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

ABSTRACT

Purpose: In this study, we characterized rabbit corneas subjected to corneal cross-linking (CXL) with açaí 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 açaí, where the samples were subjected to 4% açaí 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% açaí 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 açaí group.

Conclusions: The açaí extract was effective in promoting CXL in rabbit corneas as characterized by the different techniques.

KEYWORDS:

• Açaí extract
• corneal crosslinking
• differential scanning calorimetry
• elastic modulus
• keratoconus
• riboflavin

Declaration of interest

The authors report no conflict of interest.

Funding

This work was supported by the grant numbers #2013/20857-3 and #2012/07343-8, São Paulo Research Foundation (FAPESP) and the National Council for Scientific and Technological Development (CNPq).

Additional information

Funding

This work was supported by the grant numbers #2013/20857-3 and #2012/07343-8, São Paulo Research Foundation (FAPESP) and the National Council for Scientific and Technological Development (CNPq).