Patent Application
20080312661
This invention relates to intraocular lenses (IOLs) and more particularly to cartridges 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 U.S. Pat. Nos. 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.), U.S. Pat. No. 5,653,715 (Reich, et al.), and U.S. Pat. No. 5,947,976 (Van Noy, et al).
These prior art devices were intended to inject an IOL into the posterior chamber of an aphakic eye through a relatively large (approximately 3.0 mm or larger) incision. Surgical techniques and IOLs have been developed that allow the entire surgical procedure to be performed through much smaller incisions, 2.4 mm and smaller. As a result, surgeons began developing methods of wound assisted IOL insertion, where the IOL is delivered through a small incision without inserting the cartridge tip fully into the wound. In this type of IOL delivery, the wound itself provides a tunnel through which the IOL enters the anterior chamber. Wound assisted IOL delivery, therefore, eliminates the need for the incision to be large enough to accommodate the outer diameter of the cartridge tip, allowing a smaller incision to be used. Prior to the present invention, such wound assisted delivery was accomplished using techniques which are highly reliant on the degree of skill and confidence of the surgeon.
Accordingly, a need continues to exist for an intraocular lens injection cartridge which provides features to specifically aid in wound assisted IOL delivery.
The present invention improves upon prior art by providing a cartridge for an IOL delivery system that includes an extended canopy at the distal tip of the cartridge to open and support the wound while guiding and controlling the folded lens as it passes through the wound, and a peripheral protrusion, flange, or stop feature that provides an insertion depth limitation and prevention of full insertion of the cartridge tip. In addition, the protrusion provides support to the incision to reduce the tendency of wound damage through tearing.
It is accordingly an objective of the present invention to provide a cartridge for a lens delivery system that has an extended canopy at the distal tip.
It is a further objective of the present invention to provide a cartridge for a lens delivery system that contains a peripheral protrusion, flange, or stop that provides an insertion depth limitation.
It is yet a further objective of the present invention to provide a cartridge for a lens delivery system that contains a peripheral protrusion, flange, or stop that provides support to the incision to reduce the tendency of wound damage through tearing.
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.
As best seen in
As best seen in
Peripheral protrusion 22 may be any feature appropriate for preventing distal tip 16 from fully entering an incision, such as a flange or stop. Peripheral protrusion 22 extends laterally from outer wall 36 of distal tip 16, and may be a continuous protrusion that completely encircles nozzle 14. However, peripheral protrusion 22 may not be continuous and most preferably comprise a plurality of protrusions 22 that extend, for example, laterally from either side of outer wall 36 of distal tip 16. Peripheral protrusion 22 serves as an insertion depth limitation, and prevents the full insertion of distal tip 16 into the wound entrance. Distal face 23, of peripheral protrusion 22 may be square or sloped at an angle of between approximately 18 to 26 degrees (preferably about 22 degrees). Such a slope will allow a more contoured contact with the surface of the eye and provide for less tissue irritation because cartridge 10 generally is held at an angle to eye 52 during use, as seen in
During operation, shown in
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.
