Meibomian gland dysfunction is a widespread contributor to dry eye syndrome. It is alternatively called MGD, meibomitis, and posterior blepharitis. MGD is a complex condition, but it usually involves inflammation of the Meibomian glands in the eyelid, which produce the lipids (meiboma) that comprise the outer layer of the tear film. The infection can be caused by an obstruction in the glans outlet at the eyelid margin.
The obstruction, in turn, can be caused by an enlarged eyelid from allergies or anterior blepharitis (in the front part of the eyelid). MGD can also develop from hormonal changes or dietary habits that affect lipid density. Sometimes the extrusions can appear deeply creamy and slimy, or even toothpaste-like; at other times, a ball of compacted fat may coagulate at the entrance, sealing it off. Another variation of the dysfunction can be through a large production of lipids that inflame the eyes, although there is no blockage of the glands.
The consequence is that, due to dysfunction, the glands expel low-quality lipids. There may be excess or lack of oil; the oil may be too viscous or too thin. The consequence is that there is little stability in the tear film and drying occurs at an abnormal rate.
Associated symptoms and conditions
The symptoms of the disease generally resemble those seen with dry eye in general: burning sensation in the eye, grittiness, foreign body sensation, increased sensitivity to light, and crusting along the margins of the eye. the eyelids. The lid margins appear swollen and inflamed and the inner edge of the lid may be dented due to scarring.
Meibomitis usually arises in conjunction with insufficiency of watery tears. When this happens, you are likely to have particularly severe dry eye symptoms. It has been found that approximately 60 percent of Sjögren’s syndrome patients (who have aqueous lacrimal insufficiency) also have MGD. Other skin disorders such as rosacea and seborrheic dermatitis, which often cause blepharitis, are also linked to meibomian gland dysfunction. These intertwined diseases must also be addressed during the treatment of meibomian gland dysfunction.
The chance of developing MGD seems to increase with age. It may be that the meibomian glands gradually wear out in their function, or that age-related alterations in the eyelids contribute to the deterioration of the blinking mechanisms. What has been noted is that normal eyelids in older people show many of the changes in structure and shape seen in meibomitis.
MGD is also linked to long-term contact lens wear. Contact lenses speed up the rate of evaporation of tears. This can lead to contact lens intolerance and make the condition more severe in people whose tear films are already damaged. Similarly, MGD is also commonly seen in patients with giant papillary conjunctivitis (GPC) and chalazion (plural, chalazion; a lump that remains after a stye on the eyelid heals).
Treatment
MGD, being a fairly complex disease, has many possible causes. In any person, the condition can start from one or more of these causes. Your doctor will need to keep this in mind as your treatment program progresses.
The first priority in treatment is to reduce inflammation on the surface of the eye, to drain the damage from bacterial activity on the eyelid margin, to improve lipid function, and to relieve accompanying dry eye symptoms.
Topical steroids may be recommended to control inflammation, although these are not normally used to avoid the high risk of side effects. But newer formulations, such as loteprednol, don’t carry that risk and are reasonably effective at reducing inflammation. Specially formulated topical cyclosporine, such as cyclosporine emulsion in a castor oil base, has also been successfully tested to minimize ocular surface inflammation.
Essential fatty acids, particularly omega-3 fatty acids, have been cited in many informal accounts as having the ability to decrease dry eye symptoms, likely due to their well-established anti-inflammatory properties. Its anti-inflammatory action has also been shown to benefit meibomian gland disease.
Eyelid scrubs can be very helpful. Cleaning the edge of the eyelid helps eliminate bacteria and their toxins, as well as cleanses the ducts of the Meibomian glands. However, excessive cleaning can cause irritation and should be avoided. Tear plugs, artificial tears (without preservatives), and tear stimulants also provide relief.
