Experimental evaluation of chlorhexidine gluconate for ocular antisepsis

Abstract

Chlorhexidine gluconate is a bisguanide germicide currently available with 70% isopropanol (Hibistat, Hibitane) or a detergent (Hibiclens, Hibiscrub) for preoperative skin preparation. As these solvents are toxic to the cornea, we investigated the safety and efficacy of aqueous chlorhexidine solutions for ophthalmic use. Chlorhexidine in Tris-glycine buffer was evaluated for retardation of epithelial regeneration after experimental corneal abrasion in rabbits. Irrigant concentrations of 2.0 and 4.0% chlorhexidine significantly slowed the healing rate (0.546 and 0.076 mm/h, respectively) compared with saline controls (0.938 mm/h). Irrigant concentrations of .l% did not statistically delay healing (P > 0.4). In a separate group of animals, the right conjunctivae of pigmented rabbits were inoculated with Staphylococcus epidermidis (_107 organisms per eye) and irrigated with 40 ,lI of aqueous chlorhexidine in concentrations of 0.1, 0.5, and 1.0%; the left eyes were irrigated with saline or left untreated. Quantitative conjunctival cultures were obtained, and the total number of organisms recovered per eye was calculated. All chlorhexidine-treated eyes showed significant reduction in organisms compared with either untreated or saline-irrigated control eyes (P < 0.001). In vitro antimicrobial susceptibility testing demonstrated chlorhexidine in concentrations of 0.1 to 4% to be highly active against a variety of gram-positive and gram-negative bacterial pathogens by disk diffusion and broth diffusion assays.

Antimicrobial Assay of Chlorhexidine-Wetted Textile Napkins for Surgical Site Disinfection in Ocular Surgery

“…Thereby, the textile napkin virtually serves as a sustained release reservoir of CHG during phacoemulsification. Moreover, equal diameter of the growth inhibition zones before and after phacoemulsification cataract extraction also indicates that 0.5% levofloxacin ophthalmic solution instilled preoperatively is not an antagonist of 0.02% CHG. Additionally, antimicrobial activity of both unused textile napkins and used textile napkins, wetted with 0.02% CHG against gram-positive bacteria is more than gram-negative (Table 1), that is comparable to certain reports [5,20]. Since microbial flora under the textile napkins mixed with flora of the conjunctival sac and the lid margin, the result of microbial culture from the conjunctival sac after withdrawing the textile napkins on completion of the surgery is disputed.…”

“…Firstly, 0.02% CHG is the most stable within the pH range 5 to 8 [5], in the pH range of 0.5% levofloxacin ophthalmic solution [19]. Secondly, Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Streptococcus pyogenes, Micrococcus sp., Escherichia coli, Enterobacter aerogenes and Pseudomonas aeruginosa are sensitive to it [20] and lastly, methicillin-resistant Staphylococcus aureus exhibits low-level resistance to chlorhexidine [21]. Additionally, as conducted research reveal, CHG as a cationic molecule [5] binds to negatively charged cells of the oral cavity.…”

2018 Update on Intravitreal Injections: Euretina Expert Consensus Recommendations

“…Moreover, another recent retrospective case series of 4,322 IVI exclusively performed under chlorhexidine gluconate antisepsis presented an EO rate of 0.023% [95], which is comparable to EO rates using PI [67]. However, alcoholic chlorhexidine bears a potential toxic risk on the cornea, yet aqueous chlorhexidine is considered an alternative in patients with local irritation or allergy to PI components [96]. …”

Safety of Ozonated Solution as an Antiseptic of the Ocular Surface prior to Ophthalmic Surgery

“…Currently, the most widely used antiseptics are povidone-iodine solution and chlorhexidine solution [1, 2]. However, these antiseptics have various disadvantages.…”

“…Hanasaki [5, 6]reported that more than half of patients showed moderate or severe corneal epithelial defects due to ocular surface disinfection prior to surgery with 1.25% povidone-iodine solution. Chlorhexidine is another antiseptic for ocular surfaces, but this compound is also toxic for the cornea [2]. Therefore, an alternative antiseptic with a wider antimicrobial spectrum and less propensity to irritate corneal tissue has been sought.…”