ANIMAL STUDY TO EVALUATE REDUCTION OF POS TERIOR CAPSULE OPACIFICATION BY PLASMA-ETCHING OF INTRAOCULAR LENSES

Background: We studied ifa modification of the silicon intraocular len s (IOL) by plasma etching is able to promote a bonding of the IOL surf ace and the capsular bag which might inhibit proliferation and migrati on of lens epithelial cells. Methods: Silicon-disc lenses (90D, Adatom ed), as disposable for regular cataract surgery, were used. Their hapt ic surface was etched via the use of a SO2 plasma, leaving the optic u nmodified. The experiments were done on dwarf rabbits to allow for tig ht apposition of IOL and bag. Nine rabbits underwent extracapsular len sectomy using propofol anaesthesia and phaco/clear cornea surgical tec hnique. Six eyes each received either no, a regular or a modified IOL. After 11 weeks the eyes were enucleated. Capsular bag and IOL were di gitized using a flatbed scanner with transparency adapter. The data ob tained were calibrated against a densitometric standard. The densities of the various specimen were analyzed quantitatively using self desig ned software. Results: In aphacic eyes no significant posterior capsul e opacification (PCO) was detectable. In the same time-span the regula r IOL had developed a dense, heterogenous PCO. The plasma-treated IOL showed, especially in the central areas, a significant reduction of PC O as compared to untreated IOL. Conclusion: The reduction of PCO could not be explained by adhesion of the IOL surface and the capsular bag, which would impair migration of lens epithelial cells and thereby PCO . Likewise, lower PCO may be related to improved hydrophilic propertie s of the surface-modified IOL.