Official ESCRS | European Society of Cataract & Refractive Surgeons
Copenhagen 2016 Registration Programme Exhibitor Information Virtual Exhibition Satellite Meetings Glaucoma Day 2016 Hotel Star Alliance

10 - 14 Sept. 2016, Bella Center, Copenhagen, Denmark

This Meeting has been awarded 27 CME credits


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Corneal cross-linking with Verteporfin nonthermal laser therapy

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Session Details

Session Title: Corneal Biomechanics

Session Date/Time: Tuesday 13/09/2016 | 16:30-18:00

Paper Time: 17:48

Venue: Auditorium C6

First Author: : S.Alageel USA

Co Author(s): :                        

Abstract Details


To test if corneas treated with combined Verteporfin Nonthermal Laser Therapy increase corneal mechanical stiffness and increase resistance to enzymatic degradation.


Human research corneas were obtained from Tissue Bank International (Baltimore, Maryland) and North Carolina Eye Bank (Winston-Salem, North Carolina). Riboflavin 5'-phosphate sodium salt hydrate, 20% (w/w) dextran solution (from Leuconostoc mesenteroides) and collagenase A (from Clostridium histolyticum, E.C. were obtained from Sigma Aldrich (St. Louis, Missouri).


Human corneas were fitted into BarronR artificial anterior chambers, de-epithelialized. Corneas treated with Verteporfin alone, Irradiation with non-thermal laser (NTL), without verteporfin , and combined treatment verteporfin with non-Thermal Laser Therapy for one treatment sequence (V+NTL1) and six sequences protocol (V+NTL6). Other were pre-treated with 0.1% riboflavin/20% dextran for 30 minutes and irradiated with ultraviolet light type A (λ=370nm, irradiance= 3mW/cm2) for 30 minutes (R+UVA).To measure resistance to enzymatic degradation treated and untreated corneas were trephined and submerged in 0.3% collagenase . Biomechanical properties 1.Stress-strain with compression using a Q800 DMA 2.tensile using a Shimadzu AGS-X load frame 3.Creep Testing.


On gross examination: corneas treated by (V+NTL6) and (R+UVA) have more rigidity than untreated. Resistance to enzymatic digestion: Untreated corneas dissolved in collagenase A in 5.47h± 0.21 hours. Cross-linked corneas with R+UVA and V+NTL6 demonstrated a slower rate of dissolution than untreated (20.06h± ±1.23hours, 19.75 ± 0.95 hrs, p<0.005) Biomechanical Testing: 1.Compression Testing Corneas treated by R+UVA and V+NTL6 more stiff than untreated (0.70,0.80 vs. 0.43 MPa, p <0.05) 2.Creep Testing Corneas treated by V+NTL6 were found to have a significantly lower absolute creep rate than untreated corneas (-1.87 vs. -3.46, p < 0.05). 3.Tensile Testing the maximum stress was significantly higher for corneas that were treated with V+NTL6 and R+UVA than untreated corneas (15.17, 14.97 vs. 7.71, p < 0.05).


we report for the first time that verteporfin non-thermal photodynamic laser increases corneal mechanical stiffness and resistance to enzymatic collagenase degradation. Although a clinical study of this methodology in human patients is still needed, our results suggest that verteporfin non-thermal photodynamic laser induces crosslinking cornea tissue that is similar to that of collagen crosslinking (CXL) using ultraviolet-A (UVA) irradiation combined with riboflavin. V-NLT could represent an alternative treatment for cornea ectatic diseases.

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