Arthur Cummings FRCSEd

Transcription

1 How to Improve your Refractive Cataract Surgery Outcomes by Skilful Interpretation of Corneal Mapping Course IC-16 ESCRS Copenhagen 10 th September 2016 Consultant for Alcon / WaveLight/TearLab Arthur Cummings FRCSEd Wellington Eye Clinic, Dublin, Ireland

2 AIMS of Course Help manage refractive expectations of cataract surgery patients Help with managing toric IOL s Help with LRI s, OCCI s, effect of incision size and architecture Help with selecting multifocal IOL candidates

3 Why address astigmatism? Astigmatism is the KEY factor for success with multifocal IOL s Correcting astigmatism provides better UCVA, BCVA for distance and near Glasses that may be required are lighter, cheaper and easier to wear / get used to

4 What is Refractive Cataract? The intended outcome is emmetropia The intended outcome has addressed astigmatism The intended outcome may have addressed presbyopia too depending on patient wishes (multifocal IOL, monovision) The patient is free of glasses for at least distance vision (monofocal, emmetropia) or completely free of glasses

5 Devices Placido disk (in relative detail) Scheimpflug (in relative detail) Cassini (Introduction)

6 Topolyzer (Keratograph) Placido disk Tear film reflections Central scotoma where camera is situated Auto-capture, very repeatable

7 Oculyzer (Pentacam) Scheimpflug camera Captures scatter so does not see tear film but corneal surface No central scotoma Auto-capture, very repeatable

8 Diagnostic Applications Screening for IOL s (toric, multifocal) Screening for corneal health Screening for AC parameters

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10 Cassini Corneal Topographer Multi-spectral LED technology from i-optics Given the faster acquisition time and insensitivity to radial aberrations, corneal astigmatism is

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13 Cassini and Toric IOL s Arthur Cummings Wellington Eye Clinic

14 How does the itrace work? Simultaneous corneal topography and whole eye wavefront mapping Refraction Can separate corneal from intra-ocular optics Can therefore help manage post-op toric IOL s

15 6/ /+0.25 X42 6/10

16 Summary Value of adding posterior corneal data is understood What about the geometry and geography of the crystalline lens and the final position and orientation of the IOL? Mirricon from ClearSight may have more answers?

17 IOL Calculations Pre-Operative

18 Lenstar radius achieves a Mean Prediction Error of -0.02±0.52 D Pentacam radius achieves a Mean Prediction Error of 0.22±0.68 D Results Perfect eye, Mean Prediction Error ± Standard deviation Lenstar vs Pentacam

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20 Pre-Operative IOL calculations IOL type

21 biconvex Results Scenario III: Average Eye, Acrylic vs. Silicone convex-plano plano-convex Acrylic IOLs are considerably less affected by IOL design, whereas silicone IOLs exhibit a much higher dependency, with the poorest results obtained for convex-plano IOLs.

22 Pre-Operative IOL calculations IOL type Incision type: Scleral, limbal, corneal

23 Pre-Operative IOL calculations IOL type Incision type Incision shape: 3 step, 2-step, straight-in

24 Pre-Operative IOL calculations IOL type Incision type: Scleral, limbal, corneal Incision shape: 3 step, 2-step, straight-in Incision size: <2mm, 2.2mm, 2.5mm, 2.8mm, >2.8mm

25 Pre-Operative IOL calculations IOL type Incision type: Scleral, limbal, corneal Incision shape: 3 step, 2-step, straight-in Incision size: <2mm, 2.2mm, 2.5mm, 2.8mm, >2.8mm Incision location: Superior, Temporal, on axis

26 Incisions and OCCI s on steepest axis My OCCI nomogram: Astigmatism < 0.8D Single 2.75 mm incision Make slightly shallower to allow slippage Astigmatism 0.8D < X < 1.2D OCCI 2.2mm Astigmatism 1.2D < X < 1.5D OCCI 2.75mm Astigmatism 1.5D < X < 2.0D OCCI 3.0mm OCCI = Opposite Clear Corneal Incision

27 Toric IOL`s vs. OCCI s over 3 Months Preoperative Week 1 Month 1 Month 3 Data courtesy of Kjell Gunnar Gundersen MD, PhD (Norway) Toric IOL`s Incisions

28 Superior Cataract Incision

29 Good placement of incision. Incision enlarged in width. Incision decreased in length. Decreased corneal astigmatism by 1.3 D

30 Increased corneal astigmatism by 0.30 D Incision incorrectly placed

31 Temporal Cataract Incision

32 Good placement of incision Reduced corneal astigmatism by 0.70 D

33 Increased corneal astigmatism by 1 D Poor choice of incision

34 Cataract On-Axis Incision

35 Reduced corneal astigmatism by 1.30 D OCCI s with 2.2mm

36 Pre-Operative IOL calculations IOL type Incision type: Scleral, limbal, corneal Incision shape: 3 step, 2-step, straight-in Incision size: <2mm, 2.2mm, 2.5mm, 2.8mm, >2.8mm Incision location: Superior, Temporal, on axis

37 Shallow Anterior Chambers Mostly hyperopes Mostly shorter eyes 3 critical values AC volume < 100 mm 3 ACD < 2.1mm AC angle < 26 degrees

38 Post-Operative Detecting tight sutures Detecting wound gape Detecting irregular astigmatism Guiding suture removal with the Pentacam

39 Thank You for Your Attention