Figure 8: Accelerated corneal collagen crosslinking Group 4 (epitheliumon): Riboflavin 0.25% plus EDTA, BAK,TRIS for 4 min, Riboflavin 0.25% saline solution for 6 min, UV-A power at 45 mW/cm2 (Energy dose: 7.2 J/ cm2), 2 min. 40 sec exposure time. Postoperative confocal scans revealed a superficial diffuse edema under the Bowman’s lamina with rarefaction and damage of sub-epithelial nerves fibers (upper left yellow arrows - a); an uneven keratocytes apoptosis is detectable in the anterior stroma (upper right and bottom right yellow arrows - b and d) with a vertical transition area (bottom left yellow arrow - c) at 80-90 μm of depth on average (range 50- 120 μm).