Topical hydrogen peroxide and the safety of ocular tissues.
Hydrogen peroxide is an effective and commonly used contact lens disinfectant that is also used as a preservative in certain ocular medications. We describe the effects of hydrogen peroxide on the cornea and anterior chamber following its topical application via a contact lens or as drops. The conditions for interaction of hydrogen peroxide with corneal and palpebral tissues and its accumulation within the aqueous humor are detailed. Values are given for thresholds at which hydrogen peroxide in specified concentrations, volumes, locations, and durations of exposure can cause ocular pain, swelling of the corneal stroma, damage to the endothelium, and penetration of the compound to the anterior chamber. The cornea and the palpebral tissues, together with the tear film, form a highly effective barrier and detoxifying system that, except under extreme, accidental circumstances, prevents both extra- and intraocular damage from use of hydrogen peroxide in contact lens care or in medications.