Answers

Diagnosis - Canaliculitis

Canaliculitis presents as tenderness in the medial canthal region with epiphora and chronic mucopurulent discharge. It is chronic in nature without resolution with topical therapy.

Differential diagnoses include:

1. Carcinoma of the lacrimal canaliculus, although rare, is in the differential, based on the duration of symptoms and patient's age.
2. Dacryocystitis is lacrimal sac distension with inflammation, and would present in a more medial location than canaliculitis.
3. Preseptal cellulitis is not consistent with the duration of symptoms.
4. Nasal lacrimal duct obstruction is seen in the pediatric population due to an imperforate Valve of Hasner, with these patients having no erythema or tenderness.
5. Chalazion is unlikely to be present for two years and in the far medial location.

Canaliculitis

Canaliculitis is inflammation of the lacrimal canaliculus. It is considered a masquerading disease with up to 60% of the patients misdiagnosed on presentation and the average time to diagnosis is three years. ^[1],[2] It has a relatively low incidence, accounting for 2% of all lacrimal conditions. ^[3] Presentation is with unilateral epiphora, chronic conjunctivitis, mucopurulent discharge from the punctum and swelling in the area of the canaliculus. Treatment with topical antibiotics allows temporary relief of the symptoms, but is rarely curative. The most common causative organism is Actinomyces israelii, with other bacteria such as Arachnia propionica, Nocardia asteroides, and Staphylococcus aureus   being less common, along with various fungi.  Actinomyces israelii  uce 'sulfur' granules, which have a yellow cheese-like gritty consistency. The precipitation of salts from the tears on the sulfur granules, form dacryoliths that act as a nidus for persistent bacterial infection [Figure 3]. In the case of actinomyces, the gram stain of the expressed concretions, shows gram positive filamentous bacteria [Figure 4].

Figure 3: Dacryoliths expressed with curettage Click here to view

Figure 4: Low magnification gram stain of Gram positive branching filamentous bacilli Click here to view

The challenge of making the diagnosis requires a certain index of suspicion.

In suspected cases of canaliculitis, a culture may be taken of the mucopurulent discharge. A positive culture or a dacryocystography showing concretions, can help to make the diagnosis. If the index of suspicion is high, a canaliculotomy with curettage may be performed with gram stain and cultures confirming the diagnosis. This is performed by applying a local anesthetic to the area of the punctum. The punctum is then dilated and a vertical snip is made through the conjunctival side of the canaliculus. A curette is used to remove the dacryoliths, and the lacrimal system is lavaged out using Penicillin G. Canalicular reconstruction is rarely necessary with the overall incidence of persistent epiphora of 20%. ^[4] A one-to-two week course of systemic antibiotics, Penicillin or Amoxicillin, is also given. ^[5]