Method of making an 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.
Claims13
A method of making a one-piece intraocular lens, said lens having at least one filamentary haptic attached to and extending outwardly from the periphery of an optic portion of said lens, said method comprising the steps of:
- compression molding a polymer to produce a region radially exterior to a central region having substantial orientation due to the compression in said exterior region of said polymer and to produce in the central region balanced orientation resulting from little or no compression in the central region,
- removing excess material from said compression molded polymer to form said one-piece intraocular lens.
Dependencies are inferred from the claim text.