2. Acknowledgements:
-Wollensak et al-Effect of cross linking on
porcine cornea
-A J Kanellopoulos et al-Lasik Extra.
-Tobias Koller-UV-X-1000 and UV-X-2000.
-Luis F. Mejia.
3. History:
Theo Seiler, Spoerl and Wollensak.
Since 1998.
Mechanism:
Riboflavin:
Photosensitization.
Photo-protection.
4. Beneficial effects:
Photo-oxidation and chemical bonding.
Collagen fibrils- size.
bonding.
resists digestion.
Increases resistance and induces
stabilization.
9. Accelerated Cross linking:
Reduces time and corneal dehydration.
Coupled with SimLC and Lasik extra.
10. Accelerated Cross-Linking:
A J Kanellopoulos- Athens, Greece-2005.
Wellington Eye Clinic, New Zealand-2007.
Paolo Vinciguerra, Italy-2007-2008.
Switzerland and Bangalore, India.
11. Accelerated Cross linking:
Principle-Bunsen Roscoe law of reciprocity
Experiments:
Wernli et al-40-45 mW/cm2
Hafezi et al-30 mW/cm2
12. Accelerated Cross linking:
IROC device- 9mW/cm2 for 10 mts.
Avedro- various combinations
40mW/cm2 for 2 mts.
30mW/cm2 for 3 mts.
6mW/cm2 for 15 mts.
Time and power vary, irradiation constant-
5.4J/cm2
13. Accelerated Cross linking-Applications:
SimLC- TPG PRK with Cross linking.
The Athens protocol.
-Avedro used at 6mW/cm2 for 15 mts.
Toponeutralization- TNT-NN group,
Bangalore -Avedro used
30mW/cm2 for 4 mts.
14. Accelerated Cross linking:
Lasik extra-A J Kanellopoulos et al
Myopes, special indications.
All hyperopes.
Avedro used 30mW/cm2 for 80 seconds.
15.
16.
17.
18. Other applications:
- AJ Kanellopoulos-Avedro-45mW/cm2 for 3
mts, after astigmatic keratotomy with
femtolaser.
-5-6 hours post Keraflex-Avedro-30mW/cm2
for 3 mts.
-Also being used after Conductive
Keratoplasty.
19. Tobias Koller-8th International Crosslinking
meet-Geneva, Switzerland.
Prospective comparision between:
-Standard and Accelerated Cross linking
-One year results
20. Standard Accelerated
Technique Dresden protocol
UV source UV-X-1000 UV-X-2000
Beam profile Top hat Optimized
Exposure 3mW/cm2 9mW/cm2
Time 30 mts 10 mts
Periphery same 12mW/cm2
24. Results: At 1 year-
Standard Accelerated
BCVA- Gain:
1 line 27.6% 19.9%
2 lines 24.3% 30%
Stable 30.9% 39.9%
BCVA-Loss-1 line: 17% 10.1%
25. Results: At 1 year-
Standard Accelerated
Epithelium 3 days 4.2 days
Haze More
26. Conclusions:
Time and benefits of combining procedures.
Improves work flow
Spin offs:
Corneal endothelial damage.
Sustained effect of Cross linking.
Step in the right direction.