不同类型干眼患者泪膜脂质层厚度及其与临床特征的关系

Lipid layer thickness of tear film and its association with clinical characteristics in different types of dry eye patients

目的研究不同类型干眼患者泪膜脂质层厚度（LLT）及其与干眼临床特征的关系。方法采用系列病例观察研究方法，连续纳入2016年4—8月在北京同仁医院就诊的干眼患者306例306眼行眼表疾病指数（OSDI）问卷调查、睑缘及眼表裂隙灯显微镜检查、泪膜LLT测量、泪膜破裂时间（TBUT）测定、Schirmer试验Ⅰ（SⅠt）检测和红外线睑板腺照相，其中OSDI〉12分、睑缘评分≥2分者157例为睑板腺功能障碍（MGD）组，OSDI〉12分、SⅠt〈5 mm/5 min者53例作为水液缺乏性干眼（ADDE）组，OSDI〉12分、SⅠt〈5 mm/5 min且睑缘评分≥2分者96例作为混合型干眼组。采用LipiView？眼表面干涉仪测量干眼患者泪膜LLT的分布，分析其与患者症状、体征间的相关性。结果干眼患者泪膜LLT值平均为（60.41±18.57）nm，呈正态分布。MGD组、ADDE组和混合型干眼组患者泪膜LLT分别为（57.04±18.26）、（63.52±18.44）和（60.26±18.71）nm，总体比较差异有统计学意义（F＝2.347，P＝0.035），其中MGD组患者泪膜LLT明显薄于ADDE组，差异有统计学意义（t＝2.077，P＝0.039）。患者LLT与OSDI问卷评分呈低度负相关（r＝－0.201，P＝0.003），与SⅠt及睑板腺缺失率均呈负相关（r＝－0.146，P＝0.005；r＝－0.156，P＝0.046）。亚组分析显示，MGD组患者LLT与OSDI评分呈负相关（r＝－0.285，P＝0.000），ADDE组和混合型干眼组患者LLT与OSDI评分无明显相关性（均P〉0.05）；3个组患者LLT与SⅠt间均无明显相关性（均P〉0.05）；混合型干眼组及MGD组患者LLT与睑板腺缺失率的相关性均明显大于总体相关性（r＝－0.335、－0.248、－0.156）。患者异物感、眼酸痛、看电视后眼部不适和看计算机后眼部不适与LLT均呈负相关（r＝－0.243、－0.205、－0.223、－0.258，均P〈0.05）。结论不同类型的干眼患者LLT不同，MGD患者LLT偏薄，而ADDE患者LLT偏厚，泪膜呈现油－水互补趋势；异物感、眼酸痛、看电视或计算机引起眼部不适等症状与LLT相关。

ObjectiveTo investigate tear film lipid layer thickness （LLT） and its association with clinical symptom and sign in different types of dry eye patients.MethodsA serial case-observational study was carried out.Three hundred and six eyes of 306 dry eye patients were included in Beijing Tongren Hospital from April to August 2016.Ocular surface disease index （OSDI） questionnaire, eyelid slit lamp examination, the measurement of tear film lipid thickness （LLT）, tear film break-up time （TBUT）, Schirmer Ⅰtest （SⅠt） and the infrared meibomian photography were performed on the patients.The 157 patients with OSDI 〉12 and eyelid score ≥2 served as the MGD group; 53 patients with OSDI 〉12 and SⅠt value﹤5 mm/5 minutes served as ADDE group; 96 patients with OSDI〉12, eyelid score ≥2 and SⅠt value﹤5 mm/5 minutes served as MGD/ADDE group.Tear film LLT was detected with LipiView？ ocular surface interferometer and the association of LLT with clinical characteristics of the patients was analyzed.This study protocol was approved by Ethic Committee of Beijing Tongren Hospital and written informed consent was obtained from each patient prior to any relative medical examination.ResultsTear film LLT of the participants was normally distributed with the average was （60.41±18.57）nm.LLT in the MGD group, ADDE group, MGD/ADDE group were （57.04±18.26）, （63.52±18.44） and （60.56±18.71）nm, respectively, with a significant difference among the three groups （F=2.347, P=0.035）, and the LLT value was significantly lower in the MGD group than that in the ADDE group （t=2.077, P=0.039）. The LLT value showed negative correlations with the severity of dry eye symptom, SⅠt and meibomian gland loss rate （r=-0.201, P=0.003; r=-0.146, P=0.005; r=-0.156, P=0.046）. OSDI score was significantly correlated with LLT only in the MGD group （r=-0.285, P=0.000）. No significant correlation was seen between LLT and SⅠt in all the groups （all at P〉0.05）. In the MGD/ADDE group and MGD group, the correlation between LLT and meibomian gland loss rate was significantly greater than the overall correlation （r=-0.335, -0.248, -0.156）. The dry eye symptoms in OSDI questionnaire like foreign body sensation, eye pain, discomfort when watching TV or computer showed significant correlations with LLT （r=-0.243, -0.205, -0.223, -0.258, all at P〈0.05）.ConclusionsThe tear LLT is appeared to be varied in different types of dry eye.The LLT is thinner in the dry eyes with MGD and thicker in the dry eyes with ADDE.There are association between tear LLT and foreign body sensation, eye pain, discomfort when watching TV or computer.