Canaliculitis, which is an infection of the lacrimal canaliculus, typically occurs in individuals over 40 of age.
Obstruction of the canaliculus, foreign body in the canaliclulus such as a punctual plug or dacryolith, or even a diverticulum can promote bacterial growth causing this condition but in most cases there are no identifiable risk factors. Patients should be asked if a punctal plug had been placed in the eyelid in the past, and whether it was a punctal or intracanalicular plug, as either could cause mechanical obstruction of the canaliculus or inflammation resulting in focal fibrosis.
Canaliculitis is caused by infection of the canaliculus. Although most often caused by a bacterial pathogen, it may also result from fungal or viral infection. Actinomyces israelii (an anaerobic filamentous gram-positive bacteria) is the most common pathogen. Other less common pathogens include Candida albicans, Nocardia asteroids, Aspergillus , HSV and VZV. The infection causes small dacryoliths, or stones, to form, which are concretions consisting of sulphur granules. Multiple dacryoliths can be present and obstruct the lacrimal outflow system, from the canaliculus and extending into the common canaliculus and lacrimal sac.
Patients usually present with chronic unilateral red eye, epiphora and discharge mainly in the nasal part of the ranging from simple watery consistency to full brown mucopurulence that is refractory to conventional treatment. Patients may describe months of these symptoms and a history of several courses of antibiotic treatments from other medical providers.
The punctal orifice is swollen, red and turned outward (pouting punctum) in the involved eye. Tenderness may be found over the involved area. Pericanalicular inflammation characterized by edema of the canaliculus with conjunctivitis usually is seen. Pressing on the punctum or canaliculi will express mucoid discharge, often with solid granular concretions.
The diagnosis of canaliculitis is clinical. The punctum has a classic, red swollen appearance "pouting punctum", and the canalicular eyelid margin is also erythematous and edematous. In contrast, the lacrimal sac region itself is typically normal. Pressure over the punctum or the canaliculus will express purulent discharge confirming the diagnosis. Lacrimal probing reveals additional diagnostic signs such as a grating (bumpy, gritty) sensation while probing the canaliculus, which indicates concretions within the drainage system.
Histopathology examination of the discharge and concretions with different stains (gram stain, GMS and PAS) and culture are important to know the pathogen. A report of inflammatory granulation tissue with exudates containing branching filamentous structure is indicative of Actinomyces (the most common pathogen).
The differential diagnosis includes chronic conjunctivitis, dacryocystitis, migrated punctal plug, and rarely carcinoma of the lacrimal canaliculus.
The medical therapy includes warm compresses, digital massage, and topical antibiotics; however, they are rarely curative alone.
Although a few literature reports showed that intracanalicular irrigation with broad spectrum antibiotics may obviate the need for surgical management in treating chronic canaliculitis , canalicular debridement in the form of canaliculotomy is still the mainstay of treatment and is more effective than conservative management. Canaliculotomy is performed by a linear incision into the conjunctival side of the canaliculus, or the eyelid margin, and curetting of the concretions. Some surgeons advocate extending the incision to include the punctum or to spare the punctum. Placement of a silicone stent may also be indicated to prevent scarring of the inflamed canaliculus postoperatively. Surgical intervention should be combined with topical antibiotic drops.
- American Academy of Ophthalmology. Oculoplastics/Orbit: Canaliculitis Practicing Ophthalmologists Learning System, 2017 - 2019 San Francisco: American Academy of Ophthalmology, 2017.
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