Retinal microcirculation changes in prediabetic patients with shortterm increased blood glucose using optical coherence tomography angiography

BACKGROUND Retinal microcirculation alterations are early indicators of diabetic microvascular complications.Optical coherence tomography angiography(OCTA)is a noninvasive method to assess these changes.This study analyzes changes in retinal microcirculation in prediabetic patients during short-term increases in blood glucose using OCTA.AIM To investigate the changes in retinal microcirculation in prediabetic patients experiencing short-term increases in blood glucose levels using OCTA.METHODS Fifty volunteers were divided into three groups:Group 1[impaired fasting glucose(IFG)or impaired glucose tolerance(IGT)],Group 2(both IFG and IGT),and a control group.Retinal microcirculation parameters,including vessel density(VD),perfusion density(PD),and foveal avascular zone(FAZ)metrics,were measured using OCTA.Correlations between these parameters and blood glucose levels were analyzed in both the fasting and postprandial states.RESULTS One hour after glucose intake,the central VD(P=0.023),central PD(P=0.026),and parafoveal PD(P<0.001)were significantly greater in the control group than in the fasting group.In Group 1,parafoveal PD(P<0.001)and FAZ circularity(P=0.023)also increased one hour after glucose intake.However,no significant changes were observed in the retinal microcirculation parameters of Group 2 before or after glucose intake(P>0.05).Compared with the control group,Group 1 had a larger FAZ area(P=0.032)and perimeter(P=0.018),whereas Group 2 had no significant differences in retinal microcirculation parameters compared with the control group(P>0.05).Compared with Group 1,Group 2 had greater central VD(P=0.013)and PD(P=0.008)and a smaller FAZ area(P=0.012)and perimeter(P=0.010).One hour after glucose intake,Group 1 had a larger FAZ area(P=0.044)and perimeter(P=0.038)than did the control group,whereas Group 2 showed no significant differences in retinal microcirculation parameters compared with the control group(P>0.05).Group 2 had greater central VD(P=0.042)and PD(P=0.022)and a smaller FAZ area(P=0.015)and perimeter(P=0.016)than Group 1.At fasting,central PD was significantly positively correlated with blood glucose levels(P=0.044),whereas no significant correlations were found between blood glucose levels and OCTA parameters one hour after glucose intake.CONCLUSION A short-term increase in blood glucose has a more pronounced effect on retinal microcirculation in prediabetic patients with either IFG or IGT.

Effectiveness and the nomogram of small incision lenticule extraction in the correction of myopic anisometropia in adults

AIM:To evaluate the safety,effectiveness,and predictability of small incision lenticule extraction(SMILE)for the treatment of anisometropia,and to explore the personalized design scheme of SMILE in correcting adult myopia anisometropia based on the nomogram.METHODS:It’s a prospective cohort study.Patients with anisometropic myopia of refractive difference≥2.0 diopters(D)who underwent SMILE between September 2020 and March 2021 were enrolled.Clinical features and visual function were assessed preoperatively and at 1wk,1,3,and 6mo after the operation.The examination included tests for uncorrected distance visual acuity(UDVA),corrected distance visual acuity(CDVA),refractive errors,effectiveness index(preoperative CDVA/postoperative UDVA),safety index(postoperative CDVA/preoperative CDVA),nomogram and stereoscopic function.Paired t-test,Wilcoxon signed-rank test and repeated-measures analyses of variance were used for continuous variables,and Pearson Chi-squared test was used for categorical variables.RESULTS:The study involved 45 consecutive patients(average age:25.0±6.9y;82 out of 90 eyes underwent SMILE,while 8 eyes were not operated).The average preoperative spherical equivalent(SE)was-4.74±0.22 D.Six months after surgery,the effectiveness index was 1.05±0.12,and the safety index was 1.09±0.11.Seventy eyes(85.4%)exhibited SE correction error within±0.5 D.The percentage of eyes with Titmus stereoscopic function equal to or less than 200”significantly increased from 55.6%preoperatively to 88.9%postoperatively(P<0.05).There was statistically significant difference between higher myopia eyes and contralateral eyes in average nomogram value/spherical refraction ratio.CONCLUSION:SMILE is safe,effective and predictable in correcting myopic anisometropia,and it improves stereoscopic visual function of anisometropia patients.The precise and individualized design of the nomogram is a vital element to ensure the balance of both eyes after SMILE.