Measurement of corneal riboflavin gradients after transepithelial imbibition with different solutions using two-photon fluorescence microscopy
Session Details
Session Title: Presented Poster Session: Cornea IV
Venue: Poster Village: Pod 3
First Author: : T.G.Seiler SWITZERLAND
Co Author(s): : M. Laggner D. Adler G. Schmidinger B. Frueh
Abstract Details
Purpose:
To investigate the corneal riboflavin gradient using transepithelial crosslinking solutions in fresh human cadaver eyes and to compare it with standard epi-off gradients.
Setting:
From the Department of Ophthalmology, Medical University of Vienna, Austria and the Department of Ophthalmology, University of Bern, Switzerland
Methods:
Fresh enucleated human cadaver eyes were examined within 12 hours’ post mortem. Corneoscleral disks were mounted on an artificial chamber with physiological IOP and hydration. Corneal riboflavin gradients were measured in 3 different groups (n=5) using volumetric two-photon fluorescence microscopy with an excitation wavelength of 900nm and axial step size of 10um. Groups 1 and 2 received transepithelial imbibition with Mediocross TE (1), Paracel (2), and group 3 received an epi-off imbibition using Vibex Rapid. To obtain absolute concentrations, the corneas were saturated at a known riboflavin concentration for 2 hours and measured a second time.
Results:
Corneal riboflavin gradients were significantly higher in epi-off-treated eyes using Vibex Rapid (p<0.05). Regarding transepithelial imbibition protocols, 20 minute imbibition with Mediocross TE showed the best availability of stromal riboflavin with an average relative concentration of 60% compared to the epi-off-treated group. 10 minute Paracel imbibition resulted in less than 30% compared to the epi-off protocol.
Conclusions:
The highest transepithelial riboflavin penetration is achieved using Mediocross TE with a 20 minute imbibition, although stromal riboflavin levels do not reach the gradients obtained by epi-off protocols. These results demonstrate the potential for an epi-on approach as a less invasive solution for cross-linking. Clinical studies are needed to evaluate the minimum riboflavin concentration necessary to optimize efficacy for both therapeutic and refractive applications.
Financial Disclosure:
is employed by a for-profit company with an interest in the subject of the presentation
