The document discusses the history and evolution of LASIK eye surgery techniques. It compares microkeratome and two femtosecond laser techniques, IntraLase and Ziemer LDV, for creating corneal flaps. The IntraLase technique allows for more customization and visualization during flap creation, making complications like free or irregular flaps less likely compared to the Ziemer technique. Overall, femtosecond lasers can create thinner, more consistent flaps than microkeratomes, with IntraLase providing better outcomes and safety than Ziemer LDV.

1. The Science of Vision Correction Dean Dornic, MD (Mr. Science) Laser Eye Center of Carolina

2. A 60 Year History of LASIK 1949 Columbian Ophthalmologist Barraquer describes a lamellar corneal procedure to correct refractive error

3. ALK the Predecessor to LASIK A microkeratome is used to create a flap and to remove a disc of corneal tissue

4. Birth of LASIK: Introduction of Excimer Laser Results in Name Change 1983: First journal article describing the use of the Excimer laser to treat refractive error

5. 1989: First patent for the LASIK procedure

6. Improvements in Technology Have Resulted in Improvements in Outcomes Lower risk of complications (decentered ablations, asymmetric ablations, quality of vision issues)

7. Higher likelihood of spectacle independence

8. Higher Order Aberrations Introduction of aberrations reduce visual quality and decrease patient satisfaction

9. Spherical aberration a result of oblate cornea

10. Significant Refinements: Ablation Wider treatment zones

11. Flying spot

12. Pupil tracker

13. Wavefront-guided and optimized treatments

14. Iris registration

15. Wavefront Technology Wavefront-guided procedures utilize a wavefront analyzer to correct higher order aberrations

16. No analyzer necessary for wavefront-optimized procedures

17. Wavefront Technology Benefits are More than Just Theoretical Wavefront-guided procedures have greatest rates of 20/20 or better

18. WFG procedures have lowest enhancement and night-vision problems

19. Night Vision Satisfaction after CustomVue Patient satisfaction with night vision increases after WFG procedures

20. Ratio of improved vs worsened night vision is 4:1

21. Important Points for Patients Wavefront Guided is not equivalent to Wavefront Optimized WFG Procedures can correct HOAs WFO Procedures strive to limit new HOAs You can achieve good results with conventional LASIK WFG need not be reserved for patients with high HOAs WFG Procedures give the Opportunity for Improved BVA WFG Procedures Give the Best Night Vision Why would you not want a WFG procedure?

22. The LASIK Flap Serves to speed recovery

23. Lessens likelihood of haze, regression and infection

24. Most common source of complication

25. Significant Refinements in Flap Creation/ Improved Safety Elimination of perforation risk Elimination of exposed gears Elimination of on-eye assembly Vacuum meters/ audible tones Increased customization Femtosecond laser flap creation Sidecuts

26. Cornea Flap Creation with Microkeratome Suction ring exposes cornea.

27. Oscillating blade a set distance below metal plate creates flap

28. Variability in amount of exposed cornea results in variability of flap parameters

29. Flap Creation with IntraLase Femtosecond Laser Cleavage plane created by photodisruption and resultant gas bubbles released a set distance below cornea surface applanated by glass plate

31. Downside of IntraLase (FS30) Increased Expense Increased Time Flaps More Difficult to Lift Risk of Flap Tears Transient Light Sensitivity Syndrome

32. Ziemer LDV Portable Familiar Technique Fast Able to Create Thin Flaps

33. Ziemer Complications Free Flaps Small Irregular Flaps

34. Result of Ziemer Complications Small Irregular Flaps Managed with Immediate PRK Both Cases Required Enhancements For Quality of Vision Issues

35. IntraLase FS60 Less OBL Delay Faster Procedure Time No Free Flaps No Small Irregular Flaps

36. Head to Head Comparison of Complications: First 150 Cases Most Previous Papers Attempt to Compare Complication Rates Utilized Different Surgeons Same Surgeon 98 cases IntraLase FS30 150 cases Ziemer LDV 52 Cases IntraLase FS60 added to IntraLase Group for Equal Sample Size

37. Comparison of Complications First 150 Cases IntraLase 1 incomplete flap

38. 1 slipped flap Ziemer 2 free flaps

39. 2 small irregular flaps

40. 1 slipped flap

41. My Ziemer Complication Rate vs Pietela et al J Ref Surg My Results (150 cases) 2 Free Flaps 1.3%

42. 2 Irregular Flaps 1.3%

43. 1 Flap Displacement 0.7% Pietela (787 cases) 21 Free Flaps 2.7%

44. 16 Decentered 2.0%

45. 10 Pseudobuttonholes 1.3%

46. 2 Split Flaps 0.3%

47. 3 Flap Displacements 0.4%

48. IntraLase Flap Creation 3-Dimensional flap

49. 2-steps with side cut added last

50. Flap creation visible throughout

51. IntraLase Flap Creation Diameter and location of flap can be altered before proceeding

52. Side cut is created last as a seperate stage

53. IntraLase Control Panel Allows for perfectly centered flap

54. True customization

55. Unlimited flap diameters and flap thicknesses

56. Last minute adjustments

57. IntraLase Flap Flap creation visible throughout procedure

58. Because surface not affected, flap can still be salvaged if there is interruption

59. Ziemer Flap Creation Single Plane “Cut” Similar to Microkeratome

60. Initial Applanation and Alignment Visible

61. Creation of Flap Not Visible to Surgeon

62. Ziemer Flap Creation Diameter of Ziemer flap dependent on area applanated

63. Diameter affected by corneal curvature

64. Sidecut performed simultaneously with the rest of the flap

65. Loss of Suction with IntraLase Loss of suction visible. Procedure can be halted and resumed.

66. Loss of Suction with Ziemer Loss of full applanation before flap creation is initiated results in a free flap

67. Loss of full applanation after flap initiation results in smaller, irregular flap

68. Suction Loss is Not Rare The Consequences of Suction Loss is Different for 2 Reasons: 1. Surgeon is “Blind” to Flap Creation When the Ziemer Laser is Used: Loss of Full Applanation May not Be Apparent 2. The Side Cut is a Second Seperate Stage When the IntraLase Laser is Used: This Allows for Recovery/Salvage of the Case When Suction is Lost

69. Prevention of Complications Proper and Adequate Suction/Applanation Separate Side-Cut With “Manhole” Configuration Should Reduce Slipped Flaps Separate Side Cut Allows for Salvage/Resumation When Suction Lost Full Visualization/Proper Intervention Should Limit Incomplete or Free Flaps

70. Ziemer Pros and Cons Pros Portable

71. No OBL

72. Technique Familiar

73. Fast

74. Flaps Easy to Lift Cons Limited Customization

75. Diameter Influenced by Corneal Shape

76. Single Plane Flaps

77. Unable to Visualize

78. Interuption of Case Usually Results in Cancellation

79. Higher Complication Rate

80. IntraLase Pros and Cons Pros Customization

81. Better “Fine Tuning”

82. Manhole Configuration

83. Full Visualization

84. Free and Irregular Flaps are Rare

85. Interruption Rarely Results in Cancellation Cons More Cumbersome

86. OBL Can Slow Down Case

87. Not as Portable

88. More Uncomfortable For Patient

89. Higher Rate of Subconjunctival Hemorrhage

90. Summary Femtosecond Laser Technology Can Produce Thinner, More Consistent Flaps The IntraLase Laser Allows for Better Surgeon Control and Is Much Less Likely to Result in Complications, Postponement or Conversion to PRK than the Ziemer LDV Laser

91. Z-LASIK Flap Architecture Single plane, exactly as that created by a microkeratome

92. All complications seen with microkeratome can be seen with Z-LASIK

93. IntraLase Flap Architecure Manhole configuration

94. No free flaps

95. No Small/ irregular flaps

96. Second chance possible

97. More secure

98. Electron Micrograph Comparison IntraLase Flap

99. Z-LASIK Flap

100. Bonus Advantage Stromal bed smoother with IntraLase

101. IntraLase Flap Creation

102. Monitor View

103. Conclusion Safest way to make a flap is IntraLase

104. Best vision achievable is with CustomVue

105. Chief advantage of Z-LASIK is cost

106. Military does not perform Z-LASIK. Statements such as “technology approved by the military” are, at the very least, misleading

107. All “custom procedures” are not equivalent

108. All “all-laser” procedures are not equivalent

109. Need for New Terminology The precedence for a change in terminology is evidenced by change from ALK to LASIK

110. There is a need to differentiate iLASIK and similar technologies from LASIK and Z-LASIK

111. Side effect / complication statistics from earlier technologies are not applicable to iLASIK

112. Consumers need to be able to compare “apples to apples”