U.S. patent application number 10/702860 was filed with the patent office on 2004-07-01 for device for inserting a flexible intraocular lens.
Invention is credited to Figueroa, Dennis Alexander, Heyman, Thomas Michael, Nigam, Alok, Oviatt, Henry W. JR..
Application Number | 20040127911 10/702860 |
Document ID | / |
Family ID | 23099140 |
Filed Date | 2004-07-01 |
United States Patent
Application |
20040127911 |
Kind Code |
A1 |
Figueroa, Dennis Alexander ;
et al. |
July 1, 2004 |
Device for inserting a flexible intraocular lens
Abstract
A device for inserting a flexible intraocular lens into an eye
including a tubular member and a plunger. The tubular member
includes a staging area, a lumen, and an open distal end. The
staging area supports the lens in an unstressed state prior to
engagement by the plunger. In the unstressed state, the optic of
the lens is suspended in a pocket to avoid any substantial contact
with interior portions of the tubular member. The plunger includes
a slot in its distal tip for receiving and gripping the lens. With
this construction, the lens can be inserted into the eye in one
continuous motion. Further, the plunger holds the lens when the
lens is moved out of the tubular member.
Inventors: |
Figueroa, Dennis Alexander;
(Mission Viejo, CA) ; Nigam, Alok; (Trabuco Cyn,
CA) ; Heyman, Thomas Michael; (Chino Hills, CA)
; Oviatt, Henry W. JR.; (Mission Viejo, CA) |
Correspondence
Address: |
Bausch & Lomb Incorporated
One Bausch & Lomb Place
Rochester
NY
14604-2701
US
|
Family ID: |
23099140 |
Appl. No.: |
10/702860 |
Filed: |
November 6, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10702860 |
Nov 6, 2003 |
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09977961 |
Oct 17, 2001 |
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6685740 |
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09977961 |
Oct 17, 2001 |
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08615185 |
Jun 25, 1996 |
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6336932 |
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08615185 |
Jun 25, 1996 |
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PCT/US95/09973 |
Aug 7, 1995 |
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08615185 |
Jun 25, 1996 |
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08286557 |
Aug 5, 1994 |
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Current U.S.
Class: |
606/107 |
Current CPC
Class: |
A61F 2/1691 20130101;
A61F 2/1678 20130101; A61F 2/167 20130101 |
Class at
Publication: |
606/107 |
International
Class: |
A61F 009/00 |
Claims
What is claimed is:
1. A device for storing, shipping, and inserting an intraocular
lens having an optic portion into an eye, said device comprising:
an inserter body having a passage adapted to hold the intraocular
lens in an unstressed state with said optic portion suspended to
avoid contact thereof with the interior portions of said
inserter.
2. The device of claim 1 and further comprising a cannula for
attaching to said inserter.
3. The device of claim 2 wherein the cannula is attached to the
inserter prior to shipping said device.
4. The device of claim 2 wherein the cannula is attached to the
device after shipping and prior to inserting the intraocular lens
into an eye.
5. The device of claim 1 wherein said storage of the intraocular
lens in said device is up to and including ten years.
6. The device of claim 1 wherein said passage comprises a staging
area compartment having a shelf segment and a removable cover,
movable between open and closed positions with respect to said
shelf segment.
7. The device of claim 6 and further comprising a cannula having
opposite, open, proximal and distal ends, said proximal end
defining an inner cavity adapted to matingly receive said shelf
segment and said cover when said cover is in the closed position.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. Ser. No.
09/977,961 filed Oct. 17, 2001, which is a divisional of U.S. Ser.
No. 08/615,185 filed Jun. 25, 1996, which is a 371 of International
Appln. No. PCT/US95/09973 filed Aug. 7, 1995, which is a CIP of
U.S. Ser. No. 08/286,557 filed Aug. 5, 1994.
FIELD OF THE INVENTION
[0002] The present invention pertains to a device for inserting a
flexible intraocular lens (IOL) into the eye of a patient.
BACKGROUND OF THE INVENTION
[0003] The natural crystalline lens of the eye plays a primary role
in focusing light onto the retina for proper vision. However, the
lens can become damaged due to injury or become cloudy because of
the aging process or disease and form a cataract. To restore vision
to the eye, the natural lens must be surgically removed and an
artificial lens implanted as a replacement.
[0004] Many surgical procedures have been developed for removing
the natural lens. As an example, phacoemulsification is one such
process which has gained wide popularity. According to this
procedure, a slender implement is inserted through an incision made
in the eye and into the natural lens. The implement produces
ultrasonic vibrations and emulsifies the lens. The emulsified
portions of the lens are then aspirated out of the eye through a
passage provided in the implement. As opposed to other procedures,
this lens extraction method requires the surgeon to make only a
narrow incision in the eye. In general, the use of a small incision
can lessen the trauma and complications experienced during the
surgery and postoperatively.
[0005] A flexible IOL comprises a central optic portion which
focuses light on the retina and at least one outwardly extending
haptic. Haptics can have a variety of different configurations, but
most commonly are either a plate-like extension of the optic or
loop shaped. In any event, the haptics extend outwardly to position
the optic of the lens in alignment with the pupil. Flexible IOLs
are particularly suited for insertion in the eye following a
phacoemulsification lens extraction procedure. Whereas placement of
a hard, non-foldable IOL would require widening of the small
phacoemulsification incision, a flexible IOL can be compressed or
folded for passage through the narrow incision in the eye. Once the
lens is passed through the incision and released into the eye, it
will expand to its original shape and size.
[0006] A number of different devices have been developed to implant
a flexible IOL into an eye. See, for example, U.S. Pat. No.
4,573,998 to Mazzocco, U.S. Pat. No. 4,681,102 to Bartell, U.S.
Pat. No. 4,919,130 to Stoy et al., and U.S. Pat. No. 5,275,604 to
Rheinish et al. In general, these devices function to pass a
compressed lens through the narrow incision made in the eye. These
devices, however, require undue manipulation of the lens, include a
multiplicity of parts, and/or fail to provide ample control of the
lens as it enters the eye.
SUMMARY OF THE INVENTION
[0007] The present invention is a device which enables flexible
IOLs to be easily folded, compressed and inserted through an
incision in the eye. In general, the insertion device comprises a
tubular member for receiving the lens and a plunger for pushing the
lens through the tubular member and into the eye. As the lens is
pushed through the passage, it is compressed into a smaller
configuration. The construction of the present invention ensures an
easy, sure and consistent compression of the lens.
[0008] According to one aspect of the invention, the tubular member
includes a staging area for holding the lens in an unstressed
condition. The lens is preferably held in a suspended position by
its haptics so that the optic remains substantially free of contact
with the interior of the tubular member. In this manner, the device
can be used as the lens package, and the device can be shipped and
stored with the lens already in place and ready for use. As a
result, unnecessary manipulation of the lens is avoided. According
to another aspect of the invention, the plunger tip is provided
with a structure which holds the lens to the plunger when the lens
is pushed out of the tubular member. The distal tip of the plunger
is preferably bifurcated to define a slot for partially receiving
and gripping the lens. With this construction, the plunger is able
to hold the lens when the lens exits the tubular member and expands
into the eye. Holding the lens in this manner eases placement of
the lens in the eye and alleviates the risks associated with
uncontrolled unfolding of the lens or uncontrolled expulsion of the
lens from the inserter into the eye.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a perspective view of an insertion device in
accordance with a preferred embodiment of the present
invention.
[0010] FIG. 2 is a side elevational view of the plunger of the
insertion device.
[0011] FIG. 3 is a top plan view of the plunger.
[0012] FIG. 4 is a cross-sectional view taken along line 4-4 in
FIG. 3.
[0013] FIG. 5 is a partial top plan view of the tubular unit of the
insertion device, including the staging area, with the cover
removed and overturned, and the cannula omitted.
[0014] FIG. 6 is a cross-sectional view taken along line 6-6 in
FIG. 5 with the cover placed onto the shelf segment.
[0015] FIG. 7 is a cross-sectional view taken along line 7-7 in
FIG. 5 with the cover placed onto the shelf segment.
[0016] FIG. 8 is a cross-sectional view taken along line 8-8 in
FIG. 5 with the cover placed onto the shelf segment.
[0017] FIG. 9 is a cross-sectional view taken along line 9-9 in
FIG. 5 with the cover placed onto the shelf segment.
[0018] FIG. 10 is a cross-sectional view taken along line 10-10 in
FIG. 5 with the cover placed onto the shelf segment.
[0019] FIG. 11 is a cross-sectional view taken along line 11-11 in
FIG. 5 with the cover placed onto the shelf segment.
[0020] FIG. 12 is a cross-sectional view taken along line 12-12 in
FIG. 13.
[0021] FIG. 13 is a partial cross-sectional view taken along line
13-13 in FIG. 1, with an IOL in the staging area.
[0022] FIG. 14 is an exploded view of FIG. 13.
[0023] FIG. 15 is a partial top plan view of the tubular unit of
the insertion device with an IOL in the staging area and with the
cover and cannula omitted.
[0024] FIG. 16 is a side elevational view of the distal tip of the
plunger.
[0025] FIG. 17 is a front view of the distal end of the
plunger.
[0026] FIG. 18 is a top plan view of the distal end of the
plunger.
[0027] FIGS. 19-23 are each schematic, partial cross-sectional
views taken along line 19-19 in FIG. 1, illustrating the movement
of the plunger during insertion of the IOL into an eye.
[0028] FIG. 24 is an enlarged top plan view of the distal tip of
the plunger holding an IOL.
[0029] FIG. 25 is a front end view of the insertion device with the
plunger extended to the distal end of the cannula.
[0030] FIG. 26 is a cross-sectional view of an eye illustrating the
insertion and placement of an IOL.
[0031] FIG. 27 is a perspective view of an alternative construction
of the distal end of the cannula.
[0032] FIG. 28 is a perspective view of a second alternative
construction of the distal end of the cannula.
[0033] FIG. 29 is a perspective view of a third alternative
construction of the distal end of the cannula.
[0034] FIG. 30 is a side elevational view of a fourth alternative
construction of the distal end. of the cannula.
[0035] FIG. 31 is a front elevational view of the fourth
alternative construction of the distal end of the cannula.
[0036] FIG. 32 is a perspective view of an alternative embodiment
of the cannula.
[0037] FIG. 33 is a perspective view of another alternative
embodiment of the cannula.
[0038] FIG. 34 is a partial, longitudinal cross-sectional view of
an alternative embodiment of the tubular unit with the cover open
and the cannula removed.
[0039] FIG. 35 is a cross-sectional view taken along line 35-35 in
FIG. 34 without the cover.
[0040] FIG. 36 is a plan view of the inside of the cover of the
alternative tubular unit embodiment of FIG. 34.
[0041] FIG. 37 is a plan view of the inside of the shelf segment of
the alternative tubular unit embodiment of FIG. 34.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0042] The present invention pertains to a device 10 (FIG. 1) for
inserting a flexible IOL 12 into an eye 14 of a patient (FIG. 26).
The device comprises an outer tubular unit 16 and an inner plunger
18. In one embodiment, tubular unit 16 is formed by a base member
20, a cover 21 and a cannula 22 which are coupled together (FIGS.
1, 13 and 14). The components of device 10 may be composed of a
plastic or metal material. For example, the components can be
formed of polycarbonate or polypropylene. The plunger 18 and
cannula 22 are preferably made of polypropylene. Nevertheless, a
wide array of materials could be used.
[0043] Base member 20 is an elongate tubular member defining an
inner passage 24 which is provided with a relatively large opening
at proximal end 26 and an opening 27 of reduced size near, but
spaced from, distal end 28 (FIGS. 1, 5, 13 and 14). A forwardly
extending shelf segment 29 projects beyond opening 27 (FIGS. 5, 13
and 14). Base member 20 preferably has a generally oval
cross-sectional configuration, although other shapes could be
used.
[0044] The inner passage 24 of base member 20 is adapted to movably
receive therein plunger 18. A longitudinal groove 34 is
preferentially positioned along one of the side walls 32 defining
inner passage 24 (FIG. 13). Groove 34 cooperates with an extending
flange 35 projecting laterally from plunger 18 to ensure that the
plunger is properly oriented when fed into base member 20.
Nevertheless, the groove construction could be replaced with a
different structure for ensuring proper placement, such as forming
at least a portion of inner passage 24 and plunger 18 with a
D-shaped configuration. Near distal end 28, base member 20 forms a
narrowed neck 39. Neck 39 defines distal opening 27 through which a
portion of the plunger is passed to engage lens 12. Converging
guideways 41 are positioned along opposite interior sides of
passage 24 leading up to neck 39 (FIGS. 5, 13 and 14). Guideways 41
function to ease the passage of the plunger through neck 39 and
over the shelf segment 29 for engagement with lens 12.
[0045] Shelf segment 29 is formed as an extension of roughly one
half of the tubular base member 20. Shelf segment 29 cooperates
with cover 21 to define a staging area compartment 45 for holding
lens 12 (FIGS. 5-11 and 13-14). Lens 12 preferably has a central
optic and a pair of adjacent web or plate haptics 49a, 49b (FIGS.
14 and 24). Nevertheless, other lens constructions, such as a lens
with loop haptics, could also be used. The interior side of shelf
segment 29 is formed in part by a pair of ledges 51 a, 51b adjacent
neck 39, a pair of recessed central flats 52a, 52b, and a pair of
ramps 53a, 53b spaced forwardly of flats 52a, 52b (FIGS. 5-11 and
13-14). Ledges 51a, 51b and ramps 53a, 53b are each formed with top
surfaces 54a, 54b, 55a, 55b to engage and support the haptics 49a,
49b of lens 12 in an initial unstressed position. Ramps 53a, 53b
further include sloped surfaces 59a, 59b inclined to flats 52a,
52b. Flats 52a, 52b are recessed relative to top surfaces 54a, 54b,
55a, 55b to define a pocket 60 into which is received optic 48.
[0046] Cover 21 lies against shelf segment 29 to form staging area
compartment 45 and enclose lens 12 in its initial unstressed
position (FIG. 13). Cover 21 includes on its interior side recessed
sections 61a, 6 1b, the central portions of which lie opposed to
the proximal half of flats 52a, 52b. A pair of adjacent plateau
segments 63a, 63b lie opposed to ledges 51a, 51b define a gap 65
adapted to matingly receive and hold the proximal haptic 49a.
Haptic 49a is loosely received in gap 65 so that it can be easily
pushed out of staging area 45 during the insertion process. Ledges
51a, 51b, plateau segments 63a, 63b, and ramps 53a, 53b
collectively support lens 12 by haptics 49a, 49b. In this initial
position, optic 48 is held in suspension in pocket 60 so that the
optic avoids contact with the interior walls of the staging area
compartment 45.
[0047] The lens 12 can be installed in compartment 45 at a
manufacturing plant and shipped to the user in device 10 with or
without cannula 22 assembled in place. In this manner, device 10
can conveniently serve also as a lens package. Since lens 12 is
supported in a generally suspended and unstressed state, the lens
can be stored for a substantial length of time, perhaps as long as
10 years. Although the cover could be fixed to base member 20, it
is designed for removal to enable inspection of the lens prior to
its implantation in the eye. As shown in FIG. 14, cover 21 can be
separable from base member 20, and secured in place by a snap fit,
tape or other securing means. Nevertheless, the cover may be hinged
to cannula 22, shelf segment 29, or neck 39.
[0048] Cover 21 includes projections 67a, 67b which mate with
depressions 68a, 68b formed in shelf segment 29. In addition, shelf
segment 29 includes proximal outer walls 70a, 70b and distal outer
walls 72a, 72b. Proximal walls 70a, 70b abut the outer portions of
recessed sections 61a, 61b. Distal walls 72a, 72b likewise abut
walls 73a, 73b of cover 21. Distal walls 72a, 72b are preferably
recessed relative to proximal walls 70a, 70b to enhance the mating
fit of cover 21. During shipping of the device, the cover may be
held closed by cannula 22, tape and/or other means to avoid
inadvertent release of the lens.
[0049] Troughs 75a, 75b are formed in shelf segment 29 by extending
the inner side wall surface 78 of compartment 45 downwardly between
the outer distal sides of flats 52a, 52b and distal walls 72a, 72b.
Troughs 75a, 75b are provided to receive the opposite sides of lens
12 as they are folded or curled along inner side wall surface 78.
In the preferred embodiment, the troughs are deeper than flats 52a,
52b.
[0050] Cover 21 further includes a central, generally planar
surface 88 inclined to extend away from shelf segment 29. A
conically shaped portion 91 generally surrounding inclined surface
88 lies opposed to ramps 53a, 53b. These surfaces 88, 91 in
cooperation with ramps 53a, 53b initiate the desired folding of the
lens to its compressed state.
[0051] Cannula 22 is an elongate tubular member with an open
proximal end 93 and an opposite open distal end 95 (FIGS. 1 and
12-14). Cannula 22 is preferably subdivided into three graduated
sections 97-99. The proximal section 97 has a generally rectangular
configuration and defines an inner cavity 101 sized to matingly
receive the assembled shelf segment 29 and cover 21. Section 97
extends from distal end 28 to neck 39 of base member 20 and
functions to hold cover 21 against shelf segment 29. An axial
channel 102 is defined along one wall of cavity 101 to matingly
receive ridge 103 extending up from cover 21. A hole 104 defined at
the proximal end 93 of cannula 22 cooperates with a biased lock 106
on base member 20 to secure the cannula in place.
[0052] The medial section 98 of cannula 22 is significantly smaller
than proximal section 97 so that a rim 110 is defined therebetween.
Rim 110 acts as a shoulder in abutment with the aligned distal ends
28, 111 of base member 20 and cover 21. The inner wall of medial
section 98 converges to define a funnel-shaped passage 112. The
funnel portion 112 preferably has an oval cross-section, although
other shapes could be used. This funnel section causes the lens to
become substantially curled and compressed for entry into the
eye.
[0053] The final, distal section 99 of cannula 22 is a long, narrow
tube which defines an inner lumen 114. Distal section 99 is to be
inserted through the narrow incision made in the eye. As with
medial section 98, distal section 99 and lumen 114 preferably have
an oval cross-sectional shape. Of course, other shapes could be
utilized if desired. To facilitate manufacturing and further
compression of lens 12, lumen 114 is formed to taper slightly as it
extends forward. Distal end 95 of cannula 22 is beveled to ease the
insertion of the cannula into the incision and to assist in
facilitating a gradual expansion of the lens as it exits from lumen
114.
[0054] The distal section of the cannula may be provided with a
wide variety of cross-section configurations. As examples only, the
cannula may be shaped with a clover-type tip 22A, a collapsible bag
type tip 22B, or a wave-type tip 22C (FIGS. 27-29). These
configured tips enhance the strength of the tip and thus permit a
narrower construction to be used. The cannula tip may also be
formed with a collet-like construction 22D. In this embodiment, the
tip includes four separable leaves 23 which are expanded as the
lens is pushed into the eye. The leaves 23 are biased to naturally
close after the lens is placed into the eye and the plunger
retracted.
[0055] In the preferred embodiment, cover 221 is hinged to base
member 220 of tubular unit 216 (FIGS. 34-37). The inside
configuration of cover 221 is essentially the same as the inside
configuration of cover 21, except that projections 267 are
interconnected with plateau segments 263 by segments 264.
Similarly, the inside configuration of shelf segment 229 is
essentially the same as the inside configuration of shelf segment
29. As can be seen in FIG. 37, shelf segment 229 includes a
corresponding interconnection of depressions 268 with ledges 251.
Also, the central channel 224 of shelf segment 229, which
accommodates passage of the plunger, is enlarged across its middle
section. These modifications do not affect the operation of
compressing and inserting the lens into an eye.
[0056] Also, as an optional feature, a hole 246 may be provided
through shelf segment 229. The hole can be used to insert a
viscoelastic material in embodiments wherein the cover is fixed to
the shelf segment or otherwise not opened by the surgeon.
[0057] Cover 221 further includes a pair of rearwardly extending
arms 265, which are provided with knobs 266 on their free ends.
Arms 265 are provided to pivotally connect the cover to the neck
portion 239. Specifically, neck portion 239 includes a pair of
sockets 242. Sockets 242 are formed to include substantially
square-shaped openings 243 (although other shapes could also be
used) for receiving knobs 266, and channel portions 244 for
receiving arms 265 when cover 221 is moved to its closed position
(not shown). Recesses 245 are formed on the outside walls of
openings 243 (FIG. 35) to receive the outward projection of knobs
266. Receipt of knobs 266 in recesses 245 functions to retain the
cover 221 to base member 220.
[0058] In an alternative embodiment, cannula 160 includes a cover
162 hinged for movement between an open position and a closed
position (FIG. 32). Cannula 160 has essentially the same
construction as cannula 22, except for the incorporation of cover
162 in proximal section 164. Cover 162 has substantially the same
construction as cover 21, including the same internal configuration
for supporting and compressing the lens.
[0059] Proximal section 164 of cannula 160 comprises a base 166 and
a cover 162. The base includes a bottom wall 168 and a pair of side
walls 170 which extend upward only as high as shelf segment 29. The
internal surfaces of bottom wall 168 and side walls 170 are shaped
to matingly receive the external surface of shelf segment 29. A
pair of upstanding flanges 172 are provided at proximal end 174 of
base 166 to engage neck 39 and provide ample support for the
cannula. A hole 176 is provided to cooperate with a protrusion (not
shown) on shelf segment 29 in locking the cannula to the base
member 20.
[0060] Cover 162 is movably connected to base 166 by a living hinge
178, although other hinge constructions could also be used. The
cover is pivotally movable to an open position to permit inspection
of the lens, and to a closed position for inserting the lens into a
patient's eye. The lower edges of side walls 180 of the cover are
formed to snap into a locking engagement with base 166 by any
conventional construction (not shown); nevertheless, other
fastening arrangements could be used. The internal configuration of
cover 162 aligns with the internal configuration of shelf segment
29 in the same way as cover 21. Cover 162 further includes a
proximal tab 182 which projects between flanges 172 to engage
locking protrusion 106 in hole 184.
[0061] As an alternative construction, side walls 170a of cannula
160a extend the entire depth of proximal section 164a, and cover
162a is provided with a flattened construction (FIG. 33). The
internal side of cover 162a has the same configuration and relative
positioning to shelf segment 29 as does the above-described cover
21. The edges 180a of cover 162a are preferably constructed to snap
into locking engagement with edges 181a of side walls 170a.
Nonetheless, other fastening arrangements could be used.
[0062] Preferably, cannula 162, 162a is composed of a polypropylene
or other thermoplastic material. A disposable cover (not shown),
can be used to ship and store the IOL in device 10. The disposable
cover preferably has the same general size and shape as cover 162,
162a to enable it to snap into engagement with base 166, 166a. The
disposable cover can have a wide variety of internal constructions
so long as the IOL is adequately supported (as described above with
respect to the other covers) and protected.
[0063] Plunger 18 is an elongate member which is adapted to move
through the inner passage 115 defined by tubular unit 16 (FIGS. 1
and 13). The plunger comprises a main body 116 preferably shaped
with a cross-shaped cross-section (FIGS. 2-3). As discussed above,
one flange 35 of the body is received into groove 34 to ensure
proper placement of the plunger. A flat thumb pad 119 is provided
on the proximal end of body 116 for manual operation of the device.
Other constructions, however, may be provided to effect advancement
of plunger 18 through tubular unit 16. The forward end of body 116
includes a pair of spaced apart O-rings 120a, 120b. The O-rings
provide a level of resistance to enable a more controlled manual
operation of the plunger. The O-rings further help to prevent the
plunger from inadvertent movement when the surgeon manipulates
device 10 during the surgical procedure. Other constructions, such
as friction fit flanges, could be used in place of the O-ring.
[0064] A slender rod 122 projects forwardly beyond the main body
116 of plunger 18. The rod is intended to pass through staging area
45, funnel 112 and lumen 114. In order to provide sufficient
clearance for rod 122, shelf segment 29 defines a channel 124 and
cover 21 includes a relief 125 (FIGS. 5-11 and 13-14). Relief 125
only extends partway across cover 21 because surface 88 diverges
away from the interior side of shelf segment 29 and thus provides
sufficient clearance for rod 122. While rod 122 could have a wide
range of shapes, it preferably has a circular or a slight ellipsoid
shape adapted to pass through the distal end 95 of cannula 22 (FIG.
25).
[0065] The distal tip 128 of rod 122 is preferably bifurcated to
define a pair of prongs 131a, 131b separated by a slot 132 (FIGS.
2-3, 16-18, 24 and 25). The slot is shaped to receive and hold
proximal haptic 49a and optic 48 of lens 12. The ends 135a, 135b of
prongs 131a, 131b are chamfered to form a pair of walls 137a, 137b
which collectively form a generally V-shaped configuration.
Depending on the sturdiness of the proximal haptic, walls 137a,
137b may or may not engage the proximal end of the optic 48. Prongs
131a, 131b are preferably identical to one another. Nevertheless,
one prong 131a can be made narrower than the other prong 131b to
allow extra space for the lens 12 to curl and compress during its
passage through lumen 114 and into the patient's eye. Under
ordinary circumstances, however, the extra space is not needed.
[0066] The distal tip of plunger 18 may alternatively be formed
with other structural configurations which would hold the lens when
the lens is pushed out of the cannula. For example, when implanting
an IOL with loop-shaped haptics, the plunger may be formed with a
closed vertical slot (not shown) along the top of rod 122 in lieu
of the open horizontal slot 132. In this arrangement, the lens
would be positioned in staging area 45 with the haptics extending
from points along the sides of the tubular unit. The haptic, which
curls rearwardly would be inserted into the vertical slot when the
lens is mounted in the staging area. To avoid inadvertent release
of the haptic during shipping and storage, the plunger could be
secured in a fixed position through the use of a latch, tape, or
other securing means. In any event, the plunger would engage the
optic portion of the lens with its distal tip, formed for example
with only inclined surfaces like 137a, 137b. When the lens is
initially extended beyond cannula 22, the noted haptic would remain
entrapped in the slot which would not yet be exposed outside of
cannula 22. When release of the lens is desired, the plunger can be
pushed slightly farther to expose the vertical slot and free the
trapped haptic. The plunger can then be retracted into the tubular
unit 16 while the lens remains in the eye.
[0067] In one embodiment, a pair of resilient spring elements 140a,
140b extends laterally from rod 122 near the rod's proximal end
(FIGS. 2-3). The spring elements function to press against
guideways 41 when the free end 128 of rod 122 extends beyond
cannula 22. This engagement with guideways 41 forces spring
elements 140a, 140b to be pushed backward, and thereby create a
biasing force to pull the plunger rearward into tubular unit 16. In
the preferred construction, the spring elements (not shown) would
extend forwardly, generally parallel with rod 122, from the front
end of the main body. In this arrangement, the spring elements
would be designed to curl inward upon engagement with guideways
141. Additionally, a coil spring (not shown) may be secured around
the plunger/rod to provide the desired biasing force. Of course,
other spring arrangements could also be used. The spring may also
be omitted and the plunger retracted manually by the surgeon.
[0068] Once the lens has been inspected, device 10 can be
assembled. A viscoelastic material, typically used for such
surgical procedures, is placed in the cannula 22, typically prior
to attachment of the cannula 22 to the assembly, as a lubricant for
the insertion process. Once device 10 is assembled, the surgeon
inserts the distal end of cannula 22 into the incision 142 in the
eye 14. The surgeon then grasps lateral flanges 141 and pushes on
pad 119 to move plunger 18 in a continuous forward motion. (FIG.
1). The continuous movement of rod 122 through tubular unit 16
engages lens 12 through its distal end 128 (FIG. 24). The proximal
haptic 49a and possibly a portion of optic 48 are received into and
held by slot 132, between walls 137a, 137b. The lens is then pushed
forwardly by plunger 18 so that the distal side of optic 48 is
shifted transversely toward cover 21 by sloped surfaces 59a, 59b of
ramps 53a, 53b; that is, sloped surfaces 59a, 59b guide the central
portion of optic 48 away from flats 52a, 52b (FIGS. 19 and 20).
Inclined surface 88 and conical surface 91 provide ample clearance
for this motion of the lens. As the center of the lens is shifted
to move over ramps 53a, 53b, the sides of the lens are forced
generally in the direction opposite to the ramps, by the inner wall
surface 78 of cover 21. Specifically, the conical surface 91 in
cover 21 causes lens 12 to curl into troughs 75a, 75b. Continued
advancement of lens 12 through the tapering passage of tubular unit
16 causes continued curling and compression of the lens.
[0069] The lens continues its forward motion until plunger 18
pushes lens 12 beyond cannula 22. In the preferred construction,
plunger 18 is pushed manually forward in a controlled manner,
although other means, such as an electric motor or pneumatic drive,
may be used.
[0070] The leading haptic 49b is fed into the distal cul-de-sac 152
of the capsular bag 154. When lens 12 exits from cannula 22, it
expands to its full unstressed state (FIGS. 22, 24 and 26). The
lens, however, remains held in the slot 132 of plunger 18.
Retention of the lens by the plunger reduces the risk of the lens
expelling in an uncontrolled manner from the cannula and damaging
the interior of the eye. Retaining the lens with the plunger also
provides increased control in placing the lens in the eye. To
release the lens, the plunger is retracted into tubular unit 16 so
that the lens is pushed from slot 132 by distal end 95 of cannula
22 (FIG. 23). The retraction of plunger 18 is preferably performed
automatically by biased spring elements 140a, 140b when pressure is
released from thumb pad 119. A further implement, or perhaps device
10 itself, will typically be required to properly position the
proximal haptic 49a into capsular bag 154.
[0071] The above-discussion concerns the preferred embodiments of
the present invention. Various other embodiments as well as many
changes and alterations may be made without departing from the
spirit and broader aspects of the invention as described in the
claims. For example, although the preferred embodiments concern the
insertion of a flexible IOL into the eye, the invention is not so
limited. The teachings of the present invention are applicable to
the insertion of flexible membranes generally, including synthetic
membranes, biopolymer membranes, and natural body tissues.
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