Role of wax ester fatty alcohols in chronic blepharitis

Purpose. This study was performed to determine the difference in the composition of wax ester fatty alcohols from meibomian gland secretions from normal people and those with blepharitis, and to determine which lipids are associated significantly with specific chronic blepharitis disease groups. Methods. Fatty alcohols, isolated by thin-layer chromatography from the wax and sterol ester fraction of human meibum, were analyzed by gas chromatography-mass spectroscopy after oxidative ozonolysis and silylation of the alcohol groups. Relative amounts of individual lipids or lipid groupings in each patient group were analyzed statistically by Dunnett's comparison, with the overall significance level adjusted for multiple testing (Bonferroni adjustment). Results. Significant differences (P < 0.05) between the normal group and five disease groups were found in certain alcohol groups. These alcohols included certain normal (straight chain-methyl group on chain end) and anteiso (methyl group on second carbon from chain end) alcohols, as well as the ratio of iso (methyl group on first carbon from chain end) to anteiso alcohols. The results also suggested that alpha-oxidation activity was significantly different for certain groups. The unsaturated alcohols were primarily normal alcohols. Epoxy-fatty acids also were present in the alcohol fraction. Conclusions. These data suggest that meibomian gland lipid differences may contribute significantly to some chronic blepharitis disease signs and also suggest that peroxisomal or endoplasmic reticulum abnormalities may contribute in part to some of these lipid differences.