Lam Sin Man, Tong Louis, Duan Xinrui, Acharya U Rajendra, Tan Jen Hong, Petznick Andrea, Wenk Markus R, Shui Guanghou
State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China Department of Biological Sciences, National University of Singapore, Singapore.
Singapore Eye Research Institute, Singapore Singapore National Eye Centre, Singapore Duke-National University of Singapore Graduate Medical School, Singapore Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
J Lipid Res. 2014 Sep;55(9):1959-69. doi: 10.1194/jlr.P051185. Epub 2014 Jul 3.
Meibomian gland dysfunction (MGD) is a leading cause of evaporative dry eye and ocular discomfort characterized by an unstable tear film principally attributed to afflicted delivery of lipids to the ocular surface. Herein, we elucidated longitudinal tear lipid alterations associated with disease alleviation and symptom improvement in a cohort of MGD patients undergoing eyelid-warming treatment for 12 weeks. Remarkably, eyelid-warming resulted in stark reductions in lysophospholipids (P < 0.001 for lyso-plasmalogen phosphatidylethanolamine, lysophosphatidylcholine, and lysophosphatidylinositol), as well as numerous PUFA-containing diacylglyceride species in tears, accompanied by significant increases in several PUFA-containing phospholipids. These changes in tear lipidomes suggest that eyelid-warming leads to diminished activity of tear phospholipases that preferentially target PUFA-containing phospholipids. In addition, treatment led to appreciable increases (P < 0.001) in O-acyl-ω-hydroxy-FAs (OAHFAs), which are lipid amphiphiles critical to the maintenance of tear film stability. Longitudinal changes in the tear lipids aforementioned also significantly (P < 0.05) correlated with reduced rate of ocular evaporation and improvement in ocular symptoms. The foregoing data thus indicate that excess ocular surface phospholipase activity detrimental to tear film stability could be alleviated by eyelid warming alone without application of steroids and identify tear OAHFAs as suitable markers to monitor treatment response in MGD.
睑板腺功能障碍(MGD)是蒸发型干眼和眼部不适的主要原因,其特征是泪膜不稳定,主要归因于脂质向眼表的输送受损。在此,我们阐明了一组接受12周眼睑热敷治疗的MGD患者中与疾病缓解和症状改善相关的泪液脂质纵向变化。值得注意的是,眼睑热敷导致溶血磷脂显著减少(溶血缩醛磷脂酰乙醇胺、溶血磷脂酰胆碱和溶血磷脂酰肌醇的P<0.001),以及泪液中多种含多不饱和脂肪酸(PUFA)的甘油二酯种类显著减少,同时几种含PUFA的磷脂显著增加。泪液脂质组的这些变化表明,眼睑热敷导致优先靶向含PUFA磷脂的泪液磷脂酶活性降低。此外,治疗导致O-酰基-ω-羟基脂肪酸(OAHFAs)显著增加(P<0.001),OAHFAs是维持泪膜稳定性至关重要的脂质两亲物。上述泪液脂质的纵向变化也与眼蒸发率降低和眼部症状改善显著相关(P<0.05)。因此,上述数据表明,仅通过眼睑热敷即可缓解对泪膜稳定性有害的眼表磷脂酶活性过高的情况,而无需使用类固醇,并确定泪液OAHFAs作为监测MGD治疗反应的合适标志物。