The eyelids perform many functions. They cover and protect the cornea, preventing scarring, infection, epithelial defects, and vascularization. Closing the eyelids distributes tears across the surface of the eye, wetting and protecting the eye. Certain conditions, however, can compromise the function of the eyelids.
Blepharitis is a chronic condition in which the eyelid margins are inflamed. It does not cause a reduction in visual acuity or a sensitivity to light. The general public has little knowledge of the term, yet the condition is very common, and is frequently seen by ophthalmologists. There are two types: anterior and posterior.
Posterior Blepharitis. Posterior blepharitis is immunological in origin, and arises as a result of meibomian gland dysfunction. There are approximately 30 meibomian glands per lid. They are located just behind the eyelashes, in a row parallel to the lid margins.[1,3] These sebaceous glands produce the lipid layer of tears. This lipid layer is critical in preventing tear evap-oration, ensuring a smooth optical surface, and reducing the ability of lipids from the surface of the surrounding skin to enter and contaminate the eyes.
Anterior Blepharitis. Anterior blepharitis is staphylococcal or seborrheic in origin, and is less common than posterior blepharitis.[4,5] The seborrheic type is produced as a result of immunological factors and is more common in patients with preexisting acne rosacea or seborrheic dermatitis of the scalp or facial areas.[4,6] If it is caused by acne rosacea (as implicated by telangiectatic areas on the cheeks, nose, chin, and lid margins), it is known as ocular rosacea.
Mixed Blepharitis. Blepharitis may have components of anterior and posterior pathologies. For example, an inherent meibomian gland-induced blepharitis may thicken lipid secretions, impairing their elimination. This predisposes the patient to secondary staphylococcal infection at the bases of the lids. Staphylococci release lipases and toxins, which produce increased irritation of the lids, possibly even to the extent that open lesions develop.
Blepharitis is more common as patients age. Blepharitis arising from meibomian pathol-ogy is more common in fair-skinned patients, perhaps because acne rosacea is more frequently found in this group. Blepharitis asso-ciated with meibomian pathology lacks a gender differentiation, but it may occur with greater frequency in those living in cooler climates. When the ophthalmic problems associated with Down's syndrome are explored, investigators have discovered that 7%-30% of people with Down's syndrome have blepharitis.[7,8] Investigators also found that 15% of a group of mentally ill patients and 21% of patients with coexisting mental illness and mental retardation experienced blepharitis, a significantly higher percentage than in the general population.
The posterior form of blepharitis causes a gritty, burning sensation that is more pronounced when the patient awakens from sleep. The morning peak in severity is a result of inflammatory mediators collecting underneath the eyelids as the patient sleeps. As the condition progresses, the meibomian glands undergo fibrosis, which eventually lessens the nocturnal mediator release, thereby lessening the symptoms upon awakening. However, discomfort during the daytime continuously worsens, which is typical of immunological conditions.
Anterior blepharitis of staphylococcal origin produces crusting and irritation at the base of the eyelashes. The eyelids are sometimes even stuck together when the patient awakens. The eyes are red and there is a foreign body sensation. Skin adjacent to the eyelids may also become inflamed. If the condition continues for a sufficient time, the eyelid can become denuded of lashes.
If the patient's blepharitis arises as a result of seborrheic causes, the crusting will have an oily consistency, similar to the greasy feel of skin scaling with seborrheic dermatitis. The eyelids may be pruritic. Anterior blepharitis lacks the diurnal variation in intensity that is typical of the posterior form of the disease.
Photophobia is common among patients who have blepharitis. In children, it may be so severe that they refuse to play outdoors.
Blepharitis can cause blepharospasm (BSP), in which the patient experiences uncontrollable and excessive closure of the eyelids. The onset of BSP usually occurs when patients reach their 50s or 60s. It tends to occur earlier in males than it does in females. BSP patients often suffer dry eye, grittiness, irritation, and photophobia.
Blepharitis is also a common cause of dry eye.[4,5] It alters the lipid layer of tear film and accelerates its evaporation. Epithelium is damaged, the number of goblet cells is reduced, and mucin production is decreased.
Lid hygiene is critical in the care of acute cases of blepharitis. One multi-step regimen is provided in this month's patient information page. It allows the patient to gently milk the glands at the lid margins while carefully cleansing the areas. Eye makeup may contribute to acute blepharitis, especially when the patient uses eye liner. Doing so may occlude the meibomian glands, plugging their orifices and reducing their output. Patients should choose eye liners that wash off easily, since they are less likely to plug the glands. The pharmacist should also suggest that patients use gentle water-based eyelid cleansers, such as EyeScrub and OcuClenz.
Once the acute episode has subsided, patients must understand that daily lid hygiene is necessary to prevent recurrence of blepharitis, since the condition cannot be cured, and relapses are the rule.[1,6] Patients with blepharitis must begin to view lid hygiene as another daily activity, such as toothbrushing or showering.
If the simple cleansing procedures outlined on the patient information page fail to be effective, the patient should seek physician care. Tetracycline 250 mg (four times daily) or doxycycline 50 mg (twice daily) both act to decrease the production of bacterial lipases. (Children with blepharitis should notbe given tetracycline because of resulting dental problems; erythromycin is an acceptable alternative.) Effective therapy may require 6-9 months. Patients should continue lid hygiene while prescription medications are taken. In addition, topical antibacterial/antibiotic ointments or drops such as bacitracin, erythromycin, ciprofloxacin, gentamicin, or tobramycin may be helpful. If the patient experiences inflammation of the eyelids, application of a topical steroid/ antibiotic ointment for 4-6 weeks may be effective.
Blepharitis is usually confined to the eyelid margins. Patients may complain of other conditions, but there are many clues that can help differ-entiate them. Those with atopic dermatitis of the lids also experience pruritus, have a history of dermatitis beginning in childhood, and also have dermatitis in areas of the body that crease or flex (adults) or dermatitis on the face (children). Those with contact dermatitis of the lids may have irritant or aller-gic forms; females usually experience the contact form due to cosmetics use. Some patients inflame the eyelids through repeated rubbing or scratching of skin affected by allergic conjunctivitis, contact dermatitis or atopic der-matitis. If the skin is roughened and unusually thick, it may be due to scratching.
The etiologies of anterior blepharitis and posterior blepharitis are relatively benign; however, there are several more serious conditions that can cause a secondary blepharitis. If the pharmacist suspects that one of the more serious etiologies is present, the patient should be urged to consult a physician.
A condition known as Melkersson-Rosenthal syndrome is not especially rare, but is seldom recognized and diagnosed. The ideal presentation is a patient with a classic triad consisting of recurrent edema in any region of the face or oral cavity, relapsing facial paralysis, and fissured tongue. However, many patients only present with one symptom, such as eyelid edema that leads to a granulomatous blepharitis.
A group of physicians described several patients with discoid lupus erythematosus whose symptomatology included possible a symmetric posterior blepharitis. Each had a long history of unilateral eyelid inflammation, pruritus, watery discharge, and loss of lashes. Asymmetric lash loss indicates potential sebaceous cell carcinoma. Thus, the authors initiated a more intensive investigation, which revealed lupus.
© 2002 Jobson Publishing
Cite this: Blepharitis and Proper Eyelid Hygiene - Medscape - Dec 15, 2002.