Biometry for Premium IOLs 2015

Jack T. Holladay MD MSEE FACS Page 1 of 9

3/23/2015 JTH 1

The Promise of No Glasses

or Contact Lenses !

Jack T. Holladay, MD, MSEE, FACSClinical Professor of Ophthalmology

Baylor College of MedicineHouston, Tx WWW.AAO.ORG

0

AMERICAN ACADEMY OF OPHTHALMOLOGY

Financial Disclosure I have the following financial interests or relationships to disclose: Abbott Medical Optics: C; 

AcuFocus, Inc.: C,O; 

Alcon Laboratories, Inc.: C; 

ArcScan: C,O; 

Carl Zeiss Inc: C; 

Elenza: C,O; 

Oculus, Inc.: C; 

Visiometrics: C,O; 

Wavetec: C

3/23/2015 JTH 57

www.docholladay.com

Handouts

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Requirements Centration

Accurate Biometry – Optical

(IOL Master or LenStar)

Accurate K’s- Repeatable

4th Generation Formula (WTW)

Personalized Lens Constant

Eliminate Corneal Astigmatism

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Multifocal IOLOptimal Location

Cannot place on Pupil Center & Visual Axis (near P1) where axial ray is perpendicular to foveola.

Optimal location is different for each patient and somewhere between Pupil Center & P1.

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ClinicalAngle Kappa

Pupil Centerto Visual Axis

NOSE

Biometry for Premium IOLs 2015

Jack T. Holladay MD MSEE FACS Page 2 of 9

3/23/2015 JTH 9

Horizontal Angle & Alpha & Kappa

OCPC

VA

< α< Κ

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Good centration ,optimal

optical performance?

Decentration: halos Poor vision for farand near

Courtesy Paolo Vinciguerra M.D.

3/23/2015 JTH 11Diffraction Rings are perfectly concentric with patient’s pupil

Courtesy Paolo Vinciguerra M.D.

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3/23/2015 JTH 133/23/2015 Jack T. Holladay, MD, MSEE, FACS9 T  S1 SS7 3/23/2015 JTH 143/23/2015 Jack T. Holladay, MD, MSEE, FACS

9 T  S1 SS7

Biometry for Premium IOLs 2015

Jack T. Holladay MD MSEE FACS Page 3 of 9

Regression plot between the photic phenomenon of haloes (x axis) and the 

kappa angle (y axis).

(R2 = 0.26, P = 0.029)

N = 37Zero = 25Non zero = 12

Regression plot between the photic phenomenon of glare (x axis) and the kappa 

angle (y axis)

(R2 = 0.26, P = 0.033)

N = 37Zero = 30Non zero = 7

Horizontal Angle & Alpha & Kappa

OCPC

VA

< α< Κ

BEST CENTRATIONOF IOL

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Horizontal Angle & Alpha & Kappa

PCVA

< Κ

Angle Kappa on IOL Master, LenStar and penlight ~ 0.33 mm

If > 0.70 mm then concern!

●Karhanová M, Marešová K, Pluháček F, Mlčák P, Vláčil O, Sín M. Cesk Slov Oftalmol. The importance of angle kappa for centration of multifocal intraocular lenses. 2013 Jun;69(2):64-8. [Article in Czech]● G Prakash, DR Prakash, A Agarwal, DA Kumar, A Agarwal and S Jacob. Predictive factor and kappa angle analysis for visual satisfactions in patients with multifocal IOL implantation. Eye (2011) 25, 1187–1193

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Ideal LocationLeft Eye

Between Pupil Center and Purkinje Image 1 (Vertex Normal Light Reflex)Slightly NASAL to Pupil Center (~ 0.15 mm) 3/23/2015 JTH 20

LENSTAR – HAAG-STREIT

Biometry for Premium IOLs 2015

Jack T. Holladay MD MSEE FACS Page 4 of 9

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IOL MASTER - ZEISS

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Subtractfrom Ascanmeasured

Axial Length~ 0.8 mm

Zeiss - IOL Master - 2000Zaldivar-Holladay JCRS May 2000

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J Cataract Refract Surg 2011; 37:2018–2027

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Linear Regression to compensate for AVERAGE Index of Refraction in Long Eyes

Measured 36 34 mm

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Requirements

Accurate Biometry – IOL Master

Accurate K’s- Repeatable

4th Generation Formula (WTW)

Personalized Lens Constant

Eliminate Corneal Astigmatism

Biometry for Premium IOLs 2015

Jack T. Holladay MD MSEE FACS Page 5 of 9

3/23/2015 JTH 27

IOL Power Calculations Pentacam can measure FRONT &

BACK SURFACE POWER

Can Calculate: Equivalent K-Reading (EKR)

65% Mean, Peak & Average

NET POWER3/23/2015 JTH 28

EKR Reports Keratometry value but adjusts

for Back Surface Power from Normal (Current IOL Formulas)

If corneal front surface is 7.5 mm (45 D), but if back surface -0.3 D > normal:

EKR = 45.0 – 0.3 = 44.7 D

Note: Net Power = 43.3 D

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J Cataract Refract Surg Feb 2015; 41:339–347

3/23/2015 JTH 30Holladay Report Equivalent K-Reading

EKR65

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IOL Calcs – Abnormal Cornea(Use 65% MEAN EKR) Post Refractive Surgery

Post PKP

Keratoconus

Corneal Scar

Any Irregular Astigmatism

Biometry for Premium IOLs 2015

Jack T. Holladay MD MSEE FACS Page 6 of 9

3/23/2015 JTH 33

Use 65% Mean EKR( @ 4.5, 4 & 3 mm zones)

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Normal LASIK RK41 to 44 D3 D Range

36 to 41 D5 D Range

32 to 45 D13 D Range

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POST LASIK

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Post LASIK CALC Kmean = 39.8 D

Used 39.8 D => SEQ = +1.12 D

(+1.00 + 0.25 X 155 = 20/20)

65% mean = 38.8 D => +0.12 D

Use 65% mean K

3/23/2015 JTH 37

Conclusions EKR – Use 65% Mean for all

IOL Calcs

Look @ smaller zones than 4.5 mm if pupil very small

(< 3.0 mm in dim light)3/23/2015 JTH 38

Requirements

Accurate Biometry – IOL Master

Accurate K’s- Repeatable

4th Generation Formula (WTW)

Personalized Lens Constant

Eliminate Corneal Astigmatism

Biometry for Premium IOLs 2015

Jack T. Holladay MD MSEE FACS Page 7 of 9

3/23/2015 JTH 39

Vergence Formula

IOLAL ELP

DPostRxV

K(Post R)ELP

1336 13361336

10001000

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CONCLUSION: 9 EYES

Ant

erio

r S

egm

ent S

ize

Axial LengthShort Normal Long

Large

Normal

Small

Megalocornea Large Eye

+ axial Megalocornea Buphthalmos

hyperopia Megalocornea

+ axial myopia

axial hyperopia normal axial myopia

Small eye Microcornea

Nanophthalmia Microcornea + axial mopia

(20%)

(10%)(2%)

(2%)

(80%) (96%) (90%)

(0%)

(0%)

3/23/2015 JTH 42

Measurements taken forPredictors of ELP

Axial Length

Average K (Pre Ref)

Horizontal WTW

ACD

LT

Pre-opRefraction

Age

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FORMULA PERFORMANCE

15 20 25 300

12

34

56

Axial Length (mm)Mea

n A

bsol

ute

Err

or (

D)

Holladay 1Hoffer QSRK/THolladay 2

N = 997

3/23/2015 JTH 44

Requirements

Accurate Biometry – IOL Master

Accurate K’s- Repeatable

4th Generation Formula (WTW)

Personalized Lens Constant

Eliminate Corneal Astigmatism

Biometry for Premium IOLs 2015

Jack T. Holladay MD MSEE FACS Page 8 of 9

3/23/2015 JTH 45

Personalized Lens Constant Never use Manufacturer’s Constant

except to start 20 to 40 cases and continue Factors IOL Style Lens placement Post op medications Biometer, keratometer, …

3/23/2015 JTH 46

Requirements

Accurate Biometry – IOL Master

Accurate K’s- Repeatable

4th Generation Formula (WTW)

Personalized Lens Constant

Eliminate Corneal Astigmatism

TORIC IOL Calculations Commercial Calculators use a constant ratio (1.46) for

the corneal cylinder to the IOL cylinder

Exact Calculation depends on IOL SEQ Power and ELP… to correct 2D of corneal astigmatism

10 D IOL => 3.5 D Cylinder

22 D IOL => 2.9 D Cylinder

34 D IOL => 2.4 D Cylinder

A 1.1 D difference from 10 D to 34 D!3/23/2015 JTH 48

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Toric Optimization

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Biometry for Premium IOLs 2015

Jack T. Holladay MD MSEE FACS Page 9 of 9

3/23/2015 JTH 51

PREOP 6 D Toric IOLLEF

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PREOP 6 D Toric IOL -- ODLEF

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PREOP 6 D Toric IOL -- OSLEF

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!Thank You!