Objective: To investigate the distribution of tear film lipid layer thickness (LLT) and the relationship between symptoms and signs of dry eye and tear film LLT in the population of Taishitun Community in Beijing. Methods: A cross-sectional study. From May 2016 to August 2016, three streets of Taishitun Community were randomly selected as survey districts and 540 persons were taken as investigation subjects. Every participant completed 6 items of dry eye examinations as follows: questionnaire (Ocular Surface Disease Index, OSDI), measurement of tear film LLT, tear film break-up time (TBUT), corneal and conjunctival staining, SchirmerⅠtest and the infrared meibomian photography. According to their age, all participants were divided into four groups: junior group (<18 years old), youth group (18 to 40 years old), middle-aged group (41 to 59 years old) and the elderly group (over 60 years old). With the OSDI criteria, no dry eye symptom group (score, <12 points), mild to moderate dry eye symptom group (score, 12 to 32) and severe dry eye symptom group (score, 33-100) were included. With the statistical methods of variance analysis and multivariate Logistic regression analysis, distribution of the variables of LLT and the relationship between dry eye symptoms and LLT were studied. Results: A total of 473 residents finally participated in this study, and the response ratio was 87.6%. The values of LLT were normally distributed. The average LLT was (59.87±18.50) nm [(60.16±19.15) nm in males and (59.67±18.57) nm in females], and the comparison of LLT with different genders was not statistically significant (t=0.198, P=0.843). The tear film LLT of four different age groups had statistical significance (F=15.092, P<0.05), and increased with age [(56.10±18.33) nm in the junior group, (54.60±16.29) nm in the youth group, (60.61±19.18) nm in the middle-aged group and (73.25±14.58) nm in the elderly group]. The LLT was inversely proportional to the severity of dry eye symptoms. With a thinner LLT, the symptoms of the subjects turned severe. In the elderly with different degrees of symptoms, the LLT was significantly different (F=0.019, P<0.05), while in the youth and middle-aged groups with different degrees of symptoms, the LLT was not significantly different (F=0.096, P>0.05. F=0.538, P>0.05). In the OSDI symptom questionnaire, only blurred vision and decreased visual acuity were related to the tear film LLT (P<0.05). There was no significant correlation between the TBUT, SchirmerⅠtest result, meibomian gland loss rate and the tear film LLT (P>0.05). Conclusions: In Taishitun Community of Beijing, the values of tear film LLT had a normal distribution. The LLT was positively correlated with age, but inversely correlated with the severity of the symptoms of dry eye. There was no significant correlation between the LLT and the TBUT, SchirmerⅠtest result and meibomian gland loss rate.(Chin J Ophthalmol, 2017, 53: 495-501).
目的： 调查北京太师屯社区居民泪膜脂质层厚度(LLT)分布情况以及人群中干眼症状、体征与泪膜脂质层厚度的相互关系。 方法： 横断面研究。2016年5至8月随机选取北京太师屯社区3个街道作为筛查点，抽取并获得知情同意调查对象540人。对所有受试者按如下顺序进行6项检查：（1）眼表疾病评分指数（OSDI）问卷调查；（2）LLT检查；（3）泪膜破裂时间（TBUT）测定；（4）角结膜荧光素染色；（5）SchirmerⅠ试验；（6）红外线睑板腺照相。根据年龄将受试者分为4个组：少年组（<18岁）、青年组（18~40岁）、中年组（41~59岁）以及老年组（≥60岁）；根据OSDI评分将受试者分为3个组：无干眼症状组（<12分）、轻中度干眼症状组（12~32分）及重度干眼症状组（33~100分）。不同性别泪膜脂质层厚度的比较采用独立样本t检验，不同年龄分组间的差异性检验采用单因素方差分析，不同症状程度间的差异性检验同样采用单因素方差分析，两两比较采用SNK-q检验，LLT与干眼症状及其他泪液检查结果之间的相关性采用Spearman方法分析，有相关性的指标再多因素Logistic逐步回归分析。 结果： 473人参加本研究，应答率87.6%，其中男性198名，女性275名，平均年龄（39.8±15.4）岁。受试人群中泪膜LLT呈正态分布，平均为（59. 87±18.50）nm，其中男性为（60.16±19.15）nm，女性（59.67±18.57）nm，男性、女性泪膜LLT比较差异无统计学意义（t=0.198，P=0.843）。少年组LLT为（56.10±18.33）nm，青年组为（54.60±16.29）nm，中年组为（60.61±19.18）nm，老年组为（73.25±14.58）nm，差异有统计学意义（F=15.092，P<0.05），且随年龄增大有增加趋势。泪膜LLT与干眼症状严重程度呈反变关系，即症状严重的受试者，泪膜LLT有变薄的趋势。按年龄分组观察，发现老年人群中，症状不同程度受试者其LLT差异有统计学意义（F=0.019，P<0.05），而青少年及中年人群，不同程度症状受试者其LLT无统计学差异（F=0.096，0.538；P>0.05）。OSDI问卷中的12个症状中仅发现视物模糊、视力下降与泪膜LLT有关（P<0.05）。而泪膜破裂时间、Schirmer试验及睑板腺缺失率等体征与泪膜LLT无明显相关性（P>0.05）。 结论： 北京太师屯社区人群泪膜LLT呈正态分布，该数值与年龄呈明显正相关，与干眼症状严重程度呈反变关系；泪膜LLT与TBUT、Schirmer试验及睑板腺缺失率等客观指标无明显相关性。（中华眼科杂志，2017，53：495-501）.
Keywords: Cross-sectional studies; Dry eye syndromes; Interferometry; Lipids; Meibomian glands; Tears.