Amar Agarwal; 2006.
- American Optometric Association: Dry Eye
- National Eye Institute: Facts About Dry Eye
