U.S. patent number RE34,251 [Application Number 07/672,516] was granted by the patent office on 1993-05-11 for multifocal, especially bifocal, intraocular, artificial ophthalmic lens.
This patent grant is currently assigned to Storz Instrument Company. Invention is credited to Manfred Achatz, Peter Hofer, Jurgen Strobel.
United States Patent |
RE34,251 |
Achatz , et al. |
May 11, 1993 |
Multifocal, especially bifocal, intraocular, artificial ophthalmic
lens
Abstract
A multifocal, especially bifocal, intraocular, artificial
ophthalmic lens of transparent material, whose optical lens portion
is divided into near range and far range zones and, each of which
is disposed on the optical lens portion with approximately equal
surface proportions and symmetrically with the lens axis.
Inventors: |
Achatz; Manfred (Limeshain,
DE), Hofer; Peter (Aschaffenburg, DE),
Strobel; Jurgen (Marburg, DE) |
Assignee: |
Storz Instrument Company (St.
Louis, MO)
|
Family
ID: |
6208490 |
Appl.
No.: |
07/672,516 |
Filed: |
March 20, 1991 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
648639 |
Sep 7, 1984 |
04813955 |
Mar 21, 1989 |
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Foreign Application Priority Data
Current U.S.
Class: |
623/6.17 |
Current CPC
Class: |
A61F
2/1618 (20130101); A61F 2002/1683 (20130101) |
Current International
Class: |
A61F
2/16 (20060101); A61F 001/16 (); A68F 001/24 () |
Field of
Search: |
;623/6 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Grieb; William H.
Assistant Examiner: Doyle; J.
Claims
What is claimed is:
1. In a multifocal, especially bifocal, artificial, intraocular,
ophthalmic lens adapted to be implanted in the eye at a fixed
position and having a transparent optical lens portion for covering
the pupil of the iris and means for holding said lens portion in a
fixed position in the eye, the improvement wherein near range and
far range zones (N and F) of the optical lens portion have
approximately equal areas symmetrically about the axis of the
optical lens portion, such that rays received by the pupil of the
eye in which the lens is fixed pass through both near and far range
zones of the lens of approximately equal area, for simultaneous,
sharp near and far vision.
2. Ophthalmic lens of claim 1, characterized in that the near range
and far range zones (N and F) are concentric with one another.
3. Ophthalmic lens of claim 1, characterized in that the near range
and far range zones (N and F) comprises radially-alternating,
concentric annular areas.
4. Ophthalmic lens of claim 1, characterized in that the area ratio
(area or areas of the near range zone: area or areas of the far
range zone) is at least effectively constant radially from the axis
of the optical lens portion.
5. Ophthalmic lens of claim 2, characterized in that the far range
zone (F) is in the center of the optical lens portion (1).
6. Ophthalmic lens of claim 3, characterized in that the far range
zone is in the center of the optical lens portion and the
refractive power of the concentric annular areas changes
progressively radially from the axis of the optical lens
portion.
7. Ophthalmic lens of claim 2, characterized in that the near range
zone (N) is in the center and the far portion (F) around it.
8. Ophthalmic lens of claim 3, characterized in that the near range
zone is in the center of the optical lens portion and the
refractive power of the concentric annular areas changes
progressively radially towards the axis of the optical lens
portion.
9. Ophthalmic lens of claim 1, characterized in that the near and
far range zones (N and F) are alternate, radially-extending sectors
of equal angles around the axis of the optical lens portion.
10. Ophthalmic lens of claim 1, characterized in that the
transition between the near and far range zones (N and F) runs form
one margin to the opposite margin of the optical lens portion (1),
that means orienting the lens when implanted in the eye orients the
transition between the near and far range zones from the upper to
the lower lens margin for dividing the optical lens portion (1)
into a nasal (lying near the wearer's nose) and a temporal (lying
remote from the wearer's nose) zone with the near range zone (N)
lying nasally and the far range zone (F) lying temporally.
11. Ophthalmic lens of claim 1, characterized in that the near and
far range zones (N and F) are formed on at least one of the front
and rear faces of the optical lens portion (1).
12. Ophthalmic lens of claim 11, characterized in that at least one
of the far and near zones is biconvexly curved on both of the faces
of the optical lens portion.
13. Ophthalmic lens of claim 1, characterized in that the near and
far range zones (N and F) are formed by materials of different
index of refraction.
14. Ophthalmic lens of claim 1, characterized in that the near and
far range zones (N and F) are formed by a material having a
refractive index gradient in the radial direction from or towards
the axis of the optical lens portion.
15. Ophthalmic lens of claim 1, characterized in that the near and
far range zones (N and F) are a shaped surface of the optical lens
portion (1).
16. Ophthalmic lens of claim 1, characterized in that the optical
lens portion (1) is so limited around its axis that depth of focus
of the image therefrom (stenopeic effect) is achieved.
17. Ophthalmic lens of claim 16, characterized in that the
limitation around the axis of the optical lens portion is a pinhole
surrounded by at least partially opaque lens material. .Iadd.
18. In a multifocal, especially bifocal, artificial, intraocular,
ophthalmic lens adapted to be implanted in the eye at a fixed
position and having a transparent optical lens portion for covering
the pupil of the iris and means for holding said lens portion in a
fixed position in the eye, the improvement wherein the optical lens
portion has near and far range zones located symmetrically about
the axis of the optical lens portion, such that rays received by
the pupil of the eye in which the lens is fixed can pass through
approximately equal areas of said near range and far range zones
for simultaneous, sharp near and far vision. .Iaddend. .Iadd.19. In
a multifocal, especially bifocal, artificial, intraocular,
ophthalmic lens adapted to be implanted in the eye at a fixed
position and having a transparent optical lens portion for covering
the pupil of the iris and means for holding said lens portion in a
fixed position in the eye, the improvement wherein the optical lens
portion has zones located symmetrically about the axis of the
optical lens portion, such that the rays of light received by the
pupil of the eye in which the lens is fixed pass through said
zones, said rays being directed by said zones into near and far
foci of approximately equal amounts of light for simultaneous,
sharp near and far vision. .Iaddend.
Description
The invention relates to a multifocal, especially bifocal,
intraocular, artificial opthalmic lens having an optical lens
portion of transparent material which covers the pupil of the
iris.
An artificial bifocal opthalmic lens based on the alternating or
shifting segment principle, in which either only the near range or
only the far range of the vision aid is in the ray path and thus is
active, is disclosed in U.S. Pat. No. 4,010,496. This lens is
provided in the bottom lens portion with a segment-shaped
near-focus part. The segment-shaped near focus part and the
segment-shaped far focus part situated above it meet at a line of
separation. It is a disadvantage of this type of lens that a
discontinuity in the image occurs at the line of separation.
Furthermore, it has been found that, if at least three quarters of
the pupil area is not covered by one or the other zone of sharp
focus, double vision and contrast losses develop. It is therefore
extremely difficult to determine the correct segment height or the
correct shape of the line of separation.
It is the object of the invention, therefore, to create an
artificial ophthalmic lens of the kind described above, whereby
images of objects at different distances from the observer will be
produced simultaneously on the retina, so that the sharp image can
be utilized and the blurred image suppressed.
This object is achieved by the invention by disposing near range
and far range zones on a transparent optical lens portion of an
artificial, intraocular, ophthalmic lens with approximately equal
areas symmetrically from the axis of the optical lens portion.
An intraocular lens based on the simultaneous principle is thereby
created in which sharp vision is possible simultaneously in the
near and far ranges after implantation, because both the lens
portions for near vision and the lens portions for far vision are
simultaneously in the ray path of the optical lens portion of the
ophthalmic lens.
In an advantageous manner, the pupil diameter can be set either
during the implantation operation or later by medicinal or
microsurgical measures to the optical lens portion to bring the
optical lens portion perfectly into the ray path.
The artificial intraocular ophthalmic lens can be designed
variously, e.g., as a vitreous-chamber-fixed,
anterior-chamber-fixed or iris-fixed lens.
Examples of the embodiment of the intraocular lens according to the
simultaneous principle are obtained by the concentric arrangement
of the near and far portions, by vertical division of the lens area
into a near-effect zone and a far-effect zone, and by dividing the
lens area into radially extending areas of near and far effect.
In the embodiment in which the optically active area of the
intraocular lens is divided into the near and far range zones in a
plurality of concentric annular areas which are disposed
alternately in the radial direction, it is also accomplished that
visual capacity is not impaired by rapid shifts from bright to
dark. This effect can be further enhanced if the ratio of the area
of an annular near focus portion to the area of the adjacent
annular far focus portion is kept sufficiently constant from the
lens center radially toward the lens margin. If the pupil opens
rapidly upon a rapid change from light to dark, the area ratio of
the near and far range zones remains equal, thus preventing
reduction of vision and impairments in seeing.
If the far focus portion is disposed in the center of the optical
lens portion, and the near focus portion outside, the optical
action of the concentric annular areas which form the near focus
part and the far focus part can run progressively radially
outwardly. This means that the refractive power increases from the
center to the periphery, and this increased in the vertex index of
refraction takes place preferably continuously radially from the
center to the periphery. If, vice versa, the near focus portion is
arranged in the center of the optical lens portion and the far
focus portion at the periphery, the optical action of the
concentric annular areas which form the near focus portion and the
far focus portion can run progressively radially towards the
center. This means, then, that the refractive power decreases from
the center towards the periphery, this decrease in the refractive
power preferably taking place continuously.
It is also possible to divide the near range and far range zones
into several sectors of equal angles and to dispose them
alternately around the optical axis.
It is furthermore possible to provide the near and far range zones
each in one half of the optical lens portion, with the transition
or line of separation between the near range zone and the far range
zone in the lens implanted in the eye running from the top margin
of the lens to the opposite bottom margin of the lens, and the near
range zone in the nasal portion of the lens (closer to the wearer's
nose) and the far range zone in the temporal lens portion (farther
from the wearer's nose). In this case again, brightness differences
have no effect, and the lens is independent of pupillary action.
Even in the case of pupil dilation occurring due to low lighting
and at night, this does not lead to greater blurring of vision,
because the percentages (area ratio) by which the far focus portion
and the near focus portion are simultaneously covered remain
equal.
In the lenses of the invention, images of far objects and near
objects are projected simultaneously on the retina. In the central
nervous system, the image on which the wearer of the artifical
intraocular eye lens is concentrating is selected. An image
discontinuity as in the case of the known alternating bifocal
ophthalmic lens does not occur. The near and far range zones can be
formed on the front and/or back of the optical lens portion. The
optical effects of the near and far range zones can be achieved by
appropriate surface working of the lens body or by combining
material of different index of refraction. For the achievement of a
stenopeic effect, i.e., a greater depth of focus, as in the pinhole
camera effect, the lens material can be masked off or darkened
peripherally such that a pinhole remains in the center, with a
diameter, for example, of the order of 0.5 to 2 mm. An object is
projected by this pinhole by means of a narrow bundle of rays. This
makes the scatter circles on the retina of the anetrobe eye smaller
and thus improves image sharpness.
Another advantageous development consists in the fact that at least
the optical lens portion is formed of a flexible, transparent
envelope filled with a transparent fluid, which can be attached to
the ciliar muscles. When the ciliary muscle contracts, the lens
which is at first under tension and therefore more flattened
becomes more spherical and thus is given a greater refractive
power. To this degree, a continuous changeover of focus between
near vision and far vision can be made possible by the deformation
of the lens fashioned in this manner.
The invention is further explained by embodiments with the aid of
the appended drawings, wherein:
FIG. 1 shows a first embodiment of a bivisual artificial
intraocular lens in which a near range zone and a far range zone
are disposed concentrically with one another,
FIG. 2 shows an embodiment of an artificial, intraocular ophthalmic
lens in which near range zones and far range zones are formed by
concentric annular surfaces,
FIG. 3 shows an embodiment in which the optical lens portion is
divided into two halves by a vertical line separating it into a
near range zone and a far range zone,
FIG. 4 shows an embodiment having sector-shaped near and far range
zones,
FIG. 5 shows an embodiment of the intraocular lens which is formed
by an envelope filled with a transparent fluid, in the state for
near vision,
FIG. 6 shows the embodiment represented in FIG. 5, in the state for
far vision,
FIG. 7 is a top view of the embodiment represented in FIGS. 5 and
6.
In the embodiment of a bivisual intraocular lens of FIG. 1, an
optical lens portion 1 has a far range zone F disposed int he
center in the form of a circular area, and concentrically around
it, a near range zone N in the form of an annular area. However,
the far range portion F can also be disposed in the center and the
near portion N around it. The lens body has bores 3 as near as
possible to the circumferential margin of the lens, in a peripheral
annular lens portion 2 surrounding the optical lens portion, 1, so
to avoid interference with the optical function of the lens.
Holding loops 4 serve to fix the lens in the eye. The normal size
and position of the pupil is indicated by the dashed line 7.
The embodiment shown in FIG. 2, of a multifocal, intraocular
artificial ophthalmic lens has in the center of the optical lens
portion 1 a far range zone F in the form of a circular area, and an
annular near range zone N disposed concentrically around it; these
are followed radially towards the periphery by additional annular,
concentrically-disposed, far and near range zones F and N. It is
also possible, however, to disposed the near range zone N in the
center of the optical lens portion 1 and a concentric annular far
range zone F around it, and so on. In the peripheral annular lens
portion 2, which is not optically active, the bores 3 are provided,
whereby, as in the embodiment of FIG. 1, the lens can be turned to
a suitable position, if necessary, after the implantation of the
lens and before the final closing of the eye. These bores 3 are so
arranged that they do not interfere with the optical functioning of
the lens. The lens furthermore has the holding loops 4 whereby the
lens can be fixed.
The embodiment in FIG. 3 is of the bivisual type like the
embodiment in FIG. 1, but the line of separation between the near
range zone N and the far range zone F runs, when the lens body is
installed, from the upper margin of the lens to the bottom margin
of the lens, and separates the optical lens portion 1 into two
halves of which the one half forms the far range zone F and the
other half the near range zone N. With the lens inserted into the
eye, the near range zone N is situated closer to the wearer's nose
than the far range zone F. In this example, again, the bores 3 are
disposed in a lens area close to the lens margin, so that the
optical function of the lens will not be impaired. Holding loops 4
serve to fix the lens in the eye.
In the embodiment represented in FIG. 4, two far range zones F and
two near range zones N of sector shape are provided, and have equal
sector angles. In the embodiment represented, the sector angles are
90.degree.. It is, however, also possible to provide a greater
number of near and far range zones with correspondingly smaller
sector angles. The near and far range zones N and F are disposed
alternately around the lens axis. Bore 3 are situated in a
peripheral lens portion 2, which is optically inactive. Fixation
means 4 again serve to fix the lens in the eye.
Other fixation means can be provided for the artificial opthalmic
lens. Known fixation means are described in German patent
publication Nos. 25 04 540, 26 05 847, 26 54 999 and 27 25 219.
As may be seen in the embodiments of FIGS. 1-4 the near and far
range zones (N and F) of the transparent optical lens portion
immediately in front of the pupil have approximately equal areas
symmetrically from the axis of the optical lens.
In FIG. 5, there is shown in section an embodiment of an artificial
intraocular lens which consists of a flexible, transparent envelope
5 filled with a transparent fluid. This envelope 5 with the fluid
therein substantially forms the optical lens portion. In FIG. 5 is
represented the state of the lens for near vision. The envelope
filled with the transparent fluid is attached to the ciliary muscle
of the eye by means of a fastening fringe 6 which is anchored in
the envelope. In this manner the ciliary muscle acts as it does on
the natural eye lens, i.e., when the ciliary muscle contracts, the
illustrated near action of the lens represented in FIG. 5 results,
since the lens becomes more spherical and thus receives a greater
refracting power. When the ciliary muscle elongates, a tension is
exerted on the envelope 5 filled with the transparent fluid and
flattens the latter so that it is given the shape represented in
FIG. 6. The lens then has a reduced refracting power, and serves
for far vision. In this manner a continuous change of focus from
near vision to far vision can be made possible in conjunction with
the action of the ciliary muscle.
In FIG. 7 is shown a top view of the embodiment represented in
cross section in FIGS. 5 and 6, and the anchoring of the fastening
fringe 6 in the flexible envelope body 5 can also be seen.
It will be understood that the specification and examples are
illustrative but not limitative of the present invention and that
other embodiments within the spirit and scope of the invention will
suggest themselves to those skilled in the art.
* * * * *