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).[1] 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.

Contents

Chemistry

Preparations contain carboxymethyl cellulose,[1][2] hydroxypropyl methylcellulose[2] (a.k.a. HPMC or hypromellose), and hydroxypropyl cellulose.[1] 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[1] should choose a brand without preservatives[1] or one with special non-irritating preservatives.

Effects

Application of artificial tears every few hours[3] 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.[1]

Usage

Artificial tears usually are the first line of treatment for dry eyes.[2] 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.[1] Thicker artificial tears can be used in severe cases, although these may temporarily blur vision.[1]

Precautions

Drops for red eyes can make the eyes even drier.[2] If wearing contact lenses, rewetting or lubricating drops specifically for contact lenses should be used.[2] Other types of drops may contain ingredients that damage the lens.[2]

Adverse effects, interactions and contraindications

Possible adverse effects of carboxymethyl cellulose and other similar lubricants include eye pain, irritation, continued redness, or vision changes.[1] Use should be discontinued if any of them occur.[1] Those of hydroxypropyl cellulose include hyperaemia, photophobia, stickiness of eyelashes, discomfort, and irritation.[1] Long term use of preservatives present in some artificial tears may harm the eye.

Artificial tears have no reported interactions.[1] A documented contraindication of artificial tears is hypersensitivity.[1]

Veterinary uses

Artificial tears are a part of the topical therapy for keratoconjunctivitis sicca for animals such as dogs, cats and horses.[4]

External links

References

  1. ^ a b c d e f g h i j k l m "Keratoconjunctivitis, Sicca". eMedicine. WebMD, Inc.. 2006-04-21. http://www.emedicine.com/oph/topic695.htm. Retrieved 2006-11-12. 
  2. ^ a b c d e f Meadows, Michelle (May-June 2005). "Dealing with Dry Eye". FDA Consumer Magazine. U.S. Food and Drug Administration. http://web.archive.org/web/20090120142920/http://www.fda.gov/fdac/features/2005/305_eye.html. Retrieved 2011-11-22. 
  3. ^ "Keratoconjunctivitis Sicca". The Merck Manual, Home Health Handbook. Merck & Co., Inc.. 2003-02-01. http://www.merckmanuals.com/home/eye_disorders/corneal_disorders/keratoconjunctivitis_sicca.html. Retrieved 2006-11-12. 
  4. ^ "Keratoconjunctivitis, Sicca". The Merck Veterinary Manual. Merck & Co., Inc.. http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/30107.htm. Retrieved 2006-11-18.