Low Invasive Technology of Sclera Crosslinking: an Experimental Implementation

Abstract

Purpose: an experimental implementation of scleral collagen crosslinking using a new device that enables low-invasive delivery of UVA radiation combined with riboflavin onto the equatorial and posterior pole areas of the eye. For UVA sclera crosslinking, a device was manufactured which contains a LED source of continuous UVA radiation (wavelength 370 nm, radiation intensity 3 mW/cm2), connected via a matching optics with multimode quartz optical fiber encased in a polymer shell. This fiber is located in one of the two channels of a dual removable metal ferrule; the second (hollow) channel is designed for simultaneous delivery of riboflavin solution onto the surface of the sclera. The device was used to perform scleral crosslinking on 8 eyes of Chinchilla rabbits. The intact fellow eyes served as controls. Prior to the procedure, as well as 2 days after it and 1 month after it, the acoustic density of the sclera (ADS) was measured in vivo using an ultrasound device, VOLUSON 730 Pro (Kretz). At the same time points, the elasticity modulus of scleral samples were determined on the testing machine (Autograph AGS-H, SHIMADZU, Japan) and the level of collagen crosslinking was measured using differential scanning calorimetry (calorimeter, Phoenix DSC 204, Netzsch, Germany). After UVA treatment, ADS grew from 86.7±5.1 to 98±4.9 dB, the elasticity modulus was found to be 1.5 times higher than the control, while denaturation temperature growth matched the 15–18% increase of cross linking of scleral collagen. The outcome of experimental implementation of low-invasive technology for scleral collagen crosslinking shows that it as a promising method of scleral strengthening treatment of progressive myopia which requires further clinical studies.