Artificial tears

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A subset of various brands of artificial tears displayed in a store

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.

Chemistry[edit]

Preparations contain carboxymethyl cellulose,[1][2] hydroxypropyl methylcellulose[2] (a.k.a. HPMC or hypromellose), hydroxypropyl cellulose[1] and hyaluronic acid (a.k.a. hyaluronan, HA)[3] 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 non-irritating preservatives.

Effects[edit]

Application of artificial tears every few hours[4] 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[edit]

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[edit]

Drops for red eyes can make the eyes 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 contact lenses.[2]

Adverse effects, interactions and contraindications[edit]

Possible adverse effects of carboxymethyl cellulose and similar lubricants include eye pain, irritation, continued redness, and vision changes.[1] Use should be discontinued if any of them occur.[1] Side effects 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.[citation needed]

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

Veterinary uses[edit]

Artificial tears are a part of the topical therapy for keratoconjunctivitis sicca for animals such as dogs, cats and horses.[5]

References[edit]

  1. ^ a b c d e f g h i j k l m "Keratoconjunctivitis, Sicca". eMedicine. WebMD, Inc. 2006-04-21. Archived from the original on 16 October 2006. 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. Retrieved 2011-11-22. 
  3. ^ Troiano, P; Monaco G (27 December 2008). "Effect of hypotonic 0.4% hyaluronic acid drops in dry eye patients: a cross-over study.". Cornea 10 (10): 1126–30. doi:10.1097/ICO.0b013e318180e55c. PMID 19034126. 
  4. ^ "Keratoconjunctivitis Sicca". The Merck Manual, Home Health Handbook. Merck & Co., Inc. 2003-02-01. Retrieved 2006-11-12. 
  5. ^ "Keratoconjunctivitis, Sicca". The Merck Veterinary Manual. Merck & Co., Inc. Retrieved 2006-11-18. 

External links[edit]