Shine W E, McCulley J P
Department of Ophthalmology, University of Texas Southwestern Medical Center at Dallas, USA.
Arch Ophthalmol. 1998 Jul;116(7):849-52. doi: 10.1001/archopht.116.7.849.
To determine whether an association between keratoconjunctivitis sicca (KCS) and meibomian gland lipids exists in patients with chronic blepharitis.
Meibomian gland lipids were collected from normal patients and those with chronic blepharitis. Some of the chronic blepharitis patients had an ocular surface abnormality with apparent aqueous deficiency similar to KCS. Lipids were separated by thin-layer chromatography and polar lipids were further separated by high-pressure liquid chromatography with detection by UV absorbance. Lipids were identified by retention time with comparison with standards and by gas chromatography and mass spectroscopy.
A strong association between specific lipids and KCS signs was observed only with the polar lipids. Low levels of 2 phospholipids, identified as phosphatidylethanolamine and sphingomyelin, were significantly (P < .05) associated with ocular surface abnormalities that were consistent with KCS.
Evaporative KCS syndrome (rather than tear insufficiency) in many individuals may be the result of polar lipid abnormalities. We believe that the 2 associated phospholipids identified in the patients with chronic blepharitis act as important structural components in the polar phase of the tear film lipid layer. We suggest that a deficiency in these lipids results in a poorly structured polar phase that in turn affects the nonpolar phase. Ultimately water transmission through the tear film lipid layer increases, thus resulting in evaporative KCS. These results should aid in development of tear film substitutes directed toward specific abnormalities.
确定慢性睑缘炎患者中干燥性角结膜炎（KCS）与睑板腺脂质之间是否存在关联。
从正常患者和慢性睑缘炎患者中收集睑板腺脂质。部分慢性睑缘炎患者存在类似于KCS的眼表异常，伴有明显的泪液缺乏。脂质通过薄层色谱法分离，极性脂质进一步通过高压液相色谱法分离，并通过紫外吸收进行检测。脂质通过与标准品比较的保留时间以及气相色谱和质谱法进行鉴定。
仅在极性脂质中观察到特定脂质与KCS体征之间存在强关联。两种磷脂（鉴定为磷脂酰乙醇胺和鞘磷脂）水平较低与符合KCS的眼表异常显著相关（P <.05）。
许多个体中的蒸发型KCS综合征（而非泪液不足）可能是极性脂质异常的结果。我们认为在慢性睑缘炎患者中鉴定出的两种相关磷脂在泪膜脂质层的极性相中起重要结构成分的作用。我们认为这些脂质的缺乏会导致极性相结构不良，进而影响非极性相。最终，通过泪膜脂质层的水分传输增加，从而导致蒸发型KCS。这些结果应有助于开发针对特定异常的泪膜替代品。
