Meibomian Gland Expression as Treatment

During expression, pressure is applied to the eyelid in order to see whether meibum can be delivered from the gland openings. A clinician may assess:

• •how many glands produce secretion
• •how easily secretion appears
• •what the secretion looks like
• •and sometimes how much pressure is required

Normal meibum may be relatively clear and fluid. With MGD, secretion may appear cloudy, thick, granular or toothpaste-like, or may be very difficult to express. That makes expression potentially valuable diagnostic information. But the interpretation depends heavily on how the expression was performed.

This distinction is extremely important.

Diagnostic expression

The aim is to ask: how well do these glands function under a standardized, physiologically relevant pressure?

Researchers have developed standardized expression devices precisely because using different amounts of finger pressure can produce very different results. One commonly used standardized technique applies a defined pressure to a section of the lower eyelid and counts how many glands yield liquid secretion. Studies using this approach have found that reduced gland expressibility is associated with dry-eye symptoms.

Therapeutic expression

Here the objective is different. The clinician is deliberately attempting to evacuate abnormal or obstructed gland contents. That can require considerably greater pressure.

So “this gland did not express normally during diagnostic pressure” and “nothing can physically be forced out of this gland” are not equivalent statements.

Because meibum does not simply have two states: comes out or doesn’t come out. A gland may produce secretion under relatively gentle pressure. Another may require considerably more pressure. And a severely obstructed gland may require much greater force before thick material emerges.

One study actually measured the pressure required during therapeutic expression. To obtain the first non-liquid material from nonfunctioning lower-lid glands, pressures ranged from 5 to 40 psi, with an average of about 16 psi. To evacuate all expressible material, the average pressure was about 26 psi, with some glands requiring up to 40 psi.

Those are substantial pressures. And they lead to another important problem.

It certainly can. In that same study, only 7% of patients could tolerate the pressure required to complete therapeutic expression across the entire lower eyelid. Pain was the main limiting factor.

That tells us something important. If therapeutic expression requires enough pressure to cause considerable pain, then “just squeeze harder” is not a trivial recommendation. There is a biological and practical limit to how much force can reasonably be applied.

No. This is probably one of the most important misconceptions surrounding gland expression. If no secretion appears during expression, we know that no secretion was obtained under those particular examination conditions. We do not automatically know why. Possible explanations include:

• •thick or highly viscous meibum
• •ductal obstruction
• •insufficient pressure
• •insufficient prior heating
• •poor secretory function
• •structural gland damage or loss
• •or a combination of these

The location of the gland also matters. A study of 133 people found striking regional differences in lower-lid expressibility: glands in the temporal portion of the lid were much less likely to yield liquid secretion than nasal glands under standardized expression. So even “X out of Y glands expressed” needs context.

Yes, this is entirely plausible. Expressibility is a functional measurement, not simply an anatomical photograph. It can potentially be influenced by:

• •meibum consistency
• •temperature
• •degree of obstruction
• •recent treatment
• •pressure applied during testing
• •technique

This means that a gland that produces nothing during one examination should not automatically be labelled permanently nonfunctional based on that observation alone. Conversely, obtaining secretion once does not prove that the gland is functioning normally in everyday life.

Expression tells us something important. It does not tell us everything.

It can. Warming can increase the fluidity of abnormal meibum. That is why many treatment protocols combine heat with expression. The logic is straightforward: first make thick secretion easier to move, then apply mechanical pressure to facilitate evacuation. This is also part of the rationale behind thermal-pulsation systems, which combine controlled heating with mechanical pressure.

But this creates an important issue when comparing examinations. If one clinician expresses the glands without heating and another does so after effective warming, they may not necessarily obtain identical results.

Warm Compresses & Heat for MGD

Thermal Pulsation for MGD

The rationale is to remove poorly expressed or obstructive material and improve gland outflow. Imagine a structurally viable gland that is producing secretion but cannot deliver it effectively because the contents are thick and the duct is obstructed. Removing some of that material may restore or improve outflow. That is biologically plausible. And clinical studies suggest that expression used alongside home therapy can improve symptoms in some patients.

But the evidence is not as extensive as one might assume.

A 2024 systematic review and meta-analysis specifically examined meibomian gland expression combined with home-based therapy versus home therapy alone. Only two randomized controlled trials, involving 99 patients, met the inclusion criteria. Expression plus home therapy produced a statistically significant improvement in dry-eye symptoms. However, differences in the following were not statistically significant in the pooled analysis:

• •tear break-up time
• •corneal staining
• •gland expressibility

The authors therefore concluded that there is some evidence for symptom improvement, but insufficient evidence to draw definitive conclusions about improvement in objective MGD signs.

That does not mean expression does not work. It means the evidence is much more limited than the popularity of the procedure might suggest.

This is another phrase to be careful with. A meibomian gland is not a tube containing dirty material that needs periodic cleaning. It is living tissue continuously producing secretion. Therapeutic expression may evacuate material that is currently expressible. But the goal should not necessarily be to empty every gland completely. The more meaningful goal is to restore or improve normal secretion and outflow. Those are different concepts.

We do not have good evidence establishing that every gland needs to be completely emptied during treatment. In fact, attempting complete evacuation can require substantial pressure and can be painful. So the idea that successful treatment requires “squeeze until absolutely nothing remains” should not be treated as an established scientific rule. What matters clinically is whether gland function and tear-film performance improve.

This is an important question — and one where we need to distinguish what is biologically conceivable from what has actually been demonstrated. Expression can require substantial force, and pain clearly limits how much pressure patients tolerate. However, we do not currently have strong clinical evidence demonstrating that appropriately performed gland expression routinely causes permanent meibomian gland damage.

So it would be wrong to say:

“Expression damages glands.”

But it would be equally wrong to say:

“The harder the pressure, the better, and there is no downside.”

The appropriate conclusion is more cautious: therapeutic expression can involve considerable mechanical force, so the amount of pressure and patient tolerance matter.

No. Pain is not a measure of treatment success. A painful procedure may simply mean that substantial pressure is being applied to sensitive eyelid tissue. The study measuring therapeutic expression actually found pain to be the factor preventing most patients from tolerating complete expression.

So more pain does not mean a more effective treatment. And a patient should not assume that severe pain is necessary evidence that the glands are being properly treated.

It may. If a gland remains structurally viable but contains poorly expressed material, improving outflow over time could plausibly change what is obtained during later expression sessions.

But this is where we need to be careful. There is not strong evidence establishing a universal sequence — nothing, then toothpaste, then cloudy meibum, then clear oil — that every recovering gland should follow. Individual patients may show changes in secretion quality over time, but that pattern should not be presented as an established biological law.

What we can reasonably monitor is whether more glands become expressible, less pressure is required, secretion quality improves and tear-film function improves.

Yes. In fact, this may be one of its most useful roles. Meibography tells us primarily about structure. Expression tells us something about function. A gland can look relatively intact on meibography but yield poor-quality secretion. Another eye may show substantial dropout while the remaining glands still produce useful meibum.

So structure is not the same as function. Using both kinds of information can provide a much more complete picture.

Meibography: what gland images can and can't tell you

Imagine two doctors. Doctor A applies gentle pressure. Three glands produce secretion. Doctor B presses much harder. Eight glands produce secretion. Did the patient’s glands dramatically improve? No. The test changed.

This is why researchers developed standardized expression devices. One study created a clinical scale using constant pressure applied to a defined area of the lower eyelid for 15 seconds, allowing the number of glands yielding secretion to be compared more consistently. Without some degree of standardization, comparisons between appointments — particularly between different clinics — can be misleading.

Yes. This is another surprisingly important detail. In the study of 133 clinical patients, the average number of lower-lid glands yielding liquid secretion differed substantially by region. The nasal third produced the most. The central region produced fewer. The temporal third produced dramatically fewer, and 86% of temporal regions had zero glands yielding liquid secretion, compared with only 6% of nasal regions.

So when someone says “Only two of my glands worked,” a useful question is: which glands were actually tested?

There is no good evidence supporting a universal rule that everyone with MGD must manually express their glands after every heating session. Normal blinking itself contributes to meibum delivery. Some treatment protocols use heat alone. Others combine heat with massage or expression.

Professional therapeutic expression is a much more forceful procedure than normal blinking or gentle home massage. These should not all be treated as interchangeable.

There is no well-established universal schedule — every two weeks, every month, every three months — that applies to everyone with MGD. The evidence does not support one standard maintenance interval for all patients. Frequency should logically depend on:

• •whether significant obstruction remains
• •whether secretion is improving
• •how quickly dysfunction recurs
• •what other treatments are being used
• •whether repeated expression is actually producing measurable benefit

This is an area where individualized clinical judgment is more appropriate than a fixed calendar.

This is another question for which we do not have strong evidence supporting routine aggressive expression indefinitely. If glands are producing normal secretion with reasonable pressure, the rationale for repeatedly performing forceful therapeutic evacuation becomes less obvious.

Remember the principle from the beginning of this section: what is the target? If the target was severe obstruction and that obstruction has improved, the treatment plan can be reassessed. Treatment does not necessarily need to continue unchanged simply because it helped previously.

Treating Dry Eye: Start With the Target

No established evidence shows that mechanical expression regenerates truly lost meibomian gland tissue. Expression can potentially improve function and outflow in glands that remain. That is very different from recreating glandular tissue that is no longer present. Again: functional recovery is not the same as anatomical regeneration.

Then we should reconsider the entire system. Perhaps MGD was only one contributor. There may also be:

• •aqueous deficiency
• •inflammation
• •incomplete blinking
• •exposure
• •ocular-surface damage
• •a neural component to the symptoms

The goal is not to continue expressing glands simply because the patient still has symptoms. The goal is to determine what is still wrong.

Dry Eye Is Often Mixed

Treating Meibomian Gland Dysfunction: the overview

If expression is being used therapeutically, useful questions include:

• •Are more glands becoming expressible?
• •Is the meibum becoming more fluid or clearer?
• •Is less pressure required?
• •Is obstruction decreasing?
• •Is tear-film stability improving?
• •Are symptoms improving?
• •Is everyday function improving?

That gives us considerably more information than simply “We expressed the glands again.”