AIM: To investigate the risk factors of myopia, and provide evidence for the prevention and treatment of myopia in preschool children.METHODS:This is a retrospective case-control study. A total of 168 preschool-aged children(168 eyes)were enrolled from the ophthalmology department at Affiliated Hospital of Qingdao University between September 2021 and September 2023, selecting the eye with poorer vision for inclusion; the right eye was selected when both eyes had equal vision. Grouping criteria: Children with spherical equivalent(SE)>0 D and age-appropriate normal visual acuity(≥0.5 for ages 3-5; ≥0.7 for ages 6-7)were directly assigned to the non-myopia group. Children with SE <0 D underwent cycloplegic refraction after 3 days of 1% atropine sulfate gel application(three times daily). Those with SE ≤-0.50 D and failure to achieve age-normal visual acuity(<0.5 for ages 3-5; <0.7 for ages 6-7)were assigned to the myopia group, with 84 children(84 eyes)in each group. All participants underwent measurements of visual acuity, intraocular pressure, refraction, and ocular biometric parameters. Parents or guardians completed risk factor questionnaires during the visit, covering daily outdoor activity duration, daily electronic device usage/reading time, parental myopia status, maternal delivery mode, and full-term birth status.RESULTS:Significant differences were observed in uncorrected visual acuity, spherical power, SE, and axial length between the two groups of children(all P<0.05). No statistically significant differences were found in daily sleep duration, daily reading/homework time, maternal myopia status, mode of delivery, or full-term delivery status(all P>0.05). However, significant differences existed in daily outdoor activity time, daily electronic device usage duration, maternal myopia degree, paternal myopia degree, maternal age of myopia onset, and paternal age of myopia onset(all P<0.05). Logistic regression analysis identified the following risk factors for myopia in preschool children: daily outdoor activity under 2 h, daily electronic device use exceeding 60 min, maternal myopia degree, maternal early-onset myopia, paternal high myopia, and paternal early-onset myopia. Analysis of interaction effects children gender and myopia-related factors on SE revealed significant interactions of children gender with paternal myopia degree, maternal and paternal age of myopia onset(P<0.05). Simple effects analysis further demonstrated that girls exhibited higher degree of myopia than boys in families with paternal early-onset myopia, maternal early-onset myopia, or paternal high myopia(P<0.05).CONCLUSION:Insufficient daily outdoor activity time(under 1 h), daily electronic device use exceeding 60 min, and parental myopia are significant risk factors for myopia development in preschool children. Among these children, girls' refractive status was particularly associated with parental refractive status.

Objective:To investigate the predictive value of platelet-to-neutrophil ratio (PNR) on hemorrhagic transformation (HT) and poor outcomes at 90 d after intravenous thrombolysis (IVT) in patients with acute ischemic stroke (AIS).Methods:Patients with AIS received IVT in Hefei Second People's Hospital from July 2019 to June 2021 were retrospectively enrolled. HT was defined as intracerebral hemorrhage found by CT reexamination within 24 h after IVT, and the poor outcome was defined as the modified Rankin Scale score ≥3 at 90 d after onset. Multivariate logistic regression analysis was used to determine the independent predictors of HT and poor outcomes at 90 d, and the predictive value of PNR on HT and poor outcomes at 90 d was analyzed by receiver operating characteristic (ROC) curve. Results:A total of 202 patients with AIS treated with IVT were included, of which 32 had HT and 50 had poor outcomes at 90 d after onset. Multivariate logistic regression analysis showed that PNR at 24 h after IVT was significantly and independently negatively correlated with the poor outcomes (odds ratio [ OR] 0.959, 95% confidence interval [ CI] 0.928-0.991; P=0.012); PNR at admission ( OR 0.886, 95% CI 0.827-0.948; P<0.001) and PNR at 24 h after IVT ( OR 0.923, 95% CI 0.879-0.969; P=0.001) were significantly independently and negatively correlated with HT. ROC curve analysis showed that the area under the curve of PNR at 24 h after IVT for predicting poor outcomes was 0.733 (95% CI 0.659-0.807; P=0.012), the best cutoff value was 35.03, and the predictive sensitivity and specificity were 70.4% and 74%, respectively. The area under the curve of PNR at admission for predicting HT was 0.830 (95% CI 0.774-0.886; P<0.001), the best cutoff value was 34.81, and the predictive sensitivity and specificity were 70% and 93.7%, respectively. The area under the curve of PNR at 24 h after IVT for predicting HT was 0.770 (95% CI 0.702-0.839; P=0.001), the best cutoff value was 41.73, and the predictive sensitivity and specificity were 53.5% and 96.9%, respectively. Conclusion:For patients with AIS treated with IVT, lower PNR at 24 h after IVT is an independent predictor of the poor outcomes at 90 d, while PNR at admission and 24 h after IVT are the independent predictors of HT.