21/09/04www.drmathys.be ESCRS 2004 PARIS Wavefront- and Topography- guided PRK for Myopic Eyes Bernard Mathys, MD Brussels Vision Clinic
21/09/04www.drmathys.be ESCRS 2004 PARIS Zyoptix (B&L) for PRK Procedures for Z – Lasik Orbscan and Aberrometry-guided ablation Tissue saving, wide optical zone, reduce treatment-induced aberrations Adapted for PRK – using the same preop measurements
21/09/04www.drmathys.be ESCRS 2004 PARIS Why Zyoptix ? Thin cornea: < 520 µ Large pupil Tissue saving Aberrations preop > 0.30µ RMS PSF
21/09/04www.drmathys.be ESCRS 2004 PARIS Technique Topography and aberrometry by the same well-trained technician Alignment under the laser, head position: crucial PRK: std technique Postop treatment: std
21/09/04www.drmathys.be ESCRS 2004 PARIS Results
21/09/04www.drmathys.be ESCRS 2004 PARIS Aberrations Measurements of all aberrations preoperatively Same postop: 1M, 3M, 6M, 12M Time development view Normal band view Orbscan
21/09/04www.drmathys.be ESCRS 2004 PARIS Example 1: thin corneas
21/09/04www.drmathys.be ESCRS 2004 PARIS Example 1: thin corneas
21/09/04www.drmathys.be ESCRS 2004 PARIS Example 2: large pupil
21/09/04www.drmathys.be ESCRS 2004 PARIS Example 2: large pupil
21/09/04www.drmathys.be ESCRS 2004 PARIS Example 3: limited induced aberrations
21/09/04www.drmathys.be ESCRS 2004 PARIS Contrast sensitivity
21/09/04www.drmathys.be ESCRS 2004 PARIS RMS changes
21/09/04www.drmathys.be ESCRS 2004 PARIS Discussion If thin cornea, PRK more suitable However, higher correction may induce more haze, delayed visual recovery, regression, etc… Our experience: exactly the same But Z-PRK: less haze, better astigmatic correction, wider optical zone, no contrast loss
21/09/04www.drmathys.be ESCRS 2004 PARIS Conclusion Very interesting technique Need a correction factor for the aberrometer measurements (ours: 90%) Alignment crucial Cyclotorsion Corneal marking for astigmatism
21/09/04www.drmathys.be ESCRS 2004 PARIS No higher RMS postop for high correction No higher RMS postop for large OZ Seems to reduce RMS for OZ 6 – 6.5 Safe and effective: no loss of VA
21/09/04www.drmathys.be ESCRS 2004 PARIS Thank you for your attention