Intrastromal application of riboflavin for corneal cross-linking

Session Details

Session Title: Cross-linking I

Session Date/Time: Monday 15/09/2014 | 14:30-16:30

Paper Time: 15:24

Venue: Capital Hall A

First Author: : I.Fischinger SWITZERLAND

Co Author(s): :    T. Seiler   G. Schmidinger   T. Seiler        

Abstract Details

Purpose:

To evaluate experimentally the efficacy of corneal crosslinking (CXL) where the photomediator riboflavin is injected into the corneal stroma via a system of intrastromal channels.

Setting:

IROC (Institut für refraktive und ophthalmochirurgie)

Methods:

Four groups of pig corneas, 9 corneas each, were compared regarding stress- strain relationship and UV-absorption. Group 1 had intrastromal channels floated with riboflavin 0.5%-solution followed by UVA-irradiation (5.4J/cm2); group 2 had the identical channel system, no riboflavin but identical irradiation; group 3 was treated according to the Dresden protocol (epi-off); group 4 with native corneae served as a control group. The intrastromal channels were created by means of a femtosecond laser (Wavelight/Alcon, Erlangen, Germany). The stress-strain relations were measured in corneal stripes using a material tester (UStrech, Cellscale, Ontario) at strains up to 12%. The UV-absorption of the corneas was measured by means of the UVA-source used for CXL and a UV-power meter (YK-35UV, Lutron Electronic, Taipei, Taiwan).

Results:

The stress needed for a 10% strain was significantly increased by 82% in the corneas treated with the Dresden protocol compared to native cornea (p=0.0005). With intrastromal application of riboflavin this significant increase was only 64% (p=0.007). The channel formation alone did not change the biomechanics of the cornea (p=0.923). The UVA-absorption after intrastromal riboflavin application was 97.6%, after the treatment according to the Dresden protocol 91.2% and 42.1% in the native cornea.

Conclusions:

The experiments demonstrate that the intrastromal application of riboflavin by means of fs-laser generated channelsystem is a feasible “epi-on” approach for corneal crosslinking. More experimental data will be needed before clinical testing.

Financial Interest:

One or more of the authors... receives consulting fees, retainer, or contract payments from a company producing, developing or supplying the product or procedure presented