Dr Chrissie Cockinos BScHons, MBCHB, MMed(Ophth)
Ophthalmologist, Sandhurst Eye Centre, Sandton
Blepharitis is an ophthalmologic condition characterised by
inflammation of the eyelid margins. It can also be defined based on duration either as acute or chronic, or by location, anterior or posterior. Anterior blepharitis is often a product of bacterial overgrowth and/or Demodex infestation whereas posterior blepharitis is associated with meibomian gland dysfunction (MGD).
Symptoms may be recurrent and are usually bilateral. The mainstay of management is eyelid hygiene, hot compresses, elimination
of triggers plus adjunct topical corticosteroids and topical and/or oral antibiotics.
Despite there being no cure for blepharitis the prognosis is good and adequate and regular eyelid hygiene alleviates many of the possible sequelae and complications.
Prevalence of blepharitis
It is well recognised that blepharitis is one of the most common conditions encountered in ophthalmology practices. A 2009 survey in the United States showed that 37% of patients seen by ophthalmologists and 47% of patients seen by optometrists had signs of blepharitis.
In Britain, blepharitis and conjunctivitis accounted for 71% of
ocular cases of inflammation that presented to the emergency room. 25 million Americans have blepharitis as do 86% of all patients with dry eye. In one study, Demodex blepharitis has
been recognised as a cause of blepharitis for a long time and is often overlooked. 84% of people over the age of 60 and 100% of those over 70 have Demodex blepharitis. In another study, demodex was isolated in 62.4% of adult patients with blepharitis as opposed to 24.3% controls.
Aetiology
The aetiology of blepharitis is multifactorial. Acute blepharitis may be ulcerative or non-ulcerative. Infections by Staphylococcal bacteria
cause ulcerative blepharitis. Demodex folliculorum and Demodex brevis are parasitic mites that are frequent causes of anterior blepharitis. Herpes simplex and varicella-zoster may also infect the
eyelids. Certain fungi can be involved in blepharitis. One study showed a presence of hyphae and/or spores in 79% of cases with chronic anterior blepharitis. Nonulcerative blepharitis usually has
atopic aetiologies. Anterior blepharitis is usually associated with Staphylococcus infection, Demodex infestations, rosacea or seborrheic dermatitis. Posterior blepharitis is secondary to
meibomian gland disease. The glands secrete an oily discharge which clogs the orifice of the meibomian gland and acne rosacea and hormonal imbalance are important associations. Blepharitis affects all ages of people and all ethnic groups. The eyelid’s anatomy and physiology are vital to the protection of the ocular surface, from a mechanical point of view and for providing a hydrated and
lubricated surface for optimal vision. Poor eyelid hygiene, MGD, allergies, microbial infections and Demodex mite infestation as well as dandruff are some of the predominant aetiologies of blepharitis.
Classification can be difficult due to the underlying mechanisms involved in its pathogenesis. Tear film anomalies and underlying dermatological conditions seem to add to the pathogenesis.
Symptoms of blepharitis involve a wide spectrum of complaints. Dry, red, crusty, itchy, sore, teary and burning eyes are among the more commonly described symptoms. Recently, demodicosis has been given much attention in blepharitis studies. The migration of the Demodex mites has also been charted in one study. In the case of facial demodicosis, mites are presumed to migrate along the inferior lid margin to the medial canthus, then to the superior lid margin.
Pathophysiology
The exact pathophysiology of blepharitis is unknown. Many factors are involved in the causation. Most likely, low grade ocular surface bacterial infections, atopy and skin inflammation
due to allergies and seborrhoea as well as Demodex are involved.
Broadly eyelid inflammation disturbs the flora of bacteria and changes the quality of lipid produced by the eyelid. Meibomian gland dysfunction is a chronic, diffuse abnormality of the
meibomian glands, commonly characterised by terminal duct obstruction and/or quantitative changes in glandular secretion. This may result in alteration of the tear film, symptoms of eye
irritation, clinically apparent inflammation and ocular surface disease. Hyperkeratinisation of meibomian glands may lead to the obstruction of the gland orifices by thickened meibum which contains keratinised material. This is thought to be the main cause of
MGD.
History
Patients complain of morning crusting of their eyelids and difficulty
opening their eyes. Dry, scratchy, itchy, teary, red, swollen eyes and a
foreign body sensation are common symptoms.
Clinical Signs
Slit lamp examination is required to diagnose blepharitis. Swelling and redness of the lid margins, telangiectasia and scaling on the lash
base forming collarettes, madarosis, poliosis and trichiasis are all signs. Obstruction and pouting of meibomian glands and capped meibomian gland orifices are seen.
Special Investigations
Fluorescein staining of the tear film and a reduction in tear film break up time is commonly seen. Dry spots in the tear film before 10 seconds is abnormal and indicative of an tear dysfunction.
Blepharitis is a clinical diagnosis based on history and examination.
Patients with refractory blepharitis should have a biopsy to exclude carcinoma especially if madarosis is present.
Associated Eye Conditions
Dry Eye
Dry eye is associated with blepharitis. More than one third of patients with dry eye syndrome have concurrent blepharitis and two thirds of patients with Sjogren’s syndrome have blepharitis.16
Dry eye syndromes are classified into two groups: Aqueous-deficient and evaporative. Aqueous deficiency can further be divided into Sjogren or non-Sjogren.
Evaporative dry eye disease can be due to Meibomian gland dysfunction as well as allergic conjunctivitis, disorders of the lacrimal functional unit or even the blink reflex.
Allergy, dermatological conditions and contact lenses
Dry eye syndrome and blepharitis are often seen in association with seasonal allergic conjunctivitis or exposure conjunctivitis. Contact lens use is associated with dry eye and MGD. The use of daily eyelid hygiene will improve dry eye by improving MGD and by decreasing evaporation of the tear film. Allergic conjunctivitis will improve
by removing allergens from the lid margin as well as increase contact lens tolerance by improving MGD.
Corneal ectasia and ocular Demodicosis
Hung et al recently published a study of 36 eyes with corneal ectasia all of which had symptomatic Demodex blepharitis. Their results indicated that demodex blepharitis may be one of the risk
factors triggering eye rubbing and corneal ectasia even in older patients with thick corneas. These corneal changes were stabilised or even reversed after meticulous eyelid hygiene.
Treatment
The mainstay of treatment remains the same. Eyelid hygiene with warm compresses and gentle massage to
aid the removal of crusts and stimulate expression of oils by meibomian glands is important. Today there are many adjunct therapies to assist with warm compresses in the way of heated eye pads, eye masks and masks with thermal pulsation as well as low-light therapy systems that may help to open obstructed lid glands.
Tea tree containing eye lid cleansers, the active ingredient being Terpinen-4-ol, have become routine in most ophthalmologists’ treatment schedules. Tea tree is effective in eradicating bacteria,
Demodex and fungi all of which are major causes of blepharitis. Tea tree is also a natural anti-inflammatory. Advice and assistance around how to use these commercially available tea tree cleansers and how to rinse properly is important. Different types of cleansers
are now available: Gels, foams and eye wipes. Patient compliance improves vastly when doctors explain how to perform the treatment regime or offer pamphlets with diagrammatic explanations to the patient.
Underlying conditions must be treated. Topical antibiotic creams must be used for acute anterior blepharitis. Bacitracin and erythromycin are commonly used for a few weeks. Posterior blepharitis benefits from oral tetracyclines and macrolide antibiotics.
These antibiotics regulate inflammation and lipid metabolism.
Topical corticostetoids aid in fighting lid inflammation. A short course some times combined with antibiotics or in severe cases cyclosporine drops may be helpful. With steroids one is concerned
about the possibility of intraocular pressure rise. A number of keratolytics used in dermatology have been considered to
address hyperkeratinisation in MGD.
Alpha hydroxy acids (AHAs) and Beta Hydroxy Acids (BHA’s) and are used in some shampoos. Another keratolytic agent, selenium
sulfide which has a different mechanism from AHAs and BHAs, slows the production of epithelial cells. Selenium sulfide is found in many shampoos to treat dandruff and seborrheic dermatitis. This compound used on the lid margins may help seborrheic blepharitis.
Conclusion
Blepharitis is a chronic condition with a high prevalence globally. Symptoms related to ocular surface disease and dryness are typical. Treatment involves regular eyelid hygiene, treatment for dry eyes and treatment of any underlying systemic disease.
References
1. Bernardes TF, Bonfioli AA. Blepharitis. Semin
Ophthalmol 2010; 25: 79–83.
2. Benitez-Del-Castillo JM. How to promote
and preserve eyelid health. Clin Ophthalmol
Auckl NZ 2012; 6: 1689–1698.
3. Lemp MA, Nichols KK. Blepharitis in the United States 2009: a survey-based perspective
on prevalence and treatment. Ocul Surf
2009; 7: S1–S14.
4. Lemp MA, Crews LA, Bron AJ, Foulks GN, Sullivan BD. Distribution of aqueous-deficient
and evaporative dry eye in a clinic-based patient cohort: a retrospective study. Cornea
2012; 31: 472–478.
