Canaliculitis is a common encounter in ophthalmic practice but supernumerary puncta and canaliculi (SPC) are rare congenital disorders. In a large series, only 23 patients were diagnosed over the period of 20 years.1 We report a case of canaliculitis which is associated with SPC.
A 59-year-old gentleman presented with painful swelling of the left lower lid for a week, which was associated with epiphora. This was his first episode, and he was asymptomatic prior to this presentation. The swelling was confined to the nasal aspect of the left lower lid (0.5×0.5 mm) with inflamed overlying skin (Figure 1A). Eversion of the lower eyelid revealed two puncta, 0.5 mm apart (Figure 1B). The outer punctum was situated at the normal anatomical position; whereas the inner punctum in the caruncle. Gentle pressure did not result in any regurgitation from the both puncta. The patient was treated with oral cloxacillin 500 mg, 6 hourly for 5 days. The cellulitis subsided after three days. Probing and syringing was performed after one week. The inner punctum had a hard stop with patent lacrimal drainage. The outer punctum had a soft stop with regurgitation of fluid from the same punctum. Dacryocystography confirmed the patency of the inner lower punctum. The outer punctum-canaliculus system was a cul-de-sac (Figure 1C). There were no other abnormalities.
Most SPCs (78%) present with epiphora. Among the 23 patients reported by Satchi et al., none presented with canaliculitis.1 This is the first report of SPC presented with canaliculitis. Sequestration of tear and debris in the cul-de-sac served as nidus for infection. The resultant canaliculitis with its surrounding edema caused obstruction of the lacrimal drainage; hence epiphora.2 Epiphora however, may develop despite patent lacrimal drainage system. The 2-compartment model for lacrimal canalicular drainage of Kakizaki et al., suggested that the muscle of Duverney-Horner may deviate normal flow within the accessory canaliculus and thence transport tears back to the lacrimal tear lake, leading to epiphora.3 The entire lacrimal drainage apparatus is of ectodermal origin. During development, a solid epithelial cord forms in the region of the medial lower eyelid (Figure 2A) and sends projections to form the canaliculi and the nasolacrimal duct (Figure 2B).4 SPC is due to extra out-budding of the solid epithelial cord (Figure 2C). Canalization begins at 4 months of gestation with disintegration of the central ectodermal core, forming lacrimal drainage outflow system. In this case, the extra inner canalicular epithelial bud (nearer to the main epithelial cord) underwent complete canalization and remained connected to the main epithelial cord. The outer canalicular epithelial bud, although its punctum is located at the normal anatomical position, was separated from the main epithelial cord; forming a cul-de-sac (Figure 2D).