Purpose: To assess the validity of anterior chamber irrigation with an ozonated solution as prophylaxis against endophthalmitis.
Setting: Department of Ophthalmology, Nippon Medical School, Tokyo, Japan.
Methods: Viability of human corneal endothelium in culture was assessed by the WST-8 assay, lactate dehydrogenase (LDH) release assay, and trypan blue exclusion assay after exposure to a 4 to 40 parts per million (ppm) solution for 10 to 60 seconds. The in vivo effect was observed 1 week after irrigation of a 4 ppm solution in the rabbit anterior chamber by trypan blue exclusion assay. Bactericidal efficacy of the anterior chamber irrigation with the 4 ppm solution was examined by bacterial colony count of the aqueous humor following methicillin-resistant Staphylococcus aureus (MRSA) contaminated intraocular lens implantation in the porcine eye.
Results: The WST-8 assay revealed no significant reduction of viability with 10-second exposure to a 4 ppm solution. Lactate dehydrogenase release and trypan blue exclusion assays similarly demonstrated little damage after 60-second exposure to a 4 ppm solution. In the rabbit cornea 1 week after treatment, damage caused by 30-second exposure to a 4 ppm solution was not significant. The MRSA colony count documented almost complete bactericidal action with 5-second exposure to the 4 ppm solution when no ophthalmic viscosurgical device existed in the anterior chamber.
Conclusion: Limited damage to the corneal endothelium after 10-second exposure and potent bactericidal action with 5-second exposure suggests the validity of anterior chamber irrigation with a 4 ppm ozonated solution as prophylaxis against endophthalmitis.