Anti-Pseudomonal Effect of Nephrite-Impregnated Contact Lenses.

Purpose: This study compared the anti-pseudomonal effects between nephrite-impregnated contact lenses (CLs) and conventional and cosmetic CLs.

Methods: After inoculation with Pseudomonas aeruginosa (P.aeruginosa), we counted the number of bacteria on the CL surface and observed each surface using atomic force microscopy (AFM) and scanning electron microscopy (SEM). To estimate potential harm of nephrite-impregnated CLs, we conducted a safety test using a rabbit model, treated with all CL types.

Results: Both conventional and cosmetic CLs (n = 258 ± 2.9 × 10⁴, 368 ± 2.2 × 10⁴) showed significantly decreased number of attached bacteria when compared with those without nephrite impregnation (n = 134 ± 0.8 × 10⁴, 238 ± 2.5 × 10⁴, p < 0.0001, respectively). AFM and SEM revealed that P. aeruginosa was less attached to the nephrite-impregnated CLs than to the conventional and cosmetic CLs, although those with nephrite impregnation had rougher surface. In the safety test, there were no significant differences in the findings between four groups, and the clarity and stability of all corneas were preserved.

Conclusions: Nephrite may be used as a next-generation substance to reduce infectious keratitis caused by P. aeruginosa when added to CLs.