Artificial tears

File:Eye drop.jpg

Although artificial tears are used to mimic or supplement the roles of the tear film and contain water, electrolytes, and certain polymers, they do not contain the biologically active components found in naturally-produced tears.{{Cite journal|last1=Dogru|first1=Murat|last2=Tsubota|first2=Kazuo|date=2011-01-10|title=Pharmacotherapy of dry eye|journal=Expert Opinion on Pharmacotherapy|volume=12|issue=3|pages=325–334|doi=10.1517/14656566.2010.518612|pmid=21214414|s2cid=25217717 |issn=1465-6566}} Moreover, artificial tears often contain chemicals that are not present in naturally-produced tears. Preparations can contain carboxymethyl cellulose,{{cite journal|vauthors=Moshirfar M, Pierson K, Hanamaikai K, Santiago-Caban L, Muthappan V, Passi SF|title=Artificial tears potpourri: a literature review|journal=Clin Ophthalmol|date=July 2014|volume=8|pages=1419–33|pmid=25114502|pmc=4124072|doi=10.2147/OPTH.S65263 |doi-access=free }} polyvinyl alcohol, hydroxypropyl methylcellulose (a.k.a. HPMC or hypromellose), hydroxypropyl cellulose and hyaluronic acid (a.k.a. hyaluronan, HA).{{cite journal|vauthors=Troiano P, Monaco G|title=Effect of hypotonic 0.4% hyaluronic acid drops in dry eye patients: a cross-over study.|journal=Cornea|date=27 December 2008|volume=27|pages=1126–30|pmid=19034126|doi=10.1097/ICO.0b013e318180e55c|issue=10|s2cid=41027463 }}

Preparations can also contain preservatives in order to prolong usage and avoid bacterial contamination. Preservatives include benzalkonium chloride (BAK), ethylenediaminetetraacetic acid (EDTA), purite, chlorobutanol,{{Cite journal|last1=Ribeiro|first1=Marina Viegas Moura Rezende|last2=Barbosa|first2=Fabiano Timbó|last3=Ribeiro|first3=Luiz Eduardo Feliciano|last4=Sousa-Rodrigues|first4=Célio Fernando de|last5=Ribeiro|first5=Eurica Adélia Nogueira|date=2019|title=Effectiveness of using preservative-free artificial tears versus preserved lubricants for the treatment of dry eyes: a systematic review|journal=Arquivos Brasileiros de Oftalmologia|volume=82|issue=5|pages=436–445 |doi=10.5935/0004-2749.20190097|pmid=31508669|issn=0004-2749|doi-access=free}} sodium perborate, thiomersal, disodium edetate, and oxychloro complex (SOC). Preservatives can be toxic and cause damage to the corneal epithelium. For instance, high concentrations of benzalkonium chloride (BAK) can cause cytotoxicity, cause cell lysis, and reduce tear and mucin production. Patients should limit their use of artificial tears with preservatives to less than four to six times a day. If artificial tears need to be utilized more than four to six times a day, a preservative-free formulation should be used.

Preservative-free artificial formulations are indicated for patients who cannot tolerate artificial tear formulations with preservatives, patients who are using artificial tears more than four to six times a day, and patients who are using multiple topical eye drops with preservatives. Preservative-free eye drops are found in single vials. However, single unit-dose artificial tears without preservatives are more expensive than bottled artificial tears with preservatives.

Some patients confuse over the counter drops that contain tetrahydrozoline (i.e. Visine®), a vasoconstrictor, with artificial tears.{{Cite journal|last=Soparkar|first=Charles N. S.|date=1997-01-01|title=Acute and Chronic Conjunctivitis Due to Over-the-counter Ophthalmic Decongestants|journal=Archives of Ophthalmology|volume=115|issue=1|pages=34–8|doi=10.1001/archopht.1997.01100150036004|pmid=9006422|issn=0003-9950}} Desensitization can occur with extended usage of drops containing tetrahydrozoline.

The most common indication for artificial tear use is dry eyes.

{{cite journal|url=https://www.fda.gov/fdac/features/2005/305_eye.html|title=Dealing with Dry Eye|last=Meadows|first=Michelle|volume=39|issue=3|pages=8–9|date=May–June 2005|journal=FDA Consumer|publisher=U.S. Food and Drug Administration|url-status=dead|archiveurl=https://web.archive.org/web/20090120142920/https://www.fda.gov/fdac/features/2005/305_eye.html|archivedate=January 20, 2009|accessdate=14 May 2016|pmid=16127813}}

Risk factors for developing dry eyes includes increasing age, female gender, environments with low moisture, nutritional deficiencies, certain medications, and autoimmune conditions.{{Cite web|url=https://insights.ovid.com/ShowUpgradeBrowserMessage|title=Dry Eye Disease: Prevalence, Assessment, and Management|last=|first=|date=|website=insights.ovid.com|url-status=live|archive-url=https://web.archive.org/web/20200114153534/https://insights.ovid.com/ShowUpgradeBrowserMessage |archive-date=2020-01-14 |access-date=2020-01-16}} Examples autoimmune conditions are Sjogren's syndrome, autoimmune thyroid disease, and uveitis.{{Cite journal|last1=Hessen|first1=Michelle|last2=Akpek|first2=Esen Karamursel|date=April 2014|title=Dry Eye: an Inflammatory Ocular Disease|journal=Journal of Ophthalmic & Vision Research|volume=9|issue=2|pages=240–250|issn=2008-2010|pmc=4181208|pmid=25279127}} Patients with dry eyes may have an inability to produce adequate amount or quality of tears leading to a disruption in their tear film.{{Cite journal|last1=Moshirfar|first1=Majid|last2=Pierson|first2=Kasey|last3=Hanamaikai|first3=Kamalani|last4=Santiago-Caban|first4=Luis|last5=Muthappan|first5=Valliammai|last6=Passi|first6=Samuel F|date=2014-07-31|title=Artificial tears potpourri: a literature review|journal=Clinical Ophthalmology|volume=8|pages=1419–1433|doi=10.2147/OPTH.S65263|issn=1177-5467|pmc=4124072|pmid=25114502 |doi-access=free }} In addition, those who wear contact lenses or have undergone eye surgeries such as LASIK are at increased risk of having dry eyes. Normal tears are important to keep the surface of eyes clean and moist and protect eyes from infections. They are composed of many components including enzymes that act as natural antibiotics, proteins that prevent bacterial growth, and nutrients.{{Cite web|url=https://www.aao.org/eye-health/tips-prevention/facts-about-tears|title=Facts About Tears|date=2016-12-21|website=American Academy of Ophthalmology|language=en|access-date=2020-01-23}} Without adequate lubrication, patients are at risk for infection as well as irreversible scarring and damage. Artificial tears are the recognized treatment of choice for this problem.

Artificial tears work by adding similar lubricating elements that natural tears contain. This helps thicken and stabilize the pre-corneal tear film, prolonging tear film breakup time, and allowing for tears to properly protect the surface of the eyes.{{Cite web|url=https://www.aao.org/eye-health/treatments/lubricating-eye-drops|title=Lubricating Eye Drops|date=2018-08-15|website=American Academy of Ophthalmology|language=en|access-date=2020-01-22}} Most artificial tears do not require a prescription and can be used as often as needed. Patients who use artificial tears more frequently than four to six times a day should choose a brand without preservatives or one with non-irritating preservatives.{{Cite web|url=https://www.aao.org/eye-health/diseases/dry-eye-treatment|title=Dry Eye Diagnosis and Treatment|date=2019-08-23|website=American Academy of Ophthalmology|language=en|access-date=2020-01-21}} Thicker artificial tears that come in the form of gel or ointments may be used in more severe cases as they last longer, although they may temporarily blur vision. In more severe cases, providers may prescribe a form of artificial tears that works to reduce inflammation in the tear glands in an effort to improve natural tear production and the quality of tears produced.{{Cite web|url=https://www.aao.org/headline/multi-dose-restasis-approved|title=Multi-dose Restasis approved|date=2016-10-31|website=American Academy of Ophthalmology|language=en|access-date=2020-01-23}}

Artificial tears have no reported interactions. The most common side effect of artificial tears is temporary blurry vision. Allergic reactions have been reported and are associated with itchy or swollen eyes, dizziness, and breathing problems. These symptoms warrant discontinuation of the drops and to see a physician immediately. Prescription drops may have additional side effects such as burning, redness, pain, and a foreign body sensation.

For contact lens users, specific drops should be used to avoid ingredients that can damage the contact lens. If using multiple types of eye drops, it is important to wait a few minutes in between application of each to avoid rinsing out the prior drop.{{Cite web|url=https://www.glaucoma.org/treatment/eyedrop-tips.php|title=Eye Drop Tips|website=Glaucoma Research Foundation|access-date=2020-01-23}} Proper technique should be conducted to avoid contaminating the bottle. Washing hands prior to use and avoiding contact between the bottle and eyes can prevent infections.

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.

| archive-url = https://web.archive.org/web/20070316002418/http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm%2Fbc%2F30107.htm

| archive-date = 2007-03-16

| url-status = dead

}} Similarly to human use, proper care should be performed to avoid contamination of the bottle.{{Cite web|url=https://www.petplace.com/article/drug-library/drug-library/library/artificial-tear-solutions-for-dogs-and-cats/|title=Artificial Tear Solutions for Dogs and Cats|website=www.petplace.com|language=en|access-date=2020-01-23}} A veterinarian should be contacted if any signs of allergy, irritation, or pain develop due to the usage of artificial tears.

A 2016 Cochrane Review seeking to compare the effectiveness of various over the counter artificial tears in treating dry eye. While the review stated that it is unclear which artificial tear formulation works best, two trials found that 0.2% polyacrylic acid-based tears were more effective in treating dry eye symptoms over 1.4% polyvinyl alcohol-based tears.{{cite journal |vauthors=Pucker AD, Ng SM, Nichols JJ |title= Over the counter (OTC) artificial tear drops for dry eye syndrome |journal=Cochrane Database Syst Rev|volume=2016 |pages= CD009729 |date=2016 |issue= 2 |pmid= 26905373 |doi= 10.1002/14651858.CD009729.pub2 |pmc=5045033}}

{{Main|2022-2023 United States P. aeruginosa outbreak in eye drops}}

On February 2, 2023, Global Pharma Healthcare issued a recall on artificial tears eye drops distributed by EzriCare and Delsam Pharma after reports of bacterial contamination. A multi-state cluster of Verona Integron-mediated Metallo-β-lactamase (VIM)- and Guiana-Extended Spectrum-β-Lactamase (GES)- producing carbapenem-resistant Pseudomonas aeruginosa (VIM-GES-CRPA) infections from the contaminated eye drops has led to reports of eye infections, permanent loss of vision, and one death.{{cite web |url=https://www.fda.gov/safety/recalls-market-withdrawals-safety-alerts/global-pharma-healthcare-issues-voluntary-nationwide-recall-artificial-tears-lubricant-eye-drops-due |archive-url=https://web.archive.org/web/20230203043945/https://www.fda.gov/safety/recalls-market-withdrawals-safety-alerts/global-pharma-healthcare-issues-voluntary-nationwide-recall-artificial-tears-lubricant-eye-drops-due |url-status=dead |archive-date=February 3, 2023 |title=Global Pharma Healthcare Issues Voluntary Nationwide Recall of Artificial Tears Lubricant Eye Drops Due to Possible Contamination |publisher=Food and Drug Administration |date=February 2, 2023 |access-date=February 13, 2023}}{{cite web |url=https://www.npr.org/2023/02/03/1154088634/ezricare-artificial-tears-recall-bacteria-cdc |title=Manufacturer recalls eye drops after possible link to bacterial infections |first=Ayana |last=Archie |publisher=NPR |date=February 3, 2023 |access-date=February 13, 2023}}{{cite magazine |url=https://www.consumerreports.org/health/vision-eye-care/eye-drops-recalled-due-to-potential-bacterial-contamination-a1081889113/ |title=Eye Drops Recalled Due to Potential Bacterial Contamination |first=Catherine |last=Roberts |magazine=Consumer Reports |date=February 3, 2023 |access-date=February 13, 2023}}

• Sjögren's syndrome

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

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