Objective:To observe and compare the clinical effect of single-incision and two-incision posterior chamber phakic intraocularlens implantation in the correction of extreme myopia.Methods:40 cases(80 eyes) of patients with extreme myopia underwent conventional two-incision posterior chamber phakic intraocularlens implantation in our hospital from January 2011 to June 2013 were selected as the control group and 40 cases(80 eyes) underwent single-incision posterior chamber phakic intraocularlens implantation from July 2013 to January 2016 were selected as observation group.The open hole before and after operation,best corrected visual acuity of vision,operation safety,effectiveness index,diopter (column mirror,equivalent ball for eyeglasses),intraocular pressure,ECD,anterior chamber depth and occurrence of complications were compared between two groups.Results:The uncorrected visual acuity (UCVA) of both groups at 6 months after operation were significantly higher than those before operation (P＜0.05),which was significantly higher in the observation group than that of the control group (P＜0.05);The operation safety and effectiveness index of observation group were significantly higher than those of the control group (P＜0.05);The cylinder and spherical equivalent degree of both groups at 6 months after operation were significantly better than those before operation(P＜0.05),which was significantly better in the observation group than that of the control group(P＜0.05).The corneal endothelial cell counts(ECL) of control group after operation was significantly lower than that before operation (P＜0.05),and no significant difference was found in the ECL of observation group before and after operation (P＞0.05).The ECL of observation group after operation was significantly higher than that of the control group (P＜0.05);The incidence rate of complication in observation group was significantly lower than that of the control group (P＜0.05).Conclusion:Compared with two-incision operation,the single-incision posterior chamber phakic intraocularlens implantation had remarkable clinical effect in the correction of extreme myopia with higher security.

Objective:To detect the levels of vascular endothelial growth factor (VEGF) and nitric oxide (NO) in the serum of patients with early diabetic retinopathy (DR) and to explore their value in the treatment of DR.Methods:Fifty-nine patients with type 2 diabetes mellitus from March 2019 to June 2020 in the Yulin Second Hospital were collected and divided into the non-diabetic retinopathy (NDR) group (32 cases) and background stage diabetic retinopathy (BDR) group (27 cases) according to the DR grading criteria, and 29 healthy subjects were enrolled in the healthy control (HC) group. Serum VEGF levels were measured by a double antibody sandwich enzyme-linked immunosorbent assay (ELISA), and serum NO levels were measured by the nitrate reductase method (one-step method). Pearson analysis was used to correlate serum VEGF with NO levels in each group, and a logistic regression model was used to analyze the risk factors for DR.Results:Compared with the HC group, the differences in serum VEGF and NO levels of patients in the BDR group were statistically significant (all P < 0.05). The serum VEGF and NO levels were positively correlated in all groups (all P < 0.01). Duration of diabetes, smoking, glycated hemoglobin A1c (HbA1c), serum VEGF, and NO levels were high risk factors for DR. Conclusions:Serum VEGF and NO levels may be potential pathological mechanisms for the development of microvascular complications in patients with type 2 diabetes, and the interaction may induce or accelerate the progression of DR. This study is expected to provide a new idea of complementary or combined treatment in the treatment of DR.