Demodex blepharitis might not just impact the lid margin – it can trigger a ripple effect across the ocular surface.1 As mites can burrow and feed, their claws can scrape the follicle wall, weakening its structure and contributing to lash misdirection or even lash loss.1-4 Additionally, they can unleash inflammatory mediators1,5and can carry a bacterial load5 that can amplify the immune response.
When you see collarettes, think Demodex blepharitis: they’re a pathognomonic sign at the lash line.1
The result? Symptoms like redness, crustiness, irritation, itching and fluctuating vision that can be labelled as “dry eye”, MGD or ocular allergy – while an underlying Demodex infestation can go unrecognized.1,6
Transcript
0:05 – This misdirected lash is a classic sign of Demodex blepharitis.
0:09 – It was caused by mechanical damage.
0:12 – As Demodex mites burrow and feed, their claws constantly scrape the interior lining of the follicle.
0:18 – This repeated trauma eventually weakens the follicle structure, which can lead to lash misdirection or even loss.
0:25 – But these tiny mites do more than just scratch the surface.
0:28 – They unleash a powerful ripple effect of inflammation across the entire ocular surface, driven by two distinct attacks.
0:36 – First, the chemical assault: an inflammatory soup of cytokines and chemokines unleashed by the mites. And second, the bacterial load they carry, which triggers a powerful secondary immune response.
0:49 – Because of this multifaceted damage, symptoms like redness, irritation, itching and fluctuating vision may be misattributed to conditions such as dry eye, MGD, or ocular allergies.
1:00 – But in some patients, Demodex mites may be contributing to the inflammation, so identifying their presence is key to breaking the cycle.
1:08 – The impact of DB on your patients can be profound.
1:11 – So where do we see this first?
1:14 – A perfect example is in contact lens intolerance.
1:17 – Have you ever wondered why so many patients abandon their lenses?
1:21 – A landmark study investigated that exact question, looking at the link between Demodex mites and contact lens failure.
1:28 – Their findings were astounding.
1:30 – 93% of patients with contact lens intolerance had a Demodex infestation.
1:36 – This suggests that Demodex mites may be a contributing factor for their intolerance or discomfort.
1:42 – The TITAN study, a review of over 1000 patients in US eye care clinics, quantified this further.
1:49 – It revealed that 59% of patients being treated for dry eye had Demodex blepharitis, and 56% of cataract patients had DB as identified by the presence of collarettes.
2:01 – Dr. Radhika Rampat: “I often get referrals for second opinions where the operation went well but the patients are complaining of fluctuating vision.
2:08 – I’ve learnt that an unstable ocular surface from Demodex could be a red flag, because the instability may lead directly to inconsistent keratometry and potential IOL power errors, but also just poor quality of vision as the tear film is the first surface the light hits.
2:25 – For me, diagnosing Demodex preoperatively is now about risk management.
2:29 – It tells me that the ocular surface is compromised and that I need to be extra cautious with my measurements and my entire surgical plan.
2:36 – We all have patients on the verge of dropping out of contact lenses due to dryness and irritation.
2:41 – I’ve learned the problem sometimes isn’t the lens or the solution, it’s Demodex.
2:45 – Finding Demodex explains so much.
2:48 – It tells me that we’re not just fighting dryness, we’re dealing with a chronic inflammatory infestation.
2:53 – Whilst we address it as best as we can with current options, it remains a long-term management challenge for many patients.”
3:01 – For so long we’ve treated the downstream effects — the dry eye, the MGD, the contact lens failure.
3:08 – We’ve chased the symptoms.
3:10 – But the evidence shows the ripple effect may start at the lid margin.
3:14 – So the next time you see that inflamed ocular surface, don’t just ask “How do I treat the symptom?”. Ask, “What is the source?”
3:29 – Scan the code to join the Collarettes Community and get the latest updates on Demodex blepharitis education.
