AIM: To investigate the effect of modified Zhujing pill on retinal autophagy in mice with form deprivation myopia.

METHODS: Thirty C57BL/6 mice were randomly divided into a negative control group, a myopia model group and a traditional Chinese medicine intervention group, with 10 mice in each group. Except for the negative control group, all mice in the myopia model group and the traditional Chinese medicine intervention group used translucent EP tubes to cover their right eyes to make a form deprivation myopia(FDM)model; The traditional Chinese medicine intervention group gavage Zhujing pill modified suspension 0.546g/(kg·d)(0.15mL/d), the negative control group and the myopia model group were given an equal amount of normal saline(0.15mL/d)for 4wk. At the beginning and the end of the experiment respectively, the right eye diopter of the mouse was measured with a strip retinoscope, measurement of the axial length of the right eye of mouse by A-ultrasound. At the end of the experiment, the right eyes of all mice were taken for detection, and immunofluorescence method was used to locate and detect the activity and migration of the retinal microglia marker(Iba1); Transmission electron microscope observation of autophagosome formation in retinal pigment epithelial cells; Western Blot, real-time fluorescent quantitative PCR(q-PCR)to detect the autophagy marker LC3Ⅱ and p62 protein quantitative and gene expression in retinal tissues.

RESULTS: At the end of the experiment, the refractive power of the right eyes of mice showed that the myopia model group and the traditional Chinese medicine intervention group formed relative myopia, the myopia model group and the traditional Chinese medicine intervention group were significantly lower than those of the negative control group(all P<0.01). At the end of the experiment, the axial length of the myopia model group and the Chinese medicine intervention group were significantly increased compared with the negative control group(P<0.01). Immunofluorescence method for locating and detecting Iba1 showed that the average optical density of Iba1 in the retina of the myopia model group increased the most obviously, followed by the increase in the negative control group, and the decrease in the traditional Chinese medicine intervention group. Compared with the negative control group, the myopia model group increased significantly(P<0.05), and the traditional Chinese medicine intervention group was significantly lower than the myopia model group(P<0.05). It was found that Iba1 migrated to the ganglion cell layer in the myopia model group and the traditional Chinese medicine intervention group. Transmission electron microscopy showed that autophagosomes were observed in the retinal pigment epithelial cells of the myopia model group and the Chinese medicine intervention group. The results of Western Blot and q-PCR showed that the expression of LC3Ⅱ and p62 increased most obviously in the traditional Chinese medicine intervention group, followed by the myopia model group, and the negative control group was the lowest.

CONCLUSION: The results of the study show that modified Zhujing pill may enhance retinal autophagy in mice with FDM by inhibiting the activation of microglia.