Welcome to Hidden Drivers, a new series hosted by Mile Brujic, OD, FAAO, clinical partner of Premiere Vision Group and expert on ocular disease management of the anterior segment and specialty contact lenses.
In the first episode, Dr. Brujic is joined by Laura M. Periman, MD to discuss the complexities of ocular surface disease and the relationship between Demodex blepharitis and meibomian gland dysfunction in patients. Dr. Periman is an ophthalmologist, cornea and refractive surgeon, and ocular surface disease expert at Periman Eye Institute in Seattle, Washington.
Demodex blepharitis and MGD fast facts
- Dry eye symptoms are increasingly more common with contact lens use, prolonged screen time, and reduced blinking rates. This is often due to meibomian gland dysfunction (MGD), where the meibomian glands in the eyelids do not secrete healthy meibum quality or quantity.
- Demodex mites are commensal organisms living on human skin at the hair follicle which feed on meibum. However, overpopulation of mites can lead to Demodex blepharitis.
- A 2025 retrospective study showed that Demodex and MGD are strongly linked.1
- Among patients with MGD (defined as meibum quality grades 2 to 4 or atrophy grades 1 to 4), 45% had Demodex blepharitis.
- Among patients with moderate to severe Demodex (10 or more collarettes), 96 to 99% were diagnosed with MGD.
- A promising treatment option is lotilaner ophthalmic solution 0.25% (XDEMVY, Tarsus Pharmaceuticals), for managing Demodex blepharitis in patients with MGD.2,3
- A pooled analysis of the ERSA and RHEA trials showed that patients treated with lotilaner had significant improvements in collarette reduction, meibomian gland function, and patient-reported outcomes at 6 and 12 weeks compared to baseline and to a vehicle control group.
A deeper dive into the Demodex and MGD relationship
Drs. Brujic and Periman discuss how recent data provide strong support for the link between Demodex and MGD, when historically, signs may have been missed or ignored. The reality is that it is the downstream consequence of multiple factors, Dr. Periman says.
The biology behind both MGD and dry eye disorders overlaps in a “double vicious cycle” driven by the combination of eyelid or conjunctival inflammation, corneal damage, microbiome changes, and tear film instability.4
“Demodex are an intimate part of meibomian gland dysfunction—and it turns out it's way more prevalent than we realized before.”
A 2023 study of 351 patients found a 52% overall prevalence of Demodex infestation accompanying MGD, ranging from 34.1% of patients under the age of 40 to 63.8% in those older than 60.5 Dr. Periman says that these findings support other research and clinical observations that prevalence increases with age. Furthermore, aging includes biological changes in hormones and immunity that may impact the drivers of ocular surface disease.
Mechanistic insight
The connection between Demodex overpopulation, inflammation, and gland dysfunction have started to become more clear with research advances and new tools of discovery.
“Science answers questions, but always generates more questions. And when you view new data in the context of what we already know, it starts to make more sense.”
One 2021 study used high-performancy liquid chromatography mass spectrometry to analyze changes to meibum lipid composition as a result of Demodex infection.6 They compared healthy patients, patients with autoimmune dry eye, and patients with Demodex-related dry eye. They found that the various protein and lipid levels drastically shifted in the context of Demodex infestation.
The growing body of research provides a more complete picture of MGD—the biochemistry of meibum, inflammatory responses, and association with Demodex all provide context to the gland structure and function at the lid margin.
Early diagnosis and treatment
Drs. Brujic and Periman agree that the field has advanced in many ways. In the past, one might look at corneal staining or meibography and say, “ah, that patient has dry eye,” without fully understanding the upstream cause. Now, targeted therapeutics like XDEMVY provide a first step intervention to approaching MGD rather than an afterthought.
Further research is taking a diagnostic approach. A 2025 retrospective study enrolled 76 dry eye patients and took imaging of their eyelids to calculate the energy curve of the meibomian gland.7 Using AI tools, the energy curve can help assess uneven atrophy and provide early diagnosis of Demodex blepharitis.
“We need to identify Demodex earlier and more often because it's low hanging fruit. Treating Demodex blepharitis is the first arrow out of my quiver.”
In clinical practice, educating patients on practicing and maintaining proper lid hygiene is necessary for successful long-term treatment. However, Dr. Periman suggests that prior to screening, it makes sense to recommend patients stop lid hygiene for 2 weeks to allow things to reaccumulate and assist with diagnosis.
In the absence of eyelash collarettes, you can look for other signs:
- Lid margin erythema
- Telangiectasias
- Lid thickening
- Meibom expression
- Alpenglow sign
- Dermal collarettes across the nose bridge
Don’t sweep it under the rug
In conclusion, Dr. Periman says to not be afraid to address things head on when it comes to addressing Demodex and MGD. As early as you can identify it, start to think about mite eradication strategies. With treatment options that have proven to be effective and well tolerated, you have the tools to more effectively treat your patients.
This article was written by Mariel Mohns, MS, based on the recorded video from Drs. Brujic and Periman.
