Ultrafast corneal stiffening by WST11-D and near infra red (NIR) illumination: 1,5 or 30 minutes

Session Details

Session Title: Cross-Linking

Session Date/Time: Sunday 06/09/2015 | 08:00-09:30

Paper Time: 08:12

Venue: Main Auditorium

First Author: : J.Brekelmans THE NETHERLANDS

Co Author(s): :    A. Goz   A. Brandis   Y. Salomon   A. Marcovich   R. Nuijts   A. Scherz   I. Samish   M. Dickman

Abstract Details

Purpose:

We previously reported on the safety and efficacy of WST11-D/NIR treatment for corneal stiffening using parameters similar to the Dresden protocol for Riboflavin/UVA cross-linking. In the current study we set out to determine if a shortened protocol using less overall energy achieves sufficient stiffening. We compared the corneal stiffening efficacy of the photosensitizer WST11-D and NIR illumination applied for either 1, 5, or 30 minutes.

Setting:

Department of Plant and Environmental Sciences, the Weizmann Institute of Science, Rehovot, Israel. *(Extra co-authors) *Jurriaan Brekelmans,University Eye Clinic Maastricht, Maastricht, the Netherlands. Departments of Plant and Environmental Sciences. Alexandra Goz,Plant and Environmental Sciences, Department of Ophthalmology, Kaplan Medical Center, Rehovot, Israel Alexander Brandi, Biological services, The Weizmann Institute of Science, Rehovot, Israel Ilan Samish, University Eye Clinic Maastricht, Maastricht, the Netherlands. Departments of Plant and Environmental Sciences Yoram Salomon, University Eye Clinic Maastricht, Maastricht, the Netherlands. Departments of Biological regulation Arie Marcovich, Plant and Environmental Sciences,Department of Ophthalmology, Kaplan Medical Center, Rehovot, Israel Mor Dickman,University Eye Clinic Maastricht, Maastricht, the Netherlands Rudy Nuijts, University Eye Clinic Maastricht, Maastricht, the Netherlands Avigdor Scherz,University Eye Clinic Maastricht, Maastricht, the Netherlands. Departments of Plant and Environmental Sciences

Methods:

54 paired rabbit eyes were enucleated post mortem. The corneas were de-epithelialized mechanically and treated topically with WST11 (Steba-Biotech, France) 2.5 mg/ml combined with dextran-500 (WST11-D) for 20 minutes. Next, illumination with NIR at 10mW/cm2 was applied for either 30 minutes (n=11), 5 minutes (n=5) or 1 minute (n=11) using a diode laser at 755nm. Untreated fellow eyes served as controls. The corneoscleral rings were removed post treatment. Corneal strips, 4±0.2mm in width, were cut from the epithelial side and underwent biomechanical stress-strain measurements using a micro-computer controlled biomaterial tester (Minimat, Rheometric Scientific GmbH, Germany).

Results:

Ultimate stress increased significantly by over 100%, 150% and 200% (p < 0.001) following 1, 5, and 30-minutes of NIR illumination, respectively. The difference in ultimate stress increase was significantly higher following 30-minutes of illumination compared with 1 and 5 minutes (p=0.001). Young's modulus increased significantly (p<0.001) by over 100% in all three illumination protocols. The difference in Young's modulus increase between protocols was not significant.

Conclusions:

WST11-D/NIR treatment with illumination of 10 mW/cm2 at 755 nm significantly increases the biomechanical strength of rabbit cornea even after 1 or 5 minutes of illumination. This novel treatment with reduced illumination time and overall illumination energy might be sufficient for the treatment of keratoconus and other corneal ectatic diseases.

Financial Interest:

One of the authors gains financially from product or procedure presented