SILICONE OIL ADHESION TO INTRAOCULAR LENSES - AN EXPERIMENTAL-STUDY COMPARING VARIOUS BIOMATERIALS

Purpose: To perform an in vitro experimental study comparing the degre e of adherence of silicone oil to various rigid and foldable intraocul ar lens (IOL) designs and to the human lens capsule. Setting: Center f or Research on Ocular Therapeutics and Biodevices, Department of Ophth almology, Storm Eye Institute, Medical University of South Carolina, C harleston, South Carolina, USA. Methods: Seven IOL styles comprising v arious biomaterials were studied: fluorine-treated (Fluorlens(TM)), he parin-surface-modified (HSM(TM)), hydrogel, Memory-Lens(TM), poly(meth yl methacrylate) (PMMA), soft acrylic, and silicone lenses; the human crystalline lens was also studied. Each lens was immersed in silicone oil for 12 hours, then photographed, studied by scanning electron micr oscopy (except the crystalline lens), and subjected to computer-genera ted image analysis to determine the silicone oil coverage. Results: Si licone oil coverage of dry silicone lenses was 100% and of lenses imme rsed in normal saline, 82.5%. The least coverage was on the heparin-su rface-modified lens (mean score 9.4%). Coverage of the other four lens es ranged from approximately 15.1% to 33.7%. Mean coverage of the huma n lens capsule was 10.9%. Conclusion: Although a silicone IOL shows ma ximal adherence to silicone oil, other lens biomaterials are not immun e to this complication. Silicone oil coverage was related to the dispe rsive energy component of the surface charge of the IOL biomaterial. L ow dispersive energy materials had less silicone oil coverage, while t hose with higher dispersive energy had more oil coverage.