Abstract
Purpose :
Various ocular surface disorders are linked to changes in the lipid composition of Meibomian gland (MG) secretions (meibum). However, in most described cases the changes were either small, or random, or poorly characterized. In this report we present data on a patient whose meibum and tears were severely depleted of normal meibomian lipids (ML) such as wax esters (WE) and cholesteryl esters (CE), but were enriched with triglycerides (TG) instead (abnormal meibum, or AM, patient).
Methods :
Samples from a 63-year old male AM patient were collected on 3 occasions during a 1-year period. Expressed meibum was collected using a cataract spoon. Tear samples were collected using Schirmer strips. Sebum was collected from the nasal and forehead areas using Sebutape. Regular ophthalmic evaluation of the subject's eyelids and cornea and a standard blood lipid profiling were conducted. Eight age- and gender-matched controls were recruited. All samples were analyzed using high pressure liquid chromatography and high resolution time-of-flight mass spectrometry (LC/MS).
Results :
The blood lipid panel of the AM patient was normal. Sebum of the AM patient was WE deficient. On slit lamp examination, protrusions of white, lard-like meibum at the MG orifices as well as their pluggings were observed. Noticed was an abnormally large amount of meibum in the patient's MG. Oil-like droplets were seen on the tear film (TF) stained with fluorescein. The TF break-up time (TFBUT) was >5s in both eyes. Meibography showed globular appearance of MG without ductal shadow. The LC/MS analysis demonstrated major differences between the controls and the AM patient. ML profile of the AM patient differed dramatically from that of controls, and so where the tear samples. Noted differences, among others, included severely diminished pools of normal ML such as WE and CE, skewed profiles of individual WE and CE, a 2x increase in CE/WE ratio, a ~3x increase in free cholesterol to CE ratio, and, most importantly, a 20x to 30x increase in the TG fraction over the norm. Paradoxically, these landslide changes in meibum and tears did not change the patient's TFBUT.
Conclusions :
The data imply that the AM patient had a severe metabolic disorder that affected lipid metabolism in his MG. This is, to the best of our knowledge, a first observation of the condition that we have termed High Triglycerides/Low Waxes (or HTLW) syndrome.
This is a 2020 ARVO Annual Meeting abstract.