Cytotoxicity of chlorhexidine.

We evaluated chlorhexidine, a commonly used ophthalmic preservative for sterilization of soft hydrophilic contact lenses. Light microscopy and flat preparations of the endothelium were used. Our studies indicate that chlorhexidine is safe, even when used in higher concentrations than commercially available or required for bactericidal effect. Except for its mucous binding capacity, limiting its use for hydrophilic contact lenses, it is considered to be one of the best preservatives available for ophthalmic solutions.