Customized IOLsCustomized IOLs--Post InsertionPost InsertionChristian A. Sandstedt, Ph.D.Christian A. Sandstedt, Ph.D.
Calhoun Vision, IncCalhoun Vision, IncPasadena, CAPasadena, CA
44thth International Conference of International Conference of Wavefront Sensing and Wavefront Sensing and
AberrationAberration--Free Refractive Free Refractive CorrectionCorrection
San Francisco, CASan Francisco, CAFebruary 15, 2003February 15, 2003
The Light Adjustable Lens (LAL)
The Light Adjustable Lens The Light Adjustable Lens (LAL)(LAL)
Clinical need and background
Description of technology
In-vitro testing and results
Examples and future work on higher order aberration correction
Clinical need and backgroundClinical need and background
Description of technologyDescription of technology
InIn--vitrovitro testing and resultstesting and results
Examples and future work on higher Examples and future work on higher order aberration correctionorder aberration correction
• Cataract surgery with IOL implantation is the most commonly performed surgery in patients over 65
• 50% of these patients require spectacle correction after insertion and refractive stabilization
Defocus, Lateral Displacement, Post-Operative Astigmatism (Unpredictable Wound Healing), Rotation.
• 98% of these are within ± 2 D.
• Cataract surgery with IOL implantation is the most commonly performed surgery in patients over 65
• 50% of these patients require spectacle correction after insertion and refractive stabilization
Defocus, Lateral Displacement, Post-Operative Astigmatism (Unpredictable Wound Healing), Rotation.
• 98% of these are within ± 2 D.
Clinical NeedClinical NeedClinical Need
Non-Invasive Alteration of IOL Power Post-OperativelyNonNon--Invasive Alteration of Invasive Alteration of
IOL Power PostIOL Power Post--OperativelyOperativelyFoldable IOL made of photosensitive material
Adjust IOL power post-operatively by treating with safe levels of light to alter its refractive properties
Foldable IOL made of photosensitive materialFoldable IOL made of photosensitive material
Adjust IOL power postAdjust IOL power post--operatively by treating operatively by treating with safe levels of light to alter its refractive with safe levels of light to alter its refractive propertiesproperties
Animation: Hyperopic Correction
Animation: Hyperopic Animation: Hyperopic CorrectionCorrection
Single Pass InterferometrySingle Pass Interferometry
Myopic CorrectionMyopic CorrectionMyopic Correction
Measurements made in double passThe number of interference fringes (OPD) proportional to the induced power change
Measurements made in double passMeasurements made in double passThe number of interference fringes (OPD) proportional to The number of interference fringes (OPD) proportional to the induced power changethe induced power change
Pre-irradiation +20 D LAL –2 D Correction
Sample In Vitro NomogramSample In Vitro NomogramSample In Vitro Nomogram
The intensity is kept constant and the time is varied The intensity is kept constant and the time is varied The intensity is kept constant and the time is varied
-2.0
-1.5
-1.0
-0.5
0.00 1 2 3 4 5 6 7 8 9
Dose #
∆D
iopt
ers
Method of LAL Optical Characterization: MTFMethod of LAL Optical Method of LAL Optical Characterization: MTFCharacterization: MTF
MTF measurements made in a wet cell with the ISO prescribed model eyeMTF of LAL comparable to commercial IOL
MTF measurements made in a wet cell with the ISO MTF measurements made in a wet cell with the ISO prescribed model eyeprescribed model eyeMTF of LAL comparable to commercial IOLMTF of LAL comparable to commercial IOL
0
0.2
0.4
0.6
0.8
1
0 50 100 150lp/mm
Mod
ulus
MTF LAL Post Lock-In
MTF Allergan Si40 IOL
MTF LAL Pre-Adjustment
MTF = 0.43 @100 lp/mm
Hyperopic CorrectionHyperopic CorrectionHyperopic Correction
Measurements made in double passThe number of interference fringes (OPD) proportional to the induced power change
Measurements made in double passMeasurements made in double passThe number of interference fringes (OPD) proportional to The number of interference fringes (OPD) proportional to the induced power changethe induced power change
Calhoun Vision LAL Preirradiation + 20.0 D
Calhoun Vision LAL + 2.0 D Correction
Future WorkFuture WorkInIn--Vitro AstigmatismVitro Astigmatism
Astigmatic Correction:3.50 D ± 0.15 Dof Toric Correction
Classic Astigmatic Wavefront
Multifocality
- Treatment of Presbyopia Without Need forAccommodation
- Embodiments- Diffractive Optics
- Refractive Optics- Central Add and Central Subtract- Repeating Zones (Allergan Array)
Calhoun CapabilitiesCalhoun Capabilities
Predictable Achievement of EmmetropiaMultifocal IOL Centered on Visual AxisCustomizable Zone SizeCenter Add and/or SubtractPotential Non Invasive Reversibility
Multifocality After Two Corrections
+2.0 D Add in Center 2 mm Zone Size
Patient with +22.5 D LAL –2.0 D Post-Op Myopic Error
Light Adjustment
In Situ Creation of MF
Removal of -0.5 D Of Power
Removal of –1.5 D Of Power
Light Adjustment
Digital Light Delivery DeviceDigital Light Delivery DeviceDigital Light Delivery DeviceBreadboard System Developed in Collaboration with Carl Zeiss-Meditech AGAllows Researcher/Physician Control of Applied Spatial Intensity Pattern
Digital Light Delivery DeviceDigital Light Delivery DeviceDigital Light Delivery Device
( ) θρ−ρ= 2cos34I 22Tetrafoil
Tetrafoil Bitmap Spatial Intensity Pattern for Input to the DMD
Digital Light Delivery DeviceDigital Light Delivery DeviceDigital Light Delivery Device- Tetrafoil Imprint
Spherical AberrationSpherical AberrationSpherical Aberration
CauseOPD between the paraxial and marginal rays
Different annular zones of a lens focus at different points along the optical axis
CauseCauseOPD between the paraxial and marginal rays OPD between the paraxial and marginal rays
Different annular zones of a lens focus at different Different annular zones of a lens focus at different points along the optical axispoints along the optical axis
Paraxial Focus
Marginal FocusBestFocus
Spherical AberrationSpherical AberrationSpherical AberrationTreatment Correction
Irradiation of an annular ring on the periphery of the LAL
Note the removal of ~2 fringes (1 Wave) of LSA
Treatment CorrectionTreatment CorrectionIrradiation of an annular ring on the periphery of the Irradiation of an annular ring on the periphery of the LALLAL
Note the removal of ~2 fringes (1 Wave) of LSA Note the removal of ~2 fringes (1 Wave) of LSA
Preirradiation 24 hours Post Irradiation
What The LAL Can DoWhat The LAL Can DoWhat The LAL Can Do
Correct spherical errors with high reproducibility and repeatibiltyMaintain optical quality through the entire treatment procedure Astigmatic correctionsCustomized BifocalityHigher order aberrations
All of these once it has been implanted in the eye!
Last SlideLast SlideLast Slide
Special Thanks
Calhoun Vision TeamDan Schwartz, MDShiao Chang, PhDJay Wilson, MSVeronica Jaramillo, PhD
Special ThanksSpecial Thanks
Calhoun Vision TeamCalhoun Vision TeamDan Schwartz, MDDan Schwartz, MDShiaoShiao Chang, PhDChang, PhDJay Wilson, MSJay Wilson, MSVeronica Jaramillo, PhDVeronica Jaramillo, PhD