Neodymium:YAG laser damage to UV-absorbing poly(methyl methacrylate) and UV-absorbing MMA-HEMA-EGDMA polymer intraocular lens materials.
MemoryLenses and UV-poly(methyl methacrylate) intraocular lenses, which served as controls, were individually exposed to twenty 5 mJ shots of the Nd:YAG laser focused onto the posterior surface while placed in a sterile holder containing 5 ml of saline. The MemoryLens is a new foldable intraocular lens (IOL) manufactured from a polymer consisting of methyl methacrylate (MMA), 2-hydroxyethyl methacrylate (HEMA), and ethylene glycol dimethyacrylate (EGDMA) with a UV absorber. Damage to the lenses was assessed by scanning electron microscopy. Cytotoxicity tests designed to detect potentially toxic substances released during laser damage were conducted with the saline solution by incubating it with mouse fibroblasts. Additional tests of the saline solution were conducted by high performance liquid chromatography and spectrophotometry. Damage induced by the Nd:YAG laser to the UV-poly(methyl methacrylate) IOLs was similar to that reported by other authors. Damage to the MemoryLens appeared less severe and showed no radial stress cracking. Cytotoxicity tests were negative for both types of IOLs. High performance liquid chromatography tests were negative for residual monomers (MMA, HEMA, EGDMA) and spectrophotometry did not reveal residual UV absorber.
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D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003432:Cross-Linking Reagents; D005347:Fibroblasts / Q000187:drug effects; D053685:Laser Therapy; D007910:Lenses, Intraocular; D008689:Methacrylates / Q000528:radiation effects*; D008768:Methylmethacrylates / Q000528:radiation effects*; D051379:Mice; D008855:Microscopy, Electron, Scanning; D011837:Radiation-Protective Agents; D014466:Ultraviolet Rays
D003432:Cross-Linking Reagents; D008689:Methacrylates; D008768:Methylmethacrylates; D011837:Radiation-Protective Agents; C005044:hydroxyethyl methacrylate; C004919:ethylene dimethacrylate