Intraocular lens with fracture resistant haptics
AssigneeIolab Corporation
InventorsShiao H. Chang, Charles H. Sherwood, Bruce A. Tunberg, Paul D. Rice, Walker L. Gordy
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Abstract
The polymethyl methacrylate (PMMA) or copolymer thereof used to produce one-piece intraocular lenses is modified by a compression molding process to produce a much tougher material with improved mechanical properties. The process takes material in rod form and compresses into lens blanks. The molded lens blanks receive little or no compression strain in the center 4 mm optic zone. The compression is limited to the periphery region outside the center 4 mm zone. The intraocular lens fabricated from the molded lens blank exhibits greatly increased haptic mechanical properties and resistance to breakage.
Claims9
A one-piece intraocular lens having a central optic portion body and at least one filamentary haptic attached to and extending outwardly from the periphery of said optic portion of said lens, the material of said haptic being substantially oriented and the material of the optic region being of substantially balanced orientation on a molecular basis.
A one-piece intraocular lens having a central optic portion body and at least one filamentary haptic attached to and extending outwardly from the periphery of said optic portion of said lens, the material of said haptic, which defines a thickness, being substantially oriented and the material of the optic region being of substantially balanced orientation,
- wherein the material of said haptic is compression molded to provide about 1.2 to about 2.0 compression strain along the direction extending outwardly from the periphery of said optic portion of said lens in combination with about 1.7 to about 4.7 compression strain along the thickness dimension to induce balanced orientation in the optic and highly oriented polymer chains in the haptic.
Dependencies are inferred from the claim text.