This invention relates to a pupil expansion apparatus that is placed in the eye during an ophthalmic surgical procedure.
When an ophthalmic surgical procedure is performed, usually one or more incisions are made in the corner of the eye to allow the introduction of surgical instruments. This type of procedure requires dilation of the pupil, i.e., the hole at the center of the iris, so as to provide the surgeon with a wide opening through which the surgeon can view and work on the posterior portions of the eye. Dilation involves enlarging the pupil by causing the iris tissue to retract.
Traditionally, a chemical dilation method using a mydriatic solution has been employed for this purpose. However, since this method does not provide accurate control over the expansion of the pupil, mechanical dilation is now more commonly used in clinical settings.
For example, U.S. Pat. No. 4,257,130 issued to Bayers discloses an intraocular lens that is inserted within the posterior chamber of the eye. i.e., the region behind the iris. The lens mechanism of Bayers includes a pair of appendages, each of which has one part that passes through the pupil and another part that extends along side of the iris. This apparatus is rather simple. However, it can be traumatic to the eye since a relatively large portion of the eye may be affected or possibly damaged during a procedure with this device.
Another example is shown in U.S. Pat. No. 5,441,045 and No. 5,318,011, issued to Federman, which disclose an iris dilator comprising an expansible material that can expand from a dehydrated first size and shape to a hydrated second size and shape. When hydrated, the dilator has a shape complementary to an inside diameter of the iris and a size sufficient to dilate the iris. In addition, a mammalian iris may be dilated by inserting the at least partially dehydrated iris dilator into a position radially inwardly from the iris. In the presence of bodily or surgical fluids, the dilator hydrates and expands to engage and dilate the iris. Apparatus for deforming the dilator to facilitate insertion is also utilized. However, this method not only involves a complicated, time consuming process of dehydration/hydration, but also requires expensive materials (e.g., hydrogels) and extra apparatus (e.g., deformation apparatus).
Another method is disclosed by U.S. Pat. No. 8,323,296 of Malyugin and U.S. Publication No. 2008/0243139 of Dusek, where a ring is used to maintain a pupil in an enlarged position by pushing the iris tissue outwards during an ophthalmic procedure. The ring has three or more straight sides connected by loops that capture iris tissue. Each loop consists of upper and lower helical turns or strand portions that are at an angle to each other to form a gap facing the surrounding iris tissue. The flexibility of the ring allows the turns to deflect and apply a clamping force onto the iris tissue. The clamping force assists in maintaining the pupil in an enlarged position and also stabilizes the position of the ring relative to the eye. The flexibility also allows the ring to be collapsed for insertion into the eye.
However, in Malyugin and Dusek, because it is “clamped” by the loop, the iris tissue may be susceptible to damage depending on the skill of the surgeon who performs the procedure.
Further, the loops of Malyugin are formed on the interior of the frame of straight sides. Accordingly, when the ring is in the fully extended position, these internal loops partially block a part of the viewing area during the procedure. Access to the interior of the pupil may also be partially prevented due to these internal loops.
The present invention has been conceived in view of the above circumstances, and an object of the invention is to provide a pupil expansion apparatus that can effectively provide a less invasive procedure, a clear viewing area, and easy access to the posterior portions of the eye.
The present invention is a pupil expansion apparatus that is placed in the eye during an ophthalmic surgical procedure. According to one embodiment of the present invention, the pupil expansion apparatus is a square frame structure that comprises four straight beams which cross each other at their ends to form a cross beam arrangement. The pupil expansion apparatus of the present invention is not limited to being a square frame structure, but it can be designed to be circular, or any multi-sided frame structure.
The crossed ends of the straight beams are connected by one or more curved beams, which also form iris supporting portions. In one embodiment of the present invention, each of cross beam connections contains five interconnected curved beams.
The iris supporting portion is shaped in an open, curved form so as to be perpendicular to the plane formed by the square frame. It receives the rim of the iris tissue when the pupil expansion apparatus is in its extended position, while gently pressing the iris to the periphery. In this manner, the iris tissue does not have to be “clamped” as required by conventional devices, thus providing a less invasive procedure.
The pupil expansion apparatus of the present invention is configured to be collapsed and placed into a small bore tube. During installation of the pupil expansion apparatus into the eye, the tube carrying the apparatus is placed in the iris of the eye through an incision. When located in the pupil, the apparatus is ejected from the tube and expands automatically to hold the tissue of the iris out of the way during an ophthalmic procedure, such as phacoemulsification.
According to another embodiment of the present invention, the pupil expansion apparatus is made of solid material, including, but not limited to, metal or plastic. In one preferred embodiment, the apparatus is made of polypropelene.
These and other features and advantages of the present invention will become more readily appreciated when considered in connection with the following detailed description and appended drawings, wherein like designations denote like elements in the various views, and wherein:
With reference to the drawings,
The pupil expansion apparatus of the present invention is not limited to being a square frame structure and it can be designed to be a rounded shape structure including circular or elliptical (not shown). Alternatively, the pupil expansion apparatus can be also designed to be any multi-sided frame structures including triangle, rectangle, hexagon, etc. (not shown)
The crossed ends of the straight beams are connected by one or more curved beams 20, 22, 24 and 26. Each of the iris supporting portions 30, 32, 34 and 36 is formed by connecting the curved beam or the straight beam at its ends. As noted in
Each of the iris supporting portions 30, 32, 34 and 36 is shaped in an open, curved form so as to be perpendicular to the plane formed by the square frame of the pupil expansion apparatus 1. As shown in
Further, the open, curved structure of the iris supporting portion of the present invention makes it easy for the surgeon to support the iris tissue and to release it, contributing to a reduction in the operation time. On the other hand, in existing devices, the iris tissue is clamped by a loop, or it must be engaged in a groove structure, either of which would require accurate placement of the device in the eye, requiring more skill, prolonged operation time, and a more difficult removal.
As noted in
In one preference embodiment, the angle formed at each corner of the square frame when in its extended position is 90 degrees. Preferably, the length of one side is 6.5 mm to create the pupil of 6.25-7.0 mm in diameter. Preferably, the horizontal length of the supporting portion is 1.2 mm, while the vertical length of the loop is 0.55 mm.
Because of its cross beam structure, the pupil expansion apparatus 1 can be collapsed and placed into a bore tube 50 by making the square frame into rhombic one (
Upon the completion of the procedure, the pupil expansion apparatus of the present invention is folded and removed by using forceps for example. Alternatively, the pupil expansion apparatus can be removed simply through the reverse action of the bore tube injection. Because the iris tissue is openly supported by the iris supporting portions 30, 32, 34 and 36, no further tool is necessary to disengage the apparatus from the iris tissue.
The pupil expansion apparatus 1 can be made of any solid material including, but not limited to, metal, plastic or plastic-coated metal. It can be made in multiple parts, but may also be made of a single strand of material. In one preferred embodiment, the apparatus 1 is made of polypropelene.
In the second embodiment the ends of the straight beams 110, 112, 114, 116 have curves at their ends that overlap each other, e.g., at 130a, in the corners of the frame with one above the other. In particular, they do not have a cross beam structure. The iris supporting portions extend perpendicularly away from the plane of the frame, as in the first embodiment. However, the iris supporting portions are formed by curved beams connected to the overlapped ends of the straight beams at the frame corner, which curved beams form two generally parallel open curved shapes, e.g., 130b and 130c, directed away from the frame to capture iris tissue. The two open curved shapes are connected together at their portions perpendicularly remote from the frame corners, e.g., 130d.
In any of the embodiments, the straight and curved beams of the frame and/or the iris supporting portions may be made of a single piece of wire, tubing or the like, that is bent into the various shapes.
In one embodiment, glue 150 is attached to cover a gap formed with two ends of the straight beams 112, 116.
The ring portions 140, 142 are designed to enhance the strength and flexibility of the expansion apparatus 100 so that the surgeon can easily maneuver the apparatus during an operation. A third ring portion (not shown) may be added to further stiffen the structure of the expansion apparatus 100. The third ring portion may be provided on the straight beam 112 opposite to the beam 116 where the glue is applied.
Having described preferred embodiments of the iris expansion ring (which are intended to be illustrative and not limiting), it is noted that modifications and variations can be made by persons skilled in the art in light of the above teachings. It is therefore to be understood that changes may be made in the particular embodiments of the invention disclosed which are within the scope and spirit of the invention as outlined by the appended claims.
This application claims priority to U.S. Provisional Application Ser. No. 61/761,457 filed on Feb. 6, 2013, which is incorporated by reference herein in its entirety.
Number | Date | Country | |
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61761457 | Feb 2013 | US |