Keratograph 5M下正常人群泪膜脂质层的临床分析

Clinical Evaluation of Tear Film Lipid Layer in Normal Subjects with Keratograph 5M

摘要: 目的：应用Keratograph 5M分析无眼表临床症状的正常人脂质层厚度的变化及评估影响脂质层厚薄的因素。方法：收集无眼表临床症状的18~78岁正常人79例137只眼。所有受检者接受以下检查：使用裂隙灯显微镜对睑缘及睑板腺分泌物情况进行评估，使用Keratograph 5M脂质层照相观察评估脂质层的厚度(lipid layer thickness LLT)、首次泪膜破裂时间(NITBUTf)、平均泪膜破裂时间(NITBUTavg)，并行睑板腺照相。通过结构清晰度和色彩丰富度的方法对泪膜脂质层厚度进行评分，使用Image J软件分析睑板腺缺失比例。使用Stata 14.0统计软件对数据进行统计学处理，采用多元线性回归模型分析脂质层厚度与年龄、性别、睑板腺分泌能力评分、上下睑板腺缺失程度的关系。结果：79例受试者的平均年龄为(43.89 ± 16.56)岁。137只眼中，10只眼厚脂质层，占8%，50只眼(41%)为中等厚度脂质层，而薄脂质层眼有62只，占了总数的51%，脂质层厚薄评分为0.57 ± 0.64。多元线性回归模型显示，脂质层厚度与下睑板腺缺失比例(0.80% ± 0.74%)存在显著的负相关关系，每1%面积的下睑睑板腺的缺失，泪膜脂质层厚度变薄的机会增加了10.12倍(回归系数=−10.12，P = 0.005)；而上睑睑板腺的缺失(1.04% ± 0.76%)并不影响泪膜脂质层的厚度(回归系数=1.17，P = 0.744)。通过多元线性回归方程也可以看出高龄，性别及睑板腺分泌能力不是影响泪膜脂质层变薄的因素(P ≥ 0.282)。在无眼表临床症状受试者中，脂质层的变薄尚未引起泪膜稳定性的改变(P ≥ 0.459)。结论：无眼表临床症状的正常人中，下睑板腺缺失可能是影响泪膜脂质层变薄的主要因素之一，下睑睑板腺缺失面积越大，泪膜脂质层越薄。重视下睑睑板腺缺失的检测可能为诊断泪膜脂质层厚度变薄引起的蒸发过强型干眼提供依据。

Abstract: Objective: To investigate the changes of the tear film lipid layer thickness and factors relating tear film lipid layer thickness thinning in normal subjects with Keratograph 5M. Method: One hundred and thirty seven eyes of 79 normal subjects without ocular symptoms or ocular surface disorders were recruited in this study. The lid margin and the degree of ease of meibum were evaluated by slit-lamp microscopy. The Keratograph 5M (Oculus, Wetzlar, Germany) was used to evaluate the first non-invasive tear film break-up time (NITBUTf), the average non-invasive tear film break-up time (NITBUTavg), the images of tear film lipid layer and meibomian glands on every subject consecutively. A semi-automatic measurement with image J software was used to evaluate the meibomian glands loss on each subject. Statistical analysis was performed by using Stata 14.0. Multiple linear regression analysis was performed to investigate the factors that af-fect the tear film lipid layer thickness. Results: The mean age of 79 normal subjects was (43.89 ± 16.56) years. Of 137 normal eyes, 10 (8%) were defined as thick lipid layer, 50 eyes (41%) were moderate lipid layer, while more than half of them (62 eyes, 51%) were thin lipid layer. The mean score of the tear film layer thickness was 0.57 ± 0.64. Multiple linear regression analysis showed a significant negative correlation between tear film layer thickness and meibomian glands loss of lower eyelids (0.80 ± 0.74%). For each 1 percent meibomian glands loss in lower eyelids, the tear film layer thickness tended to be 10.12 times thinner (Coefficient = −10.12, P = 0.005). No correlation was found between lipid layer thickness and meibomian glands loss of upper eyelids (1.04 ± 0.76%) (Coefficient = 1.17, P = 0.744). Age, gender and the ease of the meibum expressed were not correlated with layer lipid thickness (P ≥ 0.282). Thinner tear film lipid layer was not significantly correlated with the stability of the tear film in normal subjects (P ≥ 0.459). Conclusions: The meibomian glands loss of lower eyelids was probably a significant factor for tear film lipid layer thinning in normal subjects. The more loss of the meibomian glands in lower lids, the thinner the tear film lipid layer is. Attention should be paid on the mei-bomian glands loss of lower eyelids as it may be cause tear film lipid layer thinning and dry eye.