Surgical blade abstract
A surgical blade and method incorporating the surgical blade which
ensure uniform incision depth and angulation, and the creation of
self sealing surgical wounds during cataract surgery.
Surgical blade claims
I claim:
1. A method of creating self-sealing surgical incisions in the
eye comprising:
(a) providing a surgical blade of the type which comprises a shaft
having a proximal end and a distal end, a horizontal stabilizing
platform having a proximal end and a distal end, said proximal end
of said horizontal stabilizing platform extending from said distal
end of said shaft, and an angled active tip having a predetermined
length extending downward from said distal end of said horizontal
stabilizing platform at a predetermined angle with respect to said
distal end of said horizontal stabilizing platform,
(b) effecting a vertical incision of a known depth in the sclera
of the eye having a proximal end and a distal end by penetrating
said sclera with said active tip of said surgical blade to a depth
equal to said predetermined length of said active tip,
(c) effecting a horizontal scleral tunnel incision of a known depth
by extending an incision from said distal end of the vertical scleral
incision through to the clear cornea of the eye in a plane perpendicular
to said vertical scleral incision,
(d) inserting said surgical blade through the scleral end of said
horizontal scleral tunnel incision and into the clear corneal end
of said horizontal scleral tunnel incision and, by manipulating
a handle connected to said surgical blade, effecting a corneal incision
which extends downward from said clear corneal end of said horizontal
scleral tunnel incision at a known angle with respect to said clear
corneal end of said horizontal scleral tunnel incision; said known
angle being defined by said predetermined angle of said active tip
of said surgical blade; said corneal incision penetrating through
said clear cornea of the eye and into the anterior chamber of the
eye, and
(e) withdrawing said surgical blade from said eye.
2. The method of claim 1 wherein said step of providing comprises
providing an active tip which describes an angle of ninety degrees
with respect to said distal end of said horizontal stabilizing platform.
3. The method of claim 1 wherein said known angle of said corneal
incision with respect to said clear corneal end of said horizontal
scleral tunnel incision is ninety degrees.
4. The method of claim 1 further comprising extending said corneal
incision to a desired width by manipulating said handle of said
surgical blade.
5. The method of claim 1 further comprising inserting a device
into said horizontal scleral tunnel incision, whereby said surgical
blade can be readily inserted into and withdrawn from the eye.
6. The method of claim 1 further comprising cataract removal.
Surgical blade description
BACKGROUND-FIELD OF THE INVENTION
This invention relates to ocular surgical instruments and methods,
specifically to surgical blades and methods employed in creating
incisions during ocular surgery.
BACKGROUND-DESCRIPTION OF PRIOR ART
Opthalmologists currently performing cataract surgery by employing
self sealing, no-stitch incisions are faced with the dilemma of
creating precise surgical wounds with techniques and instrumentation
which defy precision. Ideally, self sealing surgical incisions used
in cataract surgery are trifaceted. The first facet is a vertical
incision into the outer wall of the sclera, setting the depth for
the second facet, the scleral tunnel, which is an incision extending
horizontally from the base of the vertical scleral incision into
the clear cornea. The third facet is an incision which theoretically
extends perpendicularly from the corneal base of the scleral tunnel,
downward through the underlying cornea and into the anterior chamber
of the eye.
Cataract surgeons refer to the vertical scleral incision as penetrating
half of the thickness of the sclera. However, scleral thickness
varies from patient to patient and surgeons rely on subjective,
imprecise techniques to determine whether the depth of the scleral
tunnel is appropriate. Once the vertical scleral incision is made,
the depth of which is a product of the surgeon's subjective judgment,
a common method for determining appropriate scleral tunnel depth
is for the surgeon to attempt to keep the blade used to create the
incision in sight through the scleral tissue until the horizontal
scleral tunnel incision is completed.
Although the third facet of the self sealing incision is intended
to be perpendicular to the corneal base of the horizontal scleral
tunnel incision, in practice the angle created is obtuse and the
precise measurement of the angle unknown. Currently, the third facet
incision is created by extending a straight, sharp surgical blade
into the corneal end of the scleral tunnel, then lifting the handle
of the blade so that the blade is pointing toward the center of
the eye, and plunging the blade through the underlying cornea and
into the anterior chamber of the eye. Because the surgical blades
presently employed are straight, it is extremely difficult to position
a blade in such a manner that it can be plunged through the underlying
cornea at an angle perpendicular to the scleral tunnel since the
shaft of the blade is resting in a tunnel that is itself intended
to be perpendicular to the yet to be created third facet. If two
blades are used in the same procedure, the second blade may enter
the cornea at a different angle than did the first blade. Moreover,
the angles created by this type of incision are non-uniform along
the length and width of the incision.
Perpendicularity between the horizontal scleral tunnel incision
and the corneal incision is vital to the creation of a true self
sealing surgical wound. With a perpendicular corneal incision, the
tensile forces within the tissues of the eye push the edges of the
incisions together, thereby sealing the surgical wound upon instrument
removal. When the angle of the corneal incision is obtuse, the tensile
forces within the tissues of the eye may cause the edges of the
incison to pull apart or slide over each other, causing complications
including an ineffective wound seal, wound gape, hyphema, and induced
astigmatism with resultant vision impairment.
These procedures and instrumentation have the following serious
complications:
(a) The scleral tunnel depth is set too shallow, in which case
the roof of the scleral tunnel may be ripped open during the manipulations
required to complete cataract surgery;
(b) When the scleral tunnel depth is set too shallow, the tensile
strength of the incised tissues is too weak to form self sealing
wounds within the eye;
(c) The scleral tunnel depth is set too deep, in which case the
choroidal tissue may be punctured, causing hemorrhaging;
(d) When the scleral tunnel depth is set too deep, the retina may
be punctured, in which case the retina may be torn or detached,
and intraocular bleeding may occur;
(e) If the scleral tunnel is set too deep, the ciliary body, iris
and/or uvea may be penetrated causing bleeding and permanent damage
within the eye.
(f) The incision extending from the corneal base of the scleral
tunnel, through the cornea and into the anterior chamber of the
eye is cut at an angle more than ninety (90) degrees from the corneal
base of the scleral tunnel, resulting in an incision which is susceptible
to hyphema and wound gape;
(g) The incision extending through the cornea is cut at a non-uniform
angle along its width and length, also resulting in an incision
susceptible to hyphema and wound gape; and
(h) The incision extending through the cornea is not perpendicular
to the corneal base of the scleral tunnel resulting in induced astigmatism
and increased vision impairment.
OBJECTS AND ADVANTAGES
Accordingly, several objects and advantages of the present invention
are:
(a) to provide a surgical blade and method which set a uniform
depth for a vertical incision into the sclera;
(b) to provide a surgical blade and method which set a uniform
depth for a horizontal scleral tunnel incision, ensuring the incision
is not too shallow and preventing tearing of the scleral tunnel
incision during cataract surgery manipulations;
(c) to provide a surgical blade and method which set a uniform
depth for scleral tunnel incision, ensuring sufficient tensile strength
within the incised tissues to effect a self sealing wound;
(d) to provide a surgical blade and method which ensure appropriate
scleral tunnel depth, preventing choroidal tissue puncture and consequent
hemorrhage;
(e) to provide a surgical blade and method which ensure appropriate
scleral tunnel depth, preventing retinal puncture, tearing, and
detachment, and intraocular bleeding;
(f) to provide a surgical blade and method which ensure appropriate
scleral tunnel depth, preventing penetration of the ciliary body,
iris, and/or uvea and consequent permanent tissue damage and intraocular
bleeding;
(g) to provide a surgical blade and method that produce an incision
perpendicular to the corneal base of a scleral tunnel, which incision
extends through the underlying cornea, resulting in a self sealing
surgical wound which is not vulnerable to hyphema or wound gape;
(h) to provide a surgical blade and method which produce an incision
through the cornea and into the anterior chamber at a uniform angle
along the length and width of the incision, resulting in a self
sealing surgical wound which is not vulnerable to hyphema or wound
gape; and
(i) to provide a surgical method and blade that produce an incision
perpendicular to the corneal base of the scleral tunnel, which incision
extends through the cornea and into the anterior chamber, resulting
in a self sealing surgical wound which does not induce astigmatism.
Further objects and advantages of the present invention are to
provide improved instruments and techniques for the use of ocular
surgeons. Other and further objects and advantages of the present
invention will be apparent to those skilled in the art to which
it relates or will become apparent from a consideration of the ensuing
description and drawings.
DRAWING FIGURES
FIG. 1 shows a right-sided view of the surgical blade with an angulated
shaft, horizontal stabilizing platform, and angled active tip extending
downward from the horizontal stabilizing platform.
FIG. 2 shows a left-sided view of the surgical blade.
FIG. 3 shows the surgical blade extending into the cornea of the
eye, with the active tip penetrating through the underlying portion
of the cornea.
______________________________________ Reference Numerals In Drawings
______________________________________ 10 Shaft of surgical blade
12 Horizontal stabilizing platform 14 Beveled edge of horizontal
stabilizing platform 16 Active tip 18 Beveled edge of active tip
20 Active tip point 22 Vertical scleral incision 24 Horizontal scleral
tunnel 26 Vertical corneal incision 28 Surgical blade 30 Handle
______________________________________
DESCRIPTION-FIGS. 1 TO 3
A typical embodiment of the surgical blade of the present invention
is illustrated in FIG. 1 and FIG. 2. The surgical blade has an angled
shaft 10 for connection to an appropriate handle, a horizontal stabilizing
platform 12 with a beveled edge 14 on each side, and a sharp, angled
active tip 16 of a known length and angulation, with a beveled edge
18 on each side, extending downward from the horizontal stabilizing
platform 12. In the prefered embodiment, the surgical blade 28 is
made of metal, the shaft 10 is angled upward from the horizontal
stabilizing platform 12 at a forty-five degree angle, the active
tip 16 extends downward from the horizontal stabilizing platform
12 at a ninety degree angle in a plane perpendicular to the horizontal
stabilizing platform 12 and the active tip point 20 is centrally
positioned.
The length of the shaft 10 is typically 7 mm to 25 mm in length
and the horizontal stabilizing platform 12 is 3 mm to 10 mm in length
and 1 mm to 4 mm in width. The active tip 16 is typically 0.2 mm
to 0.6 mm long, although 0.35 mm is the preferred length. Both edges
of the horizontal stabilizing platform 12 are sharply center beveled
14 from the angle created by the active tip 16 and extending backward
toward the the shaft 10 one-half the length of the horizontal stabilizing
platform 12. Both edges of the active tip 16 are completely sharply
center beveled 18 and the edges converge to form an extremely sharp,
center beveled active tip point 20.
There are various possibilities with regard to the positioning
of the active tip 16. The point active tip point 20 formed by the
convergence of the edges of the active tip 16 may be situated to
the left of center or to the right of center. The edges of the horizontal
stabilizing platform 12 and active tip 16 may be beveled in a variety
of combinations. The blade edges may all be beveled on the top or
on the bottom or the blade edges may be alternatively top and bottom
beveled or some of the blade edges may not be beveled. The shaft
10 may be square, cylindrical, or flattened in shape for attachment
to an appropriate handle and may extend horizontally from the horizontal
stabilizing platform 12 or extend from the horizontal stabilizing
platform 12 at a variety of angles. The horizontal stabilizing platform
12 may be rectangular in shape or wider at its shaft end than its
active tip end or narrower at its shaft end than its active tip
end.
FIG. 3 shows a cross sectional view of the eye with a vertical
scleral incision 22 horizontal scleral tunnel incision 24 vertical
corneal incision 26 which is perpendicular to the horizontal scleral
tunnel incision 24 and the intended placement within the eye of
the surgical blade 28 which is attached to a handle 30.
OPERATION-FIGS. 1 2 AND 3
My surgical blade and method provide a safe, efficient solution
to the problems created by the failure of instrument technology
to keep pace with the advances in ocular surgical techniques. My
invention provides an instrument and technique which permits ocular
surgeons to make intricate surgical incisions at known depths and
angles during cataract surgery, thereby facilitating the creation
of true self sealing surgical wounds.
The surgical blade 28 is used to make a trifaceted surgical wound
which is self sealing, and does not require suturing to close. The
active tip point 20 is used to puncture the sclera and the sclera
is pentrated by the active tip 16 to a depth equal to the length
of the active tip 16 creating a vertical scleral incision 22 of
a known depth. Maintaining contact between the outer scleral wall
and the horizontal stabilizing platform 12 prevents penetration
into the sclera deeper than the length of the active tip 12.
A typical sclerostomy tunnel blade is then used to create a horizontal
scleral tunnel incision 24 of a known depth by extending an incision
from the base of the vertical scleral incision 22 and into the clear
cornea of the eye in a plane perpendicular to the vertical scleral
tunnel incision 22. A sound probe which is 0.3 mm thicker than the
active tip 16 is passed through the scleral end of the horizontal
scleral tunnel incision 24 and into the clear corneal end portion,
thus providing clearance for passage of the surgical blade into
the horizontal scleral tunnel incision 24.
The surgical blade 28 is then passed into the horizontal scleral
tunnel incision 24 with the active tip 16 reaching to the clear
corneal end of the of the horizontal scleral tunnel incision 24.
The sound probe is removed and the active tip 16 of the surgical
blade 28 is caused to penetrate through the underlying cornea and
into the anterior chamber by pushing the handle 30 connected to
the surgical blade 28 in an upward and vertical direction, thereby
creating a vertical corneal incision 26 which is in a plane perpendicular
to the horizontal scleral tunnel incision 24 and passes into the
anterior chamber of the eye at a fixed angle as shown in FIG. 3.
The vertical corneal incision 26 is then extended to the desired
width by moving the surgical blade 28 laterally, creating a uniform
incision.
Prior to removal of the surgical blade 28 a sound probe 0.3 mm
thicker than the length of the active tip 16 is reintroduced into
the horizontal scleral tunnel incision and positioned next to the
surgical blade 28. The sound probe handle is gently pushed downward
in order to slightly raise the tip of the sound probe probe upward,
thereby elevating the roof of the horizontal scleral tunnel incision
24 and creating more space to remove the surgical blade 28.
Upon removal of the surgical blade 28 and the sound probe, the
surgical wound created will be sealed due to the tensile forces
existing within the eye. The ninety degree internal bevel created
between the horizontal scleral tunnel incision and the vertical
corneal incision is critical to ensure that the tensile forces of
the tissues work to seal the wound, rather than cause the different
tissue planes to ride over each other, causing complications including
an ineffective seal, wound gape, hyphema, and induced astigmatism
with resultant vision impairment.
SUMMARY, RAMIFICATIONS, AND SCOPE
Accordingly, the reader will see that the surgical blade and method
of this invention provide a safe, efficient means for ocular surgeons
to create self sealing surgical wounds of uniform depths and angulation
during cataract surgery. When the surgical blade and method described
above are implemented, a perpendicular internal bevel is created
between the horizontal scleral tunnel incision and the vertical
corneal incision, ensuring a wound that will be sealed by the tensile
forces within the tissues of the eye. Further this invention has
additional advantages in that
it ensures appropriate horizontal scleral tunnel incision depth,
thereby preventing tearing of the scleral tunnel during cataract
surgery;
it ensures appropriate horizontal scleral tunnel incision depth,
thereby maintaining tensile strength within the incised tissues
sufficient to form self sealing wounds within the eye during cataract
surgery;
it ensures appropriate horizontal scleral tunnel incision depth,
thereby preventing puncture and hemmorrhaging of the choroidal tissue;
it ensures appropriate horizontal scleral tunnel incision depth,
thereby preventing puncturing and/or tearing of the retina and intraocular
bleeding;
it ensures appropriate horizontal scleral tunnel incision depth,
thereby preventing penetration of the ciliary body, iris, and/or
uvea; and
it ensures a vertical corneal incision which is uniform along its
width and length.
Although the description above contains many specificities, these
should not be construed as limiting the scope of the invention,
but as merely providing illustrations of some of the presently preferred
embodiments of this invention. For example, the surgical blade may
be made of various metals, including stainless steel and titanium;
a sound probe or similar device providing the same function may
be incorporated into the handle connected to the surgical blade
or combined with the surgical blade; the angulation of the shaft
of the surgical blade may be varied; the lengths, widths and shapes
of the shaft, horizontal stabilizing platform and active tip may
be varied; the angulation of the active tip may be varied; the bevels
along the blade edges may be varied between top, center, and bottom
beveling; the shaft may connected to a variety of handles, including
handles made of metal and plastic; and the shaft may be connected
to an appropriate handle in a variety of ways, including insertion
into a hole centered within the tip of a handle and insertion into
a slit cut across the width of the tip of a handle, etc.
Thus, the scope of the invention should be determined by the appended
claims and their legal equivalents, rather than by the examples
given.
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