Proceedings Article | 24 February 2010
Proc. SPIE. 7556, Design and Quality for Biomedical Technologies III
KEYWORDS: Cornea, Visualization, Tissues, Image processing, Ultraviolet radiation, Luminescence, Collagen, Charge-coupled devices, Beam analyzers, 3D image processing
The treatment of keratoconus and corneal ulcers by collagen cross-linking using ultraviolet type A irradiation, combined
with photo-sensitizer Riboflavin (vitamin B2), is a promising technique. The standard protocol suggests instilling
Riboflavin in the pre-scratched cornea every 5min for 30min, during the UVA irradiation of the cornea at 3mW/cm2 for
30 min. This process leads to an increase of the biomechanical strength of the cornea, stopping the progression, or
sometimes, even reversing Keratoconus. The collagen cross-linking can be achieved by many methods, but the
utilization of UVA light, for this purpose, is ideal because of its possibility of a homogeneous treatment leading to an
equal result along the treated area. We have developed a system, to be clinically used for treatment of unhealthy corneas
using the cross-linking technique, which consists of an UVA emitting delivery device controlled by a closed loop system
with high homogeneity. The system is tunable and delivers 3-5 mW/cm2, at 365nm, for three spots (6mm, 8mm and
10mm in diameter). The electronics close loop presents 1% of precision, leading to an overall error, after the calibration,
of less than 10% and approximately 96% of homogeneity.
