角膜上皮基底神经丛结构拼图法对全视网膜光凝后糖尿病患者角膜神经损伤的评估

Evaluation of corneal nerve damage in diabetic patients after panretinal photocoagulation based on the wide-field mosaic analysis of corneal subbasal nerve plexus

目的采用结构拼图观察糖尿病患者全视网膜光凝(PRP)前后角膜上皮基底神经丛(SNP)的变化,探讨PRP对SNP的损伤及相关机制。方法采用随机对照研究方法,于2019年4—11月纳入拟在山西省眼科医院行PRP治疗的2型糖尿病合并双眼糖尿病视网膜病变(DR)Ⅳ期的患者57例114眼,采用随机数字表法将患者分为水平-垂直激光组和垂直-水平激光组。其中水平-垂直激光组29例29眼,光凝顺序为颞侧-鼻侧-下方-上方;垂直-水平激光组28例28眼,光凝顺序为下方-上方-颞侧-鼻侧。选择病情较重的眼为治疗眼,对侧眼为对照眼,分别于PRP治疗前、每次光凝后1周和PRP完成后1个月采用角膜激光扫描共焦显微镜(CCM)采集SNP涡状结构及其周围2~3 mm区域的图像,采用Photoshop CC 2017图像处理软件合成拼图,于Neuron J图像分析软件中测量涡状区神经纤维长度(NFL);于每次光凝后采用简式McGill疼痛问卷调查患者激光术后治疗眼疼痛情况;比较患者不同眼别及不同光凝顺序组间不同观察时间点SNP的NFL变化。结果治疗眼PRP后有11眼出现不同程度SNP神经结构缺失的神经损伤表现,对照眼SNP神经纤维未观察到明显变化。不同观察时间点治疗眼与对照眼NFL总体比较差异有统计学意义(F_(眼别)=2.020,P=0.039;F_(时间)=4.062,P=0.001)。水平-垂直激光组在第1次光凝后和第2次光凝后出现光凝侧SNP结构缺失;垂直-水平激光组在第3次光凝后和第4次光凝后出现光凝侧SNP结构缺失。2个组间治疗眼NFL总体比较差异无统计学意义(F_(分组)=0.099,P=0.754),治疗前后不同时间点NFL总体比较差异有统计学意义(F_(时间)=5.231,P<0.001)。PRP后治疗眼出现疼痛者9例,其中7例疼痛发生于第1次光凝后。结论DR患者PRP后可出现SNP损伤,水平径线光凝时容易导致光凝侧的SNP损伤。

Objective To explore the damage of panretinal photocoagulation(PRP)to the subbasal nerve plexus(SNP)and its related mechanisms by comparing SNP changes in wide-field mosaic between before and after PRP treatment in diabetic patients.Methods A randomized controlled study was conducted.Fifty-seven patients(114 eyes)with type 2 diabetes mellitus and binocular diabetic retinopathy(DR)stage IV to receive PRP treatment in Shanxi Eye Hospital from April to November 2019 were enrolled.The subjects were randomly divided into horizontal-vertical laser group and vertical-horizontal laser group according to a random number table.Twenty-nine eyes from 29 patients were assigned to the horizontal-vertical laser group with the photocoagulation sequence of temporal-nasal-inferior-superior.Twenty-eight eyes from 28 patients were assigned to the vertical-horizontal laser group with the photocoagulation sequence of inferior-superior-temporal-nasal.The severer eyes of each subject were chosen as the treatment eye and the contralateral eyes were chosen as the control eye.Corneal confocal laser scanning microscopy(CCM)was performed before PRP treatment,1 week after each photocoagulation,and 1 month after the completion of PRP treatment to collect images of the SNP over an area of 2-3 mm around the whorl-like pattern.Captured images at each time were merged into one image by using the Photoshop CC 2017 image processing software,and then the nerve fiber length(NFL)of whorl-like pattern was measured by Neuron J image analysis software.McGill pain questionnaire was used to investigate the pain of patients after each photocoagulation.The NFL changes of SNP at different time points were compared between different eyes and different photocoagulation sequence groups.The study protocol adhered to the Declaration of Helsinki and was approved by an Ethics Committee of Shanxi Eye Hospital(No.201804b).Written informed consent was obtained from each patient prior to entering the study cohort.Results After PRP treatment,there were different degrees of neural structure loss of SNP nerve fibers in 11 treatment eyes,but there was no significant change in SNP nerve fibers in the control eyes.There were significant differences in NFL between the treatment eyes and the control eyes at various time points(F_(eyes)=2.020,P=0.039;F_(time)=4.062,P=0.001).In the horizontal-vertical laser group,different degrees of neural structure loss on the photocoagulation side were found in SNP nerve fibers after the first and second photocoagulation.In the vertical-horizontal laser group,different degrees of neural structure loss on the photocoagulation side were found in SNP nerve fibers after the third and fourth photocoagulation.There was no significant difference in NFL of treatment eyes between the two groups(F_(group)=0.099,P=0.754),but there was a significant difference in NFL at various time points before and after treatment(F_(time)=5.231,P<0.001).There were 9(9/57)patients who complained of pain after PRP,which occurred at the first time of photocoagulation in 7 of them.Conclusions SNP damage may occur after PRP in patients with DR,and SNP is prone to be damaged on the photocoagulation side when performing horizontal photocoagulation.