Evaluation of Meibum Lipid Composition According to Tear Interferometric Patterns

Purpose

To determine the relationship between tear film interferometric patterns and properties of lipid, including rheological properties.

Design

Prospective, cross-sectional laboratory investigation.

Method

This study included 105 subjects (94 dry eye patients and 11 normal participants). The subjects were divided into 3 categories (group 1, normal; group 2, thin; and group 3, irregular) according to interferometric patterns. According to tear interferometric patterns, ultra-performance liquid chromatography (LC) quadrupole-linear ion trap/mass spectrometry (MS)-based analysis was used to investigate lipid profiling of meibum. Rheological properties were examined by using a Langmuir-Blodgett trough with saline solution.

Results

Normal subjects showed Pearl-like patterns, and dry eye patients showed either irregular or thin patterns. Group 2 tended to be the evaporative type, and group 3 tended to be the aqueous-deficient type. Lipid profiling using LC-MS identified 280 lipid species of 25 lipid classes. In the meibum of the patient groups, the content of cholesteryl esters and nonpolar lipids was lower than that in the normal group. However, the content of polar lipids such as sphingolipids and phospholipids in the patient groups was higher than that in the normal group. Rheological properties showed that the lift-off areas were comparable among the 3 groups and the surface tension was the highest in group 1, followed by group 3 and group 2.

Conclusions

The findings of this study suggest that tear interferometric patterns are associated with lipid profiling of meibum and its rheological properties. These results may contribute toward the development of new treatment modalities.