6/26/214 ANALYSIS OF RISK FACTORS FOR LOSS OF SUCTION IN FEMTO-SMILE CASES 1
6/26/214 ANALYSIS OF RISK FACTORS FOR LOSS OF SUCTION IN FEMTO-SMILE CASES Home 2
6/26/214 Introduction Femto SMILE lenticular extraction with the femtosecond laser is the real all LASER procedure. This involves making two lamellar cuts with a femtosecond laser to create an intrastromal lenticle of defined shape, which the surgeon removes. They create a huge optical zone and a slightly prolate cornea. a corneal lenticule is extracted through a single small incision 3-4 mm without lifting a flap. Introduction Advantages of femto Smile Can be done in relatively thin corneas. Post LASIK discomfort is minimal. Better tear film stability. Surgeon is free of nightmares regarding flap. Safe, effective, and predictable. Biomechanical stability. 3
6/26/214 Introduction Disadvantages & complications of femto Smile Suction loss >> short waiting period. Difficult touch up >> PRK. No tracker >> centration on visual axis. No customized profiles >> future company planes. Introduction 4
6/26/214 Home Aim of the work To analyze possible risk factors for loss of suction in cases treated by femto-smile for myopia and myopic astigmatism 5
6/26/214 Home Subjects & Methods Retrospective, Single center Roa ya vision correction center - Alexandria Multi-surgeon Case control study FEMTO-SMILE performed with the VisuMax 5kHz femtosecond laser system (Carl Zeiss Meditec). Cases with suction loss occurring during various stages were identified, different risk factors were analysed. 6
6/26/214 Subjects & Methods 7 eyes of 66 patients with suction loss during femto smile occurred between August 21 & April 214. 7 eyes were taken as a control and selected randomly from center data. Patient preoperative, operative & postoperative data recorded & then analysed. Subjects & Methods The following risk factors were analyzed; Demographic data age and sex, Eye Manifest refraction. Flat K, steep K. Optical zone. Central corneal thickness. Corneal Astigmatism. The results were tabulated and analyzed for any statistical significance. 7
Percentage Median of age (year) 6/26/214 Home Comparison between the two studied groups according to demographic data 7 61.4 67.1 3 28. 26. 6 25 5 4 38.6 32.9 2 15 3 2 1 1 5 Male Female 8
% of incidence of suction loss Percentage 6/26/214 Comparison between the two studied groups according to the eye 7 61.4 OD OS 6 5 5 5 4 38.6 3 2 1 Incidence of suction loss in femto smile 6. 5. 5.6 4. 3.59 3.41 3. 2.32 2. 1.84 1.. 21 211 212 213 214 Years 9
Mean (D) Mean (µ) 6/26/214 Manifest refraction -7-6.43-5.8-6 -5-4 -3-2 -1.46-1.14-1 Spherical (D) Cylinder (D) Comparison between the two studied groups according to Central corneal thickness & Residual stromal thickness 6 523.5 53.16 5 4 319.64 332.39 3 2 1 Central corneal thickness (µ) Residual stromal thickness (µ) 1
Mean of K astigmatism (D) Mean (D) 6/26/214 Comparison between the two studied groups K readings 6 5 42.67 43.35 44.16 44.51 4 3 2 1 Flat K (D) Steep K (D) Comparison between the two studied groups corneal astigmatism 1.6 1.49 1.4 1.16 1.2 1..8.6.4.2. 11
Mean of corneal diameter (mm) Mean of optical zone (mm) 6/26/214 Comparison between the two studied groups according to corneal diameter 14 11.85 11.89 12 1 8 6 4 2 Comparison between the two studied groups according to Optical zone 7 6.18 6.25 6 5 4 3 2 1 12
Mean of cap diameter (mm) Mean of cap thickness (µ) 6/26/214 Comparison between the two studied groups according to Cap diameter & thickness 7.63 7.68 95. 94.43 8 1 7 6 5 4 3 2 1 9 8 7 6 5 4 3 2 1 Cap Diameter Cap Thickness Home 13
6/26/214 Conclusion Surgeon Factor >> learning curve!! Patient Factor >> Patient education & assurance. Corneal & manifest astigmatism must be considered in cases of femto-smile. Machine factor >> Pump failure must be further studied. 14