Analysis of surface contaminants on intraocular lenses

Surface contaminants have been studied on a variety of intraocular lenses by three methods: scanning electron microscopy, energy dispersive x-ray analysis (EDXA), and electron spectroscopy for chemical analysis (ESCA). Many particulate contaminants were observed on both commercially available lenses packaged for implantation and experimental batches of lenses. The nature of these particles could be inferred using the EDXA technique. Thin films of sodium dodecyl sulfate (SDS) that were resistant to removal were found on many of the lenses by ESCA. Cleaning procedures were developed that did not involve SDS and that generated extremely clean lens surfaces.