Patent Application
20090112223
This invention relates to intraocular lenses (IOLs) and more particularly to devices used to inject IOLs into an eye.
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 the 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 polymethylmethacrylate (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. Pat. No. 4,681,102 (Bartell), and includes a split, longitudinally hinged cartridge. Similar designs are illustrated in U.S. Pat. Nos. 5,494,484 and 5,499,987 (Feingold) and 5,616,148 and 5,620,450 (Eagles, et al.). In an attempt to avoid the claims of U.S. Pat. No. 4,681,102, several solid cartridges have been investigated, see for example U.S. Pat. No. 5,275,604 (Rheinish, et al.) and U.S. Pat. No. 5,653,715 (Reich, et al.).
The handpieces used with prior art cartridges generally push the lens through the cartridge using a plunger. The plunger is either pushed but the user (similar to a syringe) or is threaded and is advanced by turning a thumbwheel. Surgeon preference generally dictates which style handpiece is used but it is advantageous that a single handpiece contain a mechanism that allows both typed of movement.
Accordingly, a need continues to exist for a lens delivery system handpiece having a plunger that can be advanced by pushing or by turning of a thumbscrew.
The present invention improves upon prior art by providing a lens delivery system handpiece having a threaded plunger rod with a ball lock ring. Locking the ring causes the plunger to be advanced by turning a thumbscrew or knob. Unlocking the ring allows the plunger to be advanced by pushing on the thumbscrew or knob in a manner similar to a syringe.
It is accordingly an object of the present invention to provide a lens delivery system having a handpiece with a locking ring.
It is a further object of the present invention to provide a lens delivery system having a handpiece with a plunger that can be advanced by pushing or turning a knob.
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.
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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.
