Posterior Blepharitis

Posterior blepharitis is inflammation of the posterior lid margin due to meibomian gland dysfunction. Altered meibum, gland obstruction and bacterial lipase activity cause tear film instability and evaporative dry eye.

• It is associated with rosacea, seborrhoeic dermatitis, atopy, contact lens wear and ageing.
• Demodex mites and staphylococci contribute.
• It is chronic and relapsing.

Burning, gritty, itchy or watery eyes, crusting on waking, redness of the lid margin, frothy tears and blurred vision that clears with blinking.

• Signs include capped, plugged meibomian gland orifices, telangiectasia of the posterior lid margin, thick toothpaste like secretions and recurrent chalazia.
• Differential diagnosis: anterior blepharitis, dry eye disease, allergic conjunctivitis, conjunctivitis, ocular rosacea, sebaceous carcinoma (unilateral lid thickening), chalazion, demodex infestation, atopic keratoconjunctivitis.
• Complications: chalazion, stye, marginal keratitis, corneal vascularisation and ulceration, chronic dry eye, ectropion or entropion.

Clinical diagnosis at the slit lamp.

• Examination of lid margin, expression of meibomian glands and tear break up time.
• Culture of lid margin in recalcitrant disease; consider biopsy for unilateral recurrent lid thickening.
• Screen for rosacea and seborrhoeic dermatitis.

Long term lid care with anti inflammatory treatment during flares.

• Supportive: warm compresses for 10 minutes twice daily, lid massage toward the lid margin after warming, lid hygiene with diluted baby shampoo or commercial lid wipes, stop eye make up, omega 3 fatty acid supplements, blink exercises, avoid contact lenses during flares.
• Pharmacological: doxycycline 100 mg daily for 4 to 12 weeks (or 100 mg twice daily for 2 weeks then daily); azithromycin 500 mg daily for 3 days, repeated for three monthly cycles, as an alternative; topical azithromycin 1 percent twice daily for 3 days then daily for 4 weeks; preservative free lubricants four to six times daily; fluorometholone 0.1 percent or loteprednol 0.5 percent drops three times daily for 1 to 2 weeks for severe inflammation under ophthalmology care.
• Procedures: thermal pulsation or intense pulsed light where available; incision and curettage of persistent chalazion.
• Special groups: pregnancy and children under 8 years, avoid doxycycline and use azithromycin or erythromycin ointment; acne rosacea, treat the skin disease; contact lens wearers, review fit and hygiene.
• Red flags: loss of vision, corneal ulcer, eyelid mass, loss of lashes with thickening, painless unilateral lid swelling.
• Follow-up: review at 4 to 6 weeks; condition is chronic and needs continued lid care.