The Vi-Cell analyzer offers a simple and effective method of determining amoebicidal activity. Our results show that the CL solutions tested could not satisfactorily kill Acanthamoeba.

Drying with tissue after rinsing significantly reduces numbers of adhering Acanthamoeba. Acanthamoeba were found to be able to adhere even to new unused cases, so the importance of proper cleaning and disinfection of lens cases cannot be underestimated. Air drying reduces viability but some viable cells were present at 24 h in soiled cases, confirming the role of biofilm in protecting organisms from desiccation.

Purpose To investigate the interaction between corneal, internal, and total wavefront aberrations (WAs) and their influential factors during orthokeratology (OK) treatment in Chinese adolescents. Methods Thirty teenagers (n = 30 eyes) were enrolled in the study; spherical equivalent refraction (SE), corneal curvature radius (CCR), central corneal thickness (CCT), WAs, and the difference in limbal transverse diameter and OK lens diameter (ΔLLD) were detected before and after one-month OK treatment. Every component of WAs was measured simultaneously by iTrace aberrometer. The influential factors of OK-induced WAs were analyzed. Results SE and CCT decreased while CCR increased significantly (P < 0.01). Higher-order aberrations (HOAs), Spherical aberrations (SAs), and coma increased significantly (P < 0.01). Corneal horizontal coma (Z31-C) and corneal spherical aberrations (Z40-C) increased (P < 0.01). The HOAs, coma, SAs, Z31-C, Z31-T, Z40-C, and Z40-T were positively correlated with SE and CCR (P < 0.01). Z3−1-C showed negative correlations with (ΔLLD) and positive correlations with SE (P < 0.05). Conclusions The increase in OK-induced HOAs is mainly attributed to Z31 and Z40 of cornea. Z3−1 in the internal component showed a compensative effect on the corneal vertical coma. The degree of myopic correction and increase in CCR may be the essential influential factors of the increase in Z31 and Z40. The appropriate size of the OK lens may be helpful to decrease OK-induced vertical coma.

Citation: Cho P, Shi G-S, Boost M. Inhibitory effects of 2,2 0 -dipyridyl and 1,2,3,4,6-Penta-O-galloyl-b-D-glucopyranose on biofilm formation in contact lens cases. Invest Ophthalmol Vis Sci. 2015;56:7053-7057. DOI:10.1167/ iovs.15-17723 PURPOSE. This study observed biofilm formation by Pseudomonas aeruginosa and Staphylococcus aureus in contact lens cases and investigated the inhibitory effects of 2,2 0 -dipyridyl (2DP) and 1,2,3,4,6-penta-O-galloyl-b-D-glucopyranose (PGG).METHODS. Biofilm formation of P. aeruginosa ATCC 9027 and S. aureus ATCC 25923 and ATCC 6538 in contact lens cases was determined for a range of initial inocula and incubation times using crystal violet staining. The effects of 2DP and PGG on biofilm were evaluated alone and in combination by their incorporation into the media at commencement of incubation.RESULTS. At 24 hours, biofilm production was related to initial concentration. However, with extended incubation, higher initial concentrations affected formation in S. aureus. Presence of 312 lM 2DP significantly inhibited P. aeruginosa biofilm formation, but had little effect on that of S. aureus. In contrast, PGG (50 lM) inhibited S. aureus biofilm formation, but had much less effect on that of P. aeruginosa. Combination of the agents effectively inhibited biofilm formation of all three organisms throughout a week-long incubation period with OD levels barely exceeding cell-free controls.CONCLUSIONS. Biofilm formation of P. aeruginosa could be prevented by 2DP, while biofilm formation of S. aureus was inhibited by PGG. However, combining these agents showed better inhibition of biofilm production than use of either agent alone on both species. This combination may be useful in prevention of biofilm in contact lens cases, thereby reducing infection risk due to poor compliance with lens case cleaning and replacement. Further work is needed to confirm compatibility with multipurpose solutions and investigate cytotoxicity to ocular tissues.