PURPOSE: To compare epithelial remodeling in keratoconic eyes that had 
photorefractive keratectomy and corneal collagen crosslinking (Athens protocol) 
with that in untreated keratoconic eyes and healthy eyes.
SETTING: Private clinical practice, Athens, Greece.
DESIGN: Comparative case series.
METHODS: Fourier-domain anterior segment optical coherence tomography (AS-OCT) 
was used to obtain in vivo 3-dimensional epithelial thickness maps and center, 
superior, inferior, maximum, minimum, mean, midperipheral, and variability data.
RESULTS: Group A comprised 175 treated keratoconic eyes (Athens protocol); Group 
B, 193 untreated keratoconic eyes; and Group C, 160 healthy eyes. The 1-year 
mean center epithelial thickness in Group A was 47.78 μm ± 7.36 (SD) (range 33 
to 64 μm). At the first clinical visit, it was 52.09 ± 6.80 μm (range 36 to 72 
μm) in Group B and 52.54 ± 3.23 μm (range 45 to 59 μm) in Group C. The mean 
thickness range in Group A at 1 year was -19.94 ± 7.21 μm (range -6 to -34 μm). 
It was -21.83 ± 12.07 μm (range -4 to -66 μm) in Group B and -6.86 ± 3.33 μm 
(range -3 to -29 μm) in Group C. The mean topographic thickness variability in 
Group A at 1 year was 4.64 ± 1.63 μm (range 1.6 to 8.1 μm) (P<.05). It was 5.77 
± 3.39 μm (range 1.3 to 17.8 μm) in Group B and 1.59 ± 0.79 μm (range 0.6 to 5.6 
μm) in Group C.
CONCLUSION: Anterior segment OCT indicated a thinner and more homogeneous 
remodeled epithelium in the keratoconic eyes treated using the Athens protocol.
FINANCIAL DISCLOSURE: Dr. Kanellopoulos is a consultant to Alcon Surgical, Inc.; 
Wavelight Laser Technologie AG; Avedro, Inc.; and i-Optics Optikgeräte GmbH. Dr. 
Asimellis has no financial or proprietary interest in any material or method 
mentioned.