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| United States Patent Application |
20010004702
|
| Kind Code
|
A1
|
|
PEYMAN, GHOLAM A.
|
June 21, 2001
|
INTERNAL KERATOME APPARATUS AND METHOD FOR USING THE SAME TO FORM A
POCKET/FLAP BETWEEN LAYERS OF A LIVE CORNEA
Abstract
An apparatus and method for forming a circularly or substantially
circularly shaped pocket between layers of a live cornea, and then,
expanding the pocket to form a flap-like layer at the front of the live
cornea which is pivotally attached to the remainder of the cornea by a
flap connecting section. The cutting tool of the apparatus preferably has
a circular or substantially circular cutting portion which is inserted
into the cornea and reciprocated to form the pocket. Suction is applied
to the front surface of the cornea to stabilize the cornea during the
pocket forming process.
| Inventors: |
PEYMAN, GHOLAM A.; (NEW ORLEANS, LA)
|
| Correspondence Address:
|
ROYLANCE, ABRAMS, BERDO & GOODMAN, LLP
1300 19TH STREET, NW
SUITE 600
WASHINGTON
DC
20036-2680
US
|
| Serial No.:
|
384368 |
| Series Code:
|
09
|
| Filed:
|
August 27, 1999 |
| Current U.S. Class: |
606/166 |
| Class at Publication: |
606/166 |
| International Class: |
A61B 017/32 |
Claims
What is claimed is:
1. An apparatus for separating a layer from a patient's live cornea,
comprising: a suction mechanism, adaptable to apply suction to a front
surface of the live cornea; and a separating tool, adaptable to move in a
reciprocating motion to form a pocket between the layer of the live
cornea and a remaining portion of the live cornea.
2. An apparatus as claimed in claim 1, wherein: the separating tool has
first and second portions, the first portion having a separating edge
which is adaptable to separate the layer from the remaining portion of
the live cornea; the first and second portions being arranged in a tool
extending direction toward the separating edge and transverse to a
reciprocating direction along which the separating tool reciprocates; and
the width of at least some of the first portion taken along the
reciprocating direction is larger than the width of the second portion
taken along the reciprocating direction.
3. An apparatus as claimed in claim 2, wherein the first portion is
substantially circularly shaped with a diameter thereof extending along
the reciprocating direction and a rotational axis thereof extending
substantially perpendicular to the tool extending direction.
4. An apparatus as claimed in claim 2, wherein: the tool has first and
second surfaces on opposite sides thereof, each comprising a portion of
the first and second portions, the first surface being longer than the
second surface in the tool extending direction and being adaptable to be
positioned closer than the second surface to the front surface of the
live cornea when the tool is inserted into the live cornea; and the tool
further has a third surface disposed at an angle other than 0.degree.
with respect to the first surface, the third and first surfaces
connecting to form the separating edge.
5. An apparatus as claimed in claim 2, wherein: the tool has first and
second surfaces on opposite sides thereof, each comprising a portion of
the first and second portions, the first surface having a first section
extending at an angle other than 0.degree.with respect to the tool
extending direction.
6. An apparatus as claimed in claim 5, wherein the first surface further
has a second section which is substantially parallel with the second
surface.
7. An apparatus as claimed in claim 5, wherein the first section is a
portion of the first portion and is angled with respect to the second
surface such that the distance between the first section and the second
surface measured proximate to the separating edge is less than the
distance between the first section and the second surface measured at a
location along the first section away from the separating edge in a
direction opposite to the tool extending direction.
8. An apparatus as claimed in claim 1, wherein the suction mechanism
comprises a guiding mechanism adaptable to guide the separating tool
toward the live cornea.
9. An apparatus as claimed in claim 1, wherein the suction mechanism
comprises a guide adaptable to position the separating tool to form the
pocket in the live cornea at a designated distance from the front surface
of the live cornea.
10. An apparatus as claimed in claim 1, wherein the suction mechanism
comprises a viewing device, adaptable to enable a user to view the front
surface of the live cornea to which suction is being applied.
11. An apparatus as claimed in claim 10, wherein the viewing device has a
surface adaptable to contact the front surface of the live cornea when
suction is being applied to the live cornea.
12. An apparatus as claimed in claim 1, wherein the separating tool is
adaptable to be removably attached to the suction mechanism.
13. An apparatus as claimed in claim 1, further comprising a device which
is adaptable to be positioned in a first position to restricting the
reciprocating motion of the separating tool to cause the separating tool
to form the pocket in the live cornea; and wherein the device is further
adaptable to be positioned in a second position to unrestrict the
reciprocating motion of the separating tool to cause the separating tool
to expand the pocket in the live cornea to form a flap-like layer at the
front surface of the live cornea.
14. An apparatus for forming a substantially circularly shaped pocket
between layers of a patient's live cornea, comprising: a mechanism,
adaptable to substantially stabilize the live cornea; and a separating
tool, adaptable to move in a reciprocating motion to form the
substantially circularly shaped pocket between layers of the live cornea.
15. An apparatus as claimed in claim 14, wherein the separating tool has a
substantially circularly shaped blade adaptable for forming the
substantially circularly shaped pocket.
16. An apparatus as claimed in claim 14, wherein the stabilizing mechanism
further comprises a device, adaptable to restrict the reciprocating
movement of the blade to cause the blade to form the pocket between the
layers of the live cornea; and the device is further adaptable to
unrestrict the reciprocating movement of the blade to enable the blade to
expand the pocket to form a flap-like layer at the front of the live
cornea.
17. An apparatus as claimed in claim 14, wherein the stabilizing mechanism
is adaptable to apply suction to the front surface of the live cornea to
stabilize the live cornea.
18. A separating tool for separating a layer from a patient's live cornea,
comprising: first and second portions, the first portion having a
separating edge which is adaptable to separate the layer from a remaining
portion of the live cornea; the first and second portions being arranged
in a tool extending direction toward the separating edge; and the width
of at least some of the first portion taken in a direction transverse to
the tool extending direction being larger than the width of the second
portion taken along said transverse direction.
19. A separating tool as claimed in claim 18, wherein the first portion is
substantially circularly shaped with a diameter thereof extending along a
direction transverse to the tool extending direction and a rotational
axis thereof extending substantially perpendicular to the tool extending
direction.
20. A separating tool as claimed in claim 18, wherein: the tool further
has first and second surfaces on opposite sides thereof, each comprising
a portion of the first and second portions; the first surface being
longer than the second surface in the tool extending direction, and being
adaptable to be positioned closer than the second surface to the front
surface of the live cornea when the tool is inserted into the live
cornea.
21. A separating tool as claimed in claim 18, wherein: the tool has first
and second surfaces on opposite sides thereof, each comprising a portion
of the first and second portions; the first surface having a first
section which extends at an angle other than 0.degree. with respect to
the tool extending direction.
22. A separating tool as claimed in claim 21, wherein the first surface
further has a second section which is substantially parallel with the
second surface.
23. A separating tool as claimed in claim 21, wherein the first section is
a portion of the first portion and is angled with respect to the second
surface such that the distance between the first section and the second
surface measured proximate to the separating edge is less than the
distance between the first section and the second surface measured at a
location along the first section away from the separating edge in a
direction opposite to the tool extending direction.
24. A separating tool as claimed in claim 18, further comprising a
mechanism adaptable to move the separating tool in a reciprocating motion
in a direction transverse to the tool extending direction.
25. A method for separating a front layer of a patient's live cornea from
a remainder of the live cornea, comprising the steps of: stabilizing the
live cornea to substantially restrict the live cornea from moving;
inserting a separating tool into the live cornea at a first depth to
separate a portion of the front layer of the live cornea from a portion
of an adjacent layer of the live cornea to form a space between the front
and adjacent layers defined by edges of other portions of the front and
adjacent layers which remain attached to each other, the space having a
length extending between two of the edges in a direction transverse to an
optical axis of the live cornea; moving the separating tool from the
first depth to a second depth in the live cornea; and while the
separating tool is at the second depth, moving the separating tool in a
reciprocating motion, transverse to the optical axis of the live cornea,
to separate sections of the other portions of the front and adjacent
layers of the live cornea from each other to form a pocket between the
front and adjacent layers which is defined by new edges of the other
portions of the front and adjacent layers which remain connected, such
that the pocket has a length extending between two of the new edges in a
direction transverse to the optical axis of the live cornea, the length
of the pocket being greater than the length of the space.
26. A method as claimed in claim 25, wherein the inserting step comprises
the step of: while the separating tool is at the first depth in the live
cornea, moving the separating tool in a reciprocating motion, transverse
to the optical axis of the live cornea, to separate the portion of the
front layer from the portion of the adjacent layer of the live cornea to
form the space between the front and adjacent layers.
27. A method as claimed in claim 25, further comprising the steps of:
moving the separating tool from the second depth to a third depth in the
live cornea; and while the separating tool is at the third depth, moving
the separating tool in a reciprocating motion, transverse to the optical
axis of the live cornea, to separate additional sections of the other
portions of the front and adjacent layers of the live cornea from each
other to form a further portion of the pocket between the front and
adjacent layers which is defined by additional new edges of the other
portions of the front and adjacent layers which remain connected.
28. A method as claimed in claim 27, wherein the step of moving the
separating tool in a reciprocating motion at the third depth comprises
the step of restricting movement of the separating tool such that the
further portion of the pocket has a length extending between two of the
additional new edges in a direction transverse to the optical axis of the
live cornea, the length of the further portion of the pocket being less
than the length of the pocket.
29. A method as claimed in claim 25, further comprising the step of
further separating sections of the other portions of the front and
adjacent layers from each other to form the front layer as a flap which
remains pivotably attached to the adjacent layer at a connection portion
thereof.
30. A method as claimed in claim 25, wherein the stabilizing step
comprises the step of applying suction to the front surface of the live
cornea to stabilize the live cornea.
31. A method for forming a substantially circularly shaped pocket between
layers of a patient's live cornea, comprising the step of: substantially
stabilizing the live cornea; and moving a separating tool in a
reciprocating motion transverse to the optical axis of the cornea to form
the substantially circularly shaped pocket between layers of the live
cornea.
32. A method as claimed in claim 31, wherein the separating tool has a
substantially circularly shaped blade, and the moving step comprises the
steps of: positioning the blade at a depth in the cornea; and moving the
blade in the reciprocating motion to form the substantially circularly
shaped pocket.
33. A method as claimed in claim 31, further comprising the steps of:
restricting the reciprocating movement of the blade to cause the blade to
form the pocket between the layers of the live cornea; and unrestricting
the reciprocating movement of the blade to enable the blade to expand the
pocket to form a flap-like layer at the front of the live cornea.
34. A method as claimed in claim 31, wherein the stabilizing step further
comprises the step of applying suction to the front surface of the live
cornea to stabilize the live cornea.
35. An apparatus, adaptable for removing epithelium cells from the surface
of a live cornea, comprising: a member having walls defining an opening
therein at an end of the member which is adaptable to contact the surface
of a live cornea; and an absorbing device, disposed in the opening of the
member, and being adaptable to absorb a solution which, when applied to
the surface of the live cornea by the member, will remove epithelium
cells from the surface of the live cornea.
36. An apparatus as claimed in claim 35, wherein the opening defined by
the wails of the member is one of circular, semi-circular, rectangular
and square.
37. A method for removing epithelium cells from the surface of a live
cornea, comprising the steps of: positioning an apparatus, containing a
solution capable of removing epithelium cells therein, aproximate to the
surface of a live cornea to deposit the solution onto the surface of the
live cornea; and removing the solution from the surface of the live
cornea after a predetermined period of time dependent on a characteristic
of the solution.
38. A method as claimed in claim 37, wherein the positioning, applying,
and removing steps are performed prior to performing a step of separating
a layer of the live cornea from the front surface of the live cornea.
39. A method as claimed in claim 37, wherein the solution includes
alcohol, and the characteristic is the concentration of alcohol in the
solution.
Description
[0001] This is a divisional application of U.S. patent application Ser.
No. 08/936,509, filed on Sep. 24, 1997, the entire contents of which is
incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an internal keratome apparatus and
method of using the same to form a pocket between layers of a live
cornea. More particularly, the present invention relates to an internal
keratome apparatus having a circularly-shaped reciprocating blade, and a
method for using the same to form a circularly-shaped pocket between
layers of a live cornea, and then expanding the pocket to form a
flap-like layer at the front surface of the live cornea.
[0004] 2. Description of the Related Art
[0005] A normal ametropic eye includes a cornea, lens and retina. The
cornea and lens of a normal eye cooperatively focus light entering the
eye from a far point, i.e., infinity, onto the retina. However, an eye
can have a disorder known as ametropia, which is the inability of the
lens and cornea to focus the far point correctly on the retina Typical
types of ametropia are myopia, hypermetropia or hyperopia, and
astigmatism.
[0006] A myopic eye has either an axial length that is longer than that of
a normal ametropic eye, or a cornea or lens having a refractive power
stronger than that of the cornea and lens of an ametropic eye. This
stronger refractive power causes the far point to be projected in front
of the retina.
[0007] Conversely, a hypermetropic or hyperopic eye has an axial lens
shorter than that of a normal ametropic eye, or a lens or cornea having a
refractive power less than that of a lens and cornea of an ametropic eye.
This lesser refractive power causes the far point to be focused on the
back of the retina.
[0008] An eye suffering from astigmatism has a defect in the lens or shape
of the cornea. Therefore, an astigmatic eye is incapable of sharply
focusing images on the retina.
[0009] In order to compensate for the above deficiencies, a technique
known as p
hotorefractive keratectomy has been developed which involves
the placement of lenses in front of the eye (for example, in the form of
glasses or contact lenses). However, this technique is often ineffective
in correcting severe vision disorders.
[0010] An alternative to p
hotorefractive keratectomy is surgery. For
example, in a technique known as myopic keratomileucis, a microkeratome
is used to cut away a portion of the front of the live cornea from the
main section of the live cornea. That cut portion of the cornea is then
frozen and placed in a cyrolathe where it is cut and reshaped. Altering
the shape of the cut portion of the cornea changes the refractive power
of this cut portion, which thus effects the location at which light
entering the cut portion of the cornea is focused. The reshaped cut
portion of the cornea is then reattached to the main portion of the live
cornea. Hence, this reshaped cornea will change the position at which the
light entering the eye through the cut portion is focused, so that the
light is focused more precisely on the retina, thus remedying the
ametropic condition.
[0011] Keratophakia is another known surgical technique for correcting
severe ametropic conditions of the eye by altering the shape of the eye's
cornea. In this technique, an artificial organic or synthetic lens is
implanted inside the cornea to thereby alter the shape of the cornea and
thus change its refractive power. Accordingly, as with the myopic
keratomileucis technique, it is desirable that the shape of the cornea be
altered to a degree which enables light entering the eye to be focused
correctly on the retina.
[0012] Laser in situ keratomileusis (LASIK), as described, for example, in
U.S. Pat. No. 4,840,175 to Peyman, the entire contents of which is
incorporated herein by reference, is a further known surgical technique
for correcting severe ametropic conditions of the eye by altering the
shape of the eye's cornea. In the LASIK technique, a motorized blade is
used to separate a thin layer of the front of the cornea from the
remainder of the cornea in the form of a flap. The flap portion of cornea
is lifted to expose an inner surface of the cornea. The exposed inner
surface of the cornea is irradiated with laser light and thus reshaped by
the laser light. The flap portion of the cornea is then repositioned over
the reshaped portion and allowed to heal.
[0013] In all of these techniques, it is critical that the incisions are
made in the cornea in a very precise manner. Otherwise, the vision may
not be corrected properly, and worse, severe damage to the eye may occur.
[0014] Accordingly, it is necessary that the cornea be prevented from
moving while the cutting or separating of the corneal layers is being
performed. Also, it is necessary to flatten out the front portion of the
cornea when the corneal layers are being separated or cut so that the
separation or cut between the layers can be made at a uniform distance
from the front surface of the cornea. Previous techniques for flatting
out the front surface of the cornea involve applying pressure to the
front surface of the cornea with an instrument such as a flat plate.
However, these techniques can cause damage to the eye, in particular, the
pressure can cause fluid to leak out of the eye.
[0015] In addition to stabilizing the cornea when the cutting or
separating is being performed, the cutting tool must be accurately guided
to the exact area at which the cornea is to be cut. Also, the cutting
tool must be capable of separating layers of the cornea without damaging
those layers or the surrounding layers.
[0016] Furthermore, when the keratophakia technique is being performed, it
is desirable to separate the front layer from the live cornea so that the
front layer becomes a flap-like layer that is pivotally attached to the
remainder of the cornea and which can be pivoted to expose an interior
layer of the live cornea on which the implant can be positioned. It is
therefore necessary that the cutting tool be accurately guided to form a
suitable flaplike layer without damaging the surface onto which the
implant is to be positioned. It is also necessary that the angle of the
cutting is controlled so that the surface of the exposed interior layer
is at a desired angle (e.g., normal) with respect to the optical axis of
the eye.
[0017] Additionally, because the epithelium cells which are present on the
surface of the live cornea may become attached to the blade when the
blade is being inserted into the live cornea and thus become lodged
between the layers of the live cornea, thereby clouding the vision of the
eye, it is desirable to remove the epithelium cells prior to performing
the cutting.
[0018] Examples of known apparatuses for cutting incisions in the cornea
are described in U.S. Pat. No. 4,298,004 to Schachar et al., U.S. Pat.
No. 5,215,104 to Steinert, and U.S. Pat. No. 4,903,695 to Warner, the
entire contents of which are incorporated herein by reference.
[0019] However, a continuing need exists for an improved apparatus and
method for cutting a precise incision into a live cornea. A continuing
need also exists for an effective and simple method of removing the
epithelium cells from the surface of the live cornea prior to inserting a
cutting tool into the live cornea.
SUMMARY OF THE INVENTION
[0020] Accordingly, a primary object of the present invention is to
provide an apparatus and method for precisely forming a substantially
uniformly shaped pocket between layers of a live cornea, and then
expanding the pocket to form a flap-like layer at the front of the live
cornea which is pivotally attached to the remainder of the cornea by a
flap connecting section.
[0021] This and other objects of the present invention are substantially
achieved by an apparatus having a suction device that is adapted to be
attached to the front surface of a live cornea to apply suction to the
live cornea which prevents the live cornea from moving when the cutting
is being performed. The apparatus includes a transparent or substantially
transparent viewer through which the front surface of the cornea to which
the suction is being applied can be viewed. The suction pulls the front
surface of the cornea in a direction toward the viewer so that the front
surface of the cornea contacts a bottom surface of the viewer and thus
flattens out against that bottom surface. The cutting tool preferably has
a circular or substantially circular blade which forms a circularly or
substantially circularly shaped pocket between layers of the live cornea.
[0022] Specifically, the blade has a circular or substantially
circularly-shaped portion at a location proximate to its cutting edge
which first contacts the cornea when the blade is directed toward the
cornea. The apparatus further includes a guide mechanism for guiding the
blade in a direction toward the live cornea to which suction is being
applied. The blade contacts the cornea so that the cutting edge is
inserted into the cornea to separate adjacent layers of the cornea from
each other. The blade is moved in a reciprocating manner in a direction
transverse to the direction in which the blade is guided toward the
cornea, to thus form a pocket between those adjacent layers of the live
cornea.
[0023] Because the blade has the circular or substantially circular-shaped
portion, the pocket formed between the adjacent layers of the cornea is
circular or substantially circular in shape. The reciprocating movement
of the blade is restricted to form the pocket. However, the reciprocating
motion of the blade can be extended to enable the blade to expand the
pocket to form a flap-like layer at the front surface of the cornea that
is attached to the remainder of the cornea by an attaching portion.
[0024] Another object of the present invention is to provide an apparatus
and method for effectively removing the epithelium cells from the surface
of the live cornea prior to inserting the cutting tool into the live
cornea. To achieve this object, the present invention provides an
instrument for applying an alcohol mixture to the surface of the live
cornea prior to inserting the cutting tool into the live cornea. The
amount of time that the alcohol mixture will be applied to the surface of
the live cornea is proportionate to the concentration of alcohol in the
mixture.
[0025] These and other objects and advantages of the invention will become
more apparent and more readily appreciated from the following detailed
description of the presently preferred exemplary embodiments of the
invention taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Referring now to the drawings which form a part of the original
disclosure:
[0027] FIG. 1 is a side view of an internal keratome apparatus for forming
a pocket between adjacent layers of a live cornea according to an
embodiment of the present invention;
[0028] FIG. 2 is a cross-sectional view of the cornea holding apparatus of
the internal keratome apparatus shown in FIG. 1 in relation to the
cutting tool of the internal keratome apparatus;
[0029] FIG. 3 is an exploded perspective view of the cornea holding
apparatus shown in FIGS. 1 and 2;
[0030] FIG. 4 is an exploded perspective view of the cutting tool shown in
FIGS. 1 and 2;
[0031] FIG. 5 is a top view of the internal keratome apparatus as taken
along lines V-V in FIG. 1;
[0032] FIG. 6 is a front view of the internal keratome apparatus as taken
along lines VI-VI in FIG. 5;
[0033] FIG. 7 is a bottom view of the internal keratome apparatus as taken
along lines VII-VII in FIG. 6;
[0034] FIG. 8 is a front view of the cutting tool of the internal keratome
apparatus shown in FIG. 1 as taken along lines VIII-VIII in FIG. 2;
[0035] FIG. 9 is a bottom view of the cutting tool as taken along lines
IX-IX in FIG. 8;
[0036] FIG. 10 is a top view of the cutting tool as taken along lines X-X
in FIG. 8;
[0037] FIG. 11 is an enlarged view of the cutting portion of the blade of
the cutting tool;
[0038] FIG. 12 is a side view of the cutting portion of the blade as taken
along lines XII-XII in FIG. 11;
[0039] FIG. 13 is another embodiment of the cutting portion of the blade
of the cutting tool;
[0040] FIG. 14 is a front view of the front portion of the live cornea in
which adjacent layers are being separated by the cutting tool of the
internal keratome apparatus according to the present invention;
[0041] FIG. 15 is a front view of the front portion of the live cornea in
which adjacent layers are being further separated by the cutting tool of
the internal keratome apparatus according to the present invention;
[0042] FIG. 16 is a front view of the front portion of the live cornea in
which adjacent layers are being separated by the cutting tool of the
internal keratome apparatus according to the present invention such that
a circularly-shaped or substantially circularly-shaped pocket is formed
between the adjacent layers of the live cornea;
[0043] FIG. 17 is a front view of the front portion of the live cornea in
which the pocket formed in the live cornea as shown in FIG. 16 is
expanded by the cutting tool to form a flap-like layer at the front
portion of the live cornea;
[0044] FIG. 18 is an exploded perspective view of another embodiment of a
cornea holding apparatus of an internal keratome apparatus according to
the present invention;
[0045] FIG. 19 is a front view of the embodiment of the cornea holding
apparatus shown in FIG. 18 as taken along lines XIX-XIX;
[0046] FIG. 20 a rear view of the embodiment of the cornea holding
apparatus shown in FIG. 18 as taken along lines XX-XX;
[0047] FIG. 21 is a cross-sectional view of the cornea holding apparatus
shown in FIGS. 18-20;
[0048] FIG. 22 is a top view of another embodiment of a cutting tool used
of an internal keratome apparatus according to the present invention;
[0049] FIG. 23 is a side view of the embodiment of the cutting tool
apparatus shown in FIG. 22 engaging with the cornea holding apparatus
shown in FIGS. 18-21;
[0050] FIG. 24 is a view of the ring-like member of the cornea holding
apparatus shown in FIGS. 18-21 and 23 as positioned in its lower
position;
[0051] FIG. 25 is a view of the ring-like member of the cornea holding
apparatus shown in FIGS. 18-21 and 23 as positioned in its upper
position;
[0052] FIG. 26 is a view of the guide rails of the cutting tool apparatus
shown in FIG. 22 engaging with the ring-like member of the cornea holding
apparatus shown in FIGS. 18-21 and 23 when the blade is positioned at a
first depth in the cornea;
[0053] FIG. 27 is a view of the guide rails of the cutting tool apparatus
shown in FIG. 22 engaging with the ring-like member of the cornea holding
apparatus shown in FIGS. 18-21 and 23 when the blade is positioned at a
second depth in the cornea;
[0054] FIG. 28 is a view of the guide rails of the cutting tool apparatus
shown in FIG. 22 engaging with the ring-like member of the cornea holding
apparatus shown in FIGS. 18-21 and 23 when the blade is positioned at a
third depth in the cornea;
[0055] FIG. 29 is a perspective view of an embodiment of an instrument for
use in removing epithelial cells from the outer surface of a live cornea
according to the present invention;
[0056] FIG. 30 is a perspective view of another embodiment of an
instrument for use in removing epithelial cells from the outer surface of
a live cornea according to the present invention; and
[0057] FIG. 31 is a perspective view of a further embodiment of an
instrument for use in removing epithelial cells from the outer surface of
a live cornea according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0058] An embodiment of an apparatus for performing an internal keratome
on a patient's live cornea is illustrated in FIG. 1. Specifically, the
apparatus 100 includes a cornea holding apparatus 102 and a cutting tool
104. The corneal holding apparatus 102 and cutting tool 104 are shown in
more detail in FIGS. 2-13.
[0059] The corneal holding apparatus 102 includes a cornea receiving
section 106 which receives a front portion of a live cornea 108 of a
patient's eye as shown, for example, in FIG. 1. Specifically, a tube 110
having an opening 112 therein extending along the length thereof is
coupled to the cornea receiving section 106 such that the opening 112
communicates with an interior cavity 114 of the cornea receiving section
106. As shown in FIG. 3, the tube 110 has a section 111 that is removably
attached to a section 113 that is secured to or integral with the cornea
receiving section 106. In particular, the section 113 has a threaded
portion 115 which engages with threads 117 on the interior of section 111
to couple sections 111 and 113 together.
[0060] As shown in FIG. 7, in particular, the interior surface of the
cornea receiving section 106 includes a plurality of steps or ridges 116
which contact the surface of the live cornea 108 and assist in
stabilizing the cornea from movement when the cornea is received in the
cornea receiving section 106. That is, as the front surface of the cornea
108 of the eye is received in the receiving section 106, suction will be
applied via tube 110 to the internal cavity 114 of the receiving section
106 to suck the cornea into the cavity 114.
[0061] The cornea receiving section 106 further includes an opening 118.
As shown, for example, in FIG. 1, a front portion 120 of the cornea 108
will protrude through the opening 118 when suction is applied to the
cavity 114 of the cornea receiving section 106.
[0062] The cornea holding apparatus 102 further includes a flat or
substantially flat plate 122 having an opening 124 therein. The opening
124 is aligned with or substantially aligned with the opening 118 in the
cornea receiving section 106. Hence, as shown in FIG. 1, when the cornea
108 is sucked into the cavity 114 of the cornea receiving section 106,
the front portion 120 of the cornea will protrude through the opening 118
in the section 106 and the opening 124 in the plate 122.
[0063] The cornea holding apparatus 102 further includes a clear or
substantially clear viewer 126 that is mounted in a viewer holding
section 128. The viewer 126 is preferably a synthetic material, such as
an acrylic, plexy glass, or the like, having threads which are as fine as
possible. The viewer 126 is permanently or removably mounted in the
viewer holding section 128. The viewer holding section 128 includes a
threaded rotating portion 130 and a flat or substantially flat plate 132.
The rotating portion 130 is rotatable with respect to the view piece 126
and the plate 132 about an axis the same or substantially the same as the
axis of the viewer 126.
[0064] The outer surface of the rotating piece 130 preferably has
cross-hatching 134 to enable a user of the apparatus 102 to more easily
grasp the outer surface of the rotating portion 130. The rotating portion
further includes threading 136 on the inner surface thereof. The
threading 136 is adaptable to mate with threading 138 of the cornea
receiving section 106 as shown specifically in FIG. 3. Hence, the viewer
receiving section 128 can be rotatably secured to the cornea receiving
section 106 through the engagement of threads 136 and 138 as the rotating
portion 130 is rotated onto the threaded portion 138.
[0065] The plate 132 further includes a cylindrical or substantially
cylindrical section 140 having threads 142 on the interior surface
thereof. The plate 122 further includes a protruding section 144 having
threads 146 which are adaptable to mate with the threads of the
projecting portion 140. Hence, when the plate 132 and thus the protruding
portion 140 is rotated about an axis equal to or substantially equal to
the axis of the viewer 126, the threads 142 will engage with the threads
146 to pull the plate 132 closer to the plate 122. By doing so, the
position of the bottom surface 127 of the viewer 126 with respect to the
top surface 123 of the plate 122 can be adjusted.
[0066] It is noted that pins 125 are adaptable to be inserted through
openings 127 in the flat plate 122 and through hollow pins 129 and into
openings 131 of the flat plate 132 so as to assist in coupling the flat
plate 132 to the flat plate 122. Furthermore, flat plate 132 includes an
opening therein which has any shape suitable to accommodate the cutting
tool 104 as will be discussed below.
[0067] The cornea holding apparatus 102 further includes a washer 148 made
of rubber, synthetic, or the like, and a ring-like member 150 having
threads 152 at a bottom portion thereof and an opening 154 therein. The
threads 152 are adaptable to mate with threads 133 in an opening 135 of
the plate 132. Hence, when the ring-like member 150 is rotated when the
threads 152 contact the threads 133, the ring-like member 150 is
rotatably secured to the plate 132.
[0068] The apparatus 102 further includes a second ring-like member 156
made of synthetic, plastic, or the like. The second ring-like member 156
has a-protruding portion 158 having an opening 160 therein. The
protruding portion 158 is adaptable to be received in an opening 151 of
the ring-like member 150 such that the opening 160 is positioned to align
with or substantially align with the opening 154. In order to facilitate
alignment, the ring-like member 150 includes a notch 153 that is
adaptable to engage with an opening 161 in the protruding portion 158 of
the second ring-like member 156. The second ring-like member 156 further
includes an opening 162 therein. Accordingly, as shown in FIG. 2
specifically, the opening 162, opening 151, an opening 149 in the washer
148, and the viewer 126 are aligned with or essentially aligned with each
other so that the surface 120 of the cornea can be seen through the
opening 162.
[0069] It is noted that except for the viewer 126, washer 148 and second
ring-like member 156, all of the components of the cornea holding
apparatus 102 are made of metal, steel or the like. Naturally, all
components of the cornea holding apparatus can be made of any suitable
material as would be readily appreciated by one skilled in the art.
[0070] Turning now to the cutting tool 104, as shown in FIG. 4, the
cutting tool 104 includes a blade 180, a guiding device 182, and a flat
plate 184. The blade 180, the guiding device 182 and the plate 184 are
coupled together, for example, by a screw 186, washer 188, washer 190,
nut 192, washer 194, nut 196 and a handle 198 having cross-hatching
thereon to enable its outer surface to be gripped more easily. As shown
in FIG. 9 specifically, the blade 180 and the guiding member 182 are
aligned or essentially aligned with each other.
[0071] The operation of the apparatus 100 will now be described. As shown
in FIGS. 1 and 2 specifically, the cutting tool 104 is removably attached
to the cornea holding apparatus 102 such that the front end 183 of the
guide member 182 is inserted through the opening 160 of the ring-like
member 156 and through the opening 154 of the ring-like member 150.
Furthermore, the front end 181 of the blade 180 is adaptable to be
inserted between the bottom surface 127 of the viewer 126 and the top
surface 123 of the flat plate 122.
[0072] In coupling the cutting tool 104 to the cornea holding apparatus
102, the blade 180, screw 186, washers 188 and 190, and nut 192 are
inserted through the opening 139 in the plate 132 as illustrated
specifically in FIG. 2. Accordingly, when suction is applied to the
cornea of the eye 108, the front surface 120 of the cornea is forced to
protrude through the opening 118 in the receiving section 106 and the
opening 124 and the flat plate 102 so that the cornea 120 contacts the
bottom surface 127 of the viewer 126. Hence, the front surface 120 of the
cornea will become flattened to a certain degree due to the contact with
the surface 127 of the viewer 126.
[0073] When layers of the live cornea are to be separated, the front end
181 of the blade 180 will be directed toward the protruding portion 120
of the cornea to be inserted into the protruding portion 120 and thus
separate adjacent layers of the cornea 108 from each other. As shown in
FIGS. 11 and 12 specifically, the front end portion 181 of the blade 180
is round or substantially round such that its diameter is about 4 mm. and
is greater than the width of the blade 181. The blade 180 can be any
desired shape, such as star-shaped, petal shaped, oval, or the like,
which can be adapted to form a circularly shaped or substantially
circularly shaped pocket between the layers of the live cornea. The blade
can be made of any type of suitable material such as surgical steel,
stainless steel or the like, and can have a diamond cutting edge. The
cutting edge 183 should be at the top surface of the portion 181. The top
surface 185 and bottom surface 187 of the blade can be parallel or
substantially parallel with each other.
[0074] Alternatively, as shown in FIG. 13, the front portion 181 can be
slanted as indicated by 181'. In this event, the cutting edge 183' of the
blade is formed by the contact between the slanted surface 185' and the
bottom surface 187 of the blade.
[0075] As shown in FIGS. 5 and 7, the blade 180 will be aligned with or
substantially aligned with the guide member 182. Hence, the position of
the guide member 180 with respect to the front surface of the protruding
portion 120 of the live cornea that is being flattened by the bottom
surface 127 of the viewer 126 will correspond to or substantially
correspond to the position of the blade 182 with respect to the
protruding portion of the live cornea. A spring member 141 which is
integral or attached to the flat plate 122 will function to urge the
blade 180 toward the top surface 123 of the plate 122. Hence, the bottom
surface 187 of the blade 180 will contact the top surface 123 of the
plate 122 while the spring 141 contacts the top surface 185 of the blade
180.
[0076] The cutting tool 102 can then be moved to form a pocket between
adjacent layers of the live cornea.
[0077] Specifically, as shown in FIG. 14, when the blade 180 is being
inserted into the front surface 120 of the live cornea, an incision or
separation 200 between adjacent layers of the live cornea will be formed.
As the blade 180 is further inserted into the front surface 120 of the
cornea, the spacing between the layers of the live cornea will be
expanded to form a space 202 as shown in FIG. 15. The blade 180 can then
be moved by twisting the handle 198 so that the blade 180 will
reciprocate in a direction along arrow A. By moving the blade 180 in this
reciprocating manner, the front portion of the blade 181 will form a
circularly-shaped or substantially circularly-shaped pocket 206 in the
front surface 120 of the cornea. The pocket 206 can be made at any
practical size as desired. Furthermore, the pocket 206 can be made at any
practical depth in the front surface 120 of the live cornea.
[0078] Specifically, the depth at which the pocket will be formed in the
cornea 108 is governed by the distance between the top surface 185 of the
blade 180 and the bottom surface 127 of the viewer 126. That is, since
the thickness of the blade 180 is known, the distance between the bottom
surface 127 of the viewer 126 and the top surface 123 of the flat plate
122 is set so that the cutting edge 183 of the blade will enter the front
protruding portion 120 of the cornea at the desired distance from the
front surface of the live cornea (i.e., at the desired depth into the
live cornea).
[0079] The distance between the bottom surface 127 of the viewer 126 and
the top surface 123 of the plate 122 can be adjusted when the viewer
holding section 128 is being attached to the plate 122 in the manner
discussed above. That is, the amount that the cylindrical portion 140 is
screwed onto the protruding portion 144 as shown in FIG. 3 will determine
the distance between the front surface 127 of the view-piece 126 and the
top surface 123 of the plate 122. Hence, the cylindrical portion 140 will
be threaded onto the protruding portion 144 to a degree that will space
the front surface 127 of the viewer 126 from the top surface 123 of the
plate 122 the desired distance.
[0080] It is noted that the range in which the guide member 182 will
reciprocate along the direction indicated by arrow A in FIG. 5 will be
limited by the width of the opening 154 in ring member 150. That is, if
the pocket 206 is to be made larger in a direction transverse to the
extending direction of the blade 180, the width of the opening in ring
member 150 will be larger to enable the guide member 182 to reciprocate
along a larger arc in the direction defined by arrow A. Accordingly,
because the blade 180 is aligned or substantially aligned with guide
member 182, the blade will also be able to reciprocate along an arc in
the direction defined by arrow A as limited by the width of the opening
154 in the ring-like member 150. Hence, different ring-like members
having differently sized openings 154 can be used to adjust the size of
the pocket 206 formed in the front portion 120 of the cornea.
[0081] It is noted that if desired, an implant, such as those discussed
above, can be placed inside the pocket to alter the curvature of the
cornea.
[0082] Also, if it is desirable to separate the front layer of the cornea
108 so that the front layer becomes a flap-like layer, the distance along
which the guide member 182 and hence, the blade 180, are allowed to
reciprocate can be increased to form this flap-like layer as shown, for
example, in FIG. 17. That is, the guide member 182 can be allowed to
reciprocate along an arc large enough to allow the cutting portion 181 of
the blade 180 to pass through the sides of the front protruding portion
120 of the cornea as necessary so that the flap-like layer 208 is
separated from the main portion of the live cornea except for a
connecting portion 210.
[0083] Accordingly, the flap-like layer 208 will be capable of pivoting
with respect to the remaining portion of the live cornea 108 about
connecting portion 210 to expose a surface of the cornea underneath the
flap-like layer 208. That exposed surface can be irradiated with a laser,
for example, as described in U.S. Pat. No. 4,840,175 to Peyman, the
entire contents of which are incorporated herein by reference. Also, a
ring or disc can be placed on the exposed surface of the cornea and then
covered by the flap-like layer 208 so that the shape of the ring or disc
will influence the shape of the flap-like layer and hence, change the
refractive power of the flap-like layer, thereby changing the focusing
power of the eye.
[0084] It is noted that forming the pochet prior to forming the flap-like
layer, protects the eye from losing aqueous humor if the blade 180 is
inadvertently inserted too deep into the cornea so that it enters the
anterior chamber of the eye. That is, because the pocket is only open on
one end, as contrasted with a flap which is essentially separated from
the cornea but for the connecting portion 210, the pocket will function
to retain fluid in the anterior chamber and thus prevent against fluid
loss better than would a flap-like member.
[0085] Another embodiment of the cornea holding apparatus of the present
invention is shown, for example, in FIGS. 18-20. Specifically, the
apparatus 300 includes a cornea holding section 302, a body 304 and a
viewer 306. The cornea holding section 302 includes a cornea receiving
section 308 having a cavity 310. A hollow tube 312 having an opening 314
along the length thereof is in communication with the cavity 310.
[0086] The cornea holding apparatus 302 further includes a flat plate 316
that is either attached to or integral with the cornea receiving section
310. A tubular extension 318 extends in a direction away from the top
surface 320 of the flat plate 316. The narrow section 319 of the tubular
extension 318 adjacent to the top surface 320 of the flat plate 316 has
an opening 322 therein. Furthermore, the flat plate 316 has an opening
317 therein which communicates with the cavity 310 of the cornea
receiving section 308.
[0087] The tubular opening further has a first wider section 324 having an
outer diameter greater than that of the narrow section, and a second
wider section 326 having an outer diameter greater than that of the first
wider section 324. The second wider section 326 has threading 328 along
the inner circumference thereof. The tubular extension 318 is hollow
throughout so that the interior of the second wider section 326 is in
communication with the interior of the first wider section 324, the
interior of the narrow section 319, the opening 322 and the opening 317
in the flat plate 316. Hence, the interior of the tubular extension 318
is in communication with the cavity 310 of the cornea receiving section
308.
[0088] A ring-like member 330 is positioned about the tubular extension
318 and is coupled to a handle 332 by a pivoting mechanism 334.
Specifically, the pivoting mechanism 332 has a ring 336 having an opening
338 therein through which the tube 312 extends. The ring 336 is thus
slidably attached to the tube 312.
[0089] Specifically, as shown in FIG. 21, when the handle is moved in the
direction C1, the ring 336 will slide along the tube 312 in the direction
B1, thus causing the pivoting mechanism 334 to slide the ring 330 about
the tubular extension 318 in the direction B2. Conversely, when the
handle 332 is moved in the direction C2, the ring 336 will slide about
the tube 312 in the direction B2 so that the pivoting mechanism 334 will
cause the ring 330 to slide about the tubular extension 318 in the
direction B1 toward the top surface 320 of the plate 316. In doing so,
the opening 331 in the ring 330 will align or substantially align with
the opening 322 in the tubular extension 318.
[0090] As illustrated in FIG. 18, the cornea holding section 302 is
received in an opening 340 of the body 304. The opening 340 extends
throughout the center of the body 304 such that the body will
substantially encase the tubular member 318. A screw 342 can be received
in a threaded opening 344 in the body 304 to abut against the screw
contacting surface 346 of the cornea receiving section 302 to thus
removably secure the body 304 to the cornea receiving section 302. The
body 304 further includes recesses 348 which extend on opposite sides
thereof as illustrated.
[0091] The viewer 306 is made of a synthetic material, such as acrylic or
the like, and is transparent or substantially transparent to visible
light. The viewer 306 has threads 350 which engage with the threads 328
of the cornea receiving section 302 when the viewer 306 is inserted into
the opening 340 of the body 304, and thus into the opening in the second
wider section 326 of the tubular projection 318 as illustrated.
Accordingly, the viewer 306 is threadedly engaged with the cornea
receiving apparatus 302. The threads 352 on the viewer 306 enable a user
to grip the outer surface of the viewer 306 more firmly and thus, screw
the viewer 306 into the tubular extension 318.
[0092] The operation of the apparatus 300 will now be described with
reference to FIGS. 21-28, in particular. Specifically, as shown in FIG.
21, when a cornea 108 is received in the cornea receiving section 308 and
suction is applied via tube 312 to the cavity 310, the cornea will be
sucked into the cavity 310. However, a front portion 120 of the cornea
will protrude through the opening 317 in the plate 316. Preferably, the
viewer 306 will be adjusted so that the bottom surface 353 of the viewer
contacts the front surface of the cornea 108 to flatten out the front
surface of the front portion 120 of the cornea as illustrated.
[0093] In order to separate layers of the live cornea from each other, a
tool 360 as shown in FIG. 22 can be used. Specifically, the tool 360
includes a blade 180-1 having a cutting portion 181-1 as described above
with regard to FIG. 11. The tool 360 includes a motor which functions to
move the blade 180-1 in a reciprocal motion along arrow A as illustrated.
The blade can also be shaped as the blades described above with regard to
FIGS. 12 and 13, for example, and can be made of the materials described
above. The blade 180-1 has atop surface 185-1, a bottom surface 187-1,
and a cutting edge 183-1, as shown in FIG. 12. Also, as shown in FIG. 13,
the front portion 181'-1 can be slanted, with the cutting edge 183'-1
formed by the contact between the slanted surface 185'-1 and bottom
surface 187-1.
[0094] As shown in FIG. 23, if layers of the live cornea in the front
protruding portion 120 are to be separated from each other by the blade
180-1, the tool 360 will be positioned so that the rails 362 of the tool
360 are positioned about the tubular extension 318. It is noted that a
spring-like member 349 of the body 304 will press against the top surface
185-1 of the blade 180-1 when the blade 180-1 is being positioned as
shown in FIG. 23 so that the bottom surface 187-1 of the blade will
contact the top surface 320 of the plate 316. The cutting or separating
of the layers, as illustrated in FIGS. 14-17, can then be performed as
follows.
[0095] Specifically, if it is desirable to separate adjacent layers of the
cornea so that a pocket 206 is ultimately formed between those adjacent
layers as shown in FIG. 16, the handle 332 is positioned in the direction
C1 (see FIG. 21) so that the ring-like member 318 is positioned to touch
or substantially touch the top surface 320 of the plate 316 as shown in
FIG. 24. In this event, the reciprocal motion of the blade 180 along the
direction A is limited by the contact of the inner surface 363 of the
rails 362 and the outer surface 333 of the ring 330.
[0096] Accordingly, as the blade is moved in the direction D as shown in
FIGS. 26-28, while the blade 180-1 is reciprocated by the tool 360 in a
reciprocating direction A, the separations 200, 202 and 206 between
adjacent layers of the cornea as shown in FIGS. 14-16, respectively, will
be formed. As illustrated in FIG. 23, the reciprocating tool can include
a guide 364 having guide rails 366 which each engage with the respective
grooves 348 which are on opposite sides of the body 304 so as to assist
in guiding the blade 180 in the direction D.
[0097] Hence, when the blade is positioned as shown in FIG. 26, the space
200 shown in FIG. 14 will be formed. When the blade is then moved to the
position shown in FIG. 27 and ultimately to the position shown in FIG.
28, the space 202 between the layers of the cornea as shown in FIG. 15
will be formed, and then the pocket 206 as shown in FIG. 16 will be
formed. As can be appreciated from FIGS. 26-28, due to the curved shape
of the rails 362, the reciprocal movement of the blade 180-1 in the
direction A will be limited more when the blade is positioned as shown in
FIG. 26 than when the blade is positioned as shown in FIG. 27. Also, the
movement of the blade 180-1 in the reciprocal direction A will be limited
more due to the curvature of the rails 362 when the blade 180-1 is in the
position as shown in FIG. 28 than when the blade 180-1 is in the position
as shown in FIG. 27. Accordingly, a circularly-shaped pocket 206 as shown
in FIG. 16 can be formed.
[0098] It is further noted that the depth at which the blade 180-1 will
cut into the cornea is determined based on the distance between the
bottom flat surface 353 of the viewer 306 and the top surface 320 of the
plate 316. That is, taking into account the thickness of the blade 180-1,
the viewer 306 can be screwed into the tubular extension 318 to a depth
necessary so that the distance between the bottom surface 353 of the
eye-piece and the top surface 320 of the plate 316 will position the
blade 180-1 to enter into the cornea 108 at the desired depth from the
front of the cornea 108 when the front of the cornea contacts the bottom
surface 353 of the viewer 306.
[0099] It is further noted that if it is desirable to form a flap-like
layer 208 as shown in FIG. 17, the ring 330 which restricts the
reciprocating motion of the blade can be lifted as shown in FIG. 25. That
is, as discussed above, when the handle 332 is moved in the direction
toward position C2, the ring-like member 330 will slide about the tubular
extension 318 in the direction toward position B2. Hence, the inner
surfaces 363 will no longer contact the outer surface 331 of the
ring-like member 330. Rather, the movement of the blade 180-1 will be
limited by the contact of the inner surfaces 363 of the rails 362 and the
outer surface of the tubular extension 318. Because the outer
circumference of the tubular member 318 is smaller than the outer
circumference of the ring-like member 330, the movement of the blade
180-1 will be less restricted in the direction A because the rails 362
will be allowed to move a greater direction along the direction A.
[0100] Accordingly, the cutting portion 181-1 of the blade 180-1 will cut
through the sides of the front portion 120 of the cornea to form a
flap-like layer 208 that is connected to the remainder of the cornea by a
connection portion 210. As discussed above, the flap-like layer 208 can
be lifted to expose an inner surface of the cornea, and various
techniques can be performed on that inner surface of the cornea.
[0101] Additionally, when the blade 180-1 is inserted in the cornea 108,
it may be necessary to remove corneal epithelium prior to performing the
cutting so that the corneal epithelium cells do not become attached to
the blade 180 and be forced by the blade between the adjacent layers of
the cornea. In other words, it may be necessary to remove the corneal
epithelium so that those cells do not become lodged in the pocket 206.
[0102] In order to remove the corneal epithelium cells prior to performing
the cutting, an instrument 400 as shown in FIG. 29 can be used. The
instrument 400 can be a tube-like structure having a hollow opening 402
therein in which is disposed a sponge 404 which is made of rubber or the
like. The inner diameter of the tube can be, for example, about 1-12
millimeters. If it is determined desirable to remove the corneal
epithelium cells prior to performing the cutting or layer separating
operation discussed above, the end of the instrument 400 in which the
sponge 404 is disposed can be dipped into an alcohol mixture so that the
alcohol mixture will become absorbed in the sponge 404. The end of the
instrument 400 having the sponge 404 can then be dabbed onto the front
portion 120 of the cornea that is to be cut, thus eliminating the
epithelium cells.
[0103] As shown in table 1 set forth below, the time for which the
instrument 400 must be applied to the front portion 120 of the cornea
depends on the concentration of the alcohol in the mixture.
1 TABLE 1
Alcohol Concentration Duration of
Application of Instrument
50 percent 10 seconds
30 percent 15 seconds
20 percent 20 seconds
15 percent 30
seconds
10 percent 45 seconds
[0104] As shown in FIGS. 30 and 31, the instrument 400 need not be
tubular, but rather, can be arcuate in shape (see FIG. 30) or rectangular
or square (see FIG. 31). If the instrument is arcuately-shaped, the
diameter D should be about 1-12 millimeters, and the sponge 404' will be
inserted between the outer wall 406' and inner wall 408' of the
arcuately-shaped instrument 400'. If the square or rectangularly-shaped
instrument 400" is used, the sponge 404" also will have a similar shape.
If the time at which the instruments 400' or 400" will be applied to the
front portion 120 of the cornea prior to cutting the front portion of the
cornea will be the same as illustrated in Table 1 depending on the
concentration of the alcohol mixture used. Accordingly, the instruments
shown in FIGS. 29-31 will prevent the epithelium cells from becoming
lodged between the layers of the cornea when the pocket 206 or flap 208,
as shown in FIGS. 16 and 17, respectively, are formed by insertion of the
blade 180 into the cornea.
[0105] Although only a few exemplary embodiments of this invention have
been described in detail above, those skilled in the art will readily
appreciate that many modifications are possible in the exemplary
embodiments without materially departing from the novel teachings and
advantages of this invention. Accordingly, all such modifications are
intended to be included within the scope of this invention as defined in
the following claims.
* * * * *