Conventional LASIK V/S Zyoptix LASIK

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Conventional LASIK V/S Zyoptix LASIK

• I HAVE NO FINANCIAL INTEREST
• Author Dr Rohit Nanda
• Co- Authors Dr R.S .Nanda, Dr Aditi Singh,
  Dr K.P Srinivas Rao, Dr G .Srinivas Rao, Dr Joe
  Mathew,Dr Altaf Akbar

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• RETROSPECTIVE STUDY
• 74 EYES OF 41 PATIENTS

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ROUTINE PATIENT EVALUATION

• UCVA
• BCVA
• SLITLAMP EXAMINATION
• APPLANATION TONOMETERY
• MANIFEST AND CYCLOPLEGIC REFRACTIONS
• ORBSCAN AND ABERROMETERY
• CORNEAL PACHYMETERY AND CORNEAL DIAMETER
• SCHIRMER TEST

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ROUTINE PATIENT EVALUATION Contd

• Indirect Ophthalmoscopy
• Done in all patients
• Contact lens wearer patients were asked to
  discontinue contact lens for
• One week if wearing soft contact lenses
• Two weeks if wearing RGP lenses.

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Procedure

• 45 eyes underwent Lasik Surgery
• Mean age 24 Years ( Range 18 Yrs to 30 Yrs)
• Male Female 46
• 29 eyes underwent Zyoptix Surgery using Bausch
  and Lomb technolas 217z machine .
• Parameters Used
• Wavelength 193nm,
• Fluence 130mj/cm2
• Ablation zone diameters between 4.8mm and 6mm
• HANSATOME used
• BAUSCH AND LOMB (180uM and 160M PLATE)

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RESULTS
Group A Group B
Pre Operative ( mean spherical value) -4.28D /- 0.75D -3.25 D/- 0.50D
Post Operative ( mean spherical value) 0.13D/-0.13D 0.15D /- 0.68D
Group A Group B
Pre Operative ( mean Cylindrical value) -1.16 D/- 0.24 D -2.00 D /-0.60 D
Post Operative ( mean Cylindrical value) -0.10 D /-0.20 D -0.08D /-0.24D
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RESULTS Contd
Type of Surgery LASIK ZYOPTIX
No. of Eyes where aberrations found to be Nil ( Group A) No. of Patients where aberrations found to be Nil ( Group B)
3rd Order 7 5
4th Order 17 9
5th Order 28 12
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Visual Acuity in age in Pre and Post Operative
Patients
76 of the Group B eyes attained gt6/6 UCVA post
operative
78 of the Group A eyes attained gt6/6 UCVA post
operative
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Visual Acuity in age in Pre and Post Operative
Patients
76 of the Group B eyes attained gt6/6 UCVA post
operative
84 of the Group A eyes attained gt6/6 UCVA post
operative
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• Graph showing higher order
• aberration
• detection at varying pupil
• sizes.

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• Comparison between pre postoprative aberrations
• Z20- Defocus
• Z22-Astigmatism
• Z31-Coma
• Z33-Trefoil
• Z40-Sph-aberration
• There is drastic decrease in 2nd order
  aberrations postoperatively.

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Conclusion

• Decreased aberrations in patients who underwent
  lasik and zyoptix.
• Lasik removes higher order aberrations in few
  patients but the point spread function is a large
  blur, leading to lower clarity of vision.
• Zyoptix performs customized ablation minimizing
  the wave front deformation.The point spread
  function is a small spot of light, leading to
  clarity of vision.

Removal of the wavefront aberrations may extend
the benefit of improved UCVA to patients with
abnormal wavefront.