Table 12. Summary of other biomechanical parameter outcomes from representative studies across cross-linking protocols in progressive keratoconus.

A-CXL: accelerated corneal cross-linking; CH: corneal hysteresis (viscoelastic property of the cornea; surrogate for corneal biomechanical strength); cl-ACXL: continuous light-accelerated corneal cross-linking; CRF: corneal resistance factor (a measure of viscous and elastic resistance of the cornea); CXL: corneal collagen cross-linking; DAI: deformation amplitude index (normalized corneal stiffness relative to intraocular pressure); DAR: deformation amplitude ratio (corneal stiffness); IR: integrated radius (corneal resistance to deformation); MHz: megahertz; NS: not significant (p-value > 0.05); pl-ACXL: pulsed light-accelerated corneal cross-linking; RF: riboflavin; TE-CXL: transepithelial corneal cross-linking

Study	CXL Protocol	Parameter	Timepoint	Change	Significance
Hashemi et al., 2015 [74]	A-CXL vs Dresden	CH	6 months	No significant difference	NS
Hashemi et al., 2015 [74]	A-CXL vs Dresden	CRF	6 months	No significant difference	NS
Shao et al., 2020 [55]	TE-CXL	Brillouin shift	6 months	+25 MHz cone region	p < 0.01
Karotkar et al., 2022 [80]	cl-ACXL	DAI	1 year	-0.19 mm (1.04→0.85)	p < 0.05
Karotkar et al., 2022 [80]	pl-ACXL	DAI	1 year	-0.28 mm (1.12→0.84)	p < 0.01
Manumuraleekrishna et al., 2024 [83]	A-CXL (Iso- vs Hypo-osmolar RF)	CH	1 year	Greater in iso-osmolar RF	p < 0.05
Manumuraleekrishna et al., 2024 [83]	A-CXL (Iso- vs Hypo-osmolar RF)	CRF	1 year	Greater in iso-osmolar RF	p < 0.05
Ang et al., 2025 [64]	A-CXL	DAR	6 months	-1.447	p < 0.01
Ang et al., 2025 [64]	A-CXL	IR	6 months	-1.753	p < 0.05