Cataract is an irreversible opacification of the human lens which cannot be influenced by drug therapy. The surgical extraction of the opacified lens is the most popular treatment. For optical reconstitution of the patient's eye, the procedure is normally combined with the implantation of an artificial intraocular lens (IOL). World-wide, more than two million IOLs are implanted per year. The artificial IOLs are tolerated very well intraocularly, however 50% of patients suffer from posterior capsule opacification (PCO) within 3-5 years of the operation. This secondary opacification requires an additional operative treatment with a high risk of retinal detachment and an increased number of CME (cystoid macula edema) cases. The project concerned achieving an adhesive, or preferably a covalent binding, between the haptics of the IOL, collagen IV and the laminin on the inside of the capsule in order to avoid the migration of lens epithelial cells into the optical axis of the IOL. The polymer surface of the IOL (dipolydimethylsiloxane) is functionalized with sulphur dioxide plasma before the surface is coated with collagen IV and laminin. Laminin and collagen IV enter a close binding on the inside of the capsular bag. The stable compound prevents the proliferation of lens epithelial cells into the optical part of the IOL.
In vitro migration inhibition assays revealed a decrease in cell migration of up to 10 % for a plasma treated (treatment time = 120 s) and surface coated (sandwich surface out of collagen IV and laminin) polydimethylsiloxane foil. The 'no space-no cells' concept was confirmed in animal experiments by means of the densitometric method (PCO). The treatment with sulphur dioxide plasma reduces the occurrence of PCO by more than 50% of the densitometric units. From an eye surgeon's point of view, this is an interesting, innovative approach to cataract surgery.