What it is
The word blepharitis (chronic blepharitis, allergic blepharitis) derives from the Greek "blepharos", which means "eyelid": the term indicates an inflammatory condition affecting this structure intended to protect the eye. In particular, the inflammation concerns the eyelid edge, i.e. the transition area between the skin layer (external and in contact with the environment) and the conjunctival layer (internal and facing the ocular surface) of the eyelid. The eyelid edge is characterised by eyelashes, which contribute to the protective function, and by glands, including the Meibomian glands that are responsible for the production of meibum, a special sebum that is part of the tear film that coats, lubricates and nourishes the cornea. Therefore, any eyelid disorder inevitably affects the health of the eye. The classic symptoms of mild to moderate blepharitis are burning, a sensation of heat on the eyelid edge and more or less intense itching that leads to rubbing the eyelid edge with the hands. In addition to this symptomatology, in severe blepharitis there is also eyelid swelling, localised pain aggravated by blinking (which becomes irregular) and intolerance to light (photophobia). The eyelid edge may show small white scales similar to dandruff, small scabs and, in more serious forms, the formation of real ulcers. Blepharitis can be caused by an altered secretion of the Meibomian eyelid glands, by uncorrected refractive defects, in particular hypermetropia and astigmatism, by skin diseases, such as seborrhoeic eczema, by dietary alterations such as avitaminosis and dyspepsia, by diseases such as diabetes or the excessive accumulation of fats in the blood, by allergic and environmental factors (dust, smoke) or by a bacterial infection. The bacteria responsible for blepharitis are mainly staphylococci and streptococci, which can cause the pathology or constitute a complication of the allergic form. Furthermore, blepharitis can be associated with conjunctivitis and therefore manifest itself as blepharoconjunctivitis, characterised by inflammation of both the conjunctiva and the eyelid edge or also affect the cornea and therefore be associated with keratoconjunctivitis.
The diagnosis is based on the evaluation of the presence of signs and symptoms of the eyelid typical of the pathology and on a physical examination, which is performed by the ophthalmologist using the slit lamp.
The treatment of the disease involves the instillation of antibiotic and anti-inflammatory eye drops. In the case of an infectious blepharitis, it is good to remember not to use contact lenses to avoid contamination and for women to avoid using eye cosmetics during therapy.
Blepharitis can present a sub-acute or chronic evolution, with resistance to therapeutic treatments and a marked tendency to relapse. Therefore, given this tendency and the considerable difficulty in healing, general hygiene and behavioural rules must be followed to prevent this condition. It is therefore recommended to always wash the hands thoroughly, especially before touching the eyes (a habit that should be avoided as much as possible), to follow a correct diet rich in fruit, fresh vegetables and lean proteins, such as those of chicken and fish, which are useful for eye health, to limit sugars and caffeinated drinks, which contribute to eye irritation and worsen symptoms caused by blepharitis.
In addition, to maintain an optimal state of health of the eyelids, the America Academy of Ophthalmology (AAO) recommends proper eyelid hygiene through the use of medicated gauze in case of anterior blepharitis and warm compresses also with medicated gauze in case of posterior blepharitis and meibomitis.