Safety
Corneal cross-linking is considered to be a safe procedure, provided the recommended safeguards are observed.
Minimal corneal thickness is 400 μm after removal of the epithelium. This is intended to protect the corneal endothelium from UV-A radiation. A cornea soaked with riboflavin absorbs about 95% of the total radiation so that only a small amount reaches the endothelium.
The safety design of the IROC UV-XTM device uses a special beam path according to Koehler. Due to this optical design the necessary radiant exposure at the cornea is immediately dissipated behind the cornea as a result of the optically diverging beam within the eye. Experimental measurements in porcine eyes have shown radiant exposures at the retina that were far below the laser safety thresholds, thus ensuring very safe treatments.
Safety design of the UV-XTM device: An optical design according to Koehler reduces the radiant exposure at the retina to a minimum (left). The safety was further checked experimentally (right).
Literature and presentations on the safety topic:
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Spoerl E, Mrochen M, Sliney D, Trokel S, Seiler T. Safety of UVA-Riboflavin Cross-Linking of the Cornea. Cornea. 2007 May ;26 (4):385-389 17457183
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Seiler T, Collagen crosslinking in thin corneas, Presented at the CCL 2006 congress in Zurich.