U.S. patent application number 11/656136 was filed with the patent office on 2007-05-31 for bag-in-the-lens intraocular lens with removable optic and capsular accommodation ring.
Invention is credited to Marie-Jose B. Tassignon.
Application Number | 20070123981 11/656136 |
Document ID | / |
Family ID | 37547452 |
Filed Date | 2007-05-31 |
United States Patent
Application |
20070123981 |
Kind Code |
A1 |
Tassignon; Marie-Jose B. |
May 31, 2007 |
Bag-in-the-lens intraocular lens with removable optic and capsular
accommodation ring
Abstract
This invention describes an intraocular lens (IOL) design with a
removable optic, which can be inserted in and removed from a haptic
device. In this haptic the anterior and posterior capsules are
sealed in order to have a perfect control over the lens epithelial
cell proliferation which is thereby restricted to the peripheral
part of the capsular bag. Additionally, a ring caliper is described
as new surgical device to allow a precise sizing and centration of
the anterior capsulorhexis. The removable optic allows repeatable
correction of the eye focusing over time in case the optical
parameters of the eye have changed due to a variety of factors. By
separating the optic part from the haptic part, the optic part can
easily be manufactured in any shape matching the optical errors of
the eye, including the optical aberrations. The optic part can be
manufactured out of any biomaterial restoring ocular accommodation.
The optic part may include prismatic, astigmatic or magnification
correction to improve visual performance. The optic part may
consist of or include an electronic device for the purpose of
artificial vision. In order to further assist the accommodative
capabilities of the implant a capsular accommodation ring of
specific biomechanical properties is inserted in the capsular
equator.
Inventors: |
Tassignon; Marie-Jose B.;
(Berchem-Antwerpen, BE) |
Correspondence
Address: |
Prof Dr. Marie-Jose B. Tassignon
6, Wapenhaghestraat
Berchem-Antwerpen
2600
BE
|
Family ID: |
37547452 |
Appl. No.: |
11/656136 |
Filed: |
January 20, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11110463 |
Apr 20, 2005 |
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11656136 |
Jan 20, 2007 |
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Current U.S.
Class: |
623/6.12 ;
623/6.37 |
Current CPC
Class: |
A61F 2/1613 20130101;
A61F 2/1648 20130101; A61F 2/1694 20130101; A61F 2002/1681
20130101; A61F 2210/0019 20130101; A61F 2002/1699 20150401; A61F
2002/009 20130101 |
Class at
Publication: |
623/006.12 ;
623/006.37 |
International
Class: |
A61F 2/16 20060101
A61F002/16 |
Claims
1. An intraocular lens for bag-in-the-lens implantation in the eye
to replace the natural crystalline lens, comprising of: A. a haptic
part further comprising (a) two external haptic flanges to
delineate an external groove, and (b) two internal haptic flanges
to delineate an internal groove; B. an optic part; whereby said
external groove will accommodate matched anterior and posterior
capsules of the lens bag after anterior and posterior capsulorhexis
and said internal groove will accommodate said optic part allowing
a removal or replacement of said optic part.
2. An intraocular lens according to claim 1 wherein said haptic
part and said optic part are made of deformable biomaterials so as
to allow insertion of the intraocular lens in a folded
condition.
3. An intraocular lens according to claim 1 wherein said haptic
part is sufficiently opaque so as to reduce optical edge effects
and glare.
4. An intraocular lens according to claim 1 wherein said external
flanges of said haptic part are posteriorly angulated with respect
to said internal flanges of said haptic part.
5. An intraocular lens according to claim 1 further comprising a
transparent barrier, said transparent barrier continuous with the
posterior flange of said two internal haptic flanges so as to
eliminate the chance of posterior luxation into the vitreous of
said optic part.
6. An intraocular lens according to claim 1 wherein said optic part
is made of a combination of biomaterials, said combination
permitting a better correction of the various optical aberrations
of the human eye and magnification for enhanced vision.
7. An intraocular lens according to claim 1 wherein said optic part
is made of a combination of optical components, said combination
permitting a better correction of the various optical aberrations
of the eye and magnification for enhanced vision.
8. An intraocular lens according to claim 1 wherein said optic part
contains electro-optic means for the purpose of artificial and
enhanced vision.
9. An intraocular lens according to claim 1 wherein said optic part
contains at least one doped biomaterial, so as to give said optic
part a graded index of refraction or medical properties.
10. A calibrating ring for assisting in intraocular lens
implantation, said calibrating ring made of flexible biomaterial of
sufficient memory so as to permit unfolding of said ring to its
original shape after introduction into the eye.
11. A capsular accommodation ring to be inserted at the capsular
equator and made of a biomaterial having the same biomechanical
properties than the said capsular bag so that accommodation can be
optimally restored after cataract surgery and insertion of the said
bag-in-the-lens intraocular lens or intraocular lens according to
claim 1.
12. The capsular accommodation ring according to claim 11 can only
be implanted in combination with the bag-in-the-lens intraocular
lens or with the intraocular lens according to claim 1 since said
intraocular lenses do not exert any pressure by haptics or any lens
adds at the level of the capsular equator.
13. The capsular accommodation ring according to claim 11 aims at
restoring the physiological curvature of the capsular equator after
cataract extraction from which it is understood that the angle of
said ring may vary depending on the optical parameters of the
eye.
14. The capsular accommodation ring according to claim 11 is a
U-shaped ring of which the diameter may vary based on the
physiological diameter of the natural crystalline lens.
15. The capsular accommodation ring according to claim 11 may be
open in order to facilitate its insertion and positioning into the
capsular bag.
Description
RELATED US PATENTS AND APPLICATIONS
[0001] This application is a continuation in part of U.S.
application Ser. No. 11/110,463 filed on Apr. 20, 2005. The
background of the invention is in the general field of intra-ocular
lenses, in particular lenses with accommodative properties.
BACKGROUND OF THE INVENTION
[0002] In our U.S. Pat. No. 6,027,531 a description is made of a
new concept of intraocular lens, implantable in the eye to replace
the natural crystalline lens. This IOL is inserted in a calibrated,
circular and continuous anterior and posterior capsulorhexis, of
which the diameters are slightly smaller than the optical diameter
of the lens in order to fit tightly in the groove defined at the
periphery of the optical part by two flanges (one flange is the
continuation of the anterior part of the optic and the other flange
is the continuation of the posterior part of the optic). The
perpendicularly oriented axes of the flanges facilitate the
insertion of both anterior and posterior capsule into the groove by
the surgeon and stabilize and avoid tilting of the IOL.
[0003] The IOL as described in U.S. Pat. No. 6,027,531 is being
manufactured by the company Morcher, Germany. The intraocular lens
has been implanted in children (7 months of age to 15 years), in
young adults (16 to 21 years) and in about 200 adult eyes at this
moment with a follow-up period of at least 5 years. The results of
the clinical work and experience have been published and those
publications are herewith incorporated by reference: [0004]
Tassignon M. J., De Groot V., Vrensen G. F. J. M. (2002).
Bag-in-the-lens implantation of intraocular lenses. J. Cataract
Refract. Surg. 28 (7), 1182-1188 [0005] De Groot V., Tassignon M.
J., Vrensen G. F. J. M. (2005). Effect of bag-in-the-lens
implantation on posterior capsule opacification in human donor eyes
and rabbit eyes. J. Cataract Refract. Surg. 31 (2), 398-405
[0006] These publications corroborate our hypothesis as stated in
the U.S. Pat. No. 6,027,531 that secondary cataract is avoided in
100% of the cases. Secondary cataract is the most frequent
complication corresponding to posterior capsule opacification (PCO)
in eyes operated with the traditional lens-in-the-bag implantation
technique.
[0007] Besides the long-lasting excellent optical results of 100%
transparency and besides the excellent stability of the lens within
the eye, the bag-in-the-lens presents the additional option to be
positioned electively within the eye by the surgeon. The idea of
elective positioning or centration according to a visual axis of
the eye of an intraocular lens has not yet been described.
[0008] Since the publication of the U.S. Pat. No. 6,027,531, other
authors have used the idea to fixate the IOL using the posterior
capsule (Okada Kiyashi, U.S. Pat. No. 6,881,225), but the design is
very complicated an the implantation is based on the
lens-in-the-bag technique having the permanent risk that lens
epithelial cells will encapsulate the IOL with proliferative
tissue.
[0009] Furthermore, a large number of proposals have been made to
correct the eye optics for far and for near at the time of cataract
surgery. A binocular lens system was proposed by Robert Steinert
(U.S. Pat. No. 6,537,317) and Lang Alan (U.S. Pat. No. 6,576,012),
aiming at allowing far and near vision simultaneously. However,
these IOLs are composed of two optic portions that still have the
risk of cellular deposits and proliferation between the parts.
[0010] Additionally, in order to correct the optical aberrations of
the eye, Theodore Weblin (U.S. Pat. No. 6,413,276) proposed a
three-part IOL of which at least one part can be removed and
adapted according to the ocular aberrations and repositioned in a
second surgical step. This elaborated IOL also has the risk of
cellular deposits at the level of the interfaces causing visual
impairment with over time.
OBJECTS AND ADVANTAGES OF THE INVENTION
[0011] This invention concerns an improvement of the U.S. Pat. No.
6,027,531 in two major aspects: a new device is proposed to perform
easily a calibrated, circular and continuous anterior
capsulorhexis, and an intraocular lens is proposed with a removable
optic. Some additional minor improvements in embodiments and
surgical technique are also described.
I. Device for Anterior and Posterior Capsulorhexis Size Calibration
and Positioning
[0012] To do so, a ring of 0.25 mm diameter, made of PMMA, or of
any other biomaterial with memory, has been designed (FIG. 1). This
ring can be inserted within the eye through a very small corneal or
limbal incision (3 mm or less). Because of its memory, the ring
will unfold within the eye as soon as inserted in the anterior
chamber. It then will be gently applied on top of the anterior lens
capsule and fixed with viscoelastics. The capsulorhexis can
subsequently be initiated and the surgeon will take care to follow
the internal border of the ring caliper. This ring caliper has two
functions: (1) to determine a precise diameter of the anterior
capsulorhexis. This can be achieved by manufacturing a ring with a
precise internal diameter. (2) The ring is also to be used in order
to centre the position of the anterior capsulorhexis according to
the pupillary area, or to the limbus or to any other reference used
to optimize centration of the anterior capsulorhexis along an
optical axis of the eye (line of sight, visual axis or other axis).
The optical axis can be determined according to well-established
techniques described in clinical psychophysics handbooks.
II. Intraocular Lens with a Removable Optic
[0013] Starting from the initial concept of a one piece IOL (FIG. 1
A, B and C of the Prior Art), the haptic device can be separated
from the optic part (FIG. 2 A, B and C). This removable and
replaceable optic can be versatile in design construction and
incorporate spherical, astigmatic or prismatic powers as well as
customized adaptive optics correction. In addition electro-optical
constructions for artificial vision or low vision purposed can be
incorporated. In general such optic part can be made to resemble
more the natural lens of the eye, including its GRIN properties and
furthermore such design is easier for the manufacturer to
produce.
[0014] Additional advantages of such removable optic include (1)
intraocular correction of ametropia repeatable over time in case
the axial length or corneal optical parameters have changed due to
disease, age or trauma or miscalculated previous IOL power, (2) to
introduce new biomaterials in the future with additional
characteristics, (3) easy access for the retinal surgeon in case of
complex repeat posterior segment surgeries.
[0015] The haptic device can be constructed from an opaque material
to minimize intraocular scattering and glare.
III. Capsular Accommodation Ring
[0016] This invention describes a capsular accommodation ring to be
used in combination with either the bag-in-the-lens (BIL)
intraocular lens (IOL) of which the IOL and surgical procedure has
been described in U.S. Pat. No. 6,027,531, or with the BIL-IOL with
removable optic as described in this application. Both concepts
will be further referred to as BIL-IOL.
[0017] The capsular accommodation ring is meant to be inserted into
the capsular bag once the crystalline lens has been removed. This
accommodation ring should be positioned at the level of the
capsular equator. The shape of the accommodation ring is an open,
U-shaped flexible ring, which is made of a biomaterial presenting
similar mechanical properties compare to the human lens capsule.
The mechanical properties of the lens capsule have been studied in
length by Susanne Krag et al.: [0018] Krag S., Andreassen T. T.
(2003). Mechanical properties of the human posterior lens capsule.
Invest. Ophthalmol. Vis. Sci. 44, 691-696 [0019] Krag S.,
Andreassen T. T. (2003). Mechanical properties of the human lens
capsule. Prog. Retin. Eye Res. 22 (6), 749-767
[0020] It is not the intention to exert any tension on the equator
of the capsular bag by this accommodation ring but to restore its
natural curvature. The anterior and posterior lips of this
accommodation ring will support that part of the capsular equator
where the anterior and posterior zonular fibres have their
insertion. As a result, the physiological relationship and impact
of the zonular fibres on the equatorial part of the capsular bag
will be re-established. The antero-posterior movement of the
BIL-IOL/capsular bag will again be possible and optimized during
accommodation or relaxation of the ciliary's muscle. It should be
understood that during accommodation the zonular fibres will
release all tension on the equatorial capsular bag, allowing the
capsular accommodation ring to take its original shape, designed to
mimic the physiological curvature of the equatorial part of the
capsular bag of a young adult lens during accommodation. The
BIL-IOL will move forward and correct the eye for a certain degree
of accommodation. In case of relaxation of the ciliary's muscle,
the zonular fibres will be stretched and exert tension on the
equatorial part of the capsular bag. The accommodation ring will
follow this movement and the BIL-IOL will move backward, allowing
optimal correction of the eye for distance. Because the mechanical
properties of the accommodation ring are similar to that of the
capsular bag, it is expected that the changes in physiological
curvatures of the capsular equator, at the accommodation or
relaxation position, will be released in comparable speed as in
physiological conditions.
DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 A, B, C correspond to the prior art as described in
U.S. Pat. No. 6,027,531. These figures illustrate the
bag-in-the-lens in one piece comprising the optical part 14, the
haptic parts 18 and 20 and the groove 16 to accommodate both the
anterior and posterior capsule.
[0022] FIG. 2 illustrates the ring caliper device.
[0023] FIG. 3 A, B, C illustrates the removable optic and the
haptic device as two separate parts of the new IOL. The haptic
device still consists of the outer flanges (18 and 20) defining the
external lens groove (16) to accommodate the anterior and posterior
capsule, but in addition presents internal flanges (24 and 26)
defining an internal groove (28) in order to accommodate the
removable optic part of the lens (14). This modification of the
original lens will allow the removal of the optic part of the lens
without removing the haptic device. The external outer flanges
(18-20) can be angulated posteriorly (30) compared to the straight
insertion of the internal flanges of the haptic device (24-26). The
posterior internal flanges (26) can extend further to create an
additional closed transparent and thin barrier (32) between the
removable optic and the vitreous in case posterior dislocation of
the removable optic is feared.
[0024] FIG. 4 A, B and C show an alternative to the embodiment of
the intraocular lens with removable optic as illustrated on FIG. 3
A, B and C. This second version differs with the previous one in
the fixation of the optic part 14 into the haptic part (16-18-20).
Instead of having internal haptics (24-26) defining the internal
groove 28 in which the optic 14 will take place, the external
haptics (18-20) define a sharp arc at the internal side 34 in which
the groove 36, positioned at the equator of the optic 14, will take
place. This second embodiment may be easier to manufacture and will
avoid the possible posterior dislocation of the optic 14 as
described in the previous embodiment.
[0025] FIG. 5 A illustrates the U-shape accommodation ring 42 of
which the anterior lip 38 may be slightly shorter than the
posterior lip 40. The curvature of the ring correspond to the
physiological curvature of a young adult crystalline lens
[0026] FIG. 5 B and C illustrate the accommodation ring 42
positioned at the equatorial part of the capsular bag. The
relationship with the anterior zonular fibre 44, the equatorial
zonular fibre 46 and the posterior zonular fibre 46 is schematized.
In case the ciliary's muscle is relaxed, as illustrated in FIG. 5
B, the zonular fibres 44-46 and 48 are stretched as well as the
anterior 50 and posterior 52 capsules. In this situation, both lips
38 and 40 of the accommodation ring 42, define a sharp angle. The
capsular bag together with the BIL-IOL 14 in which it is inserted
at the level of the lens groove 16, will move backward. In case the
ciliary's muscle is contracted, as illustrated in FIG. 5 C, the
zonular fibres 44-46 and 48 will become loose as will relax the
anterior 50 and posterior capsule 52, allowing the lips 38 and 40
of the accommodation ring 42 to take their original angle. The
capsular bag and the BIL-IOL will move forward
REFERENCE NUMERALS IN DRAWINGS
[0027] 14 removable optic part of the intraocular lens. This part
is joined with the haptic device in one piece in FIG. 1 A, B, C;
and it is a separate part, removable and replaceable in FIG. 3 A,
B, C
[0028] 16 external groove in the haptic device to accommodate both
capsules
[0029] 18 anterior flange of the external part of the haptic
device
[0030] 20 posterior flange of the external part of the haptic
device
[0031] 22 perforation within the anterior flange for purpose of
rotation during surgery
[0032] 24 anterior flange of the internal part of the haptic
device
[0033] 26 posterior flange of the internal part of the haptic
device
[0034] 28 internal groove in the haptic device to accommodate the
optic
[0035] 30 angulation of the external flanges of the haptic
device
[0036] 32 extension of the posterior internal flange of the
internal haptic device, create a membrane like barrier between
vitreous and removable optic part
[0037] 34 internal arc of the lens groove
[0038] 36 equatorial groove of the lens optic
[0039] 38 anterior lip of accommodation ring
[0040] 40 posterior lip of accommodation ring
[0041] 42 accommodation ring with specific angle
[0042] 44 anterior zonular fibres
[0043] 46 equatorial zonular fibres
[0044] 48 posterior zonular fibres
[0045] 50 anterior lens capsule
[0046] 52 posterior lens capsule
DESCRIPTION OF PREFERRED EMBODIMENTS
[0047] FIG. 1 A, B, C shows the preferred embodiment of the prior
art. This preferred embodiment could be slightly adapted by
introducing a posterior angulation 30 of the external flanges of
the haptic device. This is done in order to prevent capture of the
iris into the groove immediately postoperatively. The posterior
angulation will optimally vary from 5 degrees to 10 degrees. Other
angulations are possible.
[0048] FIG. 2 shows the preferred embodiment of the ring caliper
that permits a precise sizing and centration of the anterior
capsulorhexis. This ring caliper may be constructed of any
biomaterial allowing its insertion within the eye in a folded
condition after which it will unfold in the eye to its original
shape because of its material memory. The diameter of the cross
section of this ring is optimally 0.25 mm but can be made thinner
or thicker depending on the biomaterial used. It can be transparent
or coloured to enhance visibility once put in place in the eye.
When used in relation with an IOL of 5 mm diameter optic part size,
as described in the U.S. Pat. No. 6,027,531 or in current
application, a diameter of 5 mm is optimal (FIG. 2). Though this
ring can also be used when implanting of the more traditionally
lens-in-the-bag IOLs is intended.
[0049] FIG. 3 A, B and C show the preferred embodiment of the new
intraocular lens design consisting of two separate parts: a haptic
device and a removable and replaceable optic part. The haptic
device is preferably made of one piece and can be made of rigid or
deformable biomaterials such as silicone polymeric materials,
acrylic polymeric materials, hydrogel forming polymeric materials
and mixture of these materials or the like. This hatpic device can
be made opaque by coloration or using mechanical techniques. The
aim of making the haptic part partially or totally opaque is
avoiding stray light effects and glare.
[0050] The haptic device consists of an external anterior flange 18
and an external posterior flange 20, defining an external groove 16
in between. Both external flanges are made oval in shape to promote
a good insertion and fixation of the intraocular lens, but can have
any shape that may improve IOL fixation or insertion. Both flanges
can have a variety of functional extensions or perforations 22 to
promote the stability of the lens or to prevent any type of
luxation or inadvertent capture of the iris.
[0051] On the internal side, the haptic device has an anterior
internal flange 24 and a posterior internal flange 26 defining an
internal groove 28 to accommodate the removable optic part. The
diameter of the internal groove can be variable but should not be
less than 5 mm for reasons of optical quality and for ease of
centration. The internal flanges are preferably transparent but can
also be made opaque. In case a posterior luxation of the optic part
into the vitreous would be an issue, the posterior internal flanges
can be made continuous 32, defining a membrane like transparent
barrier between the optic part and the vitreous. The distance
between the internal groove and the external groove will determine
the thickness and therefore the stability and rigidity of the
haptic device. This parameter can vary depending on the
biomaterials used in constructing the haptic device.
[0052] The preferred embodiment of the optic part 14 is circular
but of variable shape depending on the intended optical errors to
be corrected, including the ocular aberrations, in particular
spherical aberration or chromatic aberration. It can be made of the
same biomaterial as the haptic device as specified above or can be
made of another biomaterial. It can be made of one biomaterial, can
use a combination of different layered biomaterials, or be made of
a GRIN substance. Each construction has specific optical and
mechanical properties in order to correct the spherical, the
cylindrical or the toric refractive errors of the eye, and to
permit accommodation (mechanically or optically mediated
accommodation). Prismatic effects could be of use in relocating the
preferential retinal locus of fixation in magnification of the
image on the retina for low vision purposes. These additions can be
fitted on the anterior surface of the optic part, within the optic
part or on the posterior surface of the optic part. The final
result is a customized optic part of one piece, containing all
optical adaptations needed to correct the optical errors of the eye
as measured preoperatively. This one piece optic part 14 may have
the same diameter as the diameter of the internal groove 28 or it
can be slightly larger or it can be slightly smaller. For the
purpose of stability, a slightly larger diameter of the optic part
14 could be beneficial, though a slightly smaller diameter of the
optic part 14 might increase an accommodative effect in the
eye.
[0053] An alternative for the fixation of the removable optic part
14 is to add an equatorial groove 36 to the optic part 14 of which
size matches the internal arc 34 defined by both the external
haptic parts 18 and 20. The capsular accommodation ring is
preferentially manufactured of a biocompatible biomaterial which
has similar biomechanical properties than the capsular bag. The
biomechanical properties of the capsular bag have been studied in
the literature and are well known.
[0054] The most appropriate shape for the accommodation ring is
U-shaped. The width of the angle of the U-shape ring is variable,
depending on the physiological angle of eyes presenting the same
optical properties e.g.: corneal curvature, white to white
measurements, sulcus to sulcus measurements and axial length.
[0055] The diameter of the accommodation ring is also variable,
depending on the physiological diameter of the natural crystalline
lenses of young adult eyes of which their optical parameters have
been measured as mentioned earlier.
[0056] The variation in physiological parameters of the diameter
and equatorial angle of young adult lenses is expected to be
important. It is therefore mandatory to match the parameters of the
accommodation ring to these measurements.
[0057] The accommodation ring may be open in order to facilitate
its insertion and positioning into the capsular bag.
[0058] The anterior lip of the accommodation ring may be slightly
shorter than the posterior lip. The length of the lips is defined
by the anatomical insertion of the anterior and posterior zonular
fibres on the anterior and posterior capsules respectively. This
can be measured in post mortem donor eyes. A longer posterior lip
will also promote a better support of the posterior capsule which
is slightly larger than the anterior capsule (the natural
crystalline lens in non equiconvex).
Description of a Preferred Surgical Procedure
[0059] The surgical procedure consists of a number of steps that
are currently used in conventional extracapsular cataract
extraction, some of which have to be modified, and some new steps
are necessary to insert the new intraocular lens in the most
optimal fashion.
[0060] The opening of the anterior chamber and the filling of the
anterior chamber with viscoelastics are well known steps in the
prior art. The anterior curvilinear continuous capsulorhexis must
be calibrated in such way that its diameter is slightly smaller
(about 1 mm) than the diameter of the optic part 14.
[0061] For this purpose, the ring caliper is inserted, either by
means of two forceps or by means of a lens manipulator. After
insertion the ring is gently pushed on top of the anterior capsule
by means of additional viscoelastics. A small opening is made in
the centre of the anterior capsule, which serves as the starting
point for the capsulorhexis. The surgeon will take care to follow
the internal border of the ring caliper.
[0062] The centration of the capsulorhexis with respect to such
landmarks as the pupil edge or the limbal edge can be done using
well-known techniques for documenting the optic, visual axis or
line of sight. To reference the centre of positioning of the ring
during surgery, a standard fiduciary reticule can be used with the
operating microscope.
[0063] After the anterior capsulorhexis is performed, the lens
consisting of nucleus and cortical material is removed in the usual
manner for an extracapsular cataract extraction technique. The
capsular accommodation ring can then be positioned at the level of
the capsular equator. The posterior curvilinear continuous
capsulorhexis must then be executed in such way that its diameter
is the same as the diameter of the anterior capsulorhexis. The
openings of both anterior and posterior capsulorhexis should match
each other as close as possible in size, location and centration.
The technique of making the posterior capsulorhexis is the same as
the one that is currently used in conventional extracapsular
cataract extraction. A puncture is made in the centre of the
posterior capsule. The posterior capsule is then separated from the
anterior hyaloid of the vitreous by injecting viscoelastic material
through the puncture in the space of Berger. After this step a
calibrated posterior curvilinear continuous capsulorhexis is
performed by following the edge of the anterior capsulorhexis
resulting in a posterior capsulorhexis of the same size than the
diameter of the anterior capsulorhexis.
[0064] The insertion of the foldable haptic device of the
intraocular lens using the bag-in-the-lens technique can then be
applied. It is different from the conventional lens-in-the-bag
insertion technique. First, the haptic is introduced into the
anterior chamber of the eye. Then the posterior flange 20 of the
haptic device is placed behind the rim of the opening of the
posterior capsule in the space of Berger and the anterior flange 18
of the haptic device of the intraocular lens is placed before the
rim of the opening of the anterior capsulorhexis.
[0065] Because the diameters of both the anterior and posterior
capsulorhexis are identical but slightly smaller than the diameter
of the lens groove 16, the capsular openings will be stretched when
inserting the lens, thus providing a tight junction around the
intraocular lens and a closed space or environment that contains
the remaining proliferating epithelial cells of the lens bag.
[0066] Once the haptic device is put in place, the removable optic
part which has been chosen preoperatively in such way that it will
correct the optics of the eye in the most optimal way (spherical
correction, astigmatism, aberrations, accommodation) can be
inserted in the anterior chamber in a foldable condition and once
unfolded in the eye, put in place in the empty central space of the
haptic device. The viscoelastic is then removed from the anterior
chamber and the anterior chamber is then closed water tight. In
case the short-term postoperative refractive or optical results are
not satisfactory for the patient or in case the optical properties
of the eye have changed as a function of time, the optic part can
be removed from the haptic and changed by an optic part matching
better the optical needs of the eye. In case the visual acuity of
the patient would drop dramatically over time because of
irreversible retinal or optic nerve problems, the optic can be
removed from the haptic and replaced by a new optic containing or
consisting of magnification elements or opto-electronic elements
for the purpose of magnification or artificial vision.
SUMMARY AND SCOPE
[0067] The clinical results obtained after implantation of the
intraocular lens as described in the U.S. Pat. No. 6,027,531, are
excellent, and even exceptional because of an incidence of zero
percent Nd-Yag laser treatments after five years of implantation.
The current continuing application describes new developments as a
result of our experience gained over this period.
[0068] Firstly, a ring caliper is positioned in order to facilitate
the surgical procedure by improving the precision of the size and
centration of the anterior and posterior capsulorhexis.
[0069] Secondly, we implemented the following modifications to the
bag-in-the-lens design: [0070] Posterior angulations of the
external haptic flanges [0071] Converting the intraocular lens to a
two component system comprising a haptic device and an optic part,
which is removable and replaceable over time [0072] The haptic
device can be rendered partially or totally opaque [0073] The optic
part can be customized to correct various optical aberrations,
permit artificial vision or low vision rehabilitation [0074] The
curvature of the capsular equatorial zone is restored by inserting
a U-shaped ring which has the same biomechanical properties than
the capsular bag in order to optimize the relationship between the
zonular fibres and the capsular bag and to enhance the backward or
forward movement of the BIL-IOL depending whether the ciliary's
muscle is in relaxation or accommodation mode.
[0075] Although the above description contains many specifications,
these should not be considered as limiting the scope of the
invention but as merely providing illustrations of some of the
presently preferred embodiments of this invention. Other
embodiments on the invention, including additions, subtractions,
deletions or modifications of the disclosed embodiment will be
obvious to those skilled in the art and are within the scope of the
following claims. As such, the scope of the invention should be
determined by the appended claims and their legal equivalents.
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