|Foldable Intraocular Lenses
Menicon Co.Ltd., Material Research Department, Kasugai, Aichi, Japan
Nippon Gomu Kyokaishi,(2005),78(4),163-167 General Review in Japanese
A plastic intraocular lens (IOL) is implanted in the eye during cataract surgery to replace the human lens. Improvements in microsurgical techniques make it possible to remove a cloudy lens through a small incision. Thus, foldable IOLs that are made of soft materials were developed. Today materials for foldable IOLs are classified in three groups: silicone elastomers, hydrophobic acrylic rubbers, and hydrophilic acrylic gels. Recently, it has been reported good results from the clinical studies performed on the hydrophobic acrylic foldable IOLs (acrylic IOLs). These results suggest that hydrophobic acrylic rubbers have suitable biocompatibility to be used as material for IOLs. Actually the acrylic IOLs are made of acrylate-methacrylate copolymers. Small amount of water in these polymers induces phase transitions by temperature change, and small vacuoles called glistening appear. Effective ways to prevent glistening are the production of uniform polymer and the control of water absorption by the polymers.
The final goal of IOLs is to restore ocular accommodation. Accordingly high performance gels are required.
Foldable Intraocular Lens, Cataract, Biocompatibility, Glistening, Refilling