Abstract: Objective: To investigate the effect of astaxanthin on the refractive status and pathological morphology of the guinea pig myopia models induced by concave lens, and to elucidate the improvement effect of astaxanthin on the refractive status of myopia. Methods: A total of 48 healthy guinea pigs were randomly divided into blank control group(n=12) and model group(n=36);the guinea pig myopia models(right eyes) were established with far vision optical method(left eyes were used as control).The guinea pig models were divided into model control group, high of astaxanthin (50 ig·kg^-1) group and low dose of astaxanthin(25 ig·kg^-1)group. After 2 and 4 weeks treatment, the diopters and the lengths of optic axis of both eyes of each guinea pig in various groups were tested, and at 4 weeks the right eyes of the pigs were removed and the pathomorphology was observed by HE staining. Results: The diopters of the model eyes in model group were lower than those of left eyes used as control(P<0.05) and those of right eyes in blank control group after 2 and 4 weeks (P<0.05 or P<0.01).The length of optic axis of the model eye in model group was increased compared with left eye used as controls and blank control group after 2 weeks (P<0.05) and especially at 4 weeks(P<0.01). Compared with model group,the axial oculi and diopters of the guinea pigs in astaxanthin groups were increased (P<0.05);the pathohistological changes were improved,the collagen fracture was obviously decreased,and the collagen fibers were orderly arranged. Conclusion: Astaxanthin can recover the length of optic axis, diopter and histomorphology of sclera of guinea pig myopia models in some extents.

Key words: astaxanthin, myopia, diopter, length of optic axis, guinea pig, disease model, animanl