Demodex

What is Demodex?

Demodex folliculorum and Demodex brevis are small mites that inhabit the face, eyelids and eyelashes.

The incidence of Demodex infestation increases with age. Occurring in 84% of the population at the age of 60 and in 100% of the population older than 70 years old. Demodex mites have a higher likelihood to be found in individuals with Acne Rosacea. All adults have some mites on their body. The eye socket is a difficult area to clean and as a result the chance of infestation increases as people get older. Demodex infestation contributes to some cases of chronic lid margin disease. Also ocular surface inflammation and Meibomium Gland Dysfunction.

The good news is the lifespan of Demodex is approximately 19 to 23 days.

The bad news is that they mate and continue to grow in number if you do not remove them all.

What are the symptoms?

Some patients with Demodex are not too bothered by them others exhibit the following symptoms:

• Itching
• Burning (including hot eyes)
• Foreign body sensation
• Crusting and redness of the eyelid margin
• Blurry vision
• General irritation of the eyes
• Cylindrical dandruff observed at the base of the eyelashes

How do we treat it?

The first treatment is hygiene. Total body cleaning with shampoo or soap is required. Not just the eye, but the whole body, because mites can spread from one territory to another. If you can prevent the mites mating through hygiene, then the population will be under control and eventually eradicated.

Wash bedding at least once a week and out through a hot dryer so that the mites can be killed.

Pets have their own mites. Whether the mites can move from pets to humans remains unclear, so it may not be a good idea to sleep with pets.

Lid scrub* with tea tree oil has been found to clean dandruff from the lash root. Also stimulating embedded mites to migrate out of the skin. Typically, a daily scrub with 50% tea tree oil and lid massage will resolve ocular Demodex infestation. However, tea tree oil can be toxic to the ocular surface. So the College of Optometrists Clinical Management Guidelines on Blepharitis recommends that only experienced practitioners should carry out this particular treatment. A new self treatment is now available containing tea tree oil called Cliradex. This is now available from our Hailsham practice.

*Blephex treatment has been proven to treat Demodex with its active ingredients and exfoliation of the lids.

Other Facts

• 30% of patients are affected by dry eye symptoms
• Significantly higher proportion of dry eye cases amongst contact lens wearers, women and in individuals 70 years of age and over
• 80% of dry eye cases have some type of Meibomian Gland Dysfunction (not enough oil in the tear film) and inflammation (Blepharitis)
• 20% of dry eye cases have Aqueous deficiency (not producing enough tears) and by plugging the tear ducts can improve symptoms
• A proportion of patients with Blepharitis actually have a mite infestation of their eyelids called Demodex Blepharitis