Chlorhexidine antiseptic is a harmful protection due to keratitis and blindness potential

Introduction Chlorhexidine (CHX) is an antiseptic used in facial and skull surgeries with potential ocular contact. It is also a preservative for eye drops and contact lens products and is used to treat infectious keratitis. Reports of corneal toxicity to CHX exist at different concentrations and presentations. The present study clarifies the mechanisms of CHX and corneal toxicity, as well as the treatment and its outcomes. Methods Two sources of data were used: a) Reports of toxicity to the cornea by CHX at different concentrations in in vitro studies and case reports, collected from the medical literature in PubMed between 1980 and 2024 using the terms “chlorhexidine” AND “cornea"; b) Cases observed by our group (tertiary hospital service) between 2021 and 2024 were compiled. Results Sixteen clinical articles describing CHX keratitis were identified. In addition, four cases of chemical keratitis secondary to CHX antisepsis were treated at our referral center between 2021 and 2024. Corneal damage varies according to the vehicle, concentration, route of exposure, and duration of exposure. Thirty-nine cases of severe corneal CHX toxicity were reported. Thirteen patients underwent corneal transplantation because of severe vision loss. Conclusions Using CHX as an antiseptic in regions with potential eye contact can cause keratitis and serious visual impairment. Ocular protection with lubricant ointment and closure before applying this transparent antiseptic to the patient's face under general anesthesia can partially prevent the lesions. The main antiseptic alternative is 10% aqueous povidone-iodine, which is similar in cost and effectiveness to chlorhexidine.