The Dry Eye Zone

Rebecca's Blog

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Opinion: Are some of us murdering our meibomian glands?

I have observed a trend over the past couple of years where for various reasons more people seem to be overdoing eyelid care in hopes of improving chronic MGD. They are applying heat packs twice or more each day; scrubbing and massaging their lids frequently; and attempting to express the glands regularly. I've even observed some of the savviest patients purchasing medical instruments intended for professionals and using them at home to express their glands.

As a longtime proponent of lid hygiene and heat treatment for MGD I have viewed this trend with increasing concern because I fear that inappropriate use, and over-use, of such treatments might delay rather than assist recovery of the meibomian glands. As I so often have over the years, I went to the doctor who first helped me understand dry eye diseases to elucidate this topic for me. What follows is an article that she wrote for DEZ readers in the wake of our discussion about whether some of us may be actually beating our meibomian glands to death. Enjoy, and please let us know what you think in comments here or via email/dryeyetalk/etc.

Expressing the meibomian glands
by Sandra M. Brown, MD - Cabarrus Eye Center, Concord NC

The meibomian glands live in the upper and lower eyelids. There are approximately 15 - 20 glands per lid. The gland openings lie on the edge of the eyelid just inside the eyelash line. The body of the gland is inside the tarsal plate, which is a very thin piece of cartilage that gives the eyelid its defined shape. When your doctor everts your lid (flips it inside out) he is flipping over the tarsal plate.

Although most diagrams of meibomian glands show a hollow tubular structure that looks like a permanently open space, a meibomian gland is more of a potential space. If the gland is empty of meibomian oils, it collapses in on itself. In fact even when the gland is "full" only a very thin film of oils may actually separate the cells lining the walls of the meibomian gland.

Meibomian oils are not squirted onto the surface of the eye. They seep out slowly under the gentle pumping action of eyelid blinking, combined with continuous oil production which pushes oils out onto the eye lid margin when the gland's potential space is fully expanded.

When the eyelid margin becomes inflamed, this inflammation can "cap off" the meibomian gland orifices. There are numerous causes of eyelid margin inflammation that will not be discussed here. If the glands continue to vigorously produce oils, the oils erupt through the sides of the glands and coalesce into a mass commonly referred to as a stye. However in many patients, obstruction of normal oil seepage causes the meibomian gland to decrease production and the oils retained in the gland become thick and degraded.

In the past 2 - 4 years, eye care providers have become more widely aware of the connection between meibomian gland dysfunction and ocular surface symptoms. One simple office test is to lightly press on the glands while the patient is seated at the slit lamp. The examiner is looking for the quantity and quality of oils, how many glands express, how hard s/he has to push to make this happen, and how readily the oils disperse into the tear film. Meibomian oils are quite easy to see at the slit lamp but essentially impossible to see with the naked eye except through elaborate magnification methods.

It is not necessary for 100% of the meibomian glands to function for adequate oils to be secreted into the tear film. Many asymptomatic patients have far fewer than 100% of the glands producing oils at any given time. Lower lid meibomian glands seem to "take a hit" sooner that upper lid glands, so it is important for your doctor to express both upper and lower lids to give your glands an overall function score. Patients with about 80% of their upper lid glands functioning well may have no symptoms even if the lower lid glands are producing almost nothing.

Eye care providers sometimes prescribe meibomian gland self-expression or patients take it upon themselves to "clear out" their glands periodically. Generally the process is to apply heat to liquefy the oils, followed by eyelash cleaning (or sometimes the reverse order) and then gland expression.

A note on hot compresses. The temperature of eyelid skin is slightly below core "body temperature" and meibomian oils become more liquid just a little above core body temperature. So moderate, sustained heat can keep viscous oils thinner. Patients who use very hot compresses that they can tolerate for only 1-2 minutes are going about it the wrong way. Washclothes are ridiculous due to the very rapid cool-down. There is no difference between dry and wet heat from the perspective of the interior of the meibomian gland. A compress that stays "definitely warm" witout being uncomfortable for at least 4 minutes is probably the most effective approach. It is impossible to really "study" the differences between compress methods.

As regards meibomian gland self-expression, there are several problems with this activity.

First, not all meibomian gland problems are due to blockage of the orifices. If the glands are simply under-producing oils (a common problem in peri-menopausal women) pushing on them won't do anything. If the lid margin inflammation is not under control and the orifices are tightly blocked, oils may not express even with hard pressure. So the treatment is not helpful. But secondly, self-expression can be harmful.

Remember that the gland is a potential space containing a small volume of oil. If you express all the oil out of the gland, you have probably expressed several days' worth of "production". You have depleted your supply. When the gland is empty, it collapses in on itself and the cells lining the potential space come into contact with each other without an intervening "oil slick". This allows the cells to adhere to each other. As the gland refills with oil the potential space expands and the cells separate. Repeated expression can lead to the cells permanently adhering, causing obstructions deeper in the gland. This process will be hastened by the microtrauma induced through the mechanical pressure, especially if applied vigorously and often.

I have seen patients who have basically murdered their meibomian glands through excessive self-expression. How do I know? Because the glands in the far nasal and temporal (ear side) areas are harder to reach. It is also more difficult to apply direct firm pressure to the glands in the upper lids than to those in the lower lids. So I see more non-functioning glands in the centers of both lids than the corners, and the lower lids have more non-functioning glands than the upper lids.

When is self-expression helpful? Some patients have mildly occluded orifices or tend to produce oils that don't seep well. They get into a "stagnation" situation. As part of their overall rehabilitation which MUST include efforts to improve oil quality and open the orifices, mild self-expression following a hot compress can be beneficial.

If you are a frequent (more than once per week) or aggressive self-expresser, ask yourself whether you are doing this "philosophically" because it seems like a smart thing to do or whether expressing truly improves your symptoms. If you are expressing several times per day, it is extraordinarily unlikely that you are getting a "useful" amount of oils onto the ocular surface each time. This habit will only increase the microtrauma to the meibomian gland structure.

Meibomian gland self-expression can be useful at certain stages of treatment. It is recommended by eye care providers, including those who specialize in ocular surface disease. It is important to understand that you can overdo it. You should not use self-expression unless instructed to do so by your eye care provider. If you have ocular surface pain and your provider has never expressed your glands, find a different doc.

What if you are a non-producer? Patients whose meibomian glands have ceased production are in a particularly difficult state. Peri- and post-menopausal women are most prone to this condition since meibomian gland function is regulated by androgen hormones. Some women become abruptly dry during pregnancy and don’t recover after pregnancy. Conversely some women have symptoms before pregnancy and actually feel better during pregnancy. We do not have a good understanding of the complex hormonal interplay that affects meibomian gland function. However, if your glands aren't making oils because they aren't receiving "go" signals from hormones or ocular surface nerves, many of the treatments described above will not be effective. Low production can combine with eyelid inflammation to further reduce the quality and quantity of oils reaching the tear film. Certainly related problems such as eyelid inflammation should be addressed. But for patients whose essential problem is markedly reduced production, it is particularly important to leave your meibomian glands alone!

Remember that the purpose of meibomian gland oils is to stabilize the tear film structure and slow evaporation. Barrier methods to slow evaporation (goggles, masks, etc.) are particularly helpful in this circumstance.

What helps meibomian glands and how:

heat - liquifies oils which tend to become more viscous just below body temperature (eyelid skin cooler than core body temp); see comments above about correct hot compress

doxycycline and minocycline, erythromycin - low dose for at least 60 days - acts as an anti-inflammatory which opens the orifices, thins out the oils in some fashion that we don't understand, decreases the bacterial load on the eye lid margins which opens the orifices

TobraDex ointment - anti-inflammatory, decreased bacterial load; intraocular pressure must be followed if used for more than 1 month

Restasis - in my experience anti-inflammatory effects can improve meibomian gland inflammation as well

omega oils - antiinflammatory, antioxidant, 'good ingredient' for oil production

Azasite applied to eye lid margins (topical equivalent of erythromycin) - antibacterial, maybe something else as well? seems to work for some people not others
RebeccaComment