Purpose

This study evaluated the presence and roles of cholesteryl esters (CEs) and wax esters (WEs) from human tear film and meibum in meibomian gland dysfunction (MGD).

Methods

Out of 195 enrolled subjects, 164 and 179 subjects provided tear and meibum samples, respectively. Subjects were classified into normal, asymptomatic MGD, MGD, and mixed (MGD & aqueous deficient). The precorneal tear film (PCTF) thinning rate (evaporation) was measured using optical coherence tomography. Lipids extracted from tear and meibum samples were infused into a SCIEX 5600 TripleTOF mass spectrometer. CE and WE intensities quantified with Analyst 1.7 TF and LipidView 1.3 were compared across disease groups in MetaboAnalyst 5.0 and correlated with PCTF thinning rates.

Results

The numbers of unique CEs and WEs identified in the samples were 125 and 86, respectively. Unsupervised Principal Component (PC) analysis and supervised Partial Least Square Discriminant analysis exhibited little separation among groups for both CEs and WEs in tears and meibum. Spearman's correlation analyses showed no association between either the first or second PC scores with PCTF thinning rates.

Conclusion

The abundances of human PCTF and meibum-derived CEs and WEs were independent of MGD disease status and PCTF thinning (evaporation). CEs and WEs alterations do not contribute to alterations in tear film dynamics in MGD, such as has been demonstrated by the (O-acyl) ω-hydroxy fatty acids (OAHFAs).

中文翻译：

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人睑板腺和泪膜衍生的胆固醇和蜡酯在睑板腺功能障碍和泪膜结构中的作用

目的

本研究评估了人泪膜和睑脂中胆固醇酯 (CE) 和蜡酯 (WE) 在睑板腺功能障碍 (MGD) 中的存在和作用。

方法

在 195 名登记受试者中，分别有 164 名和 179 名受试者提供了泪液和睑脂样本。受试者分为正常、无症状 MGD、MGD 和混合型（MGD 和缺水）。使用光学相干断层扫描测量角膜前泪膜 (PCTF) 变薄率（蒸发）。将从泪液和睑脂样品中提取的脂质注入 SCIEX 5600 TripleTOF 质谱仪。使用 Analyst 1.7 TF 和 LipidView 1.3 量化的 CE 和 WE 强度在 MetaboAnalyst 5.0 中跨疾病组进行比较，并与 PCTF 稀释率相关。

结果

样本中识别出的独特 CE 和 WE 数量分别为 125 和 86。无监督主成分 (PC) 分析和有监督的偏最小二乘判别分析显示，眼泪和睑脂中的 CE 和 WE 组之间几乎没有分离。Spearman 的相关性分析显示第一个或第二个 PC 分数与 PCTF 细化率之间没有关联。

结论

人类 PCTF 和睑脂来源的 CE 和 WE 的丰度与 MGD 疾病状态和 PCTF 变薄（蒸发）无关。CE 和 WE 的改变不会导致 MGD 中泪膜动力学的改变，例如（O-酰基）ω-羟基脂肪酸（OAHFA）已经证明了这一点。