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FacultyAchieving Proper Centration and Alignment for VisionCorrection in Intraocular and Keratorefractive SurgeryASCRS and ASOA Symposium and Congress George O. Waring, IV, M.D.- Storm Eye InstituteNew Orleans 2016- Medical University of South Carolina- Magill Vision CenterMt Pleasant, SCDaniel H. Chang, M.D.George O. Waring, IV, M.D.John P. Berdahl, MDEmpire Eye & Laser CenterBakersfield, CAStorm Eye Institute / Magill Vision CenterMedical University of South CarolinaMt Pleasant, SCVance Thompson VisionSioux Falls, SD Financial Disclosure Accelerated Vision, AcuFocus, Inc., Alcon,Allergan, AMO, Bausch & Lomb, CXL USA,RevitalVision, FocalPoint, Asia, Gerson LehrmanBiomedical Council, Riechert, SRD Vision,VisiometricsMonday, May 9, 20161Faculty2Faculty John P. Berdahl, M.D. Michael Greenwood, M.D.- Vance Thompson VisionSioux Falls, SD- Vance Thompson VisionSioux Falls, SD- University of South Dakota School of Medicine Financial Disclosure- No financial interests Financial Disclosure- Alcon, Allergan, AMO, Avedro, Bausch and Lomb,Clarvista, Digisight, Envisia, Equinox, Glaukos, NewWorld Medical, Omega Ophthalmics, Ocular SurgicalData, Ocular Therapeutix, Vision 5, Vittamed34

FacultyCourse Outline Introduction (Chang)- Importance of centration andalignment Daniel H. Chang, M.D.- Empire Eye and Laser CenterBakersfield, CA- Ocular axes and angles- Purkinje images Centering and aligningkeratorefractive procedures Financial Disclosure- Abbott Medical Optics, Allergan, Carl Zeiss Meditec,ClarVista Medical, Mynosys Cellular Devices, OmegaOphthalmics, Rapid Pathogen Screening Centering and aligningintraocular procedures- Diffractive and Toric IOLs (Chang)- Toric IOL re-alignment (Berdahl) Discussion / Conclusion- Laser Vision Correction (Waring)- Corneal inlays (Waring)56IOL CentrationIntroduction Good centration importantImportance of centration and alignment- Maximize visual quality- Minimize visual side-effects Aspheric IOLs- Advantage lost when 0.8 mm decentration Diffractive multifocal IOLsIntraoperative- Effects not yet quantified- “Scapegoat” to explain why some patients with goodSnellen VA are unhappyPostoperative78

IOL CentrationDefinitionIntroduction Laboratory studiesOcular Axes and Angles- Optical center or pupil (dilated) center- Scheimpflug or Purkinje devices to find IOL center Clinical observation- Monofocal IOLs Edge not seen in pupil- Multifocal IOLs Pupil centerDecentered Multifocal IOL- Rings concentric with pupil* What about visual axis?9Ocular AxesOcular Axes and Angles Ocular Axes10Optical Axis Ocular Angles- Optical Axis- Angle α (alpha) Alignment of all 3 Purkinje images- Pupillary Axis Optical Axis to Visual AxisOptical Axis- Angle κ (kappa) Pupil center / orthogonal to cornea Pupillary Axis to Line of Sight Originally: Pupillary Axis to Visual Axis- Line of Sight Pupil center to fixation pointFixationPoint- Angle λ (lambda)PIVPIPIII* Pupillary Axis to Line of Sight- Visual Axis Nodal point to fixation point Less commonly used than angle κAlignment of all 3 Purkinje imagesEye model / research definitions werenot intended for intraocular surgery use.1112

Ocular AxesOcular AxesOptical AxisPupillary AxisOptical FixationPoint**Pupil center / orthogonal to corneaUndefined with lens / IOL tilt or decentration(Purkinje images do not align)13Ocular Axes14Ocular AxesPupillary AxisPupillary AxisFixationPointLine of SightPupilCenterPupilCenterFixationPoint**Line of SightFoveaPupil center to fixation pointChanges with pupil centroid shift(Can occur with dilation)1516

Ocular AxesOcular AxesLine of SightVisual e of Sight*Visual AxisNodalPointFoveaCornealVertexNodal point to fixation pointChanges with pupil centroid shift(Can occur with dilation)17Ocular Axes18Ocular AxesVisual AxisAngle αHas been defined as0, 1, or 2 Nodal PointsOptical AxisPIVFixationPoint*N N’Visual AxisNodalPointFixationPointFoveaAngle α* Visual AxisPIPIIINodalPointFoveaOptical Axis to Visual AxisWhere is the nodal point?Theoretical concept in paraxial eye model1920

Ocular AxesOcular AxesAngle κ (original definition)PupillaryFixationPointAngle λ / Angle κ (new definition)PupillaryPupilCenterAxisAngle κ* Visual AxisFixationPointNodalPointPupillary Axis to Visual AxisAxisPupilCenterAngle κ (or λ)*Line of SightPupillary Axis to Line of Sight21Chang DH, Waring IV GO, The Subject-Fixated Coaxially Sighted Corneal Light Reflex: a ClinicalMarker for Centration of Refractive Treatments and Devices. Am J Ophthalmol. 2014;158:863-74.2322Chang DH, Waring IV GO, The Subject-Fixated Coaxially Sighted Corneal Light Reflex: a ClinicalMarker for Centration of Refractive Treatments and Devices. Am J Ophthalmol. 2014;158:863-74.24

Ocular AxesOcular Axes and AnglesFoveal Fixation AxisProblems with Application Cannot be defined in some (all?) eyes- Somewhat useful to communicate conceptsLine that connectsthe Fovea and the Fixation Point How to translate into clinical and surgical practice- How do we find the visual axis or pupillary axis on a real eye?FixationPoint- What about pupil centroid shifting?*Foveal Fixation Axis (FFA)FoveaCornealVertex*In concept onlyUnless there is perfect alignment of all 4 refractivesurfaces, no light ray goes unbent25Ocular Landmarks for Positional Reference26Ocular Landmarks for Positional ReferenceNeedsCandidates Feasibility in identification (of landmarks) Pupil (center) Precision in definition Purkinje images- May need additional qualifications Limbus (center) Lighting conditions Anatomical apexes Viewing / light source arrangement Fixation Consistency in usageWe need a consistentlyregistered coordinate system2728

Ocular Landmarks for Positional ReferenceOcular Landmarks for Positional ReferencePupil CenterPurkinje ImagesNeed to specifylighting conditionPhotopicScotopicIntraoperative29Need to specifyfixationPostoperative30Purkinje ImagesOcular Landmarks for Positional Reference Reflections from the light-transmitting interfaces Four Purkinje reflectionsPurkinje Images- PI: anterior cornea- PII: posterior cornea- PIII: anterior lens/IOL- PIV: posterior lens/IOLPIIIPI / PIIPIVTecnis MultifocalAcrysof IQ ReSTORCrystalens Five-0ZMB00SN6AD1AT50SE3132

Purkinje Images: PIPurkinje Images: PI PI: Reflection from anterior corneal surface- Corneal light reflex Intraoperative appearance Air / anterior cornea (tear film)- Depends on microscope lightconfiguration Bright, upright image- Applications Zeiss Opmi Lumera has threelights Keratometry- Broad illumination beam Corneal topography /Video keratoscopy Commercial eye trackingapplicationsPhakic- Stereo coaxial illumination (SCI)Corneal Light Reflex- Unaffected by surgicalinstrumentationVideo keratoscopy- Altered by shape of corneaAphakic3334Purkinje Images: PIIPurkinje Images: PIII PII: Reflection from posterior corneal surface PIII: Reflection from anterior lens / IOL surface- Specular reflection- Not seen in phakic eyesPIII Posterior cornea : aqueous Aqueous : anterior lens / IOL Dim, upright image Variable brightness, typically upright- Can be seen intraoperatively with air in the AC- Depends on IOL power- Fringing with diffractive rings- Application- “Cat’s eye reflex” Specular microscopy High index materials Flat anterior IOL curvaturePosterior Diffractive RingsAnterior Diffractive RingsSpecular Microscopy3536

Purkinje Images: PIV PIV: Reflection from posterior lens / IOL surface- Faintly visible in some phakic eyesPIV Posterior IOL : aqueous / capsule / vitreous Variable brightness, typicallyinverted- Depends on IOL power- Fringing with diffractive rings- Stretched by toric surface- Affected by IOL chromophorePosterior Diffractive RingsAnterior Diffractive Rings3738Z-axisPIV PIPIV PIPIIIPIVPIIICorneaPIIOL39PIII40

Centration)and)Keratorefractive)SurgeryPurkinje VCornea,anterior surfaceCornea,posterior surfaceLens/IOL,anterior surfaceLens/IOL,posterior surfaceSeen ClinicallyYesRarelyYesYesImage LocationAnterior lens/IOL—Anterior vitreousCorneal �Dim to very brightMedium to brightOrientation*Upright—Upright (usually)Inverted leasant,)SC)*PIII and PIV dependent on IOL Economic ):51P62.Source: CIA World Factbook for Population/Age & Market Scope2Waring)IV,)GO

)GOCentration)guidance)systemInlay)Placement Target)inlay)placement)over)the)1st)Purkinje) ween) hin&300µns&from)desired)positionWaring)IV,)GO

PrePOp)Purkinje)Results Provided)centration)planning)metrics:)– Purkinje&vs&Pupil&Cord&Length&(μm))– Purkinje&vs&Pupil&Angle&(degree))– PostPOp)Purkinje)Results Provided achieved centration metrics:– Purkinje vs Pupil Cord Length(μm)– Purkinje vs Pupil Angle (degree)– Purkinje vs Pupil (x/y distance inμm, direction)– Inlay vs Pupil (x/y distance in μm)– Inlay vs Purkinje (x/y distance pAfter)RecentrationDay)1)PostPOp)20/25,)J3Inlay Location511 microns temporal98 microns superiorInlay Location9 microns temporal90 microns superiorWaring)IV,)GOInlay Location511 microns temporal98 microns superiorInlay Location9 microns temporal90 microns superiorWaring)IV,)GO

Case)1:)Centration)Planning yPrePOp)Data:)1) Purkinje&vs&Pupil:) P375μm)(x)) P219μm)(y))2) Cord&Length:&435μm) xCORD&LENGTH&435μmPUPIL&CENTER1) Purkinje&vs&Pupil:) 110μm)(x)) 50μm)(y))2) E&300μmPURKINJE&VS&PUPIL& Y375μm&(X)& Y219μm&(Y)0μm)(x))0μm)(y) yPrePOp)Data:)ODInlay)Placement)Target:)1) Inlay&vs&Pupil:& P186μm)(x)) P110μm)(y))2) Inlay&vs&Purkinje:& 186μm)(x)) ay)Placement:)1) Inlay&vs&Pupil:& 110μm)(x)) 50μm)(y))2) Inlay&vs&Purkinje:& 0μm)(x)) 0μm)(y))OSPURKINJE&VS&PUPIL& 110μm&(X)& 50μm&(Y) orrectionCourtesy,of,Ray,ApplgegateWaring)IV,)GO

Thank&YouSummary refractive)surgery) natomy)aids)in)successful)placement)– Similar)to)planning)with)topography) New)diagnostic)and)intraoperative)technology) ww.georgewaringiv.com– LVC) Presbylasik)– MFIOLsWaring)IV,)GOIdentifying Ocular Axes: ClinicalUse Purkinje ImagesCentering and aligningintraocular proceduresPupil CenterDiffractive Multifocal IOLsSubject FixatedCoaxially SightedCorneal LightReflex4243

Identifying Ocular Axes: Clinical2D projection 2D anterior segment imaging- Precise X-Y axis information- No depth (Z-axis) information- Pupillary axis and Line of sightare represented as samecoordinate on the imageThe Corneal Light ReflexesBut are they?Chang DH, Waring IV GO, The Subject-Fixated Coaxially Sighted Corneal Light Reflex: a ClinicalMarker for Centration of Refractive Treatments and Devices. Am J Ophthalmol. 2014;158:863-74.44Ocular Landmarks for Positional Reference45Ocular Landmarks for Positional Reference2D projectionPupillaryFixationPoint2D projectionAxisPupillaryPupilCenterAngle κ*Foveal-Fixation lCenterLine of Sight*?Foveal-Fixation AxisClinical / Surgical ViewFoveaCornealVertex(CSCLR)Line of Sight is most accuratedescriptor of pupil location butconnotes the wrong concept.Where is the systembeing viewed from?4647

Ocular Landmarks for Positional ReferenceOcular Landmarks for Positional ReferenceSF-CSCLR AxisSF-CSCLR Axis and TiltThe Subject-Fixated CoaxiallySighted Corneal Light Reflex(SF-CSCLR) AxisFixationPoint*SF-CSCLR AxisNow that we have an axis, wecan begin to study tilt.SF-CSCLR?FixationPointFovea*SF-CSCLR AxisSF-CSCLR?FoveaThe SF-CSCLR / SF-CSCLR axiscould serve as the reference pointfor centration and tilt48Ocular Landmarks for Positional Reference49Ocular Landmarks for Positional ReferenceSF-CSCLR AxisChord mu (µ) Instead of an angle, the distance between SF-CSCLR and Pupil Centeris chord displacement Specify as a vector- From SF-CSCLR to Pupil CenterFixationPoint- DistanceLine of Sight*SF-CSCLR AxisSF-CSCLR?- AngleFovea Specify lighting conditions / dilation statusDisplacement between SF-CSCLRand Pupil Center is now defined!5051