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Evaluation & Surgical Correction of Astigmatism

Evaluation & Surgical Correction of Astigmatism. Jean Luc Febbraro MD Rothschild Foundation Paris France. jeanluc@febbraro.net. Evaluation & Surgical Correction of Astigmatism. Financial disclosure Alcon Laboratories: C, Croma: C Bausch & Lomb Surgical: C,L.

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Evaluation & Surgical Correction of Astigmatism

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  1. Evaluation & Surgical Correction of Astigmatism Jean Luc Febbraro MD Rothschild Foundation Paris France jeanluc@febbraro.net

  2. Evaluation & Surgical Correction of Astigmatism Financial disclosure Alcon Laboratories: C, Croma: C Bausch & Lomb Surgical: C,L

  3. Surgical Correction of Astigmatism • Evaluation & Principles • Prevalence & Evolution • Cataract incisions SIA

  4. Evaluation of Astigmatism • K-readings • 2mm central • Topography • Placido, Scheimflug (cornea > 2mm) • Aberrometers (cornea, internal) • Refraction • Total astigmatism (subjective, objective)

  5. Evaluation of Astigmatism • Topography (placido) • Precise measurement • Magnitude, axis • Symmetry • Regularity • Detection • K. fruste • Pellucid Deg.

  6. Evaluation of Astigmatism • Aberrometers (Hartman-Shack, OPD) • Precise measurement • Lower order ab. (Sph, cyl.) • Higher order ab. (coma, trefoil, sph. aberrations) • Distinction • Total, internal

  7. Evaluation of Astigmatism • Refraction (Subjective, objective) • Perfect match required • Subjective • (Sph, cyl) • Objective • (Sph, cyl & HOA) • Enable WF ablation

  8. Astigmatic Correction & Cataract Patients • Surgical options: • Incisional techniques • LRI, AK • Toric IOLs • Laser vision correction • PRK, LASIK

  9. Astigmatic Correction & Incisional Techniques • Principles: • The cornea flattens over an incision • Transverse incisions increase the radius of curvature in one meridian only • The flattening effect increases as incisions approach the visual axis

  10. Astigmatic Correction & Incisional Techniques • Coupling: • The flattening effect of a transverse incision is associated with a steepening effect 90° away. • Coupling ratio tend to be one to one. • The spherical equivalent remains unchanged.

  11. Astigmatic Correction & Incisional Techniques • Principles: • Incisions are always placed on the steep meridian. • The longer and deeper the incision the greater the effect. • The older the patient the greater the effect.

  12. Astigmatic Correction with LRI • LRI / PRI • Placed on the steepest meridian • Located at the limbus (9.0-11.0-mm OZ) 44 42

  13. Astigmatic Correction with LRI • Principles • Flatten the steepest meridian • Steepen the axis at 90° • Coupling ratio 1:1 42 43 44 43

  14. Astigmatic Correction: LRI / AK • LRI: pros • Less irregular astigmatism • Less chance of perforation • Convenient technique • Easy to perform • Intraoperatively

  15. Astigmatic Correction: LRI / AK • LRI: cons • Limited astigmatic correction • Regression • Variability of results

  16. Astigmatic Correction: LRI • Instruments: simple kit • Axis marker • 0.12-caliber forceps • Diamond knife • Preset (600 microns) • Micrometer

  17. STUDY • 46 eyes, 30 patients (age: 72 + 10 A) • 3.2 mm CCI, Steep axis • Preset 600 µ diamond knife • Limbal relaxing incisions • Preop Corneal Astig.: 1.66 + 0.65 D (0.75 to 3) • Follow up: 6 M

  18. Results:Astigmatism pre / postop Corneal Astigmatism (D)

  19. LRIs: Tips & Tricks Placement of incisions • Axis • 10° off: -33% • 15° off: -52% • Constant orientation • Constant depth • Preset 600µ knife • Micrometer knife set at 90% thinnest pachymetry • Steep axis +++

  20. Astigmatic Correction withToric IOLs • Reduction of Astigmatism • SN60T3 = 1.5D (1D) • SN60T4 = 2.25D (1.5D) • SN60T5 = 3.0D (2D)

  21. Astigmatic Correction withToric IOLs • FDA Data • 92% 20/40 or better • Mean residual astigmatism: 0.60 D • 50% less than 0.5D of residual postop astigmatism • 97.6% rotated less than 15 degrees

  22. Astigmatic Correction with Laser • Laser Vision Correction: • Precise correction of astigmatism • Correction of spherical component • Check MR and WF refraction

  23. Astigmatic Correction with Laser n=340 n=206 n=139 Netto et al, AJO 2006;141:360-368

  24. Laser Astigmatic Vision Correction • Refractive patients: primary choice • PRK • LASIK • Excellent accuracy (sphere & cylinder) • Constant technological improvements

  25. Laser Astigmatic Vision Correction • All types of regular astigmatisms • Simple, compound myopic astig. • Flatten the steepest meridian • Simple, compound hyperopic astig. • Steepen the flattest meridian • Mixed astig. • Combine both principles

  26. Cyclotorsion & Astigmatic Correction

  27. Iris Recognition ACE SRET DRET Static Rotational ET Dynamic Rotational ET Compensation between Intraoperative compensation upright / supine position Texte

  28. Cyclotorsion

  29. Results Cyclotorsion: Static (SRET) / Dynamic (DRET) Fondation A. de Rothschild Paris Jean-Luc Febbraro MD

  30. ACE Mean Static (SRET) / Dynamic (DRET) N:70 % Cyclotorsion Fondation A. de Rothschild Paris Jean-Luc Febbraro MD

  31. ACE Mean Absolute Amplitude (DRET) DRET Amplitude (°) Fondation A. de Rothschild Paris Jean-Luc Febbraro MD

  32. Conclusion • Surgical correction of astigmatism is a reality • Mandatory to optimize uncorrected vision • Refractive and cataract patients • Numerous surgical options Fondation A. de Rothschild Paris Jean-Luc Febbraro MD

  33. Prevalence and evolution Of astigmatism • Clinical significance • Accurate eye care • IOL manufacturers (SA , Cyl.) • Valuable information for cataract & refractive surgeons

  34. Prevalence and evolution Of astigmatism Astigmatism evolution with age Prevalence of astig. increases with age. Ferrer-Blasco T. et al. JCRS 2008; 34:424-432

  35. To evaluate Astigmatism Distribution and Evolution in Adult Patients STUDY • Retrospective study • 500 eyes of 276 patients • Autorefractometer refraction & keratometry measurements • Mean interval: 8.37 +/-2.92 y (min 5-16 max)

  36. RESULTS

  37. RESULTS Astigmatism Distribution

  38. RESULTS Astigmatism Evolution visit1 visit2 -0.02 OCULAR AST. CORNEAL AST. SPHERE

  39. Astigmatism Evolution RESULTS ATR shift over 8 years 0.26 D

  40. Astigmatism Evolution * E. Gudmundsdottir, A. Arnarsson, F. Jonasson. Five-year refractive changes in an adult population; Reykjavik Eye Study. Ophthalmology 2005;112, 672–677.

  41. Astigmatism in Cataract Patients • Knowledge of prevalence and evolution of astigmatism is valuable information • 35% negligible astig. • 35% 0.75 – 1 D • 30% > 1 D 7% 2 D • Mean magnitude +/- 1 D in adults, tends to increase with age • ATR axis shift (0.13 – 0.26 D) over time, particularly in older patients

  42. Cataract IncisionsIntroduction • Trend • Size • Standard 3-mm incision • Mini + 2.5-mm incision • Micro sub 2-mm incision • Placement • Scleral to limbal / clear corneal incision • Superior to temporal approach Texte

  43. Cataract IncisionsChoice Factors • Size • IOL implantation • Monofocal, Multifocal, Accomodative, Toric IOLs • Phaco platform • Phaco and I/A probes & sleeves • Location • Scleral to limbal / clear corneal incision • Superior to temporal approach Texte

  44. Cataract IncisionsAstigmatic Effects • Astigmatic change • Incision size • Distance from visual axis • Axis placement • Astigmatic change evaluation • Algebraic method (magnitude of ast.) • Vector Analysis (magnitude & axis of ast.) Texte

  45. Cataract IncisionsAstigmatic Effects Standard 3-3.5-mm on axis CCI PKE Long D. et al. Ophthalmology 1996; 103:226-232 Texte

  46. Cataract IncisionsAstigmatic Effects Standard 3.2-mm on axis / temp. CCI PKE Borasio E. et al. JCRS 2006; 32:565-572 Texte

  47. Cataract IncisionsAstigmatic Effects 3-3.5-mm Incision & SIA Range Literature Summary Texte

  48. Cataract incisions 3.5-2.8-mm CCIClinical Implications Choice of Incision Location 1 Kohnen T, Koch D. Curr Opin Ophthalmol. 1996; 7:75-80 2 Tejedor J, Murube J. Am J Ophthalmol. 2005; 139:767-776 3 Tejedor J, Perez-Rodriguez J. IOVS. 2009; 50:989-994 Texte

  49. Comparison3.0 / 2.2-mm Temporal CCI Masket S. et al. JRS 2009; 25:21-2424 Texte

  50. Comparison1.8-mm C-MICS / 1.7-mm B-MICS Wilczynski M. et al. JCRS 2009; 35:1563-69 Texte

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