U.S. patent number 3,866,249 [Application Number 05/448,966] was granted by the patent office on 1975-02-18 for posterior chamber artificial intraocular lens.
Invention is credited to Leonard Flom.
United States Patent |
3,866,249 |
Flom |
February 18, 1975 |
POSTERIOR CHAMBER ARTIFICIAL INTRAOCULAR LENS
Abstract
An artificial intraocular lens for implantation in the posterior
chamber of an eye after intracapsular or extracapsular lens
extraction comprises a transparent optical zone portion shaped
similar to the natural lens and a plurality of prongs protruding
forwardly from the periphery thereof, wherein after implantation of
the artificial intraocular lens the prongs extend through the iris
to anchor the lens in the posterior chamber of the eye. The prongs
protrude forwardly from the lens and are curved so that the outer
ends of the prongs extend generally along the periphery of the
lens, and the prongs are preferably arranged in pairs with the
prongs in each pair extending in opposite directions along the
periphery of the lens. A peripheral flange may be provided
surrounding the optical zone portion for attaching the prongs to
the lens, and a plurality of openings may be provided in the flange
adjacent to the optical zone portion to permit passage of aqueous
fluid from the ciliary body to the anterior chamber. Also disclosed
is an insertion necklace comprising a semirigid loop passed through
the openings in the flange surrounding the optical zone portion to
embrace and support the lens during implantation thereof. A handle
is connected to the loop for holding and manipulating the lens. The
loop may be cut for removal of the insertion necklace after
implantation of the lens.
Inventors: |
Flom; Leonard (Westport,
CT) |
Family
ID: |
23782351 |
Appl.
No.: |
05/448,966 |
Filed: |
March 7, 1974 |
Current U.S.
Class: |
623/6.12;
623/6.41; 623/6.55; D24/157 |
Current CPC
Class: |
A61F
2/14 (20130101); A61F 2/1601 (20150401); A61F
2/16 (20130101); A61F 2220/0016 (20130101); A61F
2002/1699 (20150401) |
Current International
Class: |
A61F
2/16 (20060101); A61f 001/16 (); A61f 001/24 () |
Field of
Search: |
;3/13,1 ;351/160 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
"A Weightless Iseikonic Intraocular Lens," by R. D. Binkhorst et
al., American Journal of Ophthalmology, Vol. 58, No. 1, July 1964,
pages 73-78..
|
Primary Examiner: Frinks; Ronald L.
Attorney, Agent or Firm: Wooster, Davis & Cifelli
Claims
I claim:
1. An artificial intraocular lens for implantation in the posterior
chamber of an eye, the artificial intraocular lens comprising an
optical zone portion fabricated of transparent material and shaped
similar to a natural lens, and a plurality of prongs attached to
the optical zone portion near the periphery thereof, the prongs
protruding forwardly therefrom for insertion through the iris of
the eye to hold and position the lens therein.
2. An artificial intraocular lens as defined in claim 1 and further
comprising a groove formed in the outer periphery of the optical
zone portion and an annular band formed integrally with the prongs,
the annular band matingly received in the groove whereby the prongs
are attached to the optical zone portion.
3. An artificial intraocular lens as defined in claim 1 and further
comprising openings formed in the optical zone portion near the
periphery thereof wherein the prongs are tightly received and held
in the openings and are thereby attached to the optical zone
portion.
4. An artificial intraocular lens as defined in claim 1 wherein the
inner portions of the prongs adjacent to the optical zone portion
protrude forwardly from the optical zone portion and wherein the
prongs are curved so that the outer portions of the prongs extend
along the periphery of the optical zone portion and generally
parallel to the plane of the periphery of the optical zone
portion.
5. An artificial intraocular lens as defined in claim 4 wherein the
plurality of prongs is an even number of prongs arranged in pairs
about the outer periphery of the optical zone portion, each pair of
prongs comprising two prongs attached to the optical zone portion
at adjacent points, and wherein the outer portions of the prongs in
each pair of prongs extend in opposite directions along the
periphery of the optical zone portion.
6. An artificial intraocular lens as defined in claim 1 wherein the
inner portions of the prongs adjacent to the optical zone portion
protrude forwardly from the optical zone portion and wherein the
prongs are curved so that the outer portions of the prongs extend
along the periphery of the optical zone portion.
7. An artificial intraocular lens as defined in claim 6 wherein the
plurality of prongs is an even number of prongs arranged in pairs
about the outer periphery of the optical zone portion,, each pair
of prongs comprising two prongs attached to the optical zone
portion at adjacent points, and wherein the outer portions of the
prongs in each pair of prongs extend in opposite directions along
the periphery of the optical zone portion.
8. An artificial intraocular lens as defined in claim 7 wherein the
plurality of prongs comprises eight prongs arranged in four
pairs.
9. An artificial intraocular lens as defined in claim 1 wherein the
plurality of prongs is an even number of prongs arranged in pairs
about the outer periphery of the optical zone portion, each pair of
prongs comprising two prongs attached to the optical zone portion
at adjacent points.
10. An artificial intraocular lens as defined in claim 9 wherein
each pair of prongs is integral by virtue of a connecting portion
extending therebetween and wherein the prongs are mounted by
imbedding the connecting portion in the optical zone portion.
11. An artificial intraocular lens as defined in claim 9 wherein
the pairs of prongs are evenly spaced about the periphery of the
optical zone portion.
12. An artificial intraocular lens for implantation in the
posterior chamber of an eye, the artificial intraocular lens
comprising an optical zone portion fabricated of transparent
material and shaped similar to a natural lens, a flange formed
integrally with the optical zone portion and extending radially
outwardly from the periphery of the optical zone portion, and a
plurality of prongs attached to the flange, the prongs protruding
forwardly therefrom for insertion through the iris of the eye to
hold and position the lens therein.
13. An artificial intraocular lens as defined in claim 12 and
further comprising a groove formed in the outer periphery of the
flange and an annular band formed integrally with the prongs, the
annular band matingly received in the groove whereby the prongs are
attached to the flange.
14. An artificial intraocular lens as defined in claim 12 and
further comprising openings formed in the flange near the periphery
thereof wherein the prongs are tightly received and held in the
openings and are thereby attached to the flange.
15. An artificial intraocular lens as defined in claim 12 wherein
the plurality of prongs is an even number of prongs arranged in
pairs about the outer periphery of the flange, each paif of prongs
comprising two prongs attached to the flange at adjacent
points.
16. An artificial intraocular lens as defined in claim 15 wherein
each pair of prongs is integral by virtue of a connecting portion
extending therebetween and wherein the prongs are mounted by
imbedding the connecting portion in the flange.
17. An artificial intraocular lens as defined in claim 12 wherein
the inner portions of the prongs adjacent to the flange protrude
forwardly from the flange and wherein the prongs are curved so that
the outer portions of the prongs extend along the periphery of the
flange and generally parallel to the plane of the flange.
18. An artificial intraocular lens as defined in claim 17 wherein
the plurality of prongs is an even number of prongs arranged in
pairs above the flange, each pair of prongs comprising two prongs
attached to the flange at adjacent points, and wherein the outer
portions of the prongs in each pair of prongs extend in opposite
directions along the periphery of the flange.
19. An artificial intraocular lens as defined in claim 12 wherein
the inner portions of the prongs adjacent to the flange protrude
forwardly from the flange and wherein the prongs are curved so that
the outer portions of the prongs extend along the periphery of the
flange.
20. An artificial intraocular lens as defined in claim 19 wherein
the plurality of prongs is an even number of prongs arranged in
pairs about the flange, each pair of prongs comprising two prongs
attached to the flange at adjacent points, and wherein the outer
portions of the prongs in each pair of prongs extend in opposite
directions along the periphery of the flange.
21. An artificial intraocular lens as defined in claim 20 wherein
the plurality of prongs comprises eight prongs arranged in four
pairs.
22. An artificial intraocular lens as defined in claim 20 wherein
the pairs of prongs are evenly spaced about the periphery of the
flange.
23. An artificial intraocular lens as defined in claim 22 and
further comprising a plurality of drain holes extending through the
artificial intraocular lens near the intersection of the flange and
the optical zone portion thereof, wherein a drain hole is
positioned adjacent to the inner portions of each pair of
prongs.
24. An artificial intraocular lens as defined in claim 12 and
further comprising a plurality of drain holes extending through the
artificial intraocular lens near the intersection of the flange and
the optical zone portion thereof.
25. An artificial intraocular lens as defined in claim 24 wherein
the plurality of drain holes are evenly spaced about the periphery
of the optical zone portion.
26. An artificial intraocular lens as defined in claim 24 and
further comprising an insertion necklace for holding and
manipulating the artificial intraocular lens during the
implantation thereof, the insertion necklace comprising a loop and
a handle, the loop passing through two of the drain holes in the
artificial intraocular lens wherein one portion of the loop
embraces the rear surface of the optical zone portion and another
portion of the loop extends to the handle.
27. An artificial intraocular lens as defined in claim 26 wherein
the portion of the loop of the insertion necklace extending to the
handle removeably engages at least one of the prongs.
28. An artificial intraocular lens as defined in claim 26 wherein
the drain holes through which the loop passes are located
substantially opposite from each other about the periphery of the
optical zone portion.
Description
BACKGROUND
1. Field of the Invention
This invention relates to an artificial intraocular lens for
implantation in the posterior chamber of the eye to obviate
aphakia, and further relates to a structure for supporting and
handling the artificial intraocular lens during implanation
thereof.
2. Prior Art
When no lens is rpeseent in the eye, which is known as the aphakic
condition or aphakia and is usually the result of intracapsular or
extracapsular lens extraction, the eye does not have the ability to
focus rays of light. Therefore the eye receives a blurred image and
vision is impaired.
The most common solution for producing a focusing mechanism to
obviate the aphakic condition is to interpose contact lenses or
spectacles or a combination thereof between the eye and the light
entering therein. However, both contact lenses and spectacles have
drawbacks when used in treatment of aphakia. Neither spactacles nor
contact lenses can duplicate the natural optical system because
they are positioned outside of the eye, which results in a shift of
the optical center from the in vivo state. Because the optical
center has been shifted, the image received by the eye is either
distorted and/or changed in size. In particular, spectacles and/or
contact lenses usually cannot be used to restore exactly binocular
vision after removal or loss of the lens from one eye when the
other eye continues to function normally.
Further, the most common reason for removal of a lens is the
condition of lenticular opacity known as a cataract, which occurs
primarily in aged persons who have difficulty in adjusting to
contact lenses and in manipulating the contact lenses for insertion
and removal. Cataracts are also common in animals such as dogs and
horses, and contact lenses and/or spectacles are not suitable
devices for their treatment.
The desirability of implanting an artificial lens within the eye to
obviate the condition of aphakia is well known and accepted in
countries such as England, Holland and Italy. However, practical
devices for carrying out this desirable objective have not been
prepared, although several devices have been used with a modicum of
success.
In approximately 1950 Harold Ridley developed an artificial
intraocular lens which comprised an optical lens portion having
three foot-like projections or "feet" extending radially outward
therefrom. Ridley originally placed this lens in the posterior
chamber of the eye, behind the iris, with the feet resting against
the ciliary body between the ciliary process and the base of the
iris. However, positioning of this lens in the posterior chamber
was abandoned because of instances of dislocation after
implantation and failures from glaucoma and the like, probably
caused by irritation of the ciliary body by the feet.
Ridley's failure with posterior chamber artificial lenses led him
and others, such as D. P. Choyce, to turn their attention to
intraocular artificial lenses implanted in the anterior chamber of
the eye between the iris and the cornea. The particular lens used
was similar to Ridley's original lens, and had radially protruding
feet which accomplished positioning of the lens in front of the
pupil. These efforts also met with limited success, primarily
because of the problems of irritation of the eye by the supporting
feet and dislocation of the lens from its desired position in front
of the pupil.
It should be noted that placement of the lens in the anterior
chamber is an unnatural position, with the attendant problems of
restoring accurate binocular vision. Also, an anterior chamber lens
is not positioned adjacent to the hyloid membrane for supporting
the vitreous humor, and instances of forward displacement of the
vitreous humor and retinal detachment are more likely to occur when
anterior chamber lenses are used.
E. Epstein and C. D. Binkhorst developed artificial intraocular
lenses which rely on the constrictor muscle of the iris as the
positioning mechanism. Epstein first designed a "collar-stud"
implant, with the pupil constructed in its waist for positioning
thereof, and later a "Maltese Cross" pupil-supported implant with
two leaves anterior to the iris and two leaves at right angles to
the others and behind the iris. Binkhorst developed an
iridocapsular (two-loop) lens and an iris-clip (four-loop) lens.
The former comprises a lens of larger diameter than the pupil and
placed thereover so that the periphery engages the front of the
iris, and further comprises two metal loops which protrude from the
back of the lens and extend generally parallel with the back
surface of the lens and behind the iris for clipping the lens to
the iris. Binkhorst's iris-clip lens is similar except that the
iris is held by two pairs of loops which flank the iris and support
the lens in front of the pupil. In some instances the iris is
sutured to the clips to secure the positioning of the lens. This
type of lens is also unsatisfactory in several respects. It, by
necessity, interferes with constriction of the pupil, and in fact
fixes the size of the pupil. It is also an anterior chamber lens,
wherein correct positioning of the optical center cannot be
achieved.
J. G. F. Worst considered posterior placement of an artificial lens
to be desirable,, and developed a lens having a pair of closely
spaced openings for positioning behind the iris. A suture was
placed through the two openings and attached the lens to the iris.
Although it is not believed that Worst's buttom would cause
irritation of the ciliary body, as did the earlier posterior lens
of Ridley, the difficulty of the technique necessary to suture the
lens in position without damaging the iris as well as the
possibility that the suture would not hold or would tear out from
the iris has limited the acceptance of Worst's lens.
An additional artificial lens designed for positioning in the
posterior chamber is described in U.S. Pat. No. 3,711,870 to
Deitrick. Deitrick's lens comprises a central optical portion
surrounding by a resilient silicone flange shaped to receive and
nest against the ciliary body. The lens is to be held in place by
suturing the resilient flange to the ciliary body. Although the
medical worth of the Deitrick lens is not yet known, it is known
that it would be difficult to place sutures where Deitrick directs
and it is also known that there may be reluctance on the part of
ophthalmologists or ophthalmologic surgeons to do so because of the
many risks attendant with the irritation of the ciliary body.
Several of the prior art lenses are discussed in an article by D.
P. Choyce entitled "History of Intraocular Implants" which is
printed in Annals of Ophthalmology, October, 1973. The article also
includes a list of references from which further information
concerning prior art intraocular lenses can be obtained.
Several of the above lenses rely on sutures placed in the iris for
holding the lenses in position. It should be noted that the iris
consists of spongy, flexible tissue which may be pulled and
stretched to a limited degree without damaging it. However, the
iris has the unique property of never healing together after being
cut or damaged. Thus, if a suture pulls through the iris, the
damage to the iris is permanent. Because sutures are generally of a
small diameter, if a lens positioned and held by sutures is
subjected to a dislocating force, the sutures may cut the iris,
resulting in permanent damage.
SUMMARY OF THE INVENTION
The artificial intraocular lens according to the invention herein
is a posterior chamber lens, wherein all the advantages of natural
positioning of the lens are achieved. The artificial intraocular
lens is held in place by a plurality of prongs extending forwardly
from and along the periphery of the lens, wherein the prongs pass
through the iris. The prongs are angled to prevent the lens from
being dislocated. In one embodiment the prongs are attached to a
flange peripherally surrounding the optical portion of the lens,
and openings are provided at the intersection of the lens and the
flange to permit the free flow of aqueous produced by the ciliary
body. In other embodiments, the prongs are attached to the outer
periphery of the optical portion of the lens, and no flange is
employed.
Thus, the artificial intraocular lens according to the invention
herein is firmly held in the natural position of the posterior
chamber. It requires no sutures, which simplifies the technique
necessary for implantation thereof and also reduces the possibility
of damage to the iris by sutures. The artificial intraocular lens
according to the invention herein avoids any contact with the
ciliary body, and thereby avoids the many serious risks attendant
therewith.
The case with which the artificial intraocular lens may be
implanted is enhanced by the provision of an insertion necklace
which comprises a semirigid loop passed through two of the
peripheral openings in the lens wherein the lens is embraced and
carried by the insertion necklace. The loop terminates in a handle.
Thus, the lens is easily held and manipulated during implantation,
and because the insertion necklace is attached to the lens, the
lens cannot be dropped or lost from the opthalmologic surgeon's
control. This is to be contrasted with the usual methods of holding
an artificial intraocular lens by means of a forceps or other
detachable instrument during implantation. The insertion necklace
may be removed by cutting the loop and withdrawing from the lens
after implantation has been accomplished.
True binocular vision may be achieved with the posterior chamber
lens according to the invention herein, and complications from
irritation of the ciliary body and/or forward displacement of the
vitreous humor and retinal detachment are avoided.
OBJECTS OF THE INVENTION
It is an object of the invention to provide an artificial
intraocular lens for obviating aphakia.
It is another object of the invention to provide an artificial
intraocular lens for implantation into the posterior chamber of the
eye.
It is a further object of the invention to provide an artificial
intraocular lens which includes means for positioning it in the eye
without irritation of sensitive portions thereof.
It is another object of the invention to provide an artificial
intraocular lens which is easily implanted.
It is yet another object of the invention to provide means for
holding the artificial intraocular lens during implantation
thereof.
Other and more particular objects of the invention will be in part
obvious and will in part appear from a perusal of the following
description of the preferred embodiment and the claims, taken
together with the drawings.
DRAWINGS
FIG. 1 is a front elevation view partially in section, of an
artificial intraocular lens according to the invention herein;
FIG. 2 is a side elevation view, partially in section, of the
artificial intraocular lens of FIG. 1;
FIG. 3 is a fragmentary sectional view of another embodiment of an
artificial intraocular lens according to the invention herein;
FIG. 4 is a side elevation view of another embodiment of an
artificial intraocular lens according to the invention herein;
FIG. 5 is a section view of the artificial intraocular lens of FIG.
4 taken along the lines 5--5 of FIG. 4;
FIG. 6 is a front elevation view of the artificial intraocular lens
of FIG. 1 having an insertion collar according to the invention
herein attached thereto;
FIG. 7 is a sectional view of the insertion collar handle taken
along the lines 7--7 of FIG. 6;
FIG. 8 is a front elevation view of an alternative embodiment of an
artificial intraocular lens having an insertion collar attached
thereto according to the invention herein;
FIG. 9 is a sectional view of an eye showing an artificial
intraocular lens according to the invention herein being
implanted;
FIG. 10 is a sectional view of an eye showing an artificial
intraocular lens according to the invention herein implanted
therein;
FIG. 11 is a front view of an eye having an artificial intraocular
lens according to the invention herein implanted therein;
FIG. 12 is a front view of an eye having another embodiment of an
artificial intraocular lens according to the invention herein
implanted therein; and
FIG. 13 is a front view of an eye having another embodiment of an
artificial intraocular lens according to the invention herein
implanted therein.
The same reference numbers refer to the same elements throughout
the various figures.
PREFERRED EMBODIMENTS
The invention herein relates to an artificial intraocular lens,
several embodiments of which will be described, and an insertion
necklace for holding and manipulating the artificial intraocular
lenses during implantation thereof.
Referring now to FIGS. 1 and 2, there is shown an artificial
intraocular lens 10 according to the invention herein. The lens 10
generally comprises an optical zone portion 11, a flange 12
peripherally surrounding the optical zone portion 11, and a
plurality of prongs 13-20 for anchoring the lens in an eye. A
plurality of openings 21-24 may be provided through the flange near
where the flange intersects the optical zone portion 11.
The optical zone portion 11 can be either a biconvex or planoconvex
lens, as required. It is preferable that the optical zone portion
be shaped similar to the natural ocular lens insofar as is
possible. The optical zone portion 11 may have a diameter D of 7 to
8 millimeters; however, this diameter is merely suggested and is
approximately the same diameter as a natural ocular lens, and it
should be recognized that the artificial intraocular lens can and
should be sized according to the eye into which it is to be
implanted. The power of the artificial intraocular lens generally
should be in the range of 13 to 17 diopters with the final decision
as to the exact power resting with the opthalmologic surgeon who
has examined the patient.
The flange 12 peripherally surrounds the optical zone portion 11
along its outer edge and increases the overall diameter of the
artificial intraocular lens 10 to approximately 9 to 10
millimeters. The flange 12 is provided to support the prongs 13-20,
and more particularly is provided to permit mounting of the prongs
spaced radially outwardly from the optical zone portion 11. The
drain holes 21-24 are formed at the intersection of the flange 12
and the optical zone portion 11 and arrayed about the optical zone
at 90 degree intervals. The drain holes provide for the free flow
of aqueous humor from the ciliary body to the front of a lens and
to the anterior chamber, as best seen in FIG. 10.
In the artificial intraocular lens 10, eight prongs 13-20 are
arranged in four pairs arrayed about the periphery of the flange
12. Each prong extends forwardly from the flange 12 and is curved
so that its outer end is disposed generally parallel to the plane
of flange 12. Each prong is approximately 2 millimeters in length
and its outer end is preferably enlarged and rounded. The base of
each prong is positioned at the outermost periphery of flange 12,
and the bases of each pair of prongs, such as prongs 15 and 16, are
separated by a distance S which may be approximately 1 millimeter.
The prongs in each pair extend in opposite directions from each
other along the outer periphery of flange 12. In the artificial
intraocular lens 10 the prongs 13-20 are formed integrally with an
annular band 25 which is seated in an outwardly opening peripheral
groove 26 in flange 12.
The prongs 13-20 and the annular band 25 may be fabricated of gold
or vitallium, or any other material having the desired qualities,
which include being medically acceptable for implantation into the
eye and also being sufficiently malleable or bendable to permit
adjustment or manipulation and to eliminate risk of breakage. The
optical zone portion 11 and the flange 12 are preferably fabricated
of a medical grade of polymethyl methacrylate. The annular band 25
may be at least partially encapsulated in the flange 12 by molding
the optical zone 11 and flange 12 with the annular band 25 with the
integral prongs 13-20 in position.
Referring now to FIG. 3, an intraocular lens 30 which is an
alternative embodiment according to the invention herein is shown
in a fragmentary view. The lens 30 is similar to the lens 10 except
for the means of attaching the prongs thereto. In lens 30, the
prongs, such as prong 31, are attached to a peripheral flange 35 by
inserting them into openings formed in the flange. An enlarged base
portion 32 may be formed at the end of prong 31 to prevent it from
pulling out of the opening. The prongs may be further secured to
the flange by means of adhesive applied in the openings during the
insertion of the prongs. Alternatively, the prongs may be
encapsulated by properly positioning them during molding of the
lens.
Referring now to FIGS. 4 and 5, there is shown an artificial
intraocular lens 40 which is a third embodiment according to the
invention herein. Lens 40 does not incorporate a peripheral flange,
but is shaped similarly to the natural lens and has a plurality of
pairs of prongs attached thereto near the periphery thereof.
Although this embodiment does not permit spacing the prongs as far
from the central portion of the lens as do the earlier described
embodiments, the artificial intraocular lens 40 has the advantage
of having no flange protruding outwardly therefrom which may come
into contact with the ciliary body.
FIG. 5 illustrates the attachment of the prongs to the artificial
intraocular lens 40. Two prongs 41 and 42 comprising one pair of
prongs are integral by virtue of a connecting portion 43. The
connecting portion 43 may be generally C-shaped and is capsulated
in the lens during molding thereof. Alternatively, prongs could be
attached to the lens 40 by forming the prongs integrally with an
annular band and seating the annular band in the outermost
periphery of the lens, similar to the structure described above
with respect to lens 10. The prongs could also be attached by
forming opengings through or into the lens 40 and inserting the
prongs therein, similar to the attachment of the prongs in lens 30
described above.
Because lens 40 does not incorporate a flange protruding radially
outward therefrom, there is no need to provide drain holes for
permitting the passage of aqueous about the edge of the lens.
The invention herein is also directed to an insertion necklace
which aids the ophthalmologic surgeon in handling, inserting, and
manipulating the artificial intraocular lens during implantation
thereof. An insertion necklace according to the invention herein is
indicated at 50 of FIG. 6, and it generally comprises a semirigid
loop 51 having a tail 52 extending therefrom to a handle 53. Still
referring to FIG. 6, the insertion necklace 50 is shown used with
the artificial intraocular lens 10 of FIGS. 1 and 2. The loop 51 is
passed through the drain holes 22 and 24 wherein a portion 51A of
the loop embraces the backside of the optical portion 11 of the
lens. The loop 51A is preferably sized so that the sections of the
loop converging toward the tail 52 from drain holes 22 and 24 pass
under the prongs 17 and 18 respectively, wherein the prongs help to
maintain the lens in the plane of the loop. The loop can be easily
disengaged from the prongs if and when desired.
Referring to FIG. 7, the handle 53 is preferably of an elongated
oval or flat sectional configuration, wherein the lens may be
easily twisted. The flat surface is preferably generall parallel to
the front surface of the lens wherein the handle provides an
indication of the orientation of the lens. The loop and tail are
preferably fabricated of a semirigid material such as superamid or
vitallium wire, or polyethylene or other plastic tubing or wire,
and the handle 53 into which the tail 52 is seated may be
fabricated of the same material.
In FIG. 8 there is shown another artificial intraocular lens 60
constituting a fourth embodiment in the invention herein. The lens
60 is similar to the lens 10 described above except that the drain
holes 61-64 of lens 60 are located between the tips of adjacent
pairs of prongs rather than adjacent to the bases of each pair of
prongs. The insertion necklace 50 is attached to the lens 60 with
the loop 51 passed through drain holes 62 and 64. The sections of
the loop 51 converging toward the tail 52 from drain holes 62 and
64 pass under prongs 65-66 and 67-68 respectively, and this
arrangement provides for good engagement between the prongs and the
converging sections of the loop 51. However, this arrangement may
not be preferred because it may be desirable to have one pair of
prongs positioned at the forward edge of the artificial intraocular
lens as it is being inserted, as shown in FIG. 6.
Referring now to FIGS. 9 and 10, there is shown an eye having an
artificial intraocular lens according to the invention herein being
implanted and implanted. The eye 70 comprises a transparent cornea
71 which connects with the sclera 72, better known as the white of
the eye. The sclera extends substantially around the entire eye
except for the region of the cornea. A thin membrane 73, which is
known as the conjunctiva, extends from the cornea to the underside
of the eyelid. Schlemn's canal, indicated at 74, is located near
the intersection of the cornea, sclera, and conjuctiva. In the rear
portions of the eye, the choroid 75 overlays the interior surface
of the sclera and the retina 76 overlays the inner surface of the
choroid 75. Near the front of the eye the choroid joins with the
ciliary body, generally indicated at 77, which includes the ciliary
process 80 and ciliary muscle 81. Extending from the ciliary body
is the iris 82 which defines the pupil 83. The choroid, ciliary
body, and iris are together known as the uveal tract, which is a
vascular tract surrounding most of the eye.
The interior of the eye is substantially filled with vitreous humor
90 and the hyloid membrane 91 covers the surface of the vitreous
humor. The anterior chamber of the eye is indicated at 92, and is
located between the front of the iris and the cornea 71. The
posterior chamber of the eye, indicated at 93, is located between
the iris and the vitreous humor. The natural lens, not shown in the
drawings herein, occupies the posterior chamber 93 and is held in
place by zonules 94, which are shown cut as they would be during
removal of the natural lens.
Referring now particularly to the iris 82, it defines the pupil 83
by virtue of a central opening therein. Sphincter and dilator
muscles 84 and 85 are located in the iris adjacent to the inner
periphery thereof, and control the size of the pupil. The primary
expansion and contraction of the tissue of the iris takes place in
the vicinity near the sphincter and dilator muscles. The stroma 86
of the iris extends between the ciliary body and the inner portion
of the iris including the sphincter and dilator muscles. The stroma
tissue passively folds in an accordian-like manner during dilation
and contraction of the pupil. The iris tissue, including the
stroma, is quite flexible, and can be pulled and stretched.
However, the iris has the unique property of not healing if torn or
damaged. Accordingly, care should be taken in manipulating the
iris.
Referring more specifically to FIG. 9, in order to implant an
artificial intraocular lens according to the invention herein into
the eye, the pupil is directly dilated to the point where the lens
can be inserted therethrough without need for cutting the iris.
Some stretching of the sphincter and dilator muscles is necessary
to achieve passage of the lens, but if carefully done these muscles
will not be damaged.
An incision in the cornea is made near Schlemm's canal, and the
cornea is folded back. If implantation of an artificial intraocular
lens is being undertaken because of a cataract condition, it is
preferable to perform the natural lens removal and the implantation
of the intraocular lens in the same operation. Accordingly, the
first step after opening an incision and laying back the cornea may
be to perform an intracapsular or extracapsular extraction, as the
condition of the patient dictates.
Using the insertion necklace 50, the artificial intraocular lens 10
is inserted under one edge of the iris and the leading pair of
prongs 13 (shown) and 14 (not shown) are pushed through the stroma
tissue. Thereafter, the converging sections of loop 51 of the
insertion necklace 50 may be disengaged from the anchoring prongs
and the lens inserted entirely under the iris. The remaining
prongs, such as prongs 18, 19 and 20 (show) may now be inserted
through the stroma, taking care to stretch the stroma tissue so
that the tip of each prong is inserted through the stroma tissue
approximately at the point where the base of the anchoring prong
will ultimately seat upon releasing the stroma.
After the lens has been firmly seated in the posterior chamber and
the prongs have been inserted through the stroma of the iris, the
loop 51 of the insertion necklace may be cut and the insertion
necklace removed. The ophthalmologic surgeon may then close the eye
in accordance with ordinary ophthalmologic surgical techniques.
Referring now particularly to FIG. 10, the artificial intraocular
lens 10 is shown implanted into the eye 70. The artificial
intraocular lens is positioned in the posterior chamber 93, thereby
closely duplicating the natural state and providing for restoration
of good binocular vision. The iris 82 is shown with the pupil 83
contracted to its normal position, whereby it is apparent that the
prongs extend through the stroma portion of the iris, where they
will cause no irritation. Also, because the stroma tissue passively
folds and opens during dilation and contraction of the pupil, the
lens does not cause pulling or tearing of the iris and remains in
its proper position.
It should also be noted that the artificial intraocular lens, and
specifically the flange thereof, is spaced well away from the
ciliary body, and thereby will not cause irritation thereof. The
ciliary body may contract somewhat as the ciliary muscles 81
atrophy, enhancing the separation from the implanted lens. Also,
the drain holes are positioned to insure free flow of aqueous
produced by the ciliary body to the front portion of the lens under
the iris and to the anterior chamber, even if the edge portion of
the lens should contact the iris.
The artificial intraocular lens also provides support for the
hyloid membrane and the vitreous humor. It is anticipated that
fewer instances of retinal detachment will follow cataract surgery
when using an artificial intraocular lens according to the
invention herein.
Procedure for implantation of the other embodiments of artificial
intraocular lenses according to the invention herein is similar.
The position of the other lenses in the eye after implantation is
also similar, i.e., the lenses are positioned in the posterior
chamber of the eye with the prongs extending forwardly through the
stroma of the iris.
Referring now to FIG. 11, a front view of the eye 70 having the
artificial intraocular lens 10 implanted therein is shown. It will
be noted that the prongs 13-20 protrude through the iris 82 in its
outer or stroma portion 86 and hold the lens in position without
interfering with dilaton of the pupil. The optical zone portion 11
of the lens is positioned behind the pupil 83, as desired.
Referring now to FIG. 12, there is shown an eye 100 having an iris
101 upon which a peripheral iridectomy has been performed to
obviate glaucoma, in accordance with ordinary techniques.
Therefore, the iris 101 has the usual pupil 102 positioned at the
center thereof, and in addition has a secondary, peripherally
positioned pupil 103 resulting from the peripheral iridectomy.
Another embodiment 110 of an artificial intraocular lens according
to the invention herein has been implanted into the eye 100. The
lens 110 is ccharacterized by having prongs 111-116 arranged in
three pairs evenly spaced about its periphery. Three pairs of
prongs are sufficient to hold the lens in position and are easily
placed to not interfere with the secondary pupil 103 formed during
the peripheral iridectomy.
Another eye 120 is shown in FIG. 13 wherein a sector iridectomy has
been performed on the iris 121 thereof to enlarge the pupil 122 so
that it extends to the periphery of the iris. An artificial
intraocular lens 125 comprising another embodiment of the invention
herein has been implanted into the eye 120. The lens 125 has six
prongs 126--131 arranged in three pairs spaced about the periphery
of the lens; however, in contrast to the earlier described
embodiments, prongs 126 and 127 comprising the first pair of prongs
have their bases widely separated to straddle and accommodate the
elongated pupil 122 therebetween. The remaining prongs 128--131 are
arranged in two pairs substantially evenly spaced with the first
pair of prongs about the periphery of the lens 125.
FIGS. 12 and 13 illustrate how the artificial intraocular lens
according to the invention herein may be adapted for use in a
variety of medical situations, such as the peripheral iridectomy
and the sector iridectomy.
It will be apparent to those skilled in the art that various
modifications of the artificial intraocular lenses described herein
can be made without departing from the spirit and scope of the
invention. For instance, the number of prongs and the precise
positioning of the prongs may be altered, and similarly, the number
of drain holes and their positions can be altered. Other materials
may be suitable for fabricating artificial intraocular lenses
according to the invention herein, and the materials disclosed
herein merely provide acceptable examples. The sizes of the
artificial intraocular lenses may be changed, particularly when the
lenses are to be used in animals. Also, other means for holding and
manipulating the lenses may be employed. For instance, the
artificial intraocular lenses can be held and manipulated by
conventional forceps, or by provision of a flexible tipped
instrument having an opening therethrough to which suction is
applied, wherein the lens is held to the instrument by vacuum and
released from the instrument by releasing the section. With respect
to the technique of implanting the artificial intraocular lenses
described herein, various ophthalmologic surgeons may develop
different techniques dictated by their own skills and
preferences.
The artificial intraocular lenses and the apparatus aiding
implantation thereof described above are believed to efficiently
achieve the objects of the invention. The usefulness and advantages
of the artificial intraocular lenses and the apparatus aiding
implantation thereof will be readily apparent to those skilled in
the art.
Accordingly, the above description of the preferred embodiments is
to be construed as illustrative only rather than as limiting, and
the scope of the invention is defined in the following claims.
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