@article {397811,
	title = {High-irradiance CXL combined with myopic LASIK: flap and residual stroma biomechanical properties studied ex-vivo.},
	journal = {Br J Ophthalmol},
	volume = {99},
	number = {6},
	year = {2015},
	month = {2015 Jun},
	pages = {870-4},
	abstract = {BACKGROUND/AIMS: To evaluate ex vivo biomechanical and enzymatic digestion resistance differences between standard myopic laser in-situ keratomileusis (LASIK) compared with LASIK+CXL, in which high-irradiance cross-linking (CXL) is added. METHODS: Eight human donor corneas were subjected to femtosecond-assisted myopic LASIK. Group A (n=4) served as a control group (no CXL). The corneas in LASIK+CXL group B were subjected to concurrent prophylactic high-irradiance CXL (n=4). Saline-diluted (0.10\%) riboflavin was instilled on the stroma, subsequently irradiated with UV-A through the repositioned flap. The cornea stroma and flap specimens were separately subjected to transverse biaxial resistance measurements; biomechanical differences were assessed via stress and Young{\textquoteright}s shear modulus. Subsequently, the specimens were subjected to enzymatic degradation. RESULTS: For the corneal stroma specimen, stress at 10\% strain was 128{\textpm}11 kPa for control group A versus 293{\textpm}20 kPa for the LASIK+CXL group B (relative difference Δ=+129\%, p\&lt;0.05). The stress in group B was also increased at 20\% strain by +68\% (p\&lt;0.05). Shear modulus in group B was increased at 10\% strain by +79\%, and at 20\% strain by +48\% (both statistically significant, p\&lt;0.05). The enzymatic degradation time to dissolution was 157.5{\textpm}15.0 min in group A versus 186.25{\textpm}7.5 min in group B (Δ=+18\%, p=0.014). For the flaps, both biomechanical, as well as enzymatic degradation tests showed no significant differences. CONCLUSIONS: LASIK+CXL appears to provide significant increase in underlying corneal stromal rigidity, up to +130\%. Additionally, there is significant relevant enzymatic digestion resistance confirmatory to the above. LASIK flaps appear unaffected biomechanically by the LASIK+CXL procedure, suggesting effective CXL just under the flap.},
	issn = {1468-2079},
	doi = {10.1136/bjophthalmol-2014-306411},
	author = {Kanellopoulos, Anastasios John and Asimellis, George and Salvador-Culla, Borja and Chodosh, James and Ciolino, Joseph B}
}
