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Kershner Operative Worksheet
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Eye Laser Center © 2002 · Robert M. Kershner, MD, FACS · All Rights Reserved
Robert M. Kershner, M.D., P.C., F.A.C.S. Patient
Name:____________________________________
1925 W. Orange Grove Road · Suite 303 Age:_______ Occupation:__________________________
Tucson, AZ
85704-1152 Dominant
Eye:_______ Date:______________________
(520) 797-2020 www.EyeLaserCenter.com
V R20/___ V
R20/___ J R_____ WEARS: R
. + . X______
sc L20/___ cc
L20/___ L_____ Glasses: L
. + . X______
ADD: ___________ Last Rx___________
C R . + . X________
L . + . X________ WEARS: R . + . X______
Glasses: L
. + . X______
K R . V . H________° Last Rx:
___________________________
L . V . H _______°
O.D. O.S.
O.Z.
. mm ARC LENGTH . mm O.Z.
. mm ARC LENGTH . mm
AXIS:__________ AXIS:__________
OPERATIVE EYE:____________
120 45 IOL
Style_______________Power______________
PACHYMETRY__________________ PACHYMETRY
_________________
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Keratolenticuloplasty
1.
The goal of surgery is
to fully correct or undercorrect the pre-existing astigmatism. If the patient is undercorrected, more surgery
can be performed later if needed. Overcorrecting the cylinder or shifting the
axis more than 15 degrees is to be avoided. Remember, in older patients, the
less elastic cornea responds with greater changes in curvature for a given
amount of surgery.
- Keep the incisions at the clear corneal limbus or
slightly onto the dome of the cornea.
Avoid arcuate incisions inside the 7-mm optical zone. If it is
possible to achieve the same degree of correction with a larger arc at the
limbus with a 10mm optical zone, select this option over a smaller arc at
a 8-mm or 9-mm optical zone.
Larger incisions are always preferred further away from the optical
zone than smaller arcs nearer the central cornea. Remember, the effect of
corneal incisions to flatten decreases as the distance from the optical
center of the eye increases.
- Arcuate incisions should never exceed 60º in length
at any optical zone and, ideally, the largest arc should be no greater
than 45º or 3.5 mm at an optical zone of 10mm.
- To achieve the maximum flattening and best neutralize
the astigmatism, incise the cornea to a depth of 85% to 95% of corneal
thickness. Measure pachymetry at
the proposed incision site and set the diamond blade to 90% of this
measurement or simply use the disposable accurate depth metal blade preset
at 550 or 600 microns. Do not over
cut into the cornea as perforating the cornea makes phacoemulsification
and maintaining the anterior chamber more difficult. If perforation should occur, it may be
necessary to suture the incision.
This will induce further flattening, but the suture can be removed
at the slitlamp in a few days.
- Whenever possible, a single arcuate incision will be
preferable to using two smaller incisions.
- Always use the arcuate incision closest to the
surgeon for the keratotomy into the anterior chamber. Place this incision anterior to the
limbal vascular arcade at a 11mm, 10 mm, or 9 mm optical zone. Avoid using the arcuate incision for
the subsequent cataract surgery if it is closer to the optical center of
the eye than the 8-mm optical zone.
7.
To avoid full thickness
penetration, avoid pressing on the globe with another instrument during the
creation of the arcuate incision. Use
the disposable fixation ring to stabilize the eye, if needed. Mark the proposed position of the incision
at the steepest plus-cylinder reading.
8.
It is easier to
visualize the marks and incise the cornea if the cornea is kept dry. Avoid
using marking inks. They obscure
visualization for subsequent procedures of cataract surgery. A clean marker gently pressed onto the
epithelium will create a visible mark to use as a guideline in creating the
incision.
9.
Always place the arcuate
corneal cataract incision on the axis of steepest (+) astigmatism.
Operating on the incorrect axis will always make the refractive result worse.
Axis is crucial. Never operate greater
than 15º off axis.
10. Keep the
keratome fully applanated perpendicular to the surface of the cornea. Aim the blade towards the center of the globe
and follow the curvature of the cornea closely following the mark until the
full excursion of the incision is completed.
11. The slit blade, sized for the
phacoemulsification tip and injection system, is placed at the base of the
arcuate incision to enter the eye plane-parallel to the iris. The handle should be aimed at the center of
the pupil to assure an incision which self-seals and has the proper
architecture for the best refractive result.
© 2002 · Robert M.
Kershner, MD, FACS · All Rights Reserved
__________________________________________
Kershner
Arcuate Keratotomy
Incision-Only
System Nomograms
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Correction Optical
Zone Number of Arcuate Incision Length
(Diopters) (mm) Incisions (mm)
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<1.0 10 1 2.5
1.0 9 1 2.5
1.5 9 1 3.0
2.0 8 2 2.5
2.5 8 2 3.0
3.0 7 2 2.5
3.5 7 2 3.0
4.0 6 1 2.5
10 1 2.5
4.5 6 1 3.0
10 1 2.5
5.0 6 1 3.0
10 1 2.5
5.5 5 1 2.5
10 1 2.5
6.0 5 1 3.0
10 1 3.0
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This nomogram is to
be used when incisions alone are utilized to correct the cylinder. They are a guideline
only, surgeons
should adjust for the desired result.
Corrected for age 60 +. Arcs
placed on steepest axis
of astigmatism
(plus cylinder). Pachymetry at incision
site, keratome set to 95% of pachymetry
(550-600
microns). Mark arcuate incisions and
optical zone with Kershner One-Step Marker.
Cataract keratotomy at 10 mm, 9 mm, or 8 mm only.
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© 2002 · Robert M.
Kershner, MD, FACS · All Rights Reserved
__________________________________________
Kershner Arcuate
Keratotomy
With Toric IOL
System Nomograms
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Correction Optical
Zone Number
of Arcuate Incision
Length TORIC IOL
(Diopters) (mm) Incisions (mm)
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<1.0 10 1 2.5
1.0 9 1 2.5
1.5 9 1 3.0 +2.00
Toric
2.0 9 1 3.0 +2.00 Toric
2.5 9 1 3.0 +3.50 Toric
3.0 9 2 3.5 +3.50 Toric
3.5 8 1 3.0 +3.50 Toric
10 1 3.0
4.0 8 1 3.5 "
10 1 3.5
4.5 8 1 4.0 "
10
1 4.0
5.0 8 1 4.5 "
10 1 4.5
5.5 8 1 5.0 "
10 1 5.0
6.0 8 1 5.5 "
10 1 5.5
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This nomogram is to be used when incisions are utilized in
combination with the toric IOL to correct the cylinder. They are to be used as a guideline only,
surgeons should adjust for the desired result.
Corrected for age 60 +. Arcs
placed on steepest axis of astigmatism (plus cylinder). Pachymetry at incision site, keratome set to
95% of pachymetry (550-600 microns).
Mark arcuate incisions and optical zone with Kershner One-Step
Marker. Cataract keratotomy at 10 mm, 9 mm, or 8 mm only.
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