Artificial tears

Artificial tears are lubricant eye drops used to treat the dryness and irritation associated with deficient tear production in keratoconjunctivitis sicca (dry eyes).cite web
url = http://www.emedicine.com/oph/topic695.htm
title = Keratoconjunctivitis, Sicca
accessdate = 2006-11-12
date = 2006-04-21
work = eMedicine
publisher = WebMD, Inc.] They are also used to moisten contact lenses and in eye examinations.

Artificial tears are available over-the-counter. Artificial tears are supplemented with other treatments in moderate to severe forms of dry eyes.

Chemistry

Preparations contain carboxymethyl cellulose, hydroxypropyl methylcellulose (a.k.a. HPMC or hypromellose), and hydroxypropyl cellulose. They contain water, salts and polymers but lack the proteins found in natural tears. Patients who use them more frequently than once every three hours should choose a brand without preservatives or one with special non-irritating preservatives.

Effects

Application of artificial tears every few hourscite web
url = http://www.merck.com/mmhe/sec20/ch230/ch230d.html
title = Keratoconjunctivitis Sicca
accessdate = 2006-11-12
date = 2003-02-01
work = The Merck Manual, Home Edition
publisher = Merck & Co., Inc.] can provide temporary relief from the symptoms of dry eyes.Hydroxypropyl cellulose stabilizes and thickens the precorneal tear film, and prolongs the tear film breakup time.

Usage

Artificial tears usually are the first line of treatment for dry eyes. While mild cases require application of lubricant drops four times a day, severe cases require more aggressive treatment, such as ten to twelve times a day. Thicker artificial tears can be used in severe cases, although these may temporarily blur vision.

An artificial tear insert such as Lacrisert which contains hydroxypropyl cellulose can also be used every morning.

Precautions

Drops for red eyes can make the eyes even drier.cite web
url = http://www.fda.gov/fdac/features/2005/305_eye.html
title = Dealing with Dry Eye
accessdate = 2006-11-16
author = Michelle Meadows
last = Meadows
first = Michelle
year = 2005
month = May-June
work = [http://www.fda.gov/fdac/ FDA Consumer Magazine]
publisher = U.S. Food and Drug Administration] If wearing contact lenses, rewetting or lubricating drops specifically for contact lenses should be used. Other types of drops may contain ingredients that damage the lens.

Adverse effects, interactions and contraindications

Possible adverse effects of carboxymethyl cellulose and other similar lubricants include eye pain, irritation, continued redness, or vision changes. Use should be discontinued if any of them occur. Those of hydroxypropyl cellulose include hyperaemia, photophobia, stickiness of eyelashes, discomfort, and irritation. Long term use of preservatives present in some artificial tears may harm the eye.Fact|date=June 2007

Artificial tears have no reported interactions. A documented contraindication of artificial tears is hypersensitivity.

Veterinary uses

Artificial tears are a part of the topical therapy for keratoconjunctivitis sicca for animals such as dogs, cats and horses.cite web
url = http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/30107.htm
title = Keratoconjunctivitis, Sicca
accessdate = 2006-11-18
work = The Merck Veterinary Manual
publisher = Merck & Co., Inc.]

External links

* [http://preservative.free.fr/English/indexen.htm Use of preservatives in artificial tears]

References