WO2003043547A1

WO2003043547A1 - Method of tipping an intraocular lens injector cartridge

Info

Publication number: WO2003043547A1
Application number: PCT/US2002/026437
Authority: WO
Inventors: David A. Downer; John R. Periard
Original assignee: Alcon, Inc.
Priority date: 2001-11-15
Filing date: 2002-08-20
Publication date: 2003-05-30
Also published as: AU2002323272A1

Abstract

A method of smoothing the tip (115) of an intraocular lens cartridge (110) by inserting the tip (115) into a tipping die. The die is heated to at or above the melting temperature of the material used to manufacture the tip (115), thereby form the distal tip (115) to the shape of the tipping die and smoothing the molding flash or sharp or rough edges from the tip (115).

Description

METHOD OF TIPPING AN INTRAOCULAR LENS INJECTOR CARTRIDGE

This invention relates to intraocular lenses (IOLs) and more particularly to cartridges used to inject IOLs into an eye.

Background of the Invention

The human eye in its simplest terms functions to provide vision by transmitting and refracting light through a clear outer portion called the cornea, and further focusing the image by way of lens onto the retina at the back of the eye. The quality of the focused image depends on many factors including the size, shape and length of the eye, and the shape and transparency of the cornea and lens.

When trauma, age or disease cause the lens to become less transparent, vision deteriorates because of the diminished light which can be transmitted to the retina. This deficiency in the lens of the eye is medically known as a cataract. The treatment for this condition is surgical removal of the lens and implantation of an artificial lens or IOL.

While early IOLs were made from hard plastic, such as polymethylmtharcrylate (PMMA), soft foldable IOLs made from silicone, soft acrylics and hydrogels have become increasingly popular because of the ability to fold or roll these soft lenses and insert them through a smaller incision. Several methods of rolling or folding the lenses are used. One popular method is an injector cartridge that folds the lenses and provides a relatively small diameter lumen through which the lens may be pushed into the eye, usually by a soft tip plunger. The most commonly used injector cartridge design is illustrated in U.S. Patent No. 4,681,102 (Bartell), the entire contents of which is incorporated herein by reference, and includes a split, longitudinally hinged cartridge. Similar designs are illustrated in U.S. Patent Nos. 5,494,484 and 5, 499, 987 (Feingold) and 5,616,148 and 5,620,450 (Eagles, et al.), the entire contents of which are incorporated herein by reference. In an attempt to avoid the claims of U.S. Patent No. 4,681,102, several solid cartridges have been investigated, see for example U.S. Patent No. 5,275,604 (Rheinish, et al.) and 5,653,715 (Reich, et al.), the entire contents of which are incorporated herein by reference.

These prior art cartridges all can contain molding flash, roughened areas or sharp edges at the tip. Prior art methods for smoothing the tip of the cartridge centered around improvements in the cartridge mold. Accordingly, a need continues to exist for an effective and repeatable method for smoothing the tip of an IOL injector cartridge.

Brief Summary of the Invention

The present invention improves upon prior art injector cartridges by providing a cartridge having a distal tip that has been smoothed by inserting the tip into a tipping die. The die is heated to at or above the melting temperature of the tip, thereby smoothing any molding flash or sharp or rough edges from the tip.

It is accordingly an object of the present invention to provide a lens injector cartridge that has a distal tip free from rough or sharp edges.

It is a further object of the present invention to provide a lens injector cartridge that generally folds the lens.

It is a further object of the present invention to provide a lens injector cartridge that minimizes the potential for damage to the optics and/or the haptics.

Other objectives, features and advantages of the present invention will become apparent with reference to the drawings, and the following description of the drawings and claims.

Brief Description of the Drawings

FIG. 1 is a perspective view of an intraocular lens cartridge that may be used with the method of the present invention.

FIG. 2 is a schematic illustration of a tipping fixture that may be used with the method of the present invention.

Detailed Description of the Invention

As best seen in FIG. 1, intraocular lens injector cartridge 110 of the present invention generally has body 112 and injection nozzle 114 containing distal tip 115. Cartridge 110 preferably is molded as a single piece from any suitable thermoplastic,' such as polyproplyene, and the thermoplastic may contain a lubricity enhancing agent such as those disclosed in U.S. Patent No. 5,716,364, or may be coated with a lubricous coating such as those described in U.S. Patent Nos. 4,487,865, 4,500,676, 4,663,233, 4,801,475, 4,959,074, 5,023,114 and 5,037,677, the entire contents of which are incorporated herein by reference. Nozzle 114 preferably is round, oval or elliptical in cross-section and has a cross-sectional area of preferably between 1.0 mm² to around 6.5 mm² at distal tip 115. Suitable designs for cartridge 110 are illustrated in U.S. Patent Nos! 5,947,976, 6,083,231 and 6,143,001, the entire contents of which are incorporated herein by reference.

Distal tip 115 preferably is smooth and rounded in order to minimize trauma to the surgical site as well as damage to the lens during use. Typically, distal tip 115 contains sharp edges or molding flash. In order to reduce substantially or even eliminate such molding defects, and to smooth and round distal tip 115, the tipping method of the present invention uses tipping fixture 20 having a tipping die 22, as best seen in FIG. 2. Die 22 is shaped to receive nozzle 114, and to shape or form distal tip 115 into any desired configuration. Cartridge 110 is placed in die 22 over pin 24 (pin 24 helps to maintain the interior diameter of nozzle 114 during the tipping process). Die 22 is then heated by, for example, radio frequency (RF) energy, to at or near the melting temperature of the material used to manufacture cartridge 110. Distal tip 115 is softened by the heating of die 22 and conforms to the shape of die 22, thereby removing any molding defects. Suitable tipping fixtures 20 are commercially available Engineering & Research Associates, Inc., Tucson, Arizona, under the trademark PIRF® and described in U.S. Patent Nos. 5,160,396 and 5,306,377 (Jensen, et al.), the entire contents of which being incorporated herein by reference.

While certain embodiments of the present invention have been described above, these descriptions are given for purposes of illustration and explanation. Variations, changes, modifications, and departures from the systems and methods disclosed above may be adopted without departure from the scope or spirit of the present invention.

Claims

We claim:

1. A method of tipping an intraocular lens injector cartridge, comprising the steps of: a) forming an intraocular lens injector cartridge having an injection nozzle, the injection nozzle having a distal tip; b) inserting the distal tip of the injection nozzle into a tipping die; and c) heating the tipping die to at or near a melting temperature of the intraocular lens injector cartridge, whereby the heating of the tipping die causes the distal tip of the injection nozzle to soften and conform to the shape of the tipping die.

2. The method of claim 1, wherein the tipping die is heated using radio frequency energy.

3. The method of claim 1 wherein the cartridge comprises a thermoplastic.

4. An intraocular lens injection cartridge, comprising: a) a body; b) an injection nozzle integrally formed with the body; and c) a distal tip on the injection nozzle opposite the body, the distal tip being formed in a tipping die so as to be substantially free from rough edges and molding flash.

5. A method of tipping an intraocular lens injector cartridge, comprising the steps of: a) forming an intraocular lens injector cartridge having an injection nozzle, the injection nozzle having a distal tip; and b) inserting the distal tip of the injection nozzle into a means for heating and forming the distal tip so that the distal tip is substantially free from rough edges and molding flash.