Benzalkonium chloride induces anterior chamber inflammation in previously untreated patients with ocular hypertension as measured by flare meter: a randomized clinical trial

Abstract

ABSTRACT.Purpose: The deleterious effects of benzalkonium chloride (BAK) on the ocular surface are well known. However, few clinical data are available to prove a toxic effect at the level of the anterior chamber. The laser flare meter is a reliable tool to detect low levels of inflammation in the anterior chamber. We wanted to know whether instillation of BAK-preserved timolol in one eye would result in higher laser flare values than the instillation of preservativefree timolol in the fellow eye. Methods: Randomized prospective, single-masked clinical trial. Twenty-eight untreated patients with ocular hypertension were recruited. After obtaining baseline flare values, we randomly assigned one eye to BAK-preserved timolol and the fellow eye to preservative-free timolol. After 1 month, flare measurements were repeated. Results: There was a significant increase in the flare values in the two treatment regimens, but the increase in the BAK-treated eyes was higher than in the preservative-free treated eyes, and this difference in increase was statistically significant. Conclusion: This is the first study to show that short-term BAK administration produces inflammation in the anterior segment of previously untreated patients whose blood-aqueous barrier was not affected by recent intraocular surgery.

Effects of SofZia‐preserved travoprost and benzalkonium chloride‐preserved latanoprost on the ocular surface – a multicentre randomized single‐masked study

“…Additionally, it has been reported that BAKpreserved timolol increased anterior chamber inflammation in comparison with BAK-free timolol. In future, preservative-induced anterior inflammation should be evaluated in BAK, SofZia or other preservatives (Stevens et al 2012). …”

The Eye Drop Preservative Benzalkonium Chloride Potently Induces Mitochondrial Dysfunction and Preferentially Affects LHON Mutant Cells

“…5,6 In a clinical trial comparing the effects of BAK-containing and preservative-free eye drops, anterior chamber inflammation was reported in response to BAK after 1 month of exposure. 7 In spite of indications of mitochondrial injury by BAK over 30 years, 8–11 a clear mechanism for its biochemical toxicity has remained elusive.…”

Open-Angle Glaucoma: Drug Development Pipeline during the Last 20 Years (1995-2015)

“…The toxic effects of preservatives are dose dependent and cumulative. These substances tend to be responsible for disease of the ocular surface and have also been associated with increased intraocular inflammation after surgery [19,20] . The development of clinical trials for preservative-free glaucoma drug formulations is also important for the evaluation of the possible pharmacokinetic differences [21] .…”