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Description  |
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FIELD OF THE INVENTION
The present invention generally relates to a suture and/or incision marking
device for placing ink markings on the sclera and/or limbal area of a
patient's eye. Additionally, the invention relates to a method for placing
ink markings on the sclera and/or limbal area of a patient's eye prior to
cataract or intraocular surgery in order to standardize and define the
location and length of the incision and suture placement.
BACKGROUND OF THE INVENTION
Intraocular lens surgical procedures, and specifically cataract surgery to
which the present invention is directed primarily, have become more
sophisticated, with less intraoperative complications occurring. Hence,
ophthalmologists now are focusing more attention on the refinements, one
of which is the correction and prevention of corneal astigmatism. In order
for the surgeon to be able to properly evaluate the effects of their
cataract incisions and closures, several requirements are necessary.
The incision must be as standardized and reproducible as possible, as
should be the closure, including the number and type of sutures, the
suture material and the placement of sutures and their corresponding
knots. The suture tension should also be adjustable according to the
individual surgical requirements. The sclera and/or limbal marker and
method of using it in intraocular surgery according to the present
invention are effective in refining the intraocular surgical techniques
required in procedures such as cataract removal and intraocular lens
implantation. The use herein of the terms "sclera and/or limbus" and
"sclera and/or limbal area" with respect to procedures involving the use
of the present invention relate to the personal preferences of surgeons as
to the location of making incisions for this type of surgery as opposed to
corneal surgery. Thus, in some procedures, a surgeon may wish to mark the
sclera and in others, the limbus or limbal area which defines the boundary
region between the cornea and the sclera.
Final astigmatism correction, at the time of closure, may be monitored by
any one of a number of available hand-held or microscope-mounted surgical
keratometers, or may merely be estimated by the surgeon.
Various types of instruments have been used to aid in standardizing
incisions in the cornea during radial and non-radial keratotomy
ophthalmosurgery for the control of astigmatism. However, prior to the
present invention, no one has devised a sclera and/or limbal marker and
method of using it for other types of ophthalmosurgery. One device
comprises a case in the form of a bush having a central opening to
accommodate a sight centering means, and a series of plates at right
angles to the sight centering means. The plates are adapted to be brought
into contact with the cornea to be marked out. The plates are provided
with sharpened curvilinear edges corresponding to the curvature of the
cornea. In use, the plates of the device are pressed into the eye to cause
temporary elastic deformation or indentations of the cornea to mark areas
for incising the cornea.
A similar marking device has the same basic structure as the prior art
device described above, except that each plate is mounted on a separate
holder for adjustable movement radially with respect to the bush. The
sharp bladed tips of the plates cause corneal indentations when pressed
against the eye. The eye may be prestained with brilliant green dye prior
to pressing the plates of the blades onto the eye.
These devices, however, mark the cornea of a patient's eye and are used in
radial keratotomy or corneal transplants. Their purpose is to make radial
marks for radial incisions on the cornea in order to help reduce myopia.
Non-radial incisions or combinations of non-radial and radial incisions on
the cornea are used to reduce postoperative astigmatism and/or myopia
associated with corneal surgery.
Other devices are known for use as blanks or templates against a patient's
skin to define the proper incision pattern to promote proper handling with
a hairline scar. One of these devices is a skin biopsy device which
includes a plurality of short members extending outwardly from the
template sides. The members act as markers to indicate the location of
sutures when the device is pressed against the skin to make the skin red
or discolored in the area of the marker members.
A problem encountered in using ophthalmosurgical or skin marking devices of
the prior art is that they are not adapted for use in cataract surgery to
mark the sclera and/or limbus of an eye to indicate the location of
sutures instead of or in addition to incisions. Furthermore, due to their
sharp edges, the ophthalmosurgical marker devices are designed to mark the
cornea of an eye, prior to corneal surgery, by indenting the corneal
surface. Cataract surgery on the other hand, requires the marking of the
sclera and/or limbal area. The incision used in cataract and/or
intraocular lens surgery is made perpendicular to the marking lines of the
present invention and not parallel to the marking lines as described in
the prior art. The marking lines are also used for suture placement after
the incision is made. The skin marking devices are also not adapted for
use in any way in cataract surgery.
Some surgeons presently use ink to mark the sclera prior to making the
incision. They use ink-dipped dividers preset to the desired dimensions.
Depending on the desired dimensions, this may require the use of more than
one set of dividers, the dividers have to be carefully aligned in each
instance, and, because of the extra care and manipulation required, the
procedure is rather time consuming.
The present invention provides an incision and/or suture marking device
having a plurality of precisely oriented, outwardly extending projections
coated with a waterproof ink, such as gentian violet, which when pressed
gently onto a patient's eye places ink markings on the sclera and/or
limbal areas after the conjunctiva is "reflected" (cut and folded back,
usually distally, to form a "fornix based flap"), indicating the length
and location where incisions and sutures are to be placed during surgery.
The inked projections make ink marks which will define the proper length
bites for a suture needle on either side of an incision line during suture
placement. By indicating the placement of sutures on the sclera and/or
limbus, rather than merely the location of incisions on the cornea as in
the ophthalmosurgical devices of the prior art, surgeon induced
astigmatism often resulting from tangential displacement of tissue at the
incision line caused by uneven or improper suture placement after cataract
removal can be controlled or eliminated. Furthermore, where pre-existing
astigmatism exists, the skilled cataract surgeon can reduce or even
eliminate it by judicious placement of the cataract incision, and/or
varying the suture tension.
The marking device, when pressed onto the sclera and/or limbus of any eye
prior to surgery, among other things: defines the length and location of
incisions and suture placement by making predetermined patterns of ink
marks on the scleral and/or limbal areas of the eye; provides for proper,
and preferably equal, spacing between sutures; defines uniform suture
bites, for example 1 mm or other desired dimensions, on each side of the
incision; and allows the surgeon to accurately reappose the proximal and
distal sides of the incision without lateral displacement along the
incision line. These in turn prevent misalignment of wound surfaces during
suture placement, thus reducing or eliminating the possibility of
postoperative astigmatism.
SUMMARY OF THE INVENTION
One aspect of the present invention relates to a marking device for marking
a sclera and/or limbal portion of an eye during intraocular surgery
comprising a generally arcuate body member having opposed first and second
major surfaces, a plurality of projections extending from the first major
surface, the projections being generally equiangularly spaced from each
other and radially arranged in a pattern along an arc of a circle, the
projections being adapted to be inked and to transfer to an eye the ink in
markings corresponding to the projections so that incisions and sutures
can be placed in the sclera and/or limbal portion of the eye relative to
the markings.
Another aspect of the present invention relates to a method for marking the
sclera and/or limbal portion of an eye prior to intraocular surgery to
help control and prevent postoperative astigmatism using a marking device
wherein the marking device comprises a generally arcuate body member
having opposed first and second major surfaces, and a plurality of
projections extending from the first major surface, the projections being
generally equiangularly spaced from each other and radially arranged in a
pattern along the arc of a circle, the method comprising reflecting the
conjunctiva of the eye so as to expose the sclera and/or limbus of the
eye, coating waterproof ink onto the projections of the device, pressing
the device onto the sclera and/or limbus with sufficient pressure to
transfer ink from the projections onto the sclera and/or limbus to create
ink markings corresponding to the projections, and removing the device
from the eye.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing summary, as well as the following detailed description of a
preferred embodiment of the invention, will be better understood when read
in conjunction with the appended drawings, in which:
FIG. 1 is a side elevational view of a first embodiment of a marking device
according to the present invention showing projections extending from a
first, planar major surface of the arcuate body member;
FIG. 2 is a side elevational view of the embodiment of FIG. 1 taken from
the left side of FIG. 1;
FIG. 3 is a diagrammatic elevational view of a patient's eye showing the
ink markings transferred from the embodiment of the marker of the present
invention illustrated in FIGS. 1 and 2;
FIG. 4 is a side elevational view of a second embodiment of a marking
device according to the present invention showing projections extending
from a first, curvilinear major surface of the arcuate body member;
FIG. 5 is a cross-sectional view of the second embodiment of the marking
device taken along the plane defined by lines 5--5 of FIG. 4;
FIG. 6 is a general, diagrammatic side elevational view generally
corresponding to FIGS. 2 and 4 of a third embodiment of a marking device
according to present invention in which certain positioning means are used
to position the marking device on a patient's eye; and
FIG. 7 is another general, diagrammatic side elevational view generally
corresponding to FIGS. 2, 4 and 6 of a fourth embodiment of a marking
device according to the present invention in which other types of
positioning means are used to position the marking device on a patient's
eye.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings in detail, where like numerals indicate like
elements throughout the several views, there is shown in FIGS. 1 and 2 a
first embodiment of a marking device 10 in accordance with the present
invention.
The marking device 10 of the present invention, generally made of a
corrosion-resistant material such as plastic or stainless steel, comprises
a generally arcuate body member 12 having a first, planar major surface 14
and an opposed, second planar major surface 15 with a plurality of
projections 16 extending from the first major surface 14. The arcuate body
member 12 comprises an inferior arc 18 and a superior arc 20 joined by end
edges 22 and 24, the inferior arc 18 having a smaller radius than the
superior arc 20. In the presently preferred embodiment, the body member 12
covers approximately 40 to about 160 degrees of a circle, and most
preferably, about 90 degrees. The inferior arc 18 preferably has a radius
of curvature equal to the average person's limbal or corneal radius of
curvature, which is approximately 6 mm. The superior arc 20 preferably has
a radius of curvature of 10 to 11 mm. It should be understood, however,
that the radii of curvature of the body member 12 may vary, depending on
the surgeon's choice of incision and suture locations relative to the
limbus.
In the first embodiment, as best seen in FIG. 2, the projections 16 extend
radially from the inferior arc 18 in a direction toward the superior arc
20 and are in a pattern along an arc of a circle, equiangularly spaced
from each other. Although the projections 16 are illustrated in FIG. 2 as
having generally rectangular blunt faces or tips which extend in a
direction from the inferior arc 18 toward the superior arc 20, the
projections can be of any desired shape, such as dots, circles, +'s, X's,
or the like as desired. The blunt tips of the projections are adapted to
be inked and leave marks of waterproof ink on the sclera and/or limbus
which are easy for a surgeon to see and use to make an eye incision and
suture it properly.
In the first embodiment, the projections 16 are arranged in two sets 16a
and 16b of a like or different number, such as seven in each set in the
presently preferred embodiment. The first set 16a of radial projections is
located along the inferior arc 18. The second set of projections 16b are
preferably radially aligned with and equidistantly spaced from the first
set 16a, although, if desired, the second set could be aligned along a
predetermined arc of a different, non-parallel radius. A central
projection in at least one set, such as central projection 16c should have
a distinguishing characteristic to help the surgeon to discern the center
of the incision. As best illustrated in FIG. 2, the central projection 16c
is longer than the other projections.
It should be understood that any other suitable number, shape, arrangement
or spacing of projections 16 may be employed, depending on the number of
sutures a surgeon prefers to place or on the particular type of
intraocular surgery to be performed.
An alignment projection 23, as shown in FIG. 1, which could also be in the
form of a planar mark or score line, extends from the second major surface
15 and is aligned with the central projection 16c, to help the surgeon in
the proper placement of the marking device 10 on the eye. A similar
purpose is served by an alignment notch 25 formed in the edge defined by
the superior arc 20 of the marking device and aligned with projections 16c
and 23. These placement aids are optional, since the marking device may
still be used efficiently without them.
In the embodiment illustrated in FIGS. 1 and 2, the arcuate body member 12
is 11 mm long along the inferior arc 18, 5 mm wide and 2.5 mm thick. The
projections 16a and 16b are 1 mm long, from 0.10 to 0.40 mm wide and
extend 0.5 mm from the first major surface 14. The central projection 16c
is 1.5 mm long, with the remaining dimensions the same as the other
projections. The projections are equiangularly spaced 1.8 mm from each
other on center at the superior arc of the first set 16a. The inferior arc
of the second set 16b of projections is spaced 0.75 mm from the superior
arc of the first set 16a of projections. It should be understood, however,
that the dimensions and spacing of the projections 16 and the dimensions
of the body member 12 may vary in order to accommodate the suture marking
needs of a particular type of surgery without affecting the usefulness of
the device 10.
As illustrated in FIG. 1, a handle 26 is attached to the second major
surface 15 to facilitate better control of the marking device 10. One of
ordinary skill in the art will understand that the handle may be
permanently attached or removably attached by any suitable mechanical
fastening means, such as threaded connection elements, bayonet connection
elements, friction fit, etc. The removable attachment facilitates the
interchangeability of body members 12 having varying radii of curvature or
other dimensions or varying numbers or arrangements of projections 16.
Before describing the other preferred embodiments of the marking device
according to the present invention illustrated in FIGS. 4 through 7, the
method of using the above-described marking device in a typical surgical
technique for performing a cataract extraction will be described with
particular reference to FIG. 3, which illustrates, rather
diagrammatically, an eye 27. Eye 27 includes a limbus 28 forming a border
between the cornea 29 (including the iris) and the sclera 30.
A surgeon may first determine preoperative corneal astigmatism using a
surgical keratometer (not shown). A central meridian is marked on the eye
at the limbus with a 30 gauge needle dipped in methylene blue. This
central mark allows for perfect centration of the marking device 10 with
respect to the cornea. The placement of the device may, however, vary with
the operative procedure.
The conjunctiva, a thin white membrane of tissue which covers the sclera
and terminates at the limbus, is then reflected (pulled rearward) in order
to expose the sclera. This is usually done by severing the conjunctiva at
the limbus and pulling it rearward like a bedsheet, thus progressively
detaching it from and exposing the sclera. This is illustrated
schematically in FIG. 3 by reference numeral 31.
The tips of the projections 16 of the marking device 10 are then coated
with a non-toxic, waterproof, absorbable ink or stain, such as gentian
violet. This is conveniently done by pressing the projections 16 onto a
marking pad soaked with gentian violet or any other suitable, non-toxic
indelible or waterproof ink. It should be understood that any other means
of coating the projections may be employed, for example, rubbing the
projections with a surgical marking pencil (not shown) incorporating the
ink. Although the ink is waterproof to be visible during the surgical
procedure, gentian violet or other suitable inks fade gradually and
disappear completely by the first postoperative day.
The inked marking device 10 is then aligned in proper position with the
inferior arc 18 aligned with the limbus, and with the central projection
16c, the alignment projection 23 and/or the alignment notch 25 in
alignment with the marking of the central meridian. Then the device is
pressed gently against the eye 30, thus transferring the ink from the
projections 16a, 16b and 16c onto the sclera and/or limbus to form
corresponding ink marks 32a, 32b and 32c. The marking device 10 is then
removed from the eye 27. Access is then gained into the anterior chamber
of the eye to remove the cataract by means of an incision 34 made through
the sclera and/or limbus following the contour of the ink marks. The
placement of incision 34 relative to the ink marks can vary according to
the surgeon's preference. For example, the incision could also be located
along an arc formed by joining the superior ends 36 of the first set of
marks 32a or the inferior ends 38 of the second set of marks 32b. The
cataract extraction is then performed according to the surgeon's
preference. The ink marks 32 remain visible throughout the entire cataract
procedure. They act as a guide even if the situation warrants an
enlargement of the incision. Importantly, the ink marks 32 serve as a
guide for final suture placement, thus assuring that the sutures are
properly radially placed.
Although suture placement varies by preference of the surgeon, one way to
use the ink marks 32 to locate the sutures is to use the superior ends 36
of the first set of ink marks 32a to define the insertion points for the
suture needle on one side of the incision line 34 and to use the inferior
ends 38 of the second set of ink marks 32b to define the exit points for
the suture needles on the opposite side of the incision line 34.
If a smaller incision is required, as in a phacoemulsification cataract
operation, or a secondary lens implantation, the length of the incision
can be adjusted and the same marking device 10 used.
This marking device 10 has proved to be a very valuable tool in all forms
of cataract, primary intraocular lens, and secondary intraocular lens
implant surgery.
Other preferred embodiments of marking devices according to the present
invention will now be described with reference to FIGS. 4 through 7.
Turning first to FIGS. 4 and 5, there is shown a marking device 40. The
marking device has a generally arcuate body member 42 including a first
major surface 44. As best seen in FIG. 5, the first major surface 44 is
curvilinear in general, and concave, in particular. The concave surface 44
should have a radius approximating the radius of the eye, which may make
it easier to mark the eye with marking device 40 than with marking device
10, although marking device 10, including a planar first major surface 14
has been found to be acceptable in actual practice.
A second major surface 45 is generally opposed to the first major surface
44. A handle (not shown) extends from the second major surface 45.
A plurality of projections 46 extend from the first major surface 44 and
are arranged in three general sets, 46a, 46b and 46c. An elongated central
projection 46d is illustrated as being part of the third set 46c. The
projections of sets 46a and 46c are generally rectangular and are radially
aligned with each other and equiangularly spaced along the length of the
body member 42. Preferably, as illustrated in FIG. 4, the first set of
projections 46a extends radially from an inferior arc 48 of the body
member 42 toward a superior arc 50 of the body member 42. The projections
are arranged along the body member 42 from one edge 52 to the opposite
edge 54, which edges join the inferior and superior arcs 48 and 50.
The second or middle set of projections 46b are generally conical in shape,
with the blunt tips of the cones being at the same height as the blunt
tips of the first and third sets of projections 46a and 46c. The purpose
of the second set of projections 46b is to more specifically define the
location of an incision line between the other sets of projections which
define the location of the sutures. As in the first embodiment of the
present invention, the shape, dimensions and arrangement of the
projections 46 may be varied as desired. For example, if desired, the
second set of projections 46b, instead of being discrete points, could be
joined together as a single, continuous raised projection to specifically
mark an incision line. Likewise, the dimensions of the generally arcuate
body member 42 may also be varied within reasonable limits.
If desired, an alignment projection (not shown) or other alignment mark
(not shown) aligned with the central projection 46a could also extend from
or be placed on the second major surface. An optional alignment notch 55
is formed in the superior arc 50 of the body member and aligned with the
central projection 46d.
As presently preferred, the inferior arc 48 has a radius of about 6 mm,
corresponding to the average radius of curvature of a patient's limbal or
corneal radius of curvature. Each projection within first set 46a is 0.5
mm long and has a blunt tip about 0.25 mm in width. The center points of
the projections forming the second set 46b are preferably aligned on a
radius of curvature 1 mm from the superior edge of the projections of the
first set 46a. The tips of the projections of set 46b have a diameter of
0.25 mm. The inferior ends of the projections of the third set 46c are
spaced on a radius of curvature 1 mm from the center of the radius of
curvature of the middle set of projections 46b. The projections of the
third set 46c have a length of 1 mm, except for the central projection
46d, which has a length of 1.5 mm. All of the projections 46 extend 1 mm
from the concave first major surface 44 of the body member 42.
The marking device 40 is used in the same general manner as described above
with respect to the marking device 10. If it is desired to coat the blunt
projections 46 with suitable ink from a marking pad, it should be clear
that the marking pad should have a convex radius of curvature
corresponding to the concave radius of curvature of the tips of the
projections.
A marking device 60 in accordance with a third embodiment of the present
invention is illustrated schematically in FIG. 6. The marking device 60
includes an arcuate body member 62 having a first major surface 64 from
which extend a plurality of projections 66 aligned in two sets, 66a and
66b, including a central projection 66c. The first major surface 64 of the
body member 62 may be substantially planar as in the embodiment of FIGS. 1
and 2, or may be concave as in the embodiment of FIGS. 4 and 5.
The body member 62 includes an inferior arc 68 having a radius of curvature
generally corresponding to the radius of curvature of the limbus. A
superior arc 70 is opposite the inferior arc 68. The inferior and superior
arcs are connected by edges 72 and 74. As with the other embodiments, the
shape, dimensions and arrangement of the projections and the body member
may be varied as desired depending on the procedure invol | | |
