Purpose. We have previously proposed that changes in meibomian gland lipid secretions significantly contribute to chronic blepharitis signs and symptoms(IOVS 1991;32:2272). Detailed analyses of polar lipids (sphingolipids and glycerolipids) as they relate to disease signs have not been reported. Methods. Samples from six disease groups - STAPH (staphylococcal), SBBL (seborrheic), MIX (seborrheic with staph infection, MBSB (seborrheic with meibomian seborrhea), 2 MEIB seborrheic with spotty inflammation of meibomian glands, and MKC (meibomian keratoconjunctivitis), as well as controls (NCP) were collected. Polar lipids were isolated by TLC and separated by HPLC. Sphingolipids and glycerolipids were identified by retention time and GC/MS identification of fatty acids liberated by differential hydrolysis. Results. Polar lipid fatty acids' length was C18 or shorter; both normal (polar lipids) and hydroxy fatty acids (only sphingolipids) were present. Sphingolipid N-acyl fatty acid unsaturation (7-10% except MKC 20%) was observed only in disease groups; glycerolipids were unsaturated (50%) only in MKC. Cerebroside sphingolipids were dominant in controls and all disease groups (> 75%) except MKC and MBSB where amounts were very low. In contrast, the MKC group was distinguished by high levels of ceramides (50%) lacking hydroxy fatty acids while the MBSB group had high levels (80%) of an unidentified sphingolipid in which hydroxy fatty acids dominated. Very high levels of the glycerolipid phosphatidyl choline were present in the STAPH group. Conclusions. Sphingolipid fatty acid unsaturation is associated with chronic blepharitis; this relationship is accentuated in the MKC group where glycerolipid unsaturation was also present. Our results suggest that it isn't the absolute amount of sphingolipid present but the type, relative amount and fatty acid composition which is an important determinant in development of chronic blepharitis disease signs.
|Original language||English (US)|
|Journal||Investigative Ophthalmology and Visual Science|
|State||Published - Feb 15 1996|
ASJC Scopus subject areas
- Sensory Systems
- Cellular and Molecular Neuroscience