Table 1: Studies on Effectiveness of collagen crosslinking procedure.

Author Study Design Follow-Up Period Results
Wittig-Silva et al., [14] Randomized Controlled trial 12-month Collagen crosslinking procedure was effective against progression of keratoconus.
Hersh et al., [15] Complex study design 12-month 1.5 D reduction in average keratometry and 2 D decline was observed in maximum keratometry among the patients treated for keratoconus.
O’Brart et al., [16] Randomized prospective study 18-months followup period Utilization of the collagen crosslinking procedure assists in the mitigating keratoconus progression.
Spoerl et al., [21] Review Paper - Results highlights the use of the safety protocols which include riboflavin application for half an hour before exposure to ultraviolet radiations, removal of epithelium, ultraviolet irradiance of 370 nm wavelength, and 400 μm minimum corneal thickness. The adequate technique and safety procedure must be followed as it can lead to damage of retina, lens, and endothelium.
Baiocchi et al., [29] Randomized retrospective study - Epithelium removal helps in the effective and safe concentration of riboflavin.
Wachler et al., [30] Review Paper - Concentration of critical micelle and tetracaine lowers the retreatment rate.
Stojanovic et al., [26] Non-randomized retrospective study 12-month followup period Transepithelial technique was effective in decreasing Kmax, cylindrical equivalent, SE, and enhanced CDVA without any considerable harmful effects.
Raiskup et al., [32] Experimental analysis Regardless of the concentration of alcohol content in blood, similar riboflavin absorption level is observed through the cornea epithelium.
Kocak et al., [33] Retrospective study 12-months followup period Epithelium-off technique was effective in declining keratoconus progression.
Choi et al., [42] Quantitative study Corneal thickness improved by 107% post CXL administration in ex vivo models.