Abstract:
An apparatus for introducing a glaucoma drain to the eye includes an outer hub including a longitudinal slot, a nosepiece retractably mounted within said outer hub, a handle having a gripping portion and an extending portion, the extending portion removably attached to the retractable nosepiece through the longitudinal slot in the outer hub, and a tool operably disposed within the retractable nosepiece within the outer hub. Tools provided with the apparatus include a stylette configured to prepare an eye for introduction of a glaucoma drain thereto and a plunger configured for introducing a glaucoma drain from the retractable nosepiece to the eye.

Description:
FIELD OF THE INVENTION 
     The present invention is directed to surgical devices and more specifically to an apparatus for introducing a glaucoma drain to the eye of a human or animal. 
     BACKGROUND OF THE INVENTION 
     Aqueous humor, the fluid of the eye, is produced by the ciliary body in the posterior chamber. In the normal eye, the fluid migrates into the anterior chamber and filters through the trabecular meshwork into the canal of Schlemm. The canal of Schlemm drains into veins which carry the aqueous humor away from the eye. 
     Intraocular pressure is a function of the rate at which aqueous humor is produced in and released from the eye. Glaucoma is a disease of the eye characterized by an abnormally high intraocular pressure. Usually, glaucoma is caused by a problem with release, as opposed to production, of aqueous humor. 
     One method of treating glaucoma is to surgically introduce a drainage device to the eye. Such devices are generally configured to provide a controlled release of aqueous humor to alleviate intraocular pressure. It is critical to the proper functioning of these devices that they be introduced to the eye properly. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is a first object of the present invention to provide an apparatus for introducing a glaucoma drain to the eye. 
     It is a second object of the present invention to provide an improved apparatus for introducing a glaucoma drain to the eye. 
     It is a third object of the present invention to provide an apparatus which is configured such that the distal end thereof closely contours the surface of the eye. 
     It is a fourth object of the present invention to provide an apparatus device which is easy to use. 
     It is a fifth object of the present invention to provide an apparatus which is configured such that an operable portion thereof is encased until placed into position proximal to the eye. 
     It is a sixth object of the present invention to provide an apparatus device which is safe to use. 
     It is a seventh object of the present invention to provide an apparatus device which may be used to perform multiple functions involved in the introduction of a glaucoma drain to the eye. 
     It is an eighth object of the present invention to provide an apparatus for introducing a glaucoma drain to the eye including an outer hub including a longitudinal slot, a nosepiece retractably mounted within the outer hub, a handle having a gripping portion and an extending portion, the extending portion removably attached to the retractable nosepiece through the longitudinal slot in the outer hub, and, a tool operably disposed within the retractable nosepiece within the outer hub. 
     It is a ninth object of the present invention to provide a method of introducing a glaucoma drain to the eye including the steps of inserting a stylette into a retractable nosepiece slidably mounted within an outer hub, retracting the nosepiece into the outer hub, operating said stylette to create a small wound in the eye at a location along the periphery of the cornea, removing the stylette from the retractable nosepiece and the outer hub, extending the retractable nosepiece, loading a glaucoma drain into a distal end of the retractable nosepiece, inserting a plunger having a plunger tip including a planar end face into the retractable nosepiece slidably disposed within the outer hub, retracting the nosepiece into the outer hub, placing the outer hub in contact with the eye over the wound, and, operating the plunger to advance the glaucoma drain out the distal end of the retractable nosepiece and into the wound. 
     The present invention provides an apparatus for introducing a glaucoma drain to the eye. A preferred embodiment of the apparatus includes a tubular elongated outer hub having an open flared proximal end. The outer hub also has an open distal end which defines a plane having a normal which intersects the longitudinal axis of the outer hub at an angle. 
     A preferred embodiment of the apparatus also includes a tubular retractable nosepiece disposed within the outer hub. A longitudinal slot in the outer hub is configured such that the extending portion of a handle may pass therethrough and threadedly engage the retractable nosepiece. The slot provides a range of motion for the retractable nosepiece relative to the outer hub. Specifically, the extending portion of the handle on the nosepiece travels within the slot to allow the nosepiece to extend and to retract relative to the outer hub. The slot in the outer hub also includes a transverse portion, preferably, located at the distal end of the slot, for locking the nosepiece relative to the outer hub, preferably, in an extended position. 
     The outer hub and retractable nosepiece are adapted to receive a glaucoma drain tool. Specifically, the apparatus is provided with a stylette having a flared proximal end which is configured to engage the flared proximal end of the outer hub when the stylette is inserted therein. The distal end of the stylette defines a plane having a normal which intersects the longitudinal axis of the stylette at an angle. The stylette is preferably configured such that when the retractable nosepiece is an extended position, the distal end of the stylette does not extend beyond the distal end of the retractable nosepiece. 
     The apparatus is also preferably provided with an elongated cylindrical plunger having a planar end faced plunger tip. The plunger tip is configured for translating a glaucoma drain out of the retractable nosepiece and into the tissue of the eye. The plunger further includes a collar which is configured to engage the outer hub to prevent the plunger tip from extending beyond the retractable nosepiece when the retractable nosepiece is an extended position. The plunger also includes a thumb rest at the proximal end thereof. 
     In a preferred method of introducing a glaucoma drain to the eye with the present invention, the apparatus is brought into position proximally to the eye with the stylette operably disposed within the retractable nosepiece and outer hub. The retractable nosepiece is preferably in an extended position with the extending portion of the handle locked into the transverse portion of the slot in the outer hub. 
     Once in position near the eye, the retractable nosepiece is retracted into the outer hub by disengaging the extending portion of the handle from the transverse portion of the slot in the outer hub and sliding the nosepiece proximally relative to the outer hub. The open distal end of the outer hub is angled, as described above, relative to the longitudinal axis of the outer hub. This feature allows the longitudinal axis of the apparatus to be perpendicular to the face of the patient and simultaneously for the distal end of the outer hub to closely contour the curved surface of the eye thus providing an improved surgical orientation of the apparatus for the surgeon. 
     With the outer hub in contact with the eye at a location along the periphery of the cornea, the stylette is then advanced to create a small wound in the eye. The diameter of the wound is controlled by the diameter of the stylette. The stylette is preferably provided with a through bore such that a small volume of tissue is excised during formation of the wound. The depth of the ocular wound is limited by the extent to which the distal end of the stylette extends beyond the distal end of the outer hub when the flared proximal end of the stylette engages the flared proximal end of the outer hub. Wound depth may therefore by easily configured according to the dimensions of the glaucoma drain to be introduced to the eye with the apparatus. 
     Once the ocular wound is formed in the eye, the apparatus is moved away from the eye and the stylette is removed from the outer hub and retractable nosepiece. The retractable nosepiece is returned to and locked in the extended position. A glaucoma drain, preferably, a small cylindrical section of porous biocompatible material, is loaded into the distal end of the retractable nosepiece. The plunger is then inserted into the proximal end of the outer hub and the apparatus is again brought into close proximity to the eye and specifically to the ocular wound created with the apparatus. Again, the retractable nosepiece is placed in a retracted position. The plunger is then moved distally such that the plunger tip engages the glaucoma drain. With the distal end of the outer hub in contact with the surface of the eye, the plunger is further advanced causing the plunger tip to translate the glaucoma drain out the distal end of the retractable nosepiece and into the ocular wound, thereby introducing the glaucoma drain to the eye. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a perspective view of a preferred embodiment of an apparatus for introducing a glaucoma drain to the eye according to the present invention. 
     FIG. 2 shows a partial exploded side view of an outer hub, a retractable nosepiece and a handle assembled according to the present invention with the retractable nosepiece in a partially extended position. 
     FIG. 3 shows the assembly shown in FIG. 2 with the retractable nosepiece in a fully retracted position. 
     FIG. 4 shows a side view of a preferred embodiment of an outer hub according to the present invention. 
     FIG. 5 shows an exploded side view of a retractable nosepiece and handle assembly according to the present invention. 
     FIG. 6 shows a side view of a stylette according to the present invention. 
     FIG. 7 shows a side view of an assembly including an outer hub, retractable nosepiece, handle, and stylette according to the present invention. 
     FIG. 8 shows a side view of a plunger according to the present invention. 
     FIG. 9 shows a side view of an assembly including an outer hub, retractable nosepiece, handle and plunger with the nose piece in a partially extended position according to the present invention. 
     FIG. 10 shows a side view of the assembly shown in FIG. 9 with the retractable nosepiece in a fully retracted position. 
     FIG. 11 shows a distal portion of an apparatus according to the present invention in close proximity to the surface of an eye. 
     FIG. 12 shows a distal portion of an apparatus according to the present invention with the nosepiece retracted in close proximity to the surface of an eye. 
     FIG. 13 shows a distal portion of an apparatus according to the present invention with a stylette penetrating the eye. 
     FIG. 14 shows a distal portion an apparatus according to the present invention with a glaucoma drain loaded into the nosepiece thereof 
     FIG. 15 shows a distal portion of an apparatus according to the present invention with a glaucoma drain partially introduced to the eye. 
     FIG. 16 shows a glaucoma drain introduced to an eye with an apparatus according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 shows a perspective view of a preferred embodiment of an apparatus  14  for introducing a glaucoma drain to the eye according to the present invention. Apparatus  14  includes an elongated tubular outer hub  16  including a longitudinal slot  20  having a transverse portion  22  as shown in FIGS. 1-4. Outer hub  16  also includes a flared proximal end  34  and a distal gripping portion  32 . As shown in FIG. 4, the distal end  40  of outer hub  16  defines a plane having a normal  36  which forms an angle, A, with the longitudinal axis  38  of outer hub  16 . Outer hub  16  preferably has a length of about 15 mm and a diameter of about 1 mm. Flared proximal end  34  is preferably about 2 mm in diameter and angle, A, is preferably about 45 degrees. 
     Apparatus  14  further includes a nosepiece  18  which is configured to retract into outer hub  16 . As shown in FIG. 5, nosepiece  18  is a relatively short tubular portion having a distal gripping portion  42  and a threaded proximal hole  44 . As is further shown in FIG. 5, a handle  24  including an extending portion  26  having a threaded end is configured to engage threaded proximal hole  44  in nosepiece  18 . Nosepiece  18  preferably has a length of about 10 mm and a diameter of about 1 mm. The length of handle  24  including extending portion  26  is preferably about 5 mm. nosepiece  18  is disposed within outer hub  16  such that threaded hole  44  aligns with slot  20 , as shown in FIGS. 1-3. The threaded end of extending portion  26  of handle  24  is then passed through slot  20  and attached to nosepiece  18 , thereby slidably mounting nosepiece  18  to outer hub  16 . Note that relative axial movement between nosepiece  18  and outer hub  16  is limited by length, L, of slot  20  as shown in FIG. 2 and 3. Further note that length, L, is configured such that the range, R, of the distal end  46  of nosepiece  18  beyond or behind the distal end  40  of outer hub  16 , is precisely limited. 
     The transverse portion  22  of slot  20  in outer hub  16  is configured to receive extending portion  26  of handle  24 , and thereby lock nosepiece  16  in a fully extended axial position relative to outer hub  18 . When nosepiece  16  is in a locked position (not shown), the distance by which distal end  46  of nosepiece  18  extends beyond the distal end  40  of outer hub  16  is at a maximum. 
     FIG. 2 shows nosepiece  18  in a partially extended position relative to outer hub  16 . Distal end  46  of nosepiece  18  extends beyond distal end  40  of outer hub  16 . In FIG. 3 nosepiece  18  is shown in a fully retracted position. Distal end  46  of nosepiece  18  is shown within outer hub  16  when nosepiece  18  is in a retracted position. 
     The assembly shown in FIGS. 2 and 3 is configured such that a tool may be operably disposed therein. FIG. 6 shows a stylette  50  which is configured for use in the assembly of FIGS. 2 and 3. Specifically, as shown in FIGS. 6 and 7, stylette  50  includes a flared proximal end  52  which is configured to engage the flared proximal end  34  of outer it hub  16 . Further, the distal end  58  of stylette defines a plane the normal  56  of which intersects the longitudinal axis of stylette  50  at an angle B. Preferably, angle B of stylette  50  is equal to angle A of outer hub  16 , in FIG.  4 . As will be further described later, stylette  50  also includes a through bore  60 . Stylette  50  preferably has an overall length of about 17 mm. The diameter of stylette  50  at the distal end thereof is preferably about 0.6 mm and at the flared proximal end, about 2 mm. 
     FIG. 7 shows stylette  50  fully engaged with, in other words, fully inserted into outer hub  16 . Further, nosepiece  18  is shown in a partially extended position relative to outer hub  16 . Note that the distal end  58  of stylette  50  extends beyond the distal end  40  of outer hub  16  by a distance, D. It is important to recognize that if nosepiece  18  were in a fully extended position, the distal end  46  of nosepiece  18  would extend at least as far as the distal end  58  of stylette  50 . In other words, the portion of range, R, shown in FIG. 2, outside of outer hub  16  is at least as great as distance, D. 
     FIG. 8 shows an elongated cylindrical plunger  62  which is configured for use in the assembly of FIGS. 2 and 3. Plunger  62  includes a plunger tip portion  64  having an end face  70  which defines a plane having a normal  66  which intersects the longitudinal axis  68  of the plunger at an angle, C, as shown in FIG.  8 . Preferably, angle C is equal to angle A and angle B. Plunger  62  also includes a collar  72 , which as shown in FIGS. 9 and 10, limits the distal axial movement of plunger  62  relative to outer hub  16  when plunger  62  is inserted therein as shown in FIGS. 9 and 10. Plunger  62  also includes a thumb rest  74  attached to the proximal end thereof Plunger  62  preferably has an overall length of about 15 mm and a diameter of about 0.70 mm. 
     As shown in FIGS. 9 and 10, the end face  70  of plunger tip portion  64  remains within outer hub  18  when plunger  62  is fully inserted within nosepiece  18  and outer hub  16 , in other words, when collar  72  is in contact with the flared distal end  34  of outer hub  16 . FIG. 9 shows nosepiece  18  in a partially extended position relative to outer hub  16  and FIG. 10 shows nosepiece  18  in a fully retracted position within outer hub  16 . 
     In a preferred method of using apparatus  14  for introducing a glaucoma drain to the eye according to the present invention, stylette  50  is inserted into outer hub  16  and nosepiece  18  as shown in FIG.  7 . Nosepiece  18  is preferably in an extended position and extending portion  26  of handle  24  is preferably locked into the transverse portion  22  of longitudinal slot  20 . The apparatus is then brought into close proximity to the eye. 
     As FIG. 11 shows the distal portion of apparatus  14  is preferably brought into close proximity to the surface  78  of the eye  76  near the canal of Schlemm  80 . Note that distal end  46  of nosepiece  18  extends beyond the distal end  40  of outer hub  16  when nosepiece  18  is in an extended position. 
     Nosepiece  18  is then retracted into outer hub  16  as shown in FIG.  12  and the distal end  40  of outer hub is brought into contact with the surface  78  of eye  76 . Note that the distal end  40  of outer hub  16  closely contours the surface  78  of eye  76 . Stylette  50  is then operated to create a wound in the eye  78  as shown in FIG.  13 . The through bore  60  in stylette  50  is preferably configured such that a small portion of tissue is captured therein during creation of the wound in the eye. As shown in FIGS. 7 and 13, stylette  50  is advanced into outer hub  16  until the flared proximal end  52  thereof engages the flared proximal end  34  of outer hub  16 . 
     As discussed above and shown in FIGS. 7 and 13, stylette  50  is configured such that the distal end  58  thereof extends a predetermined distance, D, beyond the distal end  40  of outer hub  16 . Accordingly the wound created by apparatus  14  has a depth, D. Distance, D, is preferably configured to approach the depth, X, of the canal of Schlemm under the surface of the eye as shown in FIG.  13 . 
     After creation of the wound, stylette  50  is withdrawn from the eye  78  and the apparatus. Nosepiece  18  is then placed into a fully extended position and a glaucoma drain  100  made of a cylindrical section of porous biomaterial is loaded into the distal end  46  thereof as shown in FIG.  14 . Note that glaucoma drain  100  is configured dimensionally according to the wound in eye  76 . Once glaucoma drain  100  is loaded into the distal end of nosepiece  18 , plunger  62  is only partially inserted into outer hub  16  and nosepiece  18  as is further shown in FIG.  14 . 
     Nosepiece  18  is then fully retracted into outer hub  16  as shown in FIG.  15 . Note that when nosepiece  18  is in a fully retracted position, a portion of glaucoma drain  100  remains extended beyond the distal end  40  of outer hub  16 . The apparatus is then brought into close proximity to the eye  78  such that glaucoma drain  100  engages the wound in eye  76  and the distal end  40  of outer hub  16  contacts the surface  78  thereof. Plunger  62  is then advanced such that the distal end  70  thereof contacts the proximal surface of the glaucoma drain  100 . Note that the plunger tip end face  70  is configured to engage the proximal surface of the glaucoma drain  100 . Plunger  62  is advanced until collar  72  engages the proximal end  34  of outer hub  16  as shown in FIGS. 9 and 10. Glaucoma drain  100  is thereby translated out of the distal end of nosepiece  18  and outer hub  16  and into the wound in the eye  76  as shown in FIG.  16 . The apparatus is then removed from close proximity to the eye thereby completing the introduction of a glaucoma drain to the eye with an apparatus according to the present invention.