STAR S4 IR Excimer Laser
System Physician Certification
Course
Place for Conference or Author
Month Day, 200X
2012.03.13-ST4862
Purpose
The purpose of this presentation is to certify physicians to use the
STAR S4 IR Excimer Laser System
In addition to completing this course, it is the responsibility of
physicians to read and understand the
• STAR S4 IR Excimer Laser System Operator’s Manual
• WaveScan Operator’s Manual
• Professional Use Information
• Patient Information Booklet
2
Agenda
Introduction to the STAR S4 IR Excimer Laser System
Introduction to CustomVue
Refractive Labeling
Pre-Operative Evaluation
WaveScan System Review
Surgical Planning
STAR S4 IR Excimer Laser System Calibration
STAR S4 IR Excimer Laser System Hardware Overview
Surgical Technique
STAR S4 IR Excimer Laser System Conventional Ablations
3
Introduction to the STAR S4 IR Excimer Laser
System
The STAR S4 IR Excimer Laser System is a 193 nm Excimer
laser system capable of delivering
• Conventional (manifest refraction based) Treatments
• Wavefront Guided Treatments
• Therapeutic Treatments
Introduction to the STAR S4 IR Excimer Laser
System
STAR S4 IR Excimer Laser System Components
• Top Hat (non Gaussian) 193 nm beam
• 3 D ActiveTrak eye tracking system
For Wavefront Guided Treatments the following features are
available
• Iris Registration (IR)
• Variable Spot Scanning (VSS)
• Variable Repetition Rate (VRR)
Components of the CustomVue Procedure
WaveScan System
Hartmann-Shack Wavefront Aberrometer
CCD-Image
Outgoing Wave
CCD Camera
Lenslet Array
6
CustomVue Procedure
The CustomVue procedure is a wavefront guided treatment
There are three components to the CustomVue procedure
1.WaveScan WaveFront system to measure the wavefront of
the eye
2.WaveScan Software to reconstruct the wavefront and
calculate ablation instructions that are transferred to the S4 IR
System
3.S4 IR Excimer Laser system that will execute the ablation
instruction
7
Components of the CustomVue Procedure
WaveScan CustomVue Software:
• Proprietary VISX smart pulse-packing software
Zernike Reconstruction
Used for Review
Fourier Reconstruction
Used for Treatment
8
Components of the CustomVue Procedure
STAR S4 IR Excimer Laser System
• 100% Variable Spot Scanning treatment with automatic
centering and Iris Registration
9
Advantages of the CustomVue Procedure
Optical zone adjustability
Variable spot scanning and thermally balanced treatments with
better adherence to an individualized target shapes
Availability of compensation for cyclorotation and compensation
for pupil centroid shift
Direct transfer (USB) of patient treatment data to the laser to
reduce transposition errors
10
Higher Order Aberrations and the CustomVue Treatment
There is no clinical data to suggest Higher Order preoperative RMS should be considered when deciding to
perform wavefront - guided ablations
11
Refractive Labeling
12
Refractive Labeling
Physicians should refer to the STAR S4 IR Excimer Laser
System Operator’s Manual for a complete discussion of FDA
approved Labeling for LASIK and PRK.
The following slides review labeling and are not intended to be a
complete or comprehensive review.
13
Refractive Indications
The VISX STAR Excimer Laser System with Variable Spot
Scanning (VSS™) and the WaveScan WaveFront System is
indicated for wavefront-guided laser assisted in situ
keratomileusis (LASIK):
• In patients who are 21 years of age or older
• With refractive stability
14
Refractive Indications
The STAR™ Excimer Laser System is indicated for
Photorefractive Keratectomy (PRK):
• In patients who are 18 years of age or older for the treatment of
spherical myopia up to - 6.00D
• In patients who are 21 years of age or older for the treatment of
myopic astigmatism and hyperopic astigmatism ( see slide 14 for full
approved range)
• With refractive stability
15
CustomVue LASIK Treatment Ranges
Sphere
Cylinder
Spherical
Equivalent
Myopic
Astigmatism
-11.75
-3.75
-11.75
Hyperopic
Astigmatism
+3.75
+2.75
+3.75
Mixed
Astigmatism
X
+0.25 to +5.75
16
X
Conventional PRK Treatment Ranges
Sphere
Cylinder
Spherical
Equivalent
Myopic
Astigmatism
-12.00D
-4.00D
-12.00D
Hyperopic
Astigmatism
+5.00D
+4.00D
+6.00D
Mixed
Astigmatism
NA
NA
NA
17
Conventional LASIK Treatment Ranges
Sphere
Cylinder
Spherical
Equivalent
Myopic
Astigmatism
-14.00D
-5.00D
-14.00D
Hyperopic
Astigmatism
+5.00D
+3.00D
+6.00D
Mixed
Astigmatism
X
<6.00D
X
18
Refractive Stability
Stable manifest refraction as evidenced by less than
or equal to the following change in either spherical or
cylindrical component of manifest refraction over the
previous year is required.
•
•
•
•
Myopia: ±0.50D
Hyperopia: ± 1.00D
Mixed Astigmatism: ±1.00D
High Myopia: ±1.00D
19
Contraindications
Laser refractive surgery based on a CustomVue treatment,
Conventional LASIK or Conventional PRK is contraindicated in:
• Patients with collagen vascular, auto-immune or immunodeficiency
diseases
• Women who are pregnant or nursing
• Patients with signs of keratoconus or abnormal corneal topography
• Patients who are taking the following medications:
– Isotretinoin (Accutane®)
– Amiodarone hydrochloride (Cordarone®)
Accutane is a registered trademark of Hoffman-La Roche, Inc.
Cordarone is a registered trademark of Sanofi
20
Warnings
LASIK or PRK is not recommended in patients who have:
•
•
•
•
Diabetes
A history of Herpes simplex or Herpes zoster keratitis
Significant dry eye that is unresponsive to treatment
Severe allergies
21
Warnings
ELECTROMAGNETIC FIELD (EMF): The thyratron emits an
electromagnetic pulse which is shielded by the metal coverings
of the STAR S4 IR Excimer Laser System. This metal covering
reduces the EMF below the limits set by applicable standards for
electromagnetic compliance.
WARNING: The effects of electromagnetic emissions from the
excimer laser system on other devices, such as cardiac
pacemakers or implanted defibrillators, are unknown.
Operation of the laser in proximity to such devices is not
recommended.
22
Precautions
The safety and effectiveness of the STAR S4 IR Excimer
Laser System has not been established in:
• Patients with corneal neovascularization within 1.0 mm of the
ablation zone
• LASIK and PRK patients under the age of 21 years
– With the exception of PRK patients who are 18 years of age or older for the
treatment of spherical myopia up to - 6.00D
23
Precautions
The safety and effectiveness of the STAR S4 IR Excimer
Laser System for LASIK correction have not been established
in patients with:
• Progressive myopia, hyperopia or astigmatism
• Ocular disease, corneal abnormality, previous corneal or
intraocular surgery, or trauma in the ablation zone
• A history of glaucoma
• Residual corneal thickness < 250 microns at the completion of the
ablation
• The medication Sumatriptan (Imitrex®)
Imitrex is a registered trademark of GlaxoSmithKline
24
Precautions
To avoid corneal ectasia, the posterior 250 microns of the
corneal stroma should not be violated by the laser or the
microkeratome
Patient pachymetry - (Non-nomogram adjusted depth of
treatment + flap thickness) = > 250 microns
25
Precautions
The safety and effectiveness of this laser for wavefront guided
LASIK correction have not been established in patients with:
• WaveScan-measured pupil size < 5.0 mm
26
Precautions
The safety and effectiveness of wavefront- guided LASIK
surgery have only been established:
• In Myopia with an optical zone of 6.0 mm and an ablation zone
of 8.0 mm
• In Hyperopia with an optical zone of 6.0 mm and an ablation
zone of 9.0 mm
• In Mixed Astigmatism with an optical zone of 6.0 mm and an
ablation zone of 9.0 mm
27
Precautions
All CustomVue treatments should be performed with humidity
between 40-45% and the temperature between 68 - 72° F.
The anticipated post-operative keratometry value in any
meridian must be >34D to < 50D.
28
Precautions
During the FDA CustomVue clinical trial for highly myopic eyes, an
"in the stromal bed" pachymetric measurement was performed to
assure a minimum residual stromal bed of 250 microns.
29
Patient Information Booklet and Professional Use
Information
Prospective patients, as soon as they express an interest in
laser vision correction and prior to undergoing surgery, must
receive from the treatment provider the Patient Information
Booklet.
Prior to undergoing surgery, prospective patients must be
informed of the alternatives for correcting their refractive error
including eyeglasses, contact lenses, and other refractive
surgeries.
All surgeons should read the Professional Use Information prior
to performing procedure procedures with the STAR S4 IR
Excimer Laser system.
30
FDA Reporting Requirement Abbott MDR Program
Abbott is required by law to report any of the following events
(MDR = Medical Device Reporting)
Serious Injury or Death
• Permanent impairment of a body function
• An injury that necessitates medical or surgical intervention by a
health care professional
• A malfunction occurred that if it were to reoccur may likely cause or
contribute to death or serious injury
31
FDA Reporting Requirements MedWatch Program
In addition to the MDR Report Abbott is required to file,
users are required to file
Form FDA 3500A
“MedWatch Mandatory Reporting”
For more information, call the DSMA at (800)638-2041
32
Pre-Operative Evaluation
33
Pre-operative Examination
Baseline evaluation of patients requesting CustomVue or
Conventional treatments should be performed within 30
days of laser refractive surgery
34
Discontinuance of Contact Lenses
Soft lenses - discontinue lens wear at least two weeks prior
to examination and treatment
Hard (PMMA) or RGP lenses - discontinue lens wear at
least three weeks prior to examination and treatment with
stable topography (keratometry) and refraction
• 3 topographic maps (central keratometry readings) and MR
taken at 1 week intervals. The last two readings must not differ
by > 0.5D
35
Discontinuance of Contact Lenses
Contact Lenses cause:
– Reversible corneal topographic changes
– Alterations in corneal thickness
Contact Lenses must be discontinued prior to CustomVue
treatments to allow these reversible corneal changes to
resolve
36
Sequence of Pre-Op Exams Wavefront-Guided
Treatments
WaveScan System
Keratometry
Corneal Topography
WaveScan Guided Manifest Refraction
SLE/Tonometry/Pachymetry
Cycloplegic Refraction
DFE
Post-Cycloplegic Refraction
• If necessary
37
WaveScan Exams
WaveScan exams with 6.0 mm wavefront diameter are
preferred for treatments
• The minimum size of the wavefront diameter must be >5.0
mm to calculate a CustomVue treatment
• Measurements with a wavefront diameter <5.0 mm will be
unavailable for selection
38
WaveScan Adjusted Manifest Refraction (WAMR)
Obtain a WaveScan exam at the beginning of the pre-operative
evaluation prior to other measurements
Place the WaveScan cylinder measurement (axis and
magnitude) in the phoropter or trial frame
Refine the sphere to yield the most letters read with the least
minus
39
Pre-operative Examination
Uncorrected Visual Acuity
Refraction (WAMR)
• Manifest Refraction
– Myopia - resolution based, not contrast based end point of
refraction
• least minus to see most letters
– Astigmatism - Jackson Cross Cylinder - maximize magnitude of
cylinder
– Hyperopia - Pushed Plus technique
Best Spectacle Corrected Visual Acuity
• Do not stop at 20/20
40
Astigmatism
Refractive, keratometric and topographic cylinder occasionally
do not match in axis or magnitude
Treatment is based on WaveScan and/or Manifest cylinder
When disparity occurs, proceed very cautiously and ascertain
stability by repeated measurements over time
41
Cycloplegic Refraction
Cycloplegic Refraction (1% cyclopentolate)
True cycloplegia reduces accommodation and allows evaluation
of:
• an over-minused myope
• maximal hyperopia (manifest and latent)
Only refine the sphere during the cycloplegic refraction
42
Comparison Between Sphere and Cylinder Myopia
Difference between WaveScan and manifest sphere or cylinder
powers must be within +/- 0.50D
Difference between manifest and cycloplegic sphere or cylinder
powers must be within +/- 0.50D
Difference between WaveScan and cycloplegic sphere or
cylinder powers must be within +/- 0.50D
For eyes with > 0.50D cylinder, the manifest cylinder axis must
be within 15° of the WaveScan cylinder axis
43
Comparison Between Sphere and Cylinder
Hyperopia/Mixed Astigmatism
Difference between WaveScan and manifest sphere or cylinder powers must
be within +/- 0.75D
Difference between manifest and cycloplegic sphere or cylinder powers must
be within +/- 0.75D
Difference between WaveScan and cycloplegic sphere or cylinder powers must
be within +/- 0.75D
For eyes with > 0.50D cylinder, the manifest cylinder axis must be within 15°
of the WaveScan cylinder axis
44
Keratometry
Keratometry is required
Manual K’s preferred
Auto K’s are acceptable
Simulated Topography K’s are sub-optimal
K1 = flat K
K2 = steep K
K2 Axis= axis of steep K
45
Pre-operative Examination
Pupillometry
• Bright and dim illumination measurement
Corneal Topography - necessary in all patients
• R/O Keratoconus or any other abnormality
• R/O CL related abnormalities
• Verify post-operative results
46
Pre-operative Examination
Slit Lamp Exam
Tonometry
Pachymetry
• Ultrasonic pachymetry required for LASIK/PRK
Dilated Media and Fundus Exam
47
Residual Posterior Stroma
There must be at least 250 microns of stroma remaining
following the ablation to prevent iatrogenic
keratoectasia
The flap does not provide tectonic support to the cornea post
LASIK
The following calculation must be done prior to treatment
Central Corneal Thickness - (Flap Thickness + Ablation
Depth) must be > 250 microns
48
Residual Posterior Stroma
The ablation depth should be based on the actual
depth of the non-nomogram adjusted myopic
desired correction as this is indicative of the
amount of tissue that is effectively removed
49
WaveScan System Review
Design
CustomVue
Treatment
Take
WaveScan
Measurement
Perform
CustomVue
Treatment
50
Surgical Planning and Surgical Technique
51
Surgical Planning and Technique
“Everything that goes on in and around the laser room
is the responsibility of the operating surgeon !!!”
52
STAR S4 IR Excimer Laser System
Nomogram Development
53
WARNING
The following nomogram recommendations serve as a guideline
for Conventional and CustomVue procedures with the STAR S4
IR Excimer Laser System
54
WARNING
The following nomogram recommendations are made based on
adherence to the refraction techniques, treatment dimensions,
surgical techniques and environmental conditions discussed in
the STAR S4 IR Physician Certification Course
55
Nomogram Warning
Nomograms developed for other laser systems CANNOT be
used with the STAR S4 IR Excimer Laser System.
Nomograms for Conventional and CustomVue procedures are
different.
56
Initial CustomVue Nomogram Recommendations
57
CustomVue Ablation Dimensions
The safety and effectiveness of wavefront- guided surgery have
only been established
• In Myopia with an optical zone of 6.0 mm and an ablation zone of 8.0
mm
• In Hyperopia with an optical zone of 6.0 mm and an ablation zone of
9.0 mm
• In Mixed Astigmatism with an optical zone of 6.0 mm and an ablation
zone of 9.0 mm
58
CustomVue Ablation Dimensions
Procedures performed with different treatment dimensions may
yield different (i.e., less predictable) results
• Enlarging the Optical Zone will result in deeper ablations that take
more time to deliver
• Enlarging the Ablation Zone will result in longer treatments
59
CustomVue Nomograms
Myopia
• Nomograms for CustomVue myopic LASIK typically
involve an increase in the WaveScan sphere relative to
the manifest refraction
60
CustomVue LASIK for Myopia
WaveScan Spherical Equivalent < -6.00D
• Use Physician Adjustment to bring the WaveScan Sphere to the
Manifest Sphere
• Add 0.25D more minus ( Physician Adjustment of -0.25D) in patients
younger than 35 years of age
61
CustomVue LASIK for Myopia
WaveScan Spherical Equivalent > - 6.00D
• Use Physician Adjustment to bring the WaveScan Sphere to the
Manifest Sphere
62
CustomVue LASIK Hyperopia and Mixed
Astigmatism
Hyperopia and Mixed Astigmatism
• No adjustment if the WaveScan and Manifest Sphere are within
0.75D
63
Refining Your CustomVue Nomogram
64
Refining Your Nomogram
It is expected your individual nomogram may differ from our initial
recommendations
In order to develop an individualized nomogram, a careful
retrospective analysis of your refractive results is required
This retrospective analysis should be made based on data
obtained after the point of refractive stability (see below)
65
Refractive Stability
Patients must be refractively stable
prior to modifying your nomogram
Refractive Stability
Myopic Astigmatism
1-3 months
Hyperopic Astigmatism
3-6 months
Mixed Astigmatism
3-6 months
66
Nomogram Development
Many factors may influence individual nomograms
•
•
•
•
•
•
•
Temperature
Humidity
Patient age
Patient refractive error
Microkeratome
Elevation
Surgical technique
67
Adjusting Your Nomogram
Start out slowly with nomogram modifications
Change one variable at a time
68
The Use of the
Percentage Nomogram Adjustment
69
CustomVue Percentage Nomogram Adjustment
The Percentage Nomogram Adjustment allows the
surgeon to make a percentage adjustment to the entire
WaveScan-defined ablation (includes that HOA’s)
• A maximum adjustment of ±10% is allowed
• The Percentage Nomogram Adjustment is programmed on
the Design screen
70
Percentage Nomogram Adjustment
Design screen
with detail of
Nomogram Field
71
Percentage Nomogram Adjustment
The Percentage Nomogram Adjustment does not change the
shape of the ablation
• A greater or lesser number of pulses are used to achieve the
WaveScan-defined target shape (including higher and lower order
terms)
• As a result, the Percentage Nomogram Adjustment does not affect
the calculated depth (Maximum Ablation Depth)
72
Percentage Nomogram Adjustment
The Percentage Nomogram Adjustment should be used to
compensate for results based on individual differences in environmental
conditions and surgical technique after a critical review of refractive
results
The Percentage Nomogram Adjustment is preferred for nomogram
adjustment purposes because it adjusts the entire wavefront treatment
(not only the sphere)
73
Percentage Nomogram Adjustment
The Percentage Nomogram Adjustment is different than the
Physician Adjustment
• The Physician Adjustment allows you to adjust the spherical component
of the WaveScan refraction by +/- 0.75D
• The Physician Adjustment can be used as an endpoint adjustment to
deviate from emmetropia
– e.g., planned post-operative target of -0.25 in a 55 year old patient
74
Percentage Nomogram Adjustment
One method to produce a percent nomogram adjustment which
may be used with the following calculation:
For each CustomVue patient perform the following
calculation post-operatively
(Post -Op MRSE )/
(Pre-Op WaveScan equivalent)x100)
Calculate the mean percent for all CustomVue patients
Please note that the above is intended as an example and does not
represent the only valid method for determining a percentage
nomogram adjustment
75
Percentage Nomogram Adjustment
For Demonstration Purposes only
> 50 eyes are recommended for this analysis
Pre-Op
WaveScan
Equivalent
Post-Op
Patient 1
-5.00
-0.25
+5.0%
Patient 2
-4.75
+0.25
-5.26%
Patient 3
-5.50
-0.50
+9.09%
Mean %
+2.94%
MRSE
76
Post Op MR
/Pre-WaveScan
x 100
STAR S4 IR
Excimer Laser System Calibration
77
System Calibration Requirements
Complete calibration is required each day when the
system is powered up
Abbott requires that a –4.00 D sphere calibration be
tested after every third ocular treatment
78
Fluence Calibration
Fluence calibration adjusts the laser system energy to maintain a
constant delivered fluence of 160 mJ/cm2.
• Fluence calibration is performed:
– at system startup
– before each patient treatment procedure (with the exception of fellow eyes)
– any time the operator selects SET FLUENCE on the Lens Calibration screen
79
System Calibration
Calibration Platform with Calibration Plastic
80
Lens Calibration
•Myopic Sphere
•Myopic Cylinder
•Flat/Block
•Flat
•Hyperopic Sphere
•Centering
81
Lens Calibration
ActiveTrak™ System Calibration in conjunction with Beam Centering required
•The ActiveTrak System Calibration and Beam
Centering are accessed on the Lens Calibration
screen by selecting “Centering”.
•The ActiveTrak System aligns the treatment
center as defined by the eye tracker in relation to
the laser beam. Beam centering, done in
conjunction with the ActiveTrak System
calibration, aligns the reticle in relation to the
laser beam. This test ablation must be done as a
part of daily calibration procedure.
82
Reticle Alignment
Check the laser beam/reticle alignment
Reticle adjustment
knobs
83
STAR S4 IR Excimer Laser System
Hardware Overview
84
Laser Safety
Emergency Stop Button
Know where the EMERGENCY STOP button is located
85
Laser Safety
The Premix cylinder contains Argon and Fluorine
• Fluorine is toxic
High voltage
(25,000 to 32,000 volts)
Never operate the laser in the presence of flammable anesthetics or other volatile
substances such as alcohol
Nominal hazard zone is 40 cm
86
Variable Spot Scanning
Combines advantages of larger and smaller diameter beams
Allows tissue to be removed in the shortest possible time
Smooth ablation
87
Variable Repetition Rate
The repetition rate will vary from 6 to 20 Hz for CustomVue treatments
VRR will allow optimal delivery of Variable Spot Scanning (VSS) pulses
to ablate tissue in a temporally and thermally efficient fashion
88
Environmental Conditions
Control of environmental conditions during CustomVue
treatments is important
Temperature should range from 68 to 72º F
Relative humidity should range from 40% to 45%
Stability of temperature and humidity is important
• Humidity lower than 40% can lead to overcorrections
• Humidity higher than 45% can lead to undercorrections
89
Laser Repetition Rate
Conventional Ablations and Phototherapeutic Ablations
• User can vary Repetition from 1.5 to 10 Hz
90
Performing the CustomVue Treatment
On the STAR Excimer Laser System, select the appropriate
CustomVue Treatment by selecting the patient’s name on the
Main Menu screen.
The CustomVue Treatment calculated on the WaveScan
System will appear.
The treatment parameters cannot be changed on this screen.
Review the information on the laser computer screen to ensure
that it is correct.
91
Flap Hinge Location
Select Flap Hinge Location
•Superior
•Nasal
•Temporal
LASIK flap hinge location must be entered on the Operating Parameters screen for each CustomVue™
treatment when using the IR system
92
Performing the CustomVue Treatment
After verifying that this is the appropriate treatment, select
TREAT to perform the patient treatment.
93
Patient Alignment
Fiducial
Line Button
•When the patient is
seated in the patient
chair, align the patient’s
head perpendicular to
the system with the
fiducial line
Fiducial Line
94
Microscope
Wild Leica Microscope
• Variable Magnification
–
–
–
–
–
0.63x
1.0x
1.6x
2.5x
4.0x
All treatments should be performed at 1.6x magnification
95
Doctor’s Keypad
Fiducial Line
IR Button
ActiveTrak™Button
Doctor’s Keypad
96
Joy Stick
Joy Stick controls the position of the Patient Chair
• The microscope does not move
Farther = faster
97
VisionKey Card
VisionKey Cards are purchased from AMO
Allow use of the STAR S4 IR Excimer Laser
• VisionKey Cards are laser specific
There are different VisionKey Cards for
•
•
•
•
•
Conventional Ablations
CustomVue Ablations
CustomVue Retreatments
PreVue Lenses
Phototherapeutic Keratectomy
98
Patient Chair
Automatic OD/OS pre-positioning
Automatic “Y” center button
Pillow evacuation button relocated to the left side of the headrest
99
Operative Illumination
Ring Illumination - allows visualization of stromal surface
Oblique Illumination - allows visualization of iris and pupil
Ring Illumination
Oblique Illumination
100
Operative Illumination
Adjust the operative illumination
to keep operative pupil diameter
as close as possible to
WaveScan pupil diameter
(between 5 and 7 mm)
Use the lowest level of illumination
possible to
• allow patient comfort
• help with patient fixation on the flashing
fixation target
101
Reticle
Reticle is projected into each ocular
Reticle can be turned off during
• Flap creation/reposition
• Epithelial Removal
The Reticle must be on to proceed with the ablation
Reticle brightness can be adjusted
Reticle Dimensions
• Inner Ring
• Middle Ring
• Outer Ring
4mm
6mm
9mm
102
Aspirator
Aspirator can be moved out of position to allow
• Creation/reposition of LASIK flap
• Removal of corneal epithelium
The Aspirator must be in the proper position to proceed with the ablation
AIRBORNE CONTAMINANTS: Airborne contaminants which are produced by the
ablation process are captured in proximity to the cornea near the point of production and
fed into an aspirator with a filter. This aspirator is designed to prevent any of the products
of ablation from contaminating the surgical suite.
Aspirates over 99% of material ejected from the cornea during the ablation
103
Laser Footswitch
Laser Footswitch has two positions
• First position activates the aspirator
• Second position activates the laser
104
ActiveTrak Eye Tracking System
105
ActiveTrak Eye Tracking System
The ActiveTrak System should be used during Conventional
and CustomVue Procedures
106
ActiveTrak Eye Tracking System
Moves the laser beam to compensate for eye movements
3D infrared eye tracker
Side-mounted infrared cameras monitor x, y, and z (up and
down) motion
107
ActiveTrak Eye Tracking System
Side-mounted, infrared cameras
monitor x, y, and z movements
Oblique IR lighting does not
interfere with procedure
108
ActiveTrak Eye Tracking System
Eye movements during LASIK/PRK are followed by the
ActiveTrak system such that it:
• Continues to monitor between pulses
• Checks eye position at least 3 times for every pulse
delivered to the cornea
109
ActiveTrak Eye Tracking System
110
ActiveTrak Eye Tracking System
The surgeon can choose to set the
treatment center manually or use the
automatic centering mode.
If using automatic centering, the
ActiveTrak will locate the pupil and set
the treatment center.
Automatic Centering should always be used when
performing CustomVue Procedures
111
ActiveTrak Use
Press ActiveTrak Button on Doctor’s Keypad
The entire reticle will begin flashing
The ActiveTrak Eye Tracking System will locate the pupil and set
the treatment center
112
ActiveTrak Use
Once the pupil is located, the outside ring on the reticle will stop
flashing
Once the treatment center is set, the center cross of the reticle
stops flashing.
The ActiveTrak System will maintain this position throughout the
treatment
113
ActiveTrak Use
Fully depress the laser footswitch to begin the treatment
The center cross of the reticle will flash slowly during the treatment
when the ActiveTrak System is on and tracking the pupil
When the ActiveTrak System is activated, you may use the joystick
to correct for head (translational) motion during the treatment
Do NOT use the joystick to correct for eye rotation when the eye
tracker is activated
114
ActiveTrak Use
Treatment will stop or pause when the ActiveTrak™ System detects the
following conditions:
• The patient’s eye moves more than 1.5 mm from the surgeonselected treatment center (the initial position from which the
ActiveTrak™ System begins tracking).
• The vertical position (z axis) of the corneal surface moves more than
2.0 mm from the initial treatment position.
• The pupil diameter is not circular to within 32% or becomes smaller
than 1.5 mm or larger than 6.0 mm during treatment.
• Eye motion exceeds 0.2 mm between video frames.
• Dark objects or reflective objects are in the ActiveTrak™ System’s
field of view.
• Surgical instruments or the surgeon’s hands cross the ActiveTrak™
System’s field of view.
115
Components of Iris Registration
Compensation for Cyclorotation
Compensation for Pupil Centroid Shift
Ozone Compensation
116
Registration of CustomVue Ablations
WaveScan exams are acquired with the patient in the upright
position
The CustomVue ablation is performed with the patient in the
supine position
117
Registration of CustomVue Ablations
Iris Registration is necessary to compensate for cyclotorsion
that occurs when the patient goes from the upright to the
supine position
118
Iris Registration Basic Principles
The image of the patient’s eye taken on the WaveScan
System is transferred to the STAR S4 IR System along with
the CustomVue treatment files via a USB Flash Drive
The amount of cyclotorsion of the eye under the laser is
determined by comparing features of the iris on the
WaveScan image to the same features of the iris on the
STAR S4 IR camera image
119
Iris Registration Basic Principles
The iris registration system is only available for CustomVue
treatments
Re-registration for intra-operative cyclotorsional movement
• If surgeon tracks significant intra-operative movement, iris image can
be re-registered under the laser
120
Iris Registration Basic Principles
There are 48 landmarks used for matching the two iris images
24 landmarks on the WaveScan iris image are matched with 24
landmarks on the STAR S4 IR laser image
One landmark for each 15 degree iris sector in each image is
identified
A minimum of 21 of the 24 landmarks must match
It is possible that the laser software will NOT be able to identify
enough (or similar) landmarks to allow iris registration to work,
regardless of the quality of the WaveScan image
121
Iris Registration Basic Principles
Find multiple matching reference
points for each iris section
WaveScan
Image
Laser
Image
122
Iris Registration Basic Principles
Calculate the torsional angles from
Torsional Angle multiple measurements
123
Compensation for Pupil Centroid Shift
Wavefront measurements and wavefront- guided ablations
are typically done under different lighting conditions
As a result, the pupil size may be different during
measurement and ablation
When the pupil size changes the pupil centroid usually shifts
124
Pupil Centroid Shift
Different Lighting Conditions
As the pupil changes size, its centroid may not remain stationary,
relative to the outer iris boundary
Diagnostic measurement (mesopic)
LVC Treatment (photopic)
Outer Iris Boundary
125
Iris Registration Compensation
for Pupil Centroid Shift
Iris Registration system compensates for pupil centroid shift
by referencing to the outer iris boundary and consistently
centering wavefront ablations on the same WaveScan pupil
centroid at the laser
126
Ozone Compensation
Ozone Compensation –
• As ozone builds up it decreases the amount of energy that passes
through the optical pathway
• Ozone compensation increases energy stability
• Prior to treatment (patient/plastic) the system will fire ten laser pulses
• Note: you will hear these additional shots prior to treatment
127
Iris Registration WaveScan Acquisition
Acquisition of high quality WaveScan images is essential to the
success of IR
WaveScan Eye Images must be in clear focus with iris details
easily visible to facilitate iris capture
128
Iris Registration WaveScan Acquisition
When capturing the WaveScan Eye Image, there must be
maximum exposure to facilitate proper iris capture
– No eyelid artifacts
– Little or no cilia
– Small lacrimal menisci
• WaveScan acquisition must be properly centered
• Visible Purkinje reflections must be crisp and clear
129
Iris Registration WaveScan Acquisition
A distance of at least 1mm (preferably more) is recommended
between the pupil boundary and the upper and lower eyelids
130
WaveScan Acquisition
Iris and pupil overlays displayed by the software need to match the
appropriate structures in the Eye Image
The outer iris boundary must be clearly visible and overlying the visible
limbal region
• Eye Images with any boundary misplaced should not be used for
treatment
131
Iris Registration
WaveScan® Acquisition
Outer Iris Boundary
132
Outer Iris Boundary (OIB)
Misplaced outer iris boundary can occur at the WaveScan
System and/or the laser
Both images must be monitored and actively verified
133
Iris Registration WaveScan Acquisition
Surgeons must view the actual exam used for treatment design
The Green Box in the bottom of the Eye image display indicates
that the quality of the selected WaveScan exam is eligible for IR
at the laser
As the criteria at the laser for IR are more stringent than at the
WaveScan, it is possible that IR might not engage at the laser
with the green box present
IR Not Eligible
IR Eligible
134
Iris Registration Surgical Technique
Flap Hinge Location
•Superior
•Nasal
•Temporal
LASIK flap hinge location must be entered on the Operating Parameters screen for each
CustomVue treatment when using the IR system to identify outer iris boundary
135
Iris Registration Surgical Technique WARNING
As with any surgical procedure, it is ultimately and entirely the
responsibility of the surgeon to ensure that the CustomVue
treatment loaded on the STAR S4 IR System belongs to the
correct eye of the correct patient positioned under the laser
The "WaveScan Image: Verified" display is an additional criterion
used to determine that the WaveScan image associated with the
selected treatment matches the image of the patient's eye under
the laser
• Iris matching technologies are probability-based and should not be
solely relied on for verification
136
Iris Registration
Prior to engaging the IR system
• Make certain no surgical instruments or devices are obscuring
the IR camera view of the iris, pupil or outer iris boundary
– Do not use a Chayet drain or any similar device that can obscure the outer iris
boundary or other ocular landmarks
– Keep your hands from obscuring the IR camera
137
Iris Registration
Prior to engaging the IR system
• With the eyelid speculum in position, make certain the cornea is
in the middle of the inter-palpebral fissure (primary position)
• Ensure that the patient’s head is centered and is not tilted to
either side
• Eliminate shadows on the iris or pupil by properly positioning the
patient’s head
138
Iris Registration Optimal Surgical Environment
Operative Illumination
• Adjust the operative
illumination to keep operative
pupil diameter as close as
possible to WaveScan pupil
diameter (between 4 mm and
7 mm)
• Use the lowest level of
illumination possible to
– allow patient comfort
– help with patient fixation on the
flashing fixation target
139
Optimal Surgical Environment
Change the illumination as little as possible or preferably
not at all after the ActvieTrak System and IR have been
engaged.
If illumination is changed after engaging the ActiveTrak
System and IR, consider restarting the ActiveTrak System
and IR
140
Iris Registration Surgical Technique
Center the patient’s eye under the laser
and focus on the corneal surface
• The pupil and iris detail will be slightly out of
focus when the laser is properly focused on
the corneal surface
• The IR infrared camera is focused on the iris
even though the surgeon is focused on the
corneal stromal surface
141
Iris Registration Surgical Technique
Procedure should be performed at
magnification 16x (the microscope dial
may read 16 or 1.6, depending on the
system microscope model)
142
Iris Registration Surgical Technique
Significant cyclorotation can occur after the flap is lifted
Therefore, Iris Registration and ActiveTrak must be
engaged AFTER the flap has been lifted
143
Iris Registration Technique Activation of IR System
Turn on the IR System by pressing the Rotation (Rot) button and
the ActiveTrak™ System by pressing the Track button on the
Doctor’s Keypad
IR Button
ActiveTrak
Button
Doctor’s Keypad
144
Iris Registration Technique Activation of IR System
IR should be turned on by pressing the “ROT” button before the
ActiveTrak System is activated
• The ActiveTrak System must be on and tracking to use IR
IR will then automatically start when the ActiveTrak System is on and
tracking
145
Iris Registration Technique Activation of IR System
Patient cooperation and fixation is critically important while IR
is engaging
Anything that interferes with patient cooperation and fixation
while IR is engaging will
• increase the time of IR capture
• reduce the success of IR capture
146
Iris Registration Technique Activation of IR System
IR can be re-initiated at any time during the treatment by turning
IR off and back on using the “ROT” button
When Iris Registration is turned off, the cyclorotation correction
and pupil centroid shift are returned to a zero position, just as if
Iris Registration had never been on in the first place
147
Iris Registration Technique Activation of IR System
Once IR has been engaged DO NOT reposition the patient’s
head
If the patient moves after IR has been engaged, IR MUST be
restarted
148
Iris Registration Technique Activation of IR System
The dialog box will add the message:
• “Treatment Registered to WaveScan References. Press
footswitch to start treatment.”
Fully depress the laser footswitch to begin the treatment
• This will automatically restore the live microscope camera image
149
Iris Registration Technique
150
Optimizing Iris Registration Three strikes
Strike One
• Check Patient Alignment
• Confirm Microscope Magnification at 1.6x
• Focus on anterior stromal surface
• Re-engage IR
151
Optimizing Iris Registration Three strikes
Strike Two
• Decrease Illumination
• Re engage IR
Strike Three
• Increase Illumination
• Re engage
If still unsuccessful after three attempts at engaging IR, proceed with
CustomVue ablation without IR
152
STAR Excimer Laser System
Conventional Ablation
Dimensions & Shapes
153
Beam Shaping
Iris Diaphragm
• 2 mm to 6.0 mm diameter for PTK
• 6 or 6.5 mm diameter for PRK/LASIK
Slit Blades
• PTK (0.6 mm to 6.0 mm)
• Hyperopic PRK (scanning slit)
Iris Diaphragm/Slit Blades
• PRKa 6 x 4.5 mm or 6.5 x 5.0 mm (minimum minor axis) ellipse
154
Beam Shaping
Variable Spot Scanning
• Blend Zone
Variable Slit Scanning
• Hyperopia
• Hyperopic Astigmatism
155
Ablation Dimensions & Shapes
Spherical Myopia
• Standard Zone
• Larger Zone
6.0 mm
6.5 mm
Myopic Astigmatism (Ellipse)
• Standard Zone
• Larger Zone
6.0 x 4.5 mm (minimum minor axis)
6.5 x 5.0 mm (minimum minor axis)
156
Myopic Astigmatism
The width of the ellipse is determined by the
relationship between sphere and cylinder
• for any given sphere, the less the cylinder the larger the
minor axis
Larger Zone treatment depth is 15-20% more than Standard Zone
157
Ablation Dimensions & Shapes
Blend Zone
•
•
•
•
Used in combination with Myopic/Myopic Astigmatic Ablation
Can be used with Standard or Larger Zone treatment
Last diopter of spherical myopia is treated at 8.0mm diameter
Must have one diopter of spherical myopia at the corneal plane
158
Blend Zone Option with VSS Treatment Profile
Ablation Diameter
8.0 mm
1.0 mm
1.0 mm
Blend Zone
Blend Zone
Creates gradual slope from optical zone to un-ablated cornea
159
Blend Zone Option with VSS How Does It Work?
Last -1.00 D is treated at 8.0 mm
• e.g. -6.00 D with Larger Zone and Blend Zone Option Selected
– - 5.00 D at 6.5 mm
– -1.00 D at 8.0 mm
160
Treatment Algorithms Myopia
< 6.00 D
Single Zone
• 6.0 mm(Standard)
• 6.5 mm(Larger)
> 6.00 D to <12.00 D
Multi-zone
– 6.0/6.5 mm
– 5.5 mm diameter
> 12.00 D
Multi-zone
– 6.0/6.5mm
– 5.5mm
– 5.0mm
161
Myopia/Astigmatism Treatment screen
162
Myopia/Astigmatism Treatment Screen
Desired correction field
• Enter amount of myopia and astigmatism to be
eliminated during the treatment
• Enter axis of astigmatism
• Enter vertex distance
• Enter Ks if not previously entered
– (Ks affect the number of pulses delivered to cornea)
163
Myopia / Astigmatism Treatment Screen
A value must be entered in the astigmatism field
even if it is zero
Results Field
• Summarizes pulse rate, depth and number of pulses
164
Myopia with Astigmatism Desired Correction Field
The computer will accept a plus cylinder manifest
refraction or a minus cylinder manifest refraction in
the desired correction field at the spectacle plane
NOTE: The final treatment is corrected for the
refractive error at the corneal plane expressed in
minus cylinder
165
Ablation Dimensions & Shapes
Hyperopia
• Ablation Diameter
9.0 mm
• Correction Diameter 5.0 mm
166
Hyperopia/Astigmatism Ablation Profile
In order to produce a steeper central cornea, the
peripheral cornea is flattened
Astigmatism is corrected by differentially steepening the flat
axis
Eccentrically rotating lens in hyperopia module displaces
laser beam out to 9 mm
Slit blades shape laser beam to rectangular scanning slit
167
Hyperopia Ablation Profile
The ablation extends out to 9.0 mm
The zone of deepest treatment is at approximately 5 mm (but
may be varied from 3 to 6 mm)
Ablation depth at 5 mm is ~ 8 microns/diopter
• Maximum depth approximately 50 microns
0.8 mm
Optical zone - 5 to 6 mm
Transition zone
Ablated area - 9.0 mm
168
Hyperopia/Astigmatism Treatment Screen
169
Hyperopia/Astigmatism Ablation Diameters
All U.S. clinical trials were conducted at 9 mm total
diameter and 5 mm diameter zone of correction
No clinical evidence for use of any other size zone.
Smaller zones may adversely affect the patient’s optical
performance
Always verify pupil diameter in bright and dim illumination
before treatment
170
Mixed Astigmatism Cross Cylinder Ablation
Cylindrical Steepening with Cylindrical Flattening
Example: -1.00 +3.00 x 090
Hyperopic Cylinder Surface
Power
+2.00 x 090
Myopic Cylinder Surface Power
-1.00 x 180
171
Cross-Cylinder Ablation Profile
Cylindrical Steepening with Cylindrical Flattening
172
Treatment Preferences Page
173
STAR Excimer Laser System
ActiveTrak System Software
Any default can be overwritten
Surgeon MUST verify all data in every field in every
screen
174
Patient Manager Patient Information Screen
175
Select Treatment Button Pre-Op Screen
176
Pre - Operative Examination Screen
Refraction Warnings
and Yellow bar on bottom left of screen says
“ No manifest refraction”
177
Operative Parameters Screen
178
Notes Screen
N.B., Epithelium
Removal is for
information on the
Operative Report
Only - Does Not
Control Treatment
179
Epithelium Removal Screen
180
Treat Button
Treat Button can only be
selected from treatment
screens
181
Treatment Summary Screen
182
183