eye

Blepharitis is a common eye inflammatory condition that affects nearly 25 million Americans in the United States. Demodex blepharitis is caused by the infestation of Demodex mites in either the hair follicles or sebaceous glands located at the base of the eyelid.1 These mites cause irritating eye symptoms that have the potential to cause eyelid damage over time if left untreated. While there is no cure, tea tree oil for Demodex blepharitis remains the main preparation used to combat Demodex mites. However, TTO treatment can cause skin irritation, which is a major drawback in this patient population.  

The Relationship between Blepharitis and Demodex Mites

Out of the 65 known Demodex species, only D. folliculorum and D. brevis can be found in humans.2 These arachnid ectoparasites can reside in the hair follicles and sebaceous glands located on our eyelids. A Demodex mite’s life cycle spans between two to three weeks, with the adult phase lasting only 5 days. A female mite can lay anywhere between 15 to 20 eggs within the hair follicle, where these eggs grow into larvae and mature in eight-legged adults. Adult males will leave the follicle to mate, while the female will remain in the hair follicle.

When the hair follicles are infested with D. folliculorum mites, this condition refers to anterior blepharitis. While inside the follicle, D. folliculorum mites ingest skin surface cells causing the follicle to bulge leading to loose lashes. Often these lashes become brittle and fall out easily over time. Micro-abrasions from the mite’s claws induce increased skin cell growth and hyperkeratinization around the eyelash base, leading to the formation of cylindrical dandruff at the eyelid base.

When the meibomian glands are infested with D. brevis mites, this condition refers to posterior blepharitis. Meibomian glands are the sebaceous glands lining the eyelid’s edge. D. brevis mites prefer to burrow deep inside these glands causing gland blockage, which eventually leads to gland dysfunction and lipid tear deficiency. This blockage may also be a potential cause for recurring chalazia or red, irritated bumps located on the eyelid’s edge. Repeat mite infestations can lead to severe eyelid margin inflammation. If untreated, this inflammation can spread to the cornea and conjunctiva causing other eye conditions such as blepharoconjunctivitis.

While Demodex mites cause significant mechanical eyelid damage, they also carry bacteria such as Streptococci and Staphylococci that contribute to the formation of blepharitis. Both healthy and dying mites can trigger bacterial antigens, leading to the inflammatory response. An effective treatment goal is to decrease mite infestation by mate suppression, direct killing, or reducing transmission from direct contact.

Patient Populations and Risk Factors Contributing to Demodex Blepharitis

Demodex blepharitis equally affects both genders and follows an age-related trend. A study by Junemann demonstrated that Demodex mites can be found in approximately a quarter of 20-year olds, a third of 50-year olds, and 100% of people older than 90 years.3

Certain health conditions predispose patients to Demodex blepharitis. Rosacea patients are particularly susceptible because their sebaceous glands are congested creating an excellent environment for Demodex mites to thrive. Patients who require immunosuppressive regimens or who are diagnosed with immunocompromising diseases are more easily susceptible to blepharitis. Cancer and HIV patients are examples of susceptible populations. 

Preventable risk factors that promote the infestation and proliferation of Demodex mites include:

  • Sunlight Exposure
  • Alcohol intake 
  • Stress
  • Smoking 
  • Hot beverages and spicy foods 
  • Abrupt temperature changes 
  • Poor eyelid hygiene 

Physical factors that can promote Demodex mite proliferation include: 

  • Certain skin phototypes 
  • Oily skin types 
  • Patients prone to dandruff 

The Common Signs and Symptoms of Demodex Blepharitis

Signs and symptoms of Demodex blepharitis are obvious and negatively impact patients. They include the following:

  • Clear cylindrical dandruff at the eyelash base 
  • Itchy eyelids and/or eyebrows 
  • Loss of eyelash or eyebrow hairs, known as madarosis 
  • Burning or itching sensation underneath the eyelid 
  • Feeling of a foreign body underneath the eyelid
  • Blurry vision 
  • Redness and crustiness at the eyelid margin

Psychosocial effects have been reported by patients affected by Demodex blepharitis. 80% of patients reported their daily lives being negatively affected in several ways4, including:

  • Longer time needed to perform daily hygiene routine 
  • Difficulty with night-time driving 
  • Decreased eye contact wear 
  • Increased self-consciousness or constant worry about their eyes 
  • Increased trouble wearing make-up 
  • Negative self-perception of appearance 
  • Decreased self-esteem 

Because of the adverse physical and emotional effects of this condition, effective Demodex blepharitis treatment is essential for improving the well-being of these patients. 

Conventional Practices for Demodex Blepharitis Treatment

While there is no cure for blepharitis, current regimens focus on Demodex eyelid treatment to maintain effective symptom control. Conventional methods center around eyelid hygiene and symptom reduction.

Warm Compresses

Warm compresses help to unclog sebaceous glands, loosen sticky lash crust, stabilize tear film, and provide relief from the bothersome effects of inflammation. Easily assemble a warm compress at home by wetting a clean cloth with warm water. Wring out excess water and place the compress over your closed eyes for a few minutes. You may have to wet the washcloth continuously to maintain its warmth. 

Antibiotics

If prescribed by your ophthalmologist, topical antibiotic ointments are effective ways to decrease mite proliferation. Apply a small amount of ointment onto a cotton swab and gently apply to your eyelash base. Either apply before bedtime or when your doctor recommends. Sometimes your doctor may prescribe an oral antibiotic to help control your symptoms if they are severe. 

Eye Drops

There are over-the-counter artificial tears you can apply to alleviate dry eyes and swelling. Your ophthalmologist may also prescribe a steroid eye drop to reduce redness and swelling or an antibiotic eye drop to improve the function of your oil glands. Excessive use should be avoided as this can increase irritation over time. 

Skin and Eyelid Hygiene

Maintaining the cleanliness of your eyelids, skin, and hair is extremely effective for keeping the irritating symptoms of blepharitis under control. Gently wash your eyelashes daily with baby shampoo diluted in clean warm water and wash your hair, including your scalp and eyebrows, with an antibacterial shampoo. Currently, tea tree shampoo and cleansers are the go-to choices for blepharitis treatment. Drawbacks exist for both TTO and baby shampoo scrubs and cleansers. Baby shampoo can negatively impact tear production, while TTO can cause skin irritation.

The Effectiveness of Tea Tree Oil in Demodex Blepharitis

While symptom control is a big part of blepharitis treatment, another treatment goal is total mite count reduction to prevent further mating and re-infestation. While tea tree oil lid scrubs can cleanse cylindrical dandruff, they also stimulate mites to migrate onto the skin surface for easier eradication. 

Four weeks of daily lid scrubs with 50% tea tree oil and lid massages with 5% tea tree oil ointment has been shown to reduce the Demodex mite count to zero in many patients. While the exact mechanism is unknown, 50% TTO has a direct miticidal effect, while the 5% TTO ointment may prevent mating.3 Ophthalmologists often prescribe tea tree oil for Demodex blepharitis due to its reliable effectiveness in symptom relief and inflammation reduction of the eyelid margin, conjunctiva, and cornea. 

The Benefits of 4-Terpineol over Current Regimens

While tea tree oil regimens are effective for decreasing overall mite count, tea tree oil can be very irritating to the skin. This is a big drawback for this patient population since eyelid irritation is the main symptom of Demodex blepharitis. To lessen the potential for skin irritation, a study examined the 15 main active ingredients of TTO and their ability to kill Demodex mites. Out of all these ingredients, Terpinen-4-ol was ranked the highest in potency, demonstrating effectiveness even at concentrations as low as 1%.5

A big advantage of T4O over tea tree oil for Demodex blepharitis is that it shows superior efficiency in killing mites. A study by Tighe and associates demonstrated that T4O had quicker kill times than tea tree oil at similar concentrations. Moreover, 1% T4O dilution was able to eradicate Demodex mites in less than 90 minutes, whereas 10% TTO dilution was unable to achieve this endpoint.2 A 0.01% hypochlorous solution has recently been promoted for use in reducing mite count in Demodex blepharitis. This same study confirmed that 4% T4O solution can neutralize Demodex mites within 40 minutes. When compared to 0.01% HOCl, the majority of Demodex mites remained alive at 90 minutes.6

In another study, patients did not report eye or skin irritation with a 2% formulation of T4O. This study also demonstrated T4O’s ability to effectively kill common ocular microorganisms within 60 seconds.7 While currently underutilized, T4O’s clinical appropriateness in Demodex blepharitis treatment is obvious due to its safety, effectiveness, and lack of irritation. 

Currently, Cliradex is the only commercially available product containing T4O specifically for ophthalmic use. It has been shown to effectively kill mites within 40 minutes of exposure8 and is safe to use every day. If you suffer from Demodex blepharitis, Cliradex is available in towelettes and cleansers for you to conveniently clean your eyelids and find the relief you need. Feel free to contact our team regarding any questions you may have on our products. 

Sources used: 

  1. https://www.aao.org/eye-health/diseases/what-is-blepharitis
  2. https://www.healio.com/news/optometry/20120225/demodex-infestation-requires-immediate-aggressive-treatment-by-doctor-patient
  3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2946818/
  4. https://iovs.arvojournals.org/article.aspx?articleid=2774001
  5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3860352/
  6. https://www.dovepress.com/in-vitro-demodicidal-activity-of-commercial-lid-hygiene-products-peer-reviewed-fulltext-article-OPTH
  7. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6093255/
  8. https://iovs.arvojournals.org/article.aspx?articleid=2693620
  9. Image by Sofie Zbořilová from Pixabay 
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