Abstract
Purpose: :
To examine whether specific structures of anthocyanins are essential for inhibitory effect on ocular elongation in chick myopia models, we compared the effects of four black currant anthocyanins (BCAs).
Methods: :
Two myopia models were used in this study. Negative lenses (-8D) or translucent lenses (to induce form deprivation) were placed on the right eyes of 8-day-old chicks. The elongation of the ocular components was calculated as the difference between the right eye and the non-treated left eye. BCAs are composed of cyanidin-3-glucoside (C3G), cyanidin-3-rutinoside (C3R), delphihidin-3-rutinoside (D3R) and delphinidin-3-glucoside (D3G). Each anthocyanin was administered intravenously at the dose of 0.027µmol/kg once a day for three days. Three days after the placement of the lenses, A-scan ultrasound instrument was used to measure the ocular parameters.
Results: :
The axial length elongations in the myopia model with the negative lenses were as follows. The values in the C3G-, C3R-, D3G-, D3R-treated and control chicks were 0.26±0.049, 0.17±0.049, 0.36±0.043, 0.17±0.036 and 0.50±0.056 mm (n=11), respectively; only those in the C3G-, C3R- and D3R-treated chicks were significantly lower than the values in the control chicks (P<0.01, P<0.001 and P<0.001). In the case of the translucent lenses, the axial length elongations in the C3G-, C3R-, D3G-, D3R-treated and control chicks were 0.32±0.051, 0.25±0.034, 0.43±0.076, 0.43±0.043 and 0.52±0.047 mm (n=12), respectively; only those in the C3G and C3R-treated chicks were significantly lower than the values in the control chicks (P<0.05 and P<0.001). Furthermore, the effects of four BCAs on the vitreous chamber depth were same results as those on the axial length in the two models.
Conclusions: :
We showed for the first time in an in vivo study that the cyanidin structure and rutinoside moiety of BCAs play important roles in inhibiting the elongation of ocular components. Furthermore, each of BCA constituents had a unique site of action.
Keywords: myopia • vitreous • injection