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

RETROSPECTIVE STUDY 74 EYES OF 41 PATIENTS

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

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.

Procedure 45 eyes underwent Lasik Surgery Mean age 24 Years ( Range 18 Yrs to 30 Yrs) Male Female : 4:6 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)

RESULTS Group A Group B -4.28D +/- 0.75D -3.25 D+/- 0.50D Pre Operative ( mean spherical value) -4.28D +/- 0.75D -3.25 D+/- 0.50D Post Operative ( mean spherical value) 0.13+D/-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

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

Visual Acuity in %age in Pre and Post Operative Patients 78% of the Group A eyes attained >=6/6 UCVA post operative 76% of the Group B eyes attained >=6/6 UCVA post operative

Visual Acuity in %age in Pre and Post Operative Patients 84% of the Group A eyes attained >=6/6 UCVA post operative 76% of the Group B eyes attained >=6/6 UCVA post operative

Graph showing higher order aberration detection at varying pupil sizes.

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.

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.