Demodex blepharitis: Closing the diagnostic gap to improve ocular surface health

Demodex blepharitis is a chronic condition caused by the infestation of Demodex mites in the eyelash follicles, characterized by eyelid margin inflammation, collarettes and symptoms that can persist for years. Despite its prevalence, it remains underdiagnosed in clinical practice, often attributed to habit or other ocular surface conditions rather than the underlying parasitic cause.

Prof Mayank A. Nanavaty, MBBS, DO, FRCOphth, FWCRS, PhD, consultant ophthalmic surgeon at University Hospitals Sussex NHS Foundation Trust and honorary professor at Brighton and Sussex Medical School, moderated a recent Ophthalmology Times Europe Case-Based Roundtable® presenting two cases from his own practice to guide discussion on diagnosis, treatment and the diagnostic gap that continues to affect patient care.

Case 1: Chronic eyelid disease and the limits of current treatment in the UK

The first case involved a patient with a long-standing history of eyelid problems, characterized by significant eczematous changes of the eyelid margins and a heavy burden of collarettes on the lashes. The patient had experienced itchy, red eyes for many years. The inflammatory changes visible on the lashes had perpetuated a cycle of chronic lid inflammation that proved difficult to break with the treatments available in the UK.

Nanavaty outlined the treatment options available within the UK context: eyelid wipes, eyelid hygiene measures and topical steroid ointment applied to the lashes to address the inflammation and concurrent eczematous changes. Following a 2-week course of treatment, redness settled to some degree but improvement was not significant. Nanavaty described the situation as an ongoing battle for the patient.

The key takeaway from this case was the limited availability of treatments for Demodex blepharitis in the UK. Lotilaner ophthalmic solution 0.25%—approved by the US Food and Drug Administration (FDA) in July 2023 as the first and only treatment specifically targeting the underlying Demodex mite infestation, and marketed in the US as Xdemvy (Tarsus Pharmaceuticals)—is not currently available in the UK. Lotilaner ophthalmic solution 0.25% received further regulatory approval in March 2026 from China’s National Medical Products Administration (NMPA) for the Greater China region, where it is being commercialized by Grand Pharmaceutical Group Limited. Nanavaty noted that patients such as this one would likely benefit from access to targeted antiparasitic therapy and expressed anticipation of its potential future availability in the UK.

Case 2: An unrecognized diagnosis hiding in plain sight

The second case offered a different perspective on the diagnostic gap in Demodex blepharitis. The patient was a 47-year-old nurse working alongside Nanavaty who had a long-standing habit of rubbing her eyes—a behaviour she and those around her had regarded as a tic rather than a symptom of underlying disease.

It was only after Nanavaty had spent the previous year learning about and teaching others about Demodex blepharitis that he thought to examine her at the slit lamp. On doing so, he identified collarettes and changes consistent with Demodex infestation. The rubbing and itching he had observed as an apparent habit was, in fact, a symptom of an undiagnosed condition. Treatment comprised a short course of topical steroids and eyelid hygiene measures.

The transferable message from this case, Nanavaty suggested, is that when a colleague, patient or family member is observed repeatedly rubbing or itching their eyes as an apparent habit or tic, it is worth examining them at the slit lamp. What appears to be a behavioural mannerism may be a treatable condition. “If you see somebody rubbing as a habit, examine them on the slit lamp,” he said. “It may not be the habit. It could be this condition.”

Emerging discussion: Experience with lotilaner from US colleagues

One of the more notable moments to emerge from the roundtable arose from the contribution of American attendees. Several colleagues from the US with clinical experience of lotilaner ophthalmic solution 0.25% shared their perspectives on its efficacy and tolerability. For the European and UK clinicians in attendance, who do not yet have access to the product, this exchange was described by Nanavaty as extremely useful.

The discussion also prompted a practical change in Nanavaty’s own examination technique. Until the roundtable, he had not routinely asked patients to look downward during slit lamp examination of the lashes. Having heard how colleagues examine for eyelash changes and correlate anterior segment findings with what is visible around the lash line, he has since incorporated this step into his practice. He noted that there are several ways to approach the same condition, and that hearing how colleagues examine, diagnose and manage Demodex blepharitis in their own practice settings broadens the frame of reference in ways that a formal lecture or published paper cannot always replicate.

For Nanavaty, the roundtable served both as an educational experience and as a prompt to reassess and refine his own clinical approach—an outcome he described as directly applicable to his everyday practice.