Canaliculitis

Canaliculitis is a chronic infection of the lacrimal canaliculus, usually the lower, which is frequently misdiagnosed as chronic conjunctivitis.

• Commonest pathogen: Actinomyces israelii (anaerobic Gram positive filamentous bacterium) forming sulphur granules (concretions). Others: Staphylococcus, Streptococcus, Fusobacterium, Nocardia, Candida and Aspergillus.
• More common in women over 60.
• Predisposing factors: punctal plugs, chronic punctal stenosis, canalicular stasis, dacryolithiasis, and intranasal obstruction.
• Concretions harbour biofilm, so antibiotics alone usually fail.

• Unilateral chronic or recurrent mucopurulent conjunctivitis, epiphora, and mild redness of the medial canthus not responding to topical antibiotics.
• A "pouting" dilated punctum with a red, swollen, erythematous peri punctal area; the canaliculus may be cord like and tender.
• Expression of purulent discharge or yellow brown sulphur granules on pressure over the canaliculus.
• Tender swelling at the medial lid margin, sometimes mimicking a chalazion, plus the history of recurrence after antibiotic courses.
• Pericanalicular abscess in some.

• Clinical, from the pouting punctum, expressed concretions and the canalicular cord.
• Culture of expressed material and Gram stain (beaded Gram positive filaments); anaerobic culture; histology of concretions.
• Canalicular irrigation (typically patent, with reflux of discharge).
• Imaging (CT dacryocystography or ultrasound) is unusual but helpful if dacryolith or diverticulum suspected.
• Exclude dacryocystitis (swelling over the lacrimal sac below the medial canthal tendon) and punctal plug retention.

• Definitive treatment is removal of concretions: canaliculotomy (a 3 to 5 mm vertical, or horizontal posterior incision on the conjunctival side of the canaliculus), curettage of all concretions, irrigation with antibiotic solution (penicillin G 100,000 units/mL or povidone iodine), and healing by secondary intention.
• Less invasive alternative: punctal dilation and expression with curettage, or canalicular intubation with a silicone stent after clearing.
• Topical antibiotics: moxifloxacin 0.5 percent or fortified penicillin G 100,000 units/mL four times daily for 2 weeks after surgery.
• Oral antibiotics for cellulitis or abscess: amoxicillin 500 mg three times daily or amoxicillin clavulanate 625 mg three times daily for 7 to 14 days. Doxycycline 100 mg twice daily for penicillin allergy.
• Remove punctal plugs if present.
• Follow up: recurrence if concretions persist; recheck at 2 weeks and 6 weeks. Treat fungal canaliculitis with canaliculotomy and topical natamycin 5 percent or amphotericin B 0.15 percent.