Allergy to Ophthalmic Preservatives

Jison Hong; Leonard Bielory


Curr Opin Allergy Clin Immunol. 2009;9(5):447-453. 

In This Article


Chlorhexidine is a cationic agent that belongs to the family of the bis-diguanides. It is used in the digluconate form, and acts by destroying the semi-permeable layer of the cytoplasmic membrane and produces its antimicrobial activity mainly against cocci and Gram-positive bacteria, Gram-negative bacteria as well as fungistatic activity.

Human Studies

Although chlorhexidine has been associated with IgE-mast cell mediated reactions, such as anaphylaxis, the evidence for localized ocular allergy is lacking.[19–22] Vaahtoranta-Lehtonen et al.[23] performed an experiment comparing ethyl-6-O-decanoyl-glucoside 0.005% (EDG) combined with 0.00025% chlorhexidine acetate (EDGC) to a commercial polyaminpropylbiguanide (PAPB) used daily as a cleaning and disinfectant agent for both ionic and nonionic contact lenses in 59 patients. The following symptoms were compared for each solution; blurred vision, dryness, foreign body sensation, redness, and dirty lenses. The following signs were also compared for each solution; conjunctival hyperemia, papillary hypertrophy, corneal deposits, purulence, limbal vascularization, subepithelial scarring, visual acuity, bulbar hyperemia, and tear breakup time. After 8 weeks, 52% of the participants in the EDGC group showed no evidence of corneal or conjunctival abnormalities. In contrast, only 19% of the participants in the PAPB group showed no abnormalities of the conjunctiva or cornea. After 8 weeks, 25% of the EDGC group showed evidence of papillary hypertrophy, whereas 50% of the PAPB group showed similar findings.[23]

In three consecutive cataract operations, chlorhexidine was inadvertently used as an intraocular irrigating solution as a result of inattentiveness of an assistant. In two of the three patients, corneal endothelium damage was so severe that penetrating keratoplasty had to be performed. Further effects included pronounced iris atrophy, anterior chamber applanation, and a retrocorneal membrane. In one case, an increase in intraocular pressure developed. No effects were observed in the retina or optic nerve.[24]