Blepharitis is a general term for inflammatory diseases of the eyelids. It can have several causes, ranging from allergies, through to infection, irritation, and is often associated with dry eye disease. The latter form is one of the most common eye diseases.
Symptoms of blepharitis are usually itchy eyes, irritation, burning, and the sensation of the presence of a foreign body. The feeling of dry eyes is also common, which is only temporarily alleviated with teardrops. Contact lens wearers often complain that they can no longer wear the lens for so long and that the contact lens irritate them more. The eyelids can become red, often with yellowish discharge accumulating at the base of the lashes.
Chronic inflammation of the eyelid is often caused by a bacterial (e.g., Staphylococcus aureus) or Demodex mite infection. One of the most important factors in the effective treatment of blepharitis and the reduction of complaints is regular cleaning of the eyelid, because with the appropriate treatment, both bacterial growth and the Demodex mite can be killed and the complaints can be permanently reduced.
The function of eyelids is to protect the eyes and keep them clean, moist, and at the right temperature. This function is performed by blinking and closing the eyelid. Reflex closure of the eyelids is triggered by strong light, corneal irritation, and an object that suddenly enters the field of view and is close to the eye. The up and down movement of the upper eyelid with each blink spreads a new, fresh layer of tears on the surface of the cornea. Since the cornea does not have its own blood supply, it is essential to maintain a healthy tear film to receive nutrients. Tear film is a complex fluid that covers both the cornea and the conjunctiva.
The Meibomian glands located in the eyelids produce the outermost, lipid layer of the tear film that prevents the tear film from evaporating. Lipid produced by the Meibomian glands is distributed on the surface of the eye by regular blinking and accumulates at the edge of the eyelid during concentrated work (e.g., work in front of a computer monitor) when there is less blinking and during sleep The quantity and quality of lipids produced are influenced by a number of factors, such as hormonal, neural effects, environmental factors, and inflammatory processes.
Meibomian gland dysfunction is an inflammation of the glands located along the edge of the eyelid which produces an oily layer of the tear film, causing irritations on the surface of the eye through the degraded tear film quality. In Meibomian gland dysfunction, the outlet tubes narrow, causing the composition of the lipids produced to change and the thickened, waxy lipid accumulates at the edge of the eyelid, causing the outlet tubes to become blocked. Due to the thickened lipid composition, there is an inflammatory effect, which also promotes the growth of bacteria.
Meibomian dysfunction is very common, occurring in about 60% of the population.
Meibomian gland dysfunction can be caused by inflammation of the eyelids and the surface of the eye, through wearing contact lenses, dry eyes, menopause, rosacea, psoriasis, atopy, and hypertension. Meibomian gland dysfunction leads to the development of evaporative dry eye syndrome.
The eye is often involved in allergic reactions, both as a stand-alone symptom and as a local manifestation of a general allergy. Although allergic conjunctivitis is usually a transient complaint, both its seasonal and year-round forms have a significant impact on the quality-of-life of those affected. By cleaning the edge of the eyelid, the allergens that accumulate there can be removed, making them less likely to reach the sensitive surface of the eye and trigger allergic conjunctivitis.