Detrimental effect of preservatives in eyedrops: implications for the treatment of glaucoma

Acta Ophthalmol. 2008 Nov;86(7):716-26. doi: 10.1111/j.1755-3768.2008.01250.x. Epub 2008 Jun 3.


Antiglaucoma medications are often associated with ocular adverse reactions such as dry eye, and burning or stinging sensations. These undesirable effects may lead to treatment discontinuation and reduced quality of life in patients with glaucoma. Antiglaucoma medications usually contain benzalkonium chloride (BAK) as a preservative. Animal studies, in vitro studies and in vivo experiments have demonstrated various adverse effects of BAK. Clinical studies have also shown an increased incidence of adverse events with BAK and have demonstrated that the withdrawal of preservatives reduces these effects. Collectively, these data suggest that preservative-free antiglaucoma treatments have clinically relevant benefits for patients.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Benzalkonium Compounds / administration & dosage
  • Benzalkonium Compounds / adverse effects*
  • Eye / drug effects*
  • Glaucoma / drug therapy*
  • Glaucoma / physiopathology
  • Humans
  • Ophthalmic Solutions / adverse effects*
  • Ophthalmic Solutions / chemistry*
  • Ophthalmic Solutions / therapeutic use
  • Patient Compliance
  • Preservatives, Pharmaceutical / adverse effects*
  • Quality of Life


  • Benzalkonium Compounds
  • Ophthalmic Solutions
  • Preservatives, Pharmaceutical