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Lasik Flap Thickness using the Zyoptix XP Microkeratome Susanne Stottmeister, Suphi Taneri * * Travel grant by Bausch & Lomb. ASCRS Symposium, April 4-9, 2008, Chicago. Purpose.
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Lasik Flap Thickness using the Zyoptix XP MicrokeratomeSusanne Stottmeister, Suphi Taneri** Travel grant by Bausch & Lomb ASCRS Symposium, April 4-9, 2008, Chicago
Purpose To evaluate predictability and possible factors affecting flap thickness in laser in situ keratomileusis (LASIK) using the Zyoptix XP microkeratome.
Methods • 250 primary LASIK Flaps created using 3 different B&L Zyoptix XP microkeratomes were evaluated. • Elements with different Serial Numbers were combined. • Ultrasound subtraction pachymetry was used to determine intraoperative flap thickness. © B&L
Methods II • Each keratome cut was performed with a new blade in a 120µm or a 140µm head coupled to a 8.5 mm or 9.5 mm suction ring with 19 or 20 mm outer diameter.
Results • Measured intraoperative flap thickness was lower than labelled. • Flap thickness in safe range
Flap Thickness vs. Different Head/Ring Combinations • Standard Deviation in most used Head/Ring combination was 22 µm
Corneal factors affecting Flap Thickness Keratometry showed no influence.
Corneal factors affecting Flap Thickness Flap thickness was not correlated to central corneal pachymetry.
Patient factors affecting Flap Thickness Age showed no influence.
Difference between 1st and 2nd Eye Intrapatient Comparison Bilateral cuts with the same head size (120 µm or 140 µm, respectively) and different blades showed no dependance.
Comparison XP vs. Hansatome XP Hansatome A similar predictability of the Zyoptix XP microkeratome compared to the predecessor model (Hansatome) was observed.
Conclusions • All flap thicknesses were in the safe range. • Heads and rings of different sets were practically interchangeable. • Factors affecting flap thickness seem to be more device-dependant than patient-related, thus obtaining flap thickness in the first eye did not enable predictions of the flap thickness in the partner eye.