Dry eye devices for blocked eyelid oil glands: IPL and thermal pulsation, what the trials show and who they suit

Dry eye that keeps returning is often an oil problem, not a water problem. The glands in the eyelids that make the oil layer of the tears can block, and two kinds of in-office device are offered for that: intense pulsed light and thermal pulsation. This article sets out what comes before a device, what each one does, what randomised trials and Cochrane reviews report, who should be careful, and why a device manages the condition rather than ending it.

What are the oil glands in my eyelids, and why do they block?

They are the meibomian glands, a row of tiny oil glands inside each eyelid, and when they block the tears evaporate too fast. Meibomian gland dysfunction, or MGD, is the medical name for that. A Cochrane review describes it as the major cause of evaporative dry eye, the more common of the two main kinds of dry eye disease.

A trial paper quotes the international definition: a chronic, diffuse abnormality of the glands, usually with blocked gland openings, a change in the quality or amount of oil, or both. The oil sits on the tear film and slows evaporation. When it thickens or stops flowing, the surface of the eye dries between blinks, which is why drops that only add water can fall short. Why the lid margin ends up like this is in my article on dry eyes after fifty, and the overlap with crusting and sore lids is in my article on blepharitis.

What comes before any dry eye device?

The basics come first: warm compresses, lid hygiene, treating blepharitis or demodex (a lash mite), lubricating drops, and changes to blinking and surroundings. The TFOS DEWS III management report, published in 2025 and now the current international report after DEWS II in 2017, lists these ahead of in-office devices.

Its summary puts first-line care as replenishing, conserving and stimulating the tear film, with ocular supplements the cornerstone. For MGD it lists warm compresses, then in-office options including device-driven technologies that warm the eyelids, intense pulsed light and low-level light therapy. Lid hygiene covers wipes, treatments aimed at demodex, blepharoexfoliation (a clinician cleaning debris from the lid margin) and topical antibiotics. Lifestyle measures, including better blinking and environmental changes, matter a great deal in long-term control, and so does sticking with the routine.

In Malaysia the environment means air-conditioning, long hours on screens and haze, covered in my article on dry eyes in Malaysia. There is a practical reason for this order too. A device added to a lid margin still full of debris, or to a routine not tried properly, is hard to judge, because nobody can tell what helped. And not every dry eye is an oil problem, which an eye examination sorts out.

What does intense pulsed light do, and what do the trials show?

Intense pulsed light, or IPL, is a series of short flashes of broad-spectrum light aimed at the skin of the lower lids and cheeks, not at the eye itself. A trial paper notes that how it works is still not well understood. The evidence is real but thinner than the marketing suggests.

The Cochrane review of IPL for MGD, published in 2020 with searches to August 2019, found three randomised trials enrolling 114 adults, followed for 45 days to nine months. None was at low risk of bias in every domain, and two had first authors who received funding from patents or manufacturers of IPL devices. Pooling the two trials that compared real with sham treatment in the same person, it found little to no reduction in symptoms on a standard questionnaire (mean difference -0.33, 95% confidence interval -2.56 to 1.89). The third trial reported a benefit. The evidence was rated very low certainty. For tear break-up time, the seconds the tear film holds before it breaks, two trials suggested a gain of about two seconds, graded low certainty. The review concluded that whether IPL helps is uncertain and that safety could not be judged, because adverse events were poorly reported.

The Toyos trial, published in 2022, randomised 88 people with moderate to severe MGD to four sessions two weeks apart of either IPL plus gland expression or sham IPL plus gland expression, with patients and examiners masked. Tear break-up time rose from 4.0 to 6.0 seconds with IPL and from 3.8 to 4.5 seconds in the sham group, a statistically significant difference, and gland oil quality improved more with IPL. The symptom questionnaire improved in both groups with no significant difference between them. The device maker designed the study with the authors and analysed parts of the data, and follow-up ended four weeks after the last session.

The fair reading is that IPL may improve some measurements of the tear film and glands, that its effect on how the eyes feel is less clear, and that the trials are small, short and often linked to industry. The Cochrane review dates from 2020, so newer trials are not pooled in it.

What does thermal pulsation do, and how does it compare with warm compresses?

Vectored thermal pulsation is a clinic device that warms the eyelids to loosen the blocked oil, in a single session of around 12 minutes. The LipiFlow system is the one named in the reviews. Trials compare it mostly with warm compresses at home, and their results do not all agree.

A 2019 meta-analysis of four randomised trials and 385 people found it better than warm compresses at two to four weeks on gland function, on tear break-up time (a mean gain of about one second) and on two symptom questionnaires, with one questionnaire still better at three months. The authors recommended shared decision-making.

A 2024 Cochrane review pooled more trials and was less impressed. It included 13 trials and 1,155 participants. Against basic warm compresses it found conflicting evidence on symptoms at four weeks and no evidence of a difference in gland expression, oil quality or tear break-up time. Against thermostatic devices, another type of device treatment, symptom scores were slightly better with the other device, at very low certainty. Adding LipiFlow to lid hygiene made no difference. No trial reported a vision-threatening adverse event related to the treatment. The reviewers concluded that it performs similarly to other common treatments, that the available evidence was at high risk of bias, and that firmer conclusions need better trials.

The two reviews are at different stages of one question. The earlier found a short-term edge over compresses; the later, with more trials and stricter grading, could not confirm it. The trials do not show thermal pulsation to be a clear step up from compresses done well, though it is one way to warm the lids for someone who cannot manage them.

Who should be careful with IPL, and what are the side effects?

The trials answer this through who they excluded. The Toyos trial left out people with darker skin types (Fitzpatrick V and VI), people who had used photosensitising medicines in the previous three months, and anyone with pigmented lesions, pre-cancerous lesions or skin cancer in the treatment area. Those exclusions are a list of questions to settle before any treatment.

Skin type matters because light is absorbed by pigment, so more melanin means more heat in the skin. The Retreat Clinic, a skin and aesthetic clinic in Setia Alam, explains in its article on why it does not offer IPL what the light is aimed at and the hazard it describes in skin tones common across Malaysia. That is about skin, not the eye, and worth reading before accepting IPL on the face.

The eyes must be shielded. In the Toyos trial they were covered with adhesive patches and opaque goggles, and the treated area stopped at the lower lid margin below the lashes. The Cochrane review lists mild pain and burning as adverse effects in individual trials, with the potential for partial eyelash loss attributed to clinician error. The Toyos trial had no serious adverse events, though one participant developed bacterial conjunctivitis thought possibly related to the gland expression. Those safety data come from small, short studies.

Is a device a cure for blocked oil glands?

No. MGD is chronic, and the sources treat devices as ways to manage it. The Toyos authors say more studies are needed on how long IPL's effect lasts, and the DEWS III report frames long-term control around sustained routines, not a one-off procedure.

Glands that have shrunk or dropped out do not return, so treatment aims to keep the working ones open and the lid margin quiet. That is why the basics stay in place after a device: stopping compresses and lid care because a machine was used undoes the point of it.

Useful questions for anyone offering a device are what is being measured, how many sessions are planned, when the review point is, and what happens if nothing changes. The eye surface section and my hub article on why eyes look tired give the wider picture.

When should dry eye be seen sooner rather than managed at home?

Pain, a red eye that is getting worse, reduced vision, light sensitivity or a hot, swollen lid are not typical dry eye and need an examination soon, before any device. So does dry eye in one eye only that does not settle, or dryness that began after eyelid surgery, which is a separate question explained here.

For ordinary evaporative dry eye, a stepwise plan is the sound approach: the basics, a proper review, and a device only if it is still needed, with its limits explained at the outset.