2型糖尿病患者不同糖尿病视网膜病变时期角膜神经纤维损害观察

Corneal nerve fiber damage in different stage of diabetic retinopathy patients with type 2 diabetes

目的 观察2型糖尿病患者不同糖尿病视网膜病变（DR）时期的角膜神经纤维损害情况.方法 横断面观察性研究.120例2型糖尿病患者120只眼（糖尿病组）纳入本研究.按照DR国际分期标准将糖尿病组患者分为无视网膜病变（NDR）、轻中度非增生型DR（mNPDR）、重度非增生型DR（sNPDR）及增生型DR（PDR）,并以此分为4个亚组,每亚组30例30只眼.纳入健康正常者30名30只眼作为对照组.所有受检者均采用HRT3激光角膜共聚焦显微镜观察角膜神经纤维长度（NFL）、角膜神经纤维密度（NFD）、角膜神经纤维分支密度（NFB）、角膜神经弯曲度（NT）等角膜神经指标.采用Spearman相关性分析法分析角膜神经指标与年龄、糖尿病病程、糖化血红蛋白（HbA1c）的相关性.结果 与对照组比较,糖尿病组患者NFL、NFD、NFB减少（F=147.315、142.586、65.898,P=0.000、0.000、0.000）,NT增加（F=39.431,P=0.000）,差异均有统计学意义.糖尿病组患者NFL、NFD、NFB随DR严重程度逐渐减少,NT随DR严重程度逐渐增加.糖尿病组各亚组组间比较,sNPDRR组与PDR组患者NFL、NFD、NFB、NT之间的差异无统计学意义（P＞0.05）;其余各组患者NFL、NFD、NFB、NT之间的差异均有统计学意义（P＜0.05）.Spearman相关性分析结果显示,年龄（r=-0.071、-0.080、0.001、0.100,P=0.391、0.328、0.991、0.224）、HbA1c（r=-0.109、-0.115、-0.126、0.025,P=0.238、0.211、0.169、0.781）与NFL、NFD、NFB、NT均无相关性;糖尿病病程与NFL、NFD呈负相关（r=-0.212、-0.264,P=0.020、0.004）,与NT呈正相关（r=0.261,P=0.004）,与NFB无相关性（r=-0.119,P=0.194）.结论 2型糖尿病患者角膜神经纤维损害主要表现为NFL、NFD、NFB减少,NT增加,且发生在未出现视网膜病变之前;随着DR病情加重,角膜神经纤维损害逐步加重,但在sNPDR、PDR时期变化不明显.

Objective To observe the corneal nerve fibres damage in different stage of diabetic retinopathy （DR） with type 2 diabetes.Methods A cross-sectional study.One hundred and twenty eyes of 120 patients with type 2 diabetes served as diabetes group.According to International Clinical Diabetic Retinopathy Disease Severity Scales （2002）,diabetes patients were classified into 4 subgroups：patients without diabetic retinopathy （NDR）,patients with mild or moderate non-proliferative diabetic retinopathy （mNPDR）,patients with severe non-proliferative diabetic retinopathy （sNPDR） and patients with proliferative diabetic retinopathy （PDR）,each subgroup has 30 eyes of 30 patients.Another 30 eyes of 30 healthy participants served as control group.All eyes were scanned with HRT3 in vivo corneal confocal microscopy.Images of sub-basal nerve plexus were quantified including nerve fiber length （NFL）,nerve fiber density （NFD）,nerve fiber branch density （NFB）,and nerve tortuosity （NT）.The correlations of corneal nerve fiber with age,duration of diabetes and glycated hemoglobin （HbA1 c） were analyzed using Spearman correlation analysis.Results NFL,NFD and NFB were found to be significantly lower in diabetic patients （F=147.315,142.586,65.898;P=0.000,0.000,0.000）,NT was significantly greater in diabetic patients （F=39.431,P=0.000）,when compared to control group.In diabetic patients,NFL,NFD and NFB were gradually reduced with DR severity,NT was gradually increased with DR severity.While the difference ofNFL,NFD,NFB,NT was not statistically significant between sNPDR and PDR subgroups （P〉.0.05）,but was statistically significant between other subgroups （P〈0.05）.Spearman correlation analysis results showed that age （r=-0.071,-0.080,0.001,0.100;P=0.391,0.328,0.991,0.224） and HbAlc （r=-0.109,-0.115,-0.126,0.025;P=0.238,0.211,0.169,0.781） had no correlation with NFL,NFD,NFB,NT.Duration of diabetes was negatively correlated with the NFL,NFD （r=-0.212,-0.264;P=0.020,0.004）,positive correlated with NT （r=0.261,P=0.004）,and had no correlation with NFB （r=-0.119,P=0.194）.Conclusions Corneal nerve fiber loss and nerve tortuosity increased were found in patients with type 2 diabetes,and even without diabetic retinopathy.The progress of corneal neuropathy was correlated with the severity of DR,but it was not change significantly between sNPDR and PDR.