Suppressive effect of metformin against experimental myopia in chick

Abstract

Purpose : Metformin, an oral hypoglycemic agent, is the drug for the treatment of type 2 diabetes which is also known as one of the anti-aging drugs. We hypothesized that the axial length elongation in myopia progression may be a process of aging. In this study, we examined the therapeutic effect of oral metformin administration against chick lens-induced experimental myopia model.

Methods : Seventeen male White-Leghorn chicks were divided into two groups, the control group and the metformin group (n = 8 and 9, respectively). The animals were attached - 9 diopters (D) lenses to the right eye at six days after hatching, and their ocular parameters were evaluated at seven days after the lens attachment. The metformin group received oral metformin (500 mg/kg/day in phosphate buffered saline) at 9 am every day for 1 week while the control group received the same amount of the vehicle. Baseline refraction, vitreous chamber depth, and axial length were measured using an auto refractometer and a high frequency B-scan ultrasonography at the beginning and the end of the one week experimental period. The changes of the ocular parameters during the period were evaluated, and the two groups were compared by Mann-Whitney U Test for the statistical analysis. A p value less than 0.05 was considered as a significant difference.

Results : The change in spherical equivalent (D) of covered eyes for 1 week was -4.48±2.51 (standard deviation) in the control group and -2.45±2.88 in the metformin group (P = 0.09). The change in vitreous chamber depth (mm) of covered eyes for 1 week was 0.86±0.13 in the control group and 0.56±0.13 in the metformin group (P < 0.05). The change in axial length (mm) of covered eyes for 1 week was 1.58±0.30 in the control group and 1.12±0.20 in the metformin group (P < 0.05).

Conclusions : Oral metformin treatment has a suppressive effect against the axial length elongation in the chick lens-induced myopia model.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.