Sponsored by Tarsus Pharmaceuticals, Inc.
Diseases like dry eye and MGD can be enigmatic. Checking for collarettes and other signs of Demodex blepharitis could uncover the root cause in some cases.
When patients keep coming back with dry, itchy, crusty, irritated lids, or blepharitis that just won’t quit—a quick eyelid check could be the solution.
At a Tarsus-sponsored symposium on Day 3 of the 43rd Congress of the European Society of Cataract and Refractive Surgeons (ESCRS 2025) in Copenhagen, Denmark, ophthalmologists Erik Mertens and Radhika Rampat urged attendees to take a few extra seconds at the slit lamp to inspect the lids for indicative signs of Demodex blepharitis (DB).
It’s a small change in examination technique that can make a big difference in spotting one of the most common yet overlooked contributors of ocular surface disease.
Underdiagnosed but highly prevalent
Demodex blepharitis (DB) is a big diagnostic blind spot. Although studies suggest1 it affects about 54% of patients presenting to EU eye care clinics,2 this mite-induced condition remains widely underrecognized across European practices.
Dr. Mertens (Belgium) and Dr. Rampat (UK) presented data showing that 69% of blepharitis patients are playing host to Demodex mites.3 Yet the vast majority continue to receive symptomatic treatments for dry eye, MGD or “non-specific” blepharitis without addressing the root cause.
“Despite this high prevalence, DB is often missed due to its nonspecific symptoms. Many clinicians don’t routinely examine for collarettes – waxy, cylindrical debris at the base of the lash – a key diagnostic marker,” said Dr. Rampat.
“But as awareness of DB grows, incorporating targeted examination techniques is critical to improving detection and management of this commonly overlooked disease,” said Dr. Rampat.
The implications extend far beyond diagnostic accuracy. Dr. Mertens believes this diagnostic delay contributes to progressive meibomian gland dysfunction, persistent ocular surface inflammation, and a frustrating cycle of symptoms for patients, all of which might be avoided with a timely mite check.
“When DB is mistaken for OSDs, this leads to repeated use of therapies that don’t match the underlying cause,” said Dr. Mertens. “When this happens, this not only delays resolution of the condition, but may actually further exacerbate ocular surface damage and contribute to patient frustration,” he explained.
These issues can also extend beyond the clinic to the cataract and refractive operating theater.
“In surgical settings, undiagnosed DB can cause fluctuating vision which may compromise preoperative ocular surface optimization, increasing the risk of suboptimal outcomes after cataract or refractive procedures. Thus, early identification and targeted treatment are needed to break the cycle of mismanagement and improve long-term ocular health,” shared Dr. Mertens.
A quick test to flip the DB script
Just a few extra seconds at the slit lamp could make all the difference in detecting DB and managing the lid, lash and ocular surface issues it may cause.
The key isn’t complicated testing or expensive tools, but a small shift in technique. Collarettes are cylindrical, waxy debris of mite waste products and eggs found at the base of the eyelashes and can be identified during a routine slit lamp exam.
Research shows that 100% of patients with collarettes are found to have Demodex mites, making this an easy and reliable diagnostic marker.4
So how do ophthalmologists get the jump on collarettes? Dr. Rampat said to simply have patients look down during slit lamp exam.5 This offers a clear view of the upper lash line, where collarettes often hide.
According to Dr. Rampat, the technique takes almost no extra time and can help you avoid missing an important diagnosis.
Integrating this into routine eyelid examinations is a simple yet powerful step in improving detection of Demodex blepharitis.
“By methodically looking for debris, lifting the lashes, pushing on the lid margin and pulling lashes to reveal mites or debris, clinicians can uncover early indicators of DB that are easily missed during standard slit lamp exams. Asking your patient to look down is quick, non-invasive and requires no additional equipment—making it a practical step that improves diagnostic accuracy and supports more targeted treatment planning in everyday clinical settings,” said Dr. Rampat.
Dr. Mertens added that this simple step has helped him catch more cases and approach stubborn ocular surface symptoms with more confidence.
“As a result, it provided us clinical clarity,” shared Dr. Mertens.
According to Dr. Mertens, routinely diagnosing DB in his practice has not only enhanced clinical confidence but also increased patient trust that their doctor is providing a complete assessment and will do everything they can do to address the issue with the tools available to them now.
The hidden cost of diagnostic inertia
A routine collarette check might be quick, but those are just a few seconds you and your patients can’t afford to miss.
The clinical consequences of a missed diagnosis are one thing, but the human toll is just as substantial. According to the ATLAS study that surveyed 311 patients with DB, 80% of patients reported disruptions to daily life. Nearly half struggle with night driving, and about a third need more time for daily hygiene routines.6
“Around the issue of Demodex blepharitis, one of the most surprising clinical insights is just how big an impact it has on a patient’s daily life. Many suffer for years, misdiagnosed or dismissed, leading to frustration and even anxiety around their eye health,” said Dr. Mertens.
And for European practitioners seeing younger patients, the contact lens intolerance data has proven striking as well. A study in 62 users of contact lenses showed that 93% of those with contact lens intolerance have Demodex mites, suggesting that many of these cases—often chalked up to dry eye or general sensitivity—might actually stem from a sneaky mite problem.4
“Today, clinicians are increasingly recognizing that acknowledging DB can result in better comfort, confidence and emotional well-being of these patients—once more highlighting the importance of looking beyond the slit lamp and listening to the patients’ experiences,” emphasized Dr. Mertens.
What’s next for Europe and DB
Dr. Mertens (Belgium) and Dr. Rampat (UK) see the “Look at the Lids” initiative as more than a diagnostic reminder, it’s a shift toward proactive, targeted care for eyelid health.
“The future of DB management lies in proactive diagnosis, standardized screening and targeted therapies. But most importantly, it starts with the first step of recognizing DB and to increase awareness to better address it. DB should no longer be a disease that should be tolerated or mismanaged,” noted Dr. Rampat.
As the understanding of eyelid health advances, accurate diagnosis is no longer a nice-to-have. It’s essential. The ATLAS study underscores the urgency: 51% of patients with DB had symptoms for four years or more before diagnosis, and 58% had never been diagnosed with blepharitis at all.6
And these patients aren’t avoiding the clinic—33% had seen a doctor more than twice.6 The takeaway? A quick lid check could make a lasting difference for a large group of overlooked patients.
“As diagnostic techniques become routine and as more clinicians routinely screen for collarettes, DB is shifting from an overlooked to a recognizable, impactful disease for our patients,” concluded Dr. Mertens.
Because we now recognize the true impact of Demodex blepharitis, overlooking it isn’t optional—it must be identified and addressed. Learn more at lookatthelids.eu.
Disclosure: Dr. Mertens and Dr. Rampat are paid consultants for Tarsus Pharmaceuticals, Inc.
Editor’s Note: The 43rd Congress of the European Society of Cataract and Refractive Surgeons (ESCRS 2025) is being held from 12-16 September in Copenhagen, Denmark. Reporting for this story took place during the event. This content is intended exclusively for healthcare professionals. It is not intended for the general public. Products or therapies discussed may not be registered or approved in all jurisdictions, including Singapore.
References
- Tarsus Data on File – Evaluation of the Real-World Burden of Demodex Blepharitis: A UK Multi-Centre Study
- Tarsus Data on File – Demodex blepharitis Patient Screening Study Brief Summary
- Trattler W, Karpecki P, Rapoport Y, et al. The Prevalence of Demodex Blepharitis in US Eye Care Clinic Patients as Determined by Collarettes: A Pathognomonic Sign. Clin Ophthalmol. 2022;16:1153-1164.
- Rhee MK, Yeu E, Barnett M, et al. Demodex Blepharitis: A Comprehensive Review of the Disease, Current Management, and Emerging Therapies. Eye Contact Lens. 2023;49(8):311-318.
- Starr CE, Gupta PK, Farid M, et al; ASCRS Cornea Clinical Committee. An algorithm for the preoperative diagnosis and treatment of ocular surface disorders. J Cataract Refract Surg. 2019;45(5):669-684.
- O’Dell L, Dierker DS, Devries DK, et al Psychosocial Impact of Demodex Blepharitis. Clin Ophthalmol. 2022;16:2979-2987.
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