In vivo study of bacterial adhesion to five types of intraocular lenses.
OBJECTIVE
To determine in vivo behavior of the ability of the Staphylococcus epidermidis strain (American Type Culture Collection [ATCC] 14990) to attach to 120 intraocular lenses (IOLs) made of five different biomaterials: fluorine polymethylmethacrylate (PMMA), heparinized PMMA, silicone, hydrophobic acrylic, and hydrogel. The pig was chosen as an animal model of endophthalmitis, after a bibliographical analysis and a personal study of its aqueous humor composition.


METHODS
Crystalline lenses from 90 domestic pigs were removed aseptically and replaced with previously infected IOLs. The animals were killed 24 hours, 72 hours, and 1 week after implantation of the IOLs. The extent of bacterial binding was then measured by counting. Results were compared with a two-factor analysis of variance (ANOVA 2), confirmed by the Kruskal-Wallis nonparametric test.


RESULTS
The extent of bacterial binding (expressed as bound bacteria per area unit) was found to range in increasing order from hydrogel, to fluorine PMMA, to hydrophobic acrylic, to heparinized PMMA, to silicone polymer. Comparison of pairs of materials showed statistically significant differences, except between hydrogel and fluorine PMMA.


CONCLUSIONS
To the authors' knowledge, no study has been published so far concerning the in vivo evolution of populations of bacteria adhering to different intraocular materials. Bacterial adhesion to the implant surface must therefore depend on the hydrophobicity or hydrophilicity of the biomaterial. Adhesion is also affected by the nature of the surrounding medium. Because of its complexity, the latter appears to be very difficult to model, thus making in vivo studies essential.
Kodjikian
Laurent
L
Department of Ophthalmology, Herriot Hospital, Lyon, France. kodjikian.laurent@wanadoo.fr
Burillon
Carole
C
Chanloy
Cécile
C
Bostvironnois
Valérie
V
Pellon
Gérard
G
Mari
Eliane
E
Freney
Jean
J
Roger
Thierry
T
D000180:Acrylic Resins; D000818:Animals; D001422:Bacterial Adhesion; D001672:Biocompatible Materials / Q000737:chemistry; D015169:Colony Count, Microbial; D009877:Endophthalmitis / Q000382:microbiology*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D019654:Lens Implantation, Intraocular; D007908:Lens, Crystalline / Q000601:surgery; D007910:Lenses, Intraocular / Q000382:microbiology*; D023421:Models, Animal; D019904:Polymethyl Methacrylate; D012826:Silicone Elastomers; D013212:Staphylococcus epidermidis / Q000302:isolation & purification / Q000502:physiology*; D013552:Swine
D000180:Acrylic Resins; D001672:Biocompatible Materials; D012826:Silicone Elastomers; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D019904:Polymethyl Methacrylate