Characterization of Rabbit Corneas Subjected to Stromal Stiffening by the Acai Extract (Euterpe oleracea)

Purpose: In this study, we characterized rabbit corneas subjected to corneal cross-linking (CXL) with acai extract compared with a riboflavin photo-stimulated procedure. Materials and Methods: The corneas of the slaughterhouse rabbits were divided into three groups: control, consisting of untreated corneal samples; riboflavin/UVA, where corneas were treated with 0.1% riboflavin photo-stimulated at 365 nm as the standard protocol; and acai, where the samples were subjected to 4% acai extract for 0.5-2 h. After the CXL procedure, corneas of the three groups were characterized by analyzing their elastic modulus and thermal denaturation profile. Results: The elastic modulus at 3% strain showed an approximately threefold increase in the riboflavin/UVA group and 10.5 times in the corneas treated with 4% acai extract for 2 h, compared with the control group (p < 0.01). The denaturation temperature values of the two groups of crosslinked corneas increased significantly (p < 0.05) and were more pronounced in the acai group. Conclusions: The acai extract was effective in promoting CXL in rabbit corneas as characterized by the different techniques.