Compatibility of intraocular lenses with blood and connective tissue cells measured by cellular deposition and inflammatory response in vitro.

Injection molded poly(methyl methacrylate) (IM-PMMA), lathe-cut PMMA (LC-PMMA), heparin surface modified PMMA (HSM-PMMA), silicone, and polyhydroxyethyl methacrylate (polyHEMA) intraocular lenses (IOLs) were incubated with platelets, granulocytes, mouse macrophage-like RAW 264.7 cells and mouse fibrosarcoma L929 cells to examine their compatibility. The number of cells attached to the IOL was counted after the central IOL area (0.04 mm2) was photographed with an inverted light microscope. Cell morphology was examined by scanning electron microscopy (SEM). More platelets and granulocytes were attached to the IM-PMMA and silicone IOLs than to the HSM-PMMA and polyHEMA IOLs (P less than .05). RAW 264.7 and L929 cells grew on PMMA-based and silicone IOLs, whereas HSM-PMMA and polyHEMA IOLs did not support an abundant growth of these cells. Granulocytes were incubated with the IOLs in the presence of Luminol and the generation of chemiluminescence was measured. Poly(methyl methacrylate)-based IOLs caused granulocytes to release significant amounts of oxygen radicals, while the polyHEMA IOL was almost inactive in stimulating granulocytes. Silicone and HSM-PMMA IOLs showed an intermediate level of stimulating activity. The light intensity reached a peak within 14 minutes with the IM-PMMA IOL, and in about 18 minutes with the other IOLs. Our results suggest that IOL hydrophilicity prevents attachment of cells and that a hydrophilic, soft surface can discourage granulocyte stimulation.