Blepharitis is an inflammation of the eyelid margins. It is a common disorder affecting external eye, the cause for which is unclear, although seborrhoea and staphylococcal infection play important roles.
Chronic blepharitis may cause secondary changes in the cornea and conjunctiva, and many patients have associated tear film instability. This condition may interfere with contact lens wear and aggravate treatment of dry eyes.
While generally not sight- threatening, it may permanently damage eyelid margin.
Blepharitis may be divided into:
Anterior blepharitis affects eyelid skin, root of eyelashes and eyelash follicles. It is divided into:-
- Staphylococcal blepharitis.
- Seborrhoeic blepharitis.
Seborrhoeic blepharitis is more common in older age group. Staphylococcal blepharitis tends to affect younger patients as compared to seborrhoeic blepharitis and may start in childhood.
Posterior blepharitis affects meibomian glands and their orifices. It has a range of potential causes, the primary cause being meibomian gland dysfunction (MGD). There are three main types:-
- Meibomian seborrhoea.
- Primary meibomitis.
- Meibomitis with secondary blepharitis.
Frequently, there is considerable overlap of these in an individual patient. Seborrhoeic blepharitis may occur in isolation or it may be associated with anterior staphylococcal blepharitis or even posterior blepharitis.
Since bacteria and inflammation are believed to contribute for the disease, long-term management may include eyelid hygiene and use of therapeutic agents which reduce infection and inflammation.
Blepharitis may be associated with diseases such as:
- Acne rosacea.
- Seborrhoeic dermatitis.
- Dry eye syndrome.
Kanski,Jack J. Clinical Ophthalmology, A Systematic Approach .Third Edition.UK. Butterworth Heinemann, 1994. P 74-77.
The symptoms of various types of blepharitis are similar, although there is frequently little correlation between their severity and the extent of clinical involvement. Many of the symptoms are secondary to tear film abnormality.
Symptoms are frequently worse in the morning and are characterised by exacerbations and remissions.
Symptoms of pure seborrhoeic blepharitis are similar but less severe than those of staphylococcal blepharitis, with less waxing and waning and fewer exacerbations.
Common symptoms are:-
- Burning sensation in eyes.
- Foreign body sensation.
- Eye irritation.
- Watering of eyes.
- Pain in eyes.
- Erythema of lids.
- Crust formation on lid margins and medial canthus with matting of eyelashes.
- Redness of eyes.
- Mild photophobia.
- Blurred or decreased vision.
Systemic diseases may have associated features of disease process:
Acne rosacea may be associated with:
Red and swollen nose (rhinophyma or potato nose).
Easy facial flushing.
Telangiectasia (visibly dilated blood vessels on skin).
Seborrhoeic skin changes may involve scalp, eyebrows, retro-auricular areas, glabella (smooth area between eyebrows just above the nose) nasolabial folds and sternum.
Seborrhoeic dermatitis may be:
Oily type: In oily type, scaly eruptions are greasy and skin is oily.
Dry type (pityriasis capitis or dandruff): There are scaly eruptions with scalp itching and flaking.