METHODS: Collected 293 adolescents aged 11-12 who were examined in our hospital from January to June 2019.According to the refractive power, they were divided into emmetropia group(76 cases), low and moderate myopia group(144 cases), high myopia group(35 cases), and hyperopia group(38 cases). Measure and compare the plasma insulin and related indexes(blood sugar, glycosylated hemoglobin, C-peptide levels)of the four groups of subjects on an empty stomach and 2h after a meal. Person correlation was used to analyze the correlation between plasma insulin and its related indexes and diopter. The receiver operating characteristic(ROC)curve was used to explore the diagnostic value of plasma insulin levels for refractive dysplasia.

RESULTS: The average levels of insulin, blood glucose, glycosylated hemoglobin, and C-peptide in the low and moderate myopia group and the high myopia group on an empty stomach or 2h after a meal were higher than those in the emmetropia group and the hyperopia group. The levels of insulin, blood sugar and glycosylated hemoglobin in the high myopia group were higher than those in the low and moderate myopia group(all P<0.01). Plasma insulin, blood glucose, glycosylated hemoglobin, and C peptide levels were negatively correlated with diopter 2h after a meal(r=-0.691, -0.756, -0.546, -0.311, all P<0.05). The ROC curve showed that the cut-off value of plasma insulin level 2h after meal for identifying refractive errors was 0.367, the maximum area under the curve was 0.708(P<0.001, 95% CI: 0.576-0.840), the sensitivity was 63%, and the specificity was 73.7%.

CONCLUSION: Elevated plasma insulin level may affect refractive development, the higher the level, the higher the degree of myopia. Therefore, regular high-glycemic carbohydrate diets during the growth period may lead to the development of refractive errors and permanent visual impairment.