Benzalkonium chloride: Re-evaluation of its pharmaceutical status

The mainstay of treatment in a chronic disease like glaucoma is topical medications. Most of these medications need to be preserved with a preservative as mandated by the US FDA. Benzalkonium chloride (BAK) is the most widely employed preservative. It causes corneal and conjunctival damage and leads to various ocular surface disorders (OSD) which affect quality of life of the patients. The causality assessment of BAK has firmly established its role in the patho-physiology of OSD. This is further reinforced by many in vitro and in vivo studies. Chronic use of BAK challenges the basic concept of ocular therapeutics as it is bound to lead to the singular and quite predictable fate i.e. iatrogenic OSD over long term use. Hence, there is a need for newer preservatives or preservative free medications so that ocular surface health is not compromised in the long-term treatment of glaucoma.