1. 29/01/05www.drmathys.be BSCRS 2005 P R K in 2005 Bernard Mathys, MD Brussels

2. 29/01/05www.drmathys.be BSCRS 2005 Brief history 15 Y of follow-up Excimer laser Relatively easy technique Short learning curve

3. 29/01/05www.drmathys.be BSCRS 2005 Limits Pain Regression Haze ( > -6D)

4. 29/01/05www.drmathys.be BSCRS 2005 PRK fights back Complications of Lasik –Epithelial ingrowth –Striae, folds –SOS –Ectasia –Flap induced HOA –Problem flap size/wide OZ for hyperopia

5. 29/01/05www.drmathys.be BSCRS 2005 PRK improved Improved lasers: scanning, flying spot, Gaussian Improved OZ, transition Z, blend Z Improved nomogram Improved tracker: centration, cyclotorsion, frequency, mechanical response ? Aspheric profile: better for HOA ?

6. 29/01/05www.drmathys.be BSCRS 2005 Advantages Limits induced HOA Lower rate of irregular astigmatism Wave-front guided: Fourier > Zernicke ? Customized treatment

7. 29/01/05www.drmathys.be BSCRS 2005 Results

8. 29/01/05www.drmathys.be BSCRS 2005 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

9. 29/01/05www.drmathys.be BSCRS 2005 RMS changes

10. 29/01/05www.drmathys.be BSCRS 2005 And so…PRK, Lasek > Lasik ? Flap induced HOA: nomogram correction FDA studies for Lasik. PRK ? In fact, photoablation creates HOA !! No « real » studies in litterature

11. 29/01/05www.drmathys.be BSCRS 2005 PRK Follow-up Pain Fluctuations Haze

12. 29/01/05www.drmathys.be BSCRS 2005 PRK best treatment Corneal cooling Quick removal of the epithelium CL AINS (ketorolac) 3d Tears Steroïds ?

13. 29/01/05www.drmathys.be BSCRS 2005 AINS (ketorolac)

14. 29/01/05www.drmathys.be BSCRS 2005 PRK haze ? Activated keratocytes – collagen I-III More frequent if: delayed epithelial response deep ablation, > -9D broad beam, more energy, retreatment Gabbato,Ophtal. online, dec 2004 Max 3 to 6 M Decreases with time: metalloprotease Kato After 1 Y: scar MMC 0.02% 2 min

15. 29/01/05www.drmathys.be BSCRS 2005 Best healing response ? Amniotic membrane ? Interferon ? Growth factor ? PA ?

16. 29/01/05www.drmathys.be BSCRS 2005 So…PRK indications ? Up to -5 D K 48 KT subclinical Thin cornea Dry eyes High astigmatism Army, pilots, athlete

17. 29/01/05www.drmathys.be BSCRS 2005 Even more indications… Hyperopes Refraction error after IOL Refraction error after RK Refraction error after corneal graft

18. 29/01/05www.drmathys.be BSCRS 2005 PRK after RK

19. 29/01/05www.drmathys.be BSCRS 2005 And PTK ? Irregular astigmatism Recurrent erosion Reshaping Herpes (under treatment)

20. 29/01/05www.drmathys.be BSCRS 2005 Then: Do not be ashamed to perform PRK Many indications Haze problems tend to diminish Lasek = disguised PRK Not a single ectasia after PRK Good PRK much better than a bad Lasik !!

21. 29/01/05www.drmathys.be BSCRS 2005 Good PRK >< Bad Lasik

22. 29/01/05www.drmathys.be BSCRS 2005 Thin corneas

23. 29/01/05www.drmathys.be BSCRS 2005 Follow-up 1 Y

24. 29/01/05www.drmathys.be BSCRS 2005 Limited induced aberrations

25. 29/01/05www.drmathys.be BSCRS 2005 High astigmatism

26. 29/01/05www.drmathys.be BSCRS 2005 Same patient, topography

27. 29/01/05www.drmathys.be BSCRS 2005 Thank you for your attention