physicain training slidesmay 25-3 final nov 7 2012.ppt
TRANSCRIPT
STAR S4 IR Excimer Laser System Physician Certification Course
Place for Conference or AuthorMonth Day, 200X
2012.03.13-ST4862
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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
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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
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)
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CCD Camera Lenslet Array
Outgoing Wave CCD-Image
WaveScan System Hartmann-Shack Wavefront Aberrometer
Components of the CustomVue Procedure
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
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Components of the CustomVue Procedure
WaveScan CustomVue Software:• Proprietary VISX smart pulse-packing software
Zernike ReconstructionUsed for Review
Fourier ReconstructionUsed for Treatment
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STAR S4 IR Excimer Laser System
• 100% Variable Spot Scanning treatment with automatic centering and Iris Registration
Components of the CustomVue Procedure
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Advantages of the CustomVue Procedure
Optical zone adjustabilityVariable spot scanning and thermally balanced treatments with better adherence to an individualized target shapesAvailability of compensation for cyclorotation and compensation for pupil centroid shiftDirect transfer (USB) of patient treatment data to the laser to reduce transposition errors
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Higher Order Aberrations and the CustomVue Treatment
There is no clinical data to suggest Higher Order pre-operative RMS should be considered when deciding to perform wavefront - guided ablations
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Refractive Labeling
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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.
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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
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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
Refractive Indications
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 X
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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
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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
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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
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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.Accutane is a registered trademark of Hoffman-La Roche, Inc.Cordarone is a registered trademark of SanofiCordarone is a registered trademark of Sanofi
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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
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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.
Warnings
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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
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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 GlaxoSmithKlineImitrex is a registered trademark of GlaxoSmithKline
Precautions
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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
Precautions
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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
Precautions
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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
Precautions
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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.
Precautions
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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.
Precautions
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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.
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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
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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
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Pre-Operative Evaluation
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Pre-operative Examination
Baseline evaluation of patients requesting CustomVue or Conventional treatments should be performed within 30 days of laser refractive surgery
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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
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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
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Sequence of Pre-Op Exams Wavefront-Guided Treatments
WaveScan System KeratometryCorneal TopographyWaveScan Guided Manifest RefractionSLE/Tonometry/PachymetryCycloplegic RefractionDFEPost-Cycloplegic Refraction• If necessary
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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
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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
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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
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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
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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
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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
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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
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Keratometry
Keratometry is required Manual K’s preferredAuto K’s are acceptableSimulated Topography K’s are sub-optimal
K1 = flat KK2 = steep KK2 Axis= axis of steep K
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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
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Pre-operative Examination
Slit Lamp Exam
Tonometry
Pachymetry
• Ultrasonic pachymetry required for LASIK/PRK Dilated Media and Fundus Exam
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Residual Posterior Stroma
There must be at least 250 microns of stroma remaining following the ablation to prevent iatrogenic keratoectasiaThe flap does not provide tectonic support to the cornea post LASIKThe following calculation must be done prior to treatmentCentral Corneal Thickness - (Flap Thickness + Ablation Depth) must be > 250 microns
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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
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WaveScan System Review
Take Take WaveScWaveScan an MeasuremMeasurem
entent
DesignDesignCustomVueCustomVueTreatmeTreatment nt
Perform Perform CustomVueCustomVueTreatmentTreatment
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Surgical Planning and Surgical Technique
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Surgical Planning and Technique
“Everything that goes on in and around the laser room is the responsibility of the operating surgeon !!!”
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STAR S4 IR Excimer Laser System Nomogram Development
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WARNING
The following nomogram recommendations serve as a guideline for Conventional and CustomVue procedures with the STAR S4 IR Excimer Laser System
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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
WARNING
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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.
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Initial CustomVue Nomogram Recommendations
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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
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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
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CustomVue Nomograms
Myopia
• Nomograms for CustomVue myopic LASIK typically involve an increase in the WaveScan sphere relative to the manifest refraction
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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
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CustomVue LASIK for Myopia
WaveScan Spherical Equivalent > - 6.00D
• Use Physician Adjustment to bring the WaveScan Sphere to the Manifest Sphere
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CustomVue LASIK Hyperopia and Mixed Astigmatism
Hyperopia and Mixed Astigmatism
• No adjustment if the WaveScan and Manifest Sphere are within 0.75D
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Refining Your CustomVue Nomogram
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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)
Refractive Stability
Refractive Stability
Myopic Astigmatism 1-3 months
Hyperopic Astigmatism 3-6 months
Mixed Astigmatism 3-6 months
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Patients must be refractively stable prior to modifying your nomogram
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Nomogram Development
Many factors may influence individual nomograms• Temperature• Humidity • Patient age• Patient refractive error• Microkeratome• Elevation• Surgical technique
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Adjusting Your Nomogram
Start out slowly with nomogram modifications
Change one variable at a time
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The Use of the Percentage Nomogram Adjustment
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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
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Percentage Nomogram Adjustment
DesignDesign screen screen with detail of with detail of
Nomogram FieldNomogram Field
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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)
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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)
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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
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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 patientsPlease note that the above is intended as an example and does not represent the only valid method for determining a percentage nomogram adjustment
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Percentage Nomogram Adjustment
Pre-Op WaveScan Equivalent
Post-Op
MRSE
Post Op MR /Pre-WaveScan x 100
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%
For Demonstration Purposes only> 50 eyes are recommended for this
analysis
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STAR S4 IRExcimer Laser System Calibration
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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
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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
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System Calibration
Calibration Platform with Calibration Plastic
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Lens Calibration
•Myopic Sphere•Myopic Cylinder•Flat/Block•Flat•Hyperopic Sphere•Centering
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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.
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Reticle Alignment
Check the laser beam/reticle alignment
Reticle adjustment knobs
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STAR S4 IR Excimer Laser System Hardware Overview
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Laser Safety
Emergency Stop Button
Know where the EMERGENCY STOP button is located
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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
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Variable Spot Scanning
Combines advantages of larger and smaller diameter beams
Allows tissue to be removed in the shortest possible time
Smooth ablation
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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
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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
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Laser Repetition Rate
Conventional Ablations and Phototherapeutic Ablations
• User can vary Repetition from 1.5 to 10 Hz
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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.
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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
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Performing the CustomVue Treatment
After verifying that this is the appropriate treatment, select TREAT to perform the patient treatment.
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Patient Alignment
Fiducial Line
•When the patient is seated in the patient chair, align the patient’s head perpendicular to the system with the fiducial line
Fiducial Line Button
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MicroscopeWild Leica Microscope• Variable Magnification
– 0.63x– 1.0x– 1.6x– 2.5x– 4.0x
All treatments should be performed at 1.6x magnification
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Doctor’s Keypad
Doctor’s KeypadDoctor’s Keypad
IR ButtonIR Button
ActiveTrakActiveTrak™™ButtonButton
Fiducial Line
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Joy Stick
Joy Stick controls the position of the Patient Chair
• The microscope does not moveFarther = faster
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VisionKey Card
VisionKey Cards are purchased from AMO
Allow use of the STAR S4 IR Excimer Laser• VisionKey Cards are laser specificThere are different VisionKey Cards for
• Conventional Ablations• CustomVue Ablations• CustomVue Retreatments• PreVue Lenses• Phototherapeutic Keratectomy
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Patient Chair
Automatic OD/OS pre-positioning
Automatic “Y” center button
Pillow evacuation button relocated to the left side of the headrest
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Operative Illumination
Ring Illumination - allows visualization of stromal surface
Oblique Illumination - allows visualization of iris and pupil
Ring Illumination
Oblique Illumination
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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
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ReticleReticle is projected into each ocular
Reticle can be turned off during • Flap creation/reposition• Epithelial RemovalThe Reticle must be on to proceed with the ablation
Reticle brightness can be adjusted
Reticle Dimensions
• Inner Ring 4mm• Middle Ring 6mm• Outer Ring 9mm
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Aspirator
Aspirator can be moved out of position to allow
• Creation/reposition of LASIK flap• Removal of corneal epitheliumThe Aspirator must be in the proper position to proceed with the ablationAIRBORNE 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
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Laser Footswitch
Laser Footswitch has two positions
• First position activates the aspirator• Second position activates the laser
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ActiveTrak Eye Tracking System
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ActiveTrak Eye Tracking System
The ActiveTrak System should be used during Conventional and CustomVue Procedures
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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
ActiveTrak Eye Tracking System
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Side-mounted, infrared cameras monitor x, y, and z movements
Oblique IR lighting does not interfere with procedure
ActiveTrak Eye Tracking System
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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
ActiveTrak Eye Tracking System
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ActiveTrak Eye Tracking System
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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
ActiveTrak Eye Tracking System
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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
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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
ActiveTrak Use
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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
ActiveTrak Use
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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 surgeon-
selected 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.
ActiveTrak Use
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Components of Iris Registration
Compensation for Cyclorotation
Compensation for Pupil Centroid Shift
Ozone Compensation
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Registration of CustomVue AblationsWaveScan exams are acquired with the patient in the upright position
The CustomVue ablation is performed with the patient in the supine position
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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
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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
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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
Iris Registration Basic Principles
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There are 48 landmarks used for matching the two iris images24 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 identifiedA minimum of 21 of the 24 landmarks must matchIt 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
Iris Registration Basic Principles
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Find multiple matching reference points for each iris section
WaveScan Image
Laser Image
Iris Registration Basic Principles
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Torsional AngleCalculate the torsional angles from
multiple measurements
Iris Registration Basic Principles
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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
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Pupil Centroid Shift Different Lighting Conditions
Diagnostic measurement (mesopic)Diagnostic measurement (mesopic) LVC Treatment (photopic)LVC Treatment (photopic)
As the pupil changes size, its centroid may not remain stationary, relative to the outer iris boundary
Outer Iris BoundaryOuter Iris Boundary
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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
Iris Registration Compensation for Pupil Centroid Shift
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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
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Iris Iris Registration WaveScan WaveScan AcquisitionAcquisition
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
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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
Iris Iris Registration WaveScan WaveScan AcquisitionAcquisition
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A distance of at least 1mm (preferably more) is recommended between the pupil boundary and the upper and lower eyelids
Iris Registration WaveScan Acquisition
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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
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Iris RegistrationIris RegistrationWaveScanWaveScan®® Acquisition Acquisition
Outer Iris Boundary
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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
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Iris Registration Iris Registration WaveScanWaveScan Acquisition
Surgeons must view the actual exam used for treatment designThe 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 laserAs 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 Eligible IR Not Eligible
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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
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Iris Registration Surgical Technique WARNING
As with any surgical procedure, it is ultimately and entirely theresponsibility of the surgeon to ensure that the CustomVue treatment loaded on the STAR S4 IRSTAR S4 IR System belongs to the correct eye of the correct patient positioned under the laserThe "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
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Iris 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
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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
Iris Iris Registration
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Iris Registration Optimal Iris Registration Optimal Surgical Environment EnvironmentOperative 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
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Optimal Surgical 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
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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
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Procedure should be performed at magnification 16x (the microscope dial may read 16 or 1.6, depending on the system microscope model)
Iris Registration Surgical Technique
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Significant cyclorotation can occur after the flap is lifted
Therefore, Iris Registration and ActiveTrak must be engaged AFTER the flap has been lifted
Iris Registration Surgical Technique
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Iris Registration Technique Activation of IR System
Doctor’s Keypad
IR ButtonIR Button
ActiveTrakActiveTrakButtonButton
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
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Iris Registration Technique Activation of IR SystemIR 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 IRIR will then automatically start when the ActiveTrak System is on and tracking
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Patient cooperation and fixation is critically important while IR is engagingAnything that interferes with patient cooperation and fixation while IR is engaging will • increase the time of IR capture• reduce the success of IR capture
Iris Registration Technique Activation of IR System
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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
Iris Registration Technique Activation of IR System
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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
Iris Registration Technique Activation of IR System
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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
Iris Registration Technique Activation of IR System
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Iris Iris Registration Technique Technique
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Optimizing Iris Registration Three strikes
Strike One
• Check Patient Alignment• Confirm Microscope Magnification at 1.6x• Focus on anterior stromal surface• Re-engage IR
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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
Optimizing Iris Registration Three strikes
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STAR Excimer Laser System Conventional Ablation Dimensions & Shapes
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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
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Variable Spot Scanning
• Blend ZoneVariable Slit Scanning
• Hyperopia• Hyperopic Astigmatism
Beam Shaping
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Ablation Dimensions & Shapes
Spherical Myopia• Standard Zone 6.0 mm• Larger Zone 6.5 mmMyopic Astigmatism (Ellipse)
• Standard Zone 6.0 x 4.5 mm (minimum minor axis)• Larger Zone 6.5 x 5.0 mm (minimum minor axis)
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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 axisLarger Zone treatment depth is 15-20% more than Standard Zone
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Ablation Dimensions & ShapesBlend 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
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Blend Zone Option with VSS Treatment Profile
1.0 mm 1.0 mm
Ablation Diameter
Blend ZoneBlend Zone
8.0 mm
Creates gradual slope from optical zone to un-ablated cornea
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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
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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
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Myopia/Astigmatism Treatment screen
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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)
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Myopia / Astigmatism Treatment ScreenA value must be entered in the astigmatism field even if it is zero
Results Field• Summarizes pulse rate, depth and number of pulses
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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
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Ablation Dimensions & Shapes
Hyperopia
• Ablation Diameter 9.0 mm• Correction Diameter 5.0 mm
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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
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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 mm0.8 mm
Optical zone - 5 to 6 mmOptical zone - 5 to 6 mm
Ablated area - 9.0 mmAblated area - 9.0 mm
Transition zoneTransition zone
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Hyperopia/Astigmatism Treatment Screen
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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
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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
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Cross-Cylinder Ablation Profile
Cylindrical Steepening with Cylindrical Flattening
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Treatment Preferences Page
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STAR Excimer Laser SystemActiveTrak System Software
Any default can be overwritten
Surgeon MUST verify all data in every field in every screen
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Patient Manager Patient Information Screen
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Select Treatment Button Pre-Op Screen
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Pre - Operative Examination Screen Refraction Warnings
and Yellow bar on bottom left of screen says“ No manifest refraction”
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Operative Parameters Screen
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Notes Screen
N.B., Epithelium
Removal is for
information on the
Operative Report
Only - Does Not
Control Treatment
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Epithelium Removal Screen
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Treat Button
Treat Button can only be
selected from treatment
screens
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Treatment Summary Screen
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