Key points to remember

Eyelid inflammation, called blepharitis, is a complex condition with multiple causes. Understanding these causes is essential for effective and lasting treatment. Here are the important things to remember:

• Different factors interact to cause blepharitis : Eyelid inflammation can be caused by problems with the meibomian glands (which produce oil from tears), bacterial infections, parasites, or skin problems such as ocular rosacea or seborrheic dermatitis (inflammation of the skin with scales).
• The meibomian glands play a central role in posterior blepharitis (on the inside of the eyelid) : These glands produce oils that stabilize the tear film and keep the eyes healthy. If they don't work properly, it leads to dry eyes that worsen inflammation, creating a vicious cycle.
• General health influences the duration of blepharitis : General health conditions like rosacea, immune system disorders, or hormonal changes can make blepharitis recurrent (it comes back often). It is therefore important to have a medical approach that considers the overall health of the patient.
• Eyelid hygiene is essential for prevention : Not cleaning your eyelids regularly can lead to an accumulation of bacteria and worsen inflammation, especially in anterior blepharitis (on the outer edge of the eyelids). Regular and appropriate cleaning is therefore essential.
• Environment and lifestyle can make blepharitis worse : Pollution, prolonged use of screens, wearing the wrong contact lenses, or a dry climate can intensify symptoms and make the condition more difficult to manage. It is important to identify and change these factors.
• Complications can occur if blepharitis is not treated : Untreated blepharitis can lead to problems such as chalazions (cysts in the eyelids), styes, corneal inflammation (keratitis), severe dry eyes, and even affect long-term vision. It is therefore important to treat it quickly.
• Effective treatment is personalized treatment : Combining local care, good eyelid hygiene, treatment of underlying conditions such as rosacea, and changes in environmental factors helps to better control relapses and improve quality of life.

Understanding the causes of blepharitis is more than just looking at the symptoms. Research shows that a thorough analysis of factors related to general health and the eyes is essential for the sustainable and personalized management of this condition. In order to better understand the complex mechanisms of this condition, let's look at these causes and their consequences in more detail.

Introduction

Understanding the causes of blepharitis: when eyelids become inflamed

Eyelid inflammation, called blepharitis, can have multiple interrelated causes, ranging from problems with the eyelid glands to environmental factors, genetic predisposition, and lifestyle.

This common eye condition is the result of complex mechanisms that affect both the surface of the eye and overall health. Identifying the causes of blepharitis is essential to better understand its symptoms, prevent relapses, and protect vision in the long term. The impact of blepharitis isn't just limited to eye health. In the world of work, for example, eye fatigue and blurred vision can affect the productivity and well-being of employees, underlining the importance of appropriate treatment.

Let's take a detailed look at the causes of blepharitis, exploring the role of the meibomian glands, general health factors like rosacea, the importance of good eyelid hygiene, and the influence of the environment.

Understanding the causes of blepharitis: when eyelids become inflamed

What is blepharitis?

Blepharitis is an inflammation of the eyelids, which can be chronic (long-term) or acute (sudden). It is often annoying and causes problems such as dry eyes, redness, burning, and blurred vision. It can affect the edge of the eyelids (the “free edge”), where the eyelashes and glands that lubricate the eye are located. This condition is multifactorial : its exact causes vary from person to person, but they include environmental factors, bacterial infections, parasitic infestations (parasites), allergies, pre-existing skin conditions, and other health conditions.

The two main types of blepharitis: anterior and posterior

Blepharitis is classified into two main categories depending on the area affected:

1. Anterior blepharitis affects the outer edge of the eyelids, at the base of the eyelashes. It is often caused by bacterial infections, in particular by Staphylococcus aureus and Staphylococcus epidermidis, but may also be linked to skin conditions such as seborrheic dermatitis (oily and scaly skin) or allergic reactions to cosmetics. Sometimes it can also be associated with dandruff at the base of the lashes.

1. Posterior blepharitis affects the inside of the eyelid and the Meibomian glands, which produce tear film oils. The main cause of this form is the malfunctioning or obstruction of these glands. Posterior blepharitis is often associated with ocular rosacea and chronic dry eyes.

These two forms can exist at the same time, and it is important to distinguish them well for correct diagnosis and treatment. An accurate diagnosis makes it possible to set up an appropriate treatment, often a combination of hygiene measures and specific treatments.

The main causes of blepharitis

1. Infections and parasites

• Bacterial infections : The excessive multiplication of bacteria such as staphylococci on the edge of the eyelids is a common cause. The toxins (harmful substances) produced by these bacteria worsen inflammation and weaken the eyelid's defenses. This results in redness, swelling, and scabs.
• Demodex infestation : These are microscopic mites that normally live on the skin, but too much around the eyelash follicles (where eyelashes grow) can cause irritation, inflammation, and blepharitis. Demodex can also clog the meibomian glands, making dry eyes worse.
• Viral infections : Less common, viral infections like herpes simplex can also cause blepharitis, which is often accompanied by other symptoms such as small blisters on the skin around the eyes.

2. Meibomian gland problems

The meibomian glands produce oils that stabilize the tear film and prevent tears from evaporating. There are several problems that can affect their functioning:

• Obstructions : The accumulation of keratin (a skin protein) in the gland ducts prevents the secretion of oils, which makes the tear film unstable and causes dry eyes.
• Hormonal dysfunction : Androgens (male hormones) stimulate oil production, while estrogens (female hormones) can sometimes decrease oil production. A lack of androgens or a hormonal imbalance can therefore cause these glands to malfunction. Postmenopausal women, for example, are more at risk of developing later blepharitis because of hormonal changes.
• Inflammation : Chronic inflammations like rosacea can affect the meibomian glands, causing inflammation and dysfunction.

3. Skin conditions and general inflammation

Skin health plays an important role in blepharitis:

• Rosacea and ocular rosacea : This chronic skin inflammation often affects the eyelids, contributing to ongoing inflammation. Ocular rosacea can cause redness, burns, and severe dry eyes.

• Seborrheic dermatitis : Linked to an overproduction of sebum (skin oil), it is common in previous blepharitis. It is manifested by oily scales at the base of the lashes and redness.
• Atopic dermatitis (eczema) : This inflammatory skin condition can also affect the eyelids, causing itching, redness, and scales.
• Autoimmune diseases : Diseases like lupus, rheumatoid arthritis, or Sjögren's syndrome increase the risk of chronic eyelid inflammation and dry eyes.

4. Environment and lifestyle

• Pollution and allergies : Exposure to allergens (pollen, dust mites, animal hair), dust, or irritants (smoke, chemicals) can worsen blepharitis symptoms.
• Cosmetics : Too much makeup or insufficient makeup removal, the use of expired or irritating products, or poorly maintained contact lenses can clog the glands and promote infections.
• Dry climate : Living in environments with low humidity (deserts, mountains, heated or air-conditioned interiors) increases dry eyes and irritates the eyelids.
• Feeding : A diet low in omega-3 fatty acids and high in omega-6 fatty acids can promote inflammation and worsen symptoms.
• Personal hygiene : Poor hygiene, such as not washing your hands regularly, can increase the risk of bacterial infections and parasite infestations.

Why do other health conditions make blepharitis worse?

Link between rosacea and blepharitis

Rosacea (chronic inflammation of the facial skin) is closely linked to blepharitis, especially the later form. Around a third to a half of people with rosacea develop ocular rosacea. Patients with ocular rosacea may have malfunctioning meibomian glands, resulting in insufficient oil production for the tear film. Recognizing this connection is important because treating rosacea (with antibiotics, topical retinoids, or laser treatments) often improves blepharitis symptoms.

Impact of hormonal disorders

Hormonal variations directly influence the meibomian glands and the risk of blepharitis. For example:

• Les hormonal changes in menopause reduce oil production, which leads to increased dryness and inflammation of the eyelids.
• Patients on anti-androgen therapy (for example for prostate cancer or severe acne) may develop severe and persistent blepharitis.
• Pregnant women may also be more likely to develop blepharitis due to hormonal fluctuations.

Autoimmune diseases and general inflammation

Diseases like lupus, rheumatoid arthritis, or Sjögren's syndrome promote chronic inflammation throughout the body, including the eyelids. These conditions also increase the risk of severe dry eyes (dry keratoconjunctivitis), which is often associated with blepharitis. Medications used to treat these conditions (such as corticosteroids and immunosuppressants) can also have side effects on the eyes, contributing to blepharitis.

Diabetes

Diabetes can affect blood flow and nerves, which can alter tear production and meibomian gland function, increasing the risk of blepharitis and dry eyes. Additionally, diabetics are more susceptible to bacterial infections, which can worsen eyelid inflammation.

The mechanisms of symptoms: inflammation and instability of the tear film

The tear film, which protects our eyes, is composed of three layers: an aqueous layer (water), a mucous layer, and a lipid layer (oil). In case of blepharitis:

• The clogging of the meibomian glands reduces oil production, which destabilizes the lipid layer tear film. The tears then evaporate more quickly, causing dry eyes and irritation.
• Chronic inflammation of the eyelids releases inflammatory substances (cytokines, enzymes) that damage cells on the ocular surface, worsening the instability of the tear film and can cause permanent damage, such as scarring on the cornea, abnormal blood vessels in the cornea, and vision loss.

The accumulation of debris or dander on the edge of the eyelids can also lead to annoying symptoms:

• Burning, tingling, or foreign object in the eye.
• Itching and irritation of the eyelids.
• Eyelids stuck when you wake up because of secretions accumulated during the night.
• Temporary blurred vision due to the alteration of the tear film and the presence of debris on the cornea.
• Increased sensitivity to light (photophobia).
• Excessive tearing as a reaction to irritation.
• Loss of eyelashes (madarosis) or abnormal eyelash growth (trichiasis).

Practical case: interaction between the environment and glandular dysfunction

Take the example of a 55-year-old accountant living in a polluted city. He spends long hours in front of a computer screen and complains of dry eyes, red and swollen eyelids, and a feeling of sand in his eyes. Here are the observations made during the review:

• Presence of plugs in the meibomian glands, indicating a malfunction.
• Redness and inflammation of the edges of the eyelids.
• Worsening of symptoms by exposure to screens, as there is less blinking, which reduces natural lubrication.
• Debris around the lashes, suggestive of a bacterial infection.
• History of mild rosacea on the face.

In this case, pollution, screen time, and rosacea worsened a pre-existing meibomian gland problem, requiring a combined approach to alleviate symptoms. Treatment could include good eyelid hygiene, artificial tears, local antibiotics, treatment for rosacea, and tips for improving your workplace to reduce eye fatigue.

Towards a global understanding and an adapted treatment

To effectively treat blepharitis, the root cause must be identified and the patient's overall health, environment, and lifestyle taken into account. Interactions with other conditions, hormonal changes, environmental factors, and lifestyle require a personalized and comprehensive approach. For example, a patient with blepharitis and rosacea will benefit from treatment that targets both conditions. Likewise, a patient working in a dry environment will need to take steps to humidify the air and take regular breaks to rest their eyes.

Conclusion

Blepharitis, whether anterior or posterior, results from a complex combination of factors: infections, meibomian gland dysfunction, skin conditions, environmental influences, and other health conditions. Understanding these causes is critical to choosing the right treatment and avoiding complications, such as tear film instability and chronic inflammation. In addition, the links between blepharitis and other health conditions, such as rosacea, hormonal disorders, diabetes, or autoimmune diseases, require comprehensive management of the patient's health.

For this condition with multiple causes, personalized treatment that combines specific eye care (eyelid cleaning, hot compresses, massages), management of other conditions and lifestyle changes (diet, environment, hygiene) is essential. This not only relieves symptoms, but also restores a lasting balance to eyelid and eye health, improving the quality of life.

In an increasingly digital world, where screen exposure is omnipresent and where environmental pollution is increasing, the prevention and early treatment of blepharitis have become public health issues. Businesses also have a role to play in educating employees about the risks of eye strain and creating a work environment that is healthier for the eyes. The future of eye health depends on a proactive approach, a better understanding of risk factors, and collaboration between patients, health professionals, and society.