What is Meibomian Gland Dysfunction (MGD)?
Meibomian Gland Dysfunction is very common. It is a feature of most Dry Eye Syndromes and a major element of Blepharitis.
Here's the science bit:
The meibomian glands run vertically in both the upper and lower eyelids. There are about 25-35 openings (orifices) on the edge of both upper and lower eyelids, just behind the roots of the eyelashes.
Whenever the Meibomian glands are dysfunctional, the oily secretions that they normally produce (known as meibum) becomes thickened, more greasy and viscous causing plugging of the terminial ducts and meibomian gland orifices. These plugs of solidified secretions prevent the normal oils from oozing out onto the free eyelid margins and this hinders lubrication of the eye surface.
In MGD the melting point of the meibomian oil increases to about 39º C, so the secretions are semi-solid as the eyelid skin is about 35º C. The meibomian oil cannot seep out onto the eyelid margins and so fails to 'lubricate the blink'.
MGD leads to 'awareness of the eyes' with burning gritty discomfort, and all the usual symptoms such as:
- • feeling there is something in the eye,
- • scratchy sore eyes,
- • bleary or blurred vision lasting a few moments, which clears with repeated blinking,
- • soreness when reading so that you feel unable to read for more than 10 or 15 minutes without resting the eyes.
Eye Care Professionals frequently recommend the application of regular warm compresses (by which they often mean a hot wet flannel) to melt the solidified meibomian secretions.
Using a hot wet flannel is not very effective. The flannel cools rapidly, so there is not enough time for the Meibomian secretions to be sufficiently softened or melted.
The EyeBag® maintains a temperature of over 40º C for 8 minutes and stays above body temperature for about 10 minutes.