Refractive Cataract Surgery: It's Complicated

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Refractive Cataract SurgeryIt’s Complicated!! Alan R. Faulkner, MD, FAAO Aloha Laser Vision Honolulu, Hawaii, USA

Disclosures Alcon- speaker bureau

B&L Pharmaceuticals- speaker, advisory boards LenSx-clinical studies

Traditional Cataract Surgery All cataract surgery since the implantation of the first IOL has had a desired refractive outcome However the tolerance of refractive deviation from planned is fairly high and is based more on avoiding significant anisometropia than UCVA Patients expect to wear glasses and are happy with improved BSCVA and any improvement in UCVA is a bonus!

Refractive Cataract Surgery Any cataract, (or lens based) procedure that seeks to reduce or eliminate spectacle independence Surgeon must clearly understand the patient’s goals and expectations

Surgeon must then reset the patient’s goals and expectations to today’s “reality” The tolerance for deviation from planned refractive outcome is much lower, often approaching zero depending on IOL type

Refractive Cataract Surgery In the absence of a perfect solution we must choose: Patient may only care about UCDVA or UCNVA More often desire wider range of vision Monovision or blended vision Multi-focal IOL’s Restoration of accommodation

All IOLs and combinations of IOLs unfortunately have visual compromises with none offering full range of vision!

We must attempt to achieve the result with the least number of procedures, risks, and compromises

My Toys Used on Every Refractive Case Clinical IOL-Master-now Lenstar Pentacam Magellan Cirrus OCT

Surgical LenSx femto-laser ORA-intraoperative aberrometry Alcon Refractive Suite- FS-200/EX-500-as needed

Pre-Operative PlanningIt’s Complicated! IOL calculations Axial length by optical inferometry or immersion very accurate- we are ok there Keratometry/astigmatism assessment IOL-M, Magellan, and Pentacam results most often vary in both the axis and the power. Which one is right? What about the effect of posterior cornea curvature? All extremely sensitive to ocular surface changes!!

IOL formulas all flawed at certain axial lengths and by failure to account accurately for ELP or other variables

Intraocular Lens Power Calculations 1977- state of art – Add +19D to pre-cataractous refraction Decade later ±1D considered good 2006 UK Study “Benchmark Standards for refractive outcomes after NHS cataract surgery” –nml eyes 55% within ±0.5D, 85% within ±1D

BUT……This is not good enough!

Warren Hill, MD “Today, by carefully optimizing the individual component parts of IOL power calculations, combined with advanced surgical techniques, it is possible to be within ±0.50 D for better than 70 percent of surgeries and ±1.00 D for better than 90% of surgeries.” BUT…….This is not good enough!

Surgical Execution: It’s Complicated! Need perfect surgery!!! Femto-Laser Capsulorhexis more precise but: Should be centered on visual axis/undilated pupil, as should the IOL Difficult to know where that is in dilated pupil/often decentration of rhexis vs. IOL final position

Femto-Laser LRI-more precise but: Relies on pre-op assessment of astigmatism Should be centered on visual axis/undilated pupil Studies show alignment of LRI’s and t-IOLs based on marking not that good- 3.3% loss per 1 deg error Less predictable than excimer correction!

ORA-Intraoperative Aberrometry Provides aphakic wavefront generated refraction Prediction of IOL power by proprietary formulas that factor axial length Provides guidance for power selection and axis alignment of toric IOLs Guidance for management of LRI’s

ORA (Optiwave Refractive Analysis)

VerifEye VerifEye is a new monitoring hardware upgrade that continuously provides refractive information resulting in more refined outcomes

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Copyright © 2013 WaveTec Vision® 4.14.13

Lens Stability

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Results ORA + Femto One Center:

84%

88%

92%

96% 95%

100%

98% 98%100%

65% 61% 63%

≤ 0.25 D

≤ 0.50 D

≤ 0.75 D

≤ 1.00 D

ORA & Non Femto

ORA + Femto

ORA w/ VerifEye + Femto

N=122, Mean 0.27 ± 0.29

N=115, Mean 0.26 ± 0.24

N=26, Mean 0.25 ± 0.15

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MASKET STUDY Purpose – Evaluate ORA spherical refractive outcomes as compared with usual method with 5 standard IOL Formulae Methods – Pre-Op IOL Master (500), Lenstar for Toric IOLs Holladay 1 Holladay 2 Haigis Hoffer Q SRK – T

Final IOL power selected from above or ORA if > .5 D ^

Surgical Technique ORA 2.2 mm micro-coaxial phacoemulsification OVD fully removed with completion of cortex removal CCI hydrated IOP established between 15 – 20 mmHg by tonometry (Kratz-Terry - Ocular Instruments) ORA Aberrometry performed – 3 measurements OVD instilled, LECs polished, IOL implanted

Study Design 200 Consecutive Cases with WaveTec ORA Device For current analysis only “best case eyes” with Alcon SN aspheric series “in the bag” IOLs included; VA >20/30 Post Refractive or Corneal Surgery (any type) excluded 131 Eyes for analysis: 56 eyes (42.7%) changed by ORA, 75 unchanged Spherical Manifest refraction recorded at 2 -4 weeks post-op

Results – Difference from Intended Dioptric Target Changed by ORA

Unchanged

N = 56

N = 75

Mean Error - 0.03 D

Mean Error +0 .08 D

SD = .296

SD = .291

Range -1.0 to +1.0

Range -0.75 to +0.75

94.6% +/- 0.5 D

94.7% +/- 0.5D

100% +/- 1.0 D

100% +/- 1.0 D

Pitfalls of ORA Must keep ocular surface in good condition

Must normalize IOP and avoid over hydration of CCI If Femto LRI’s placed then useful to determine whether to open incisions But if axis/power not c/w LRI placement????? Better than pre-op IOL calculations in post-refractive eyes but not as good as virgin eyes

Post Surgical It’s Still Complicated! Post-op OSD is a significant issue Often responsible for poor VA and “bizarre” Rx

Enhancement Techniques are no panacea in post-cataract age group with increased healing time/complications Further exacerbation of OSD Severe TLS (transient light sensitivity) Prolonged flap edema with LASIK Slow healing and poor epithelial regrowth with PRK

Disconnect between K’s and Refraction still exists despite pseudophakia

Conclusion Refractive Cataract Surgery is coming of age but it is still a mere teenager lacking maturity

Improvements will come with: Better pre-op diagnostics that include the ability to track and register the eye for more accurate astigmatism correction Adjust intra-op for centroid shift for rhexis and IOL placement Better IOL designs that will hopefully: Restore accommodation negating the need for multifocality Reduce the need for incisional techniques for astigmatism

Improved management of OSD-both iatrogenic and existing