Experimental study of riboflavin-ultraviolet A collagen crosslinking for the treatment of alkali-induced corneal burns in rabbits

Objective To evaluate the efficacy of riboflavin-ultraviolet A (UVA) collagen crosslinking (CXL) combined with drugs for the treatment of alkali-induced corneal burns in rabbits. Methods Prospective experimental study.The corneas of left eyes of 40 healthy New Zealand rabbits were established alkali burn model. All rabbits were randomly divided into 4 groups: the model group, drugs treatment group, crosslinking group and combined group, with 10 cases in each group. The model goup received no treatments. The drug goup received drug treatment. Riboflavin-UVA collagen crosslinking was appied in crosslinking group and the combined group received CXL combined with drug treatment. Therapeutic efficacy of each group were compared at 1 and 3 months after operation. Results The corneal epithelial healing time in the model group, drug group, cross-linking group and combined group were (32.9±5.8 ), (12.8±2.3), (25.9±3.2 ) and (10.7±2.5 )days, respectively. The difference were statistically significant among the four groups (F=67.647, P=0.000) . The corneal turbidity score of combined group was the lowest among the 4 groups, followed by the drug group, and the score of model group was the heaviest (F=6.446, P=0.001). The number of inflammatory cells were (162.6±33.3), (46.0±21.3 ), (87.9±7.5)and (8.3±6.5)cells respectively under single confocal microscopy field of vision ( 400 μm×400 μm). The difference among the 4 groups was statistically significant (χ2=36.040, P=0.000). The corneal collagen fibers with pathological examination in the combined group were the thickest and densely arranged, followed by crosslinking group. Conclusion The efficacy of drug combined with cross-linking for the treatment of corneal alkali burn in rabbits is better than that of simple drug therapy or simple corneal collagen cross-linking. Key words: Riboflavin-ultraviolet A; Collagen; Crosslinking; Burn, alkali, coreal