A supernumerary duct with associated absence of punctum and canaliculus
With a lacrimal cannula , irrigate a small amount of diluted methylene blue into the duct to outline the mucosal lining down to the lacrimal sac.
Place an appropriately sized probe into the supernumerary duct.
Cut a conservative ellipse of the skin around the probe, following the duct lumen down to the lacrimal sac.
Use an absorbable suture to ligate the base of the duct at its junction with the sac.
Perform a layered closure of the muscle and skin.
Illustrations of surgical steps in repair of a supernumerary duct. (a) After diluted methylene blue is injected into the duct with the lacrimal cannula, an ellipse is cut through the skin and muscle. Using a probe as a guide, careful dissection is completed to the junction of the duct and the sac. (b) The supernumerary duct is ligated at its junction with the sac with 5-0 absorbable suture and cut. The subcutaneous tissue and skin are closed with appropriate interrupted sutures as shown in the inset
Clinical example of corresponding surgical steps in repair of supernumerary duct. (a) Diluted methylene blue is injected into the duct with the lacrimal cannula. (b) An ellipse is cut through the skin and muscle. (c) Using a probe as a guide, careful dissection is completed to the junction of the duct and the sac. The supernumerary duct is ligated at its junction with the sac with 5-0 absorbable suture and cut. (d) The subcutaneous tissue and skin are closed with appropriate interrupted sutures
This simple excision and closure will be sufficient to prevent fistula reformation if there is no blockage to tear flow more distally in the nasolacrimal duct. In the authors’ experience, simple probing and irrigation combined with excision and ligation of the fistula have proven successful in the majority of cases . However, if there is a lower system obstruction that appears unresponsive to simple probing, silicone stent intubation of the nasolacrimal duct or a dacryocystorhinostomy (DCR) will be required to eliminate this problem.
Abnormalities of the Puncta and Canaliculi
There is a wide spectrum of obstructive abnormalities of the puncta and canaliculi, ranging from simple congenital veils to complete canalicular atresia [2, 3]. These abnormalities can sometimes be associated with other systemic findings in certain genetic disorders. For example, Levy-Hollister syndrome , otherwise known as the lacrimo-auriculo-dento-digital (LADD) syndrome , involves an underdeveloped or absent punctum and/or nasolacrimal duct obstruction leading to chronic epiphora and occasionally dacryocystitis. The lacrimal abnormalities of LADD are accompanied by syndromic features including low-set cup-shaped ears, mild to severe hearing loss, underdeveloped peg-shaped front teeth, xerostomia due to hypoplastic salivary glands, and hand deformities such as small, absent, or duplicated thumbs. Ectrodactyly-ectodermal dysplasia-clefting (EEC) syndrome , which is characterized by cleft lip/cleft palate and absent or anomalous digits, is also associated with punctal or canalicular abnormalities [6–10]. Congenital anomalies of the upper lacrimal system in conjunction with abnormal digits, limbs, or ears should prompt an evaluation by a pediatric genetic specialist.
The mildest form of punctal agenesis presents as a congenital veil, which is an epithelial membrane covering the punctal opening of an otherwise-normal canaliculus. Surgery of the punctum should always be as conservative as possible. For simple punctal veils, a gentle puncture followed by dilation and irrigation often will suffice (Fig. 29.4). In contrast to simple veils, severe punctal agenesis may include a greater degree of atresia involving the vertical and horizontal canaliculus as well.
Punctum . (a) Congenital veil of punctum in the right eye. (b) One year after simple puncture and dilation of the opened punctum without the use of any stent
Canalicular atresia or agenesis is a congenital narrowing or the absence of any portion of the canaliculus. It can be categorized as (1) proximal (adjacent to the punctum), (2) midcanalicular, or (3) distal (adjacent to or involving the common internal punctum). For greater degrees of canalicular atresia, more significant surgical steps are required.
The use of dacryocystography may be helpful in exploring for the presence or absence of canaliculi. However, this test always requires a general anesthetic in the pediatric age group and should therefore be coordinated with the surgical correction when possible. If dacryocystography is not readily available, an alternative approach is the use of dilute methylene blue to determine the pathway of fluid flow within the lacrimal system:
If one normal punctum and canaliculus is present, then methylene blue is irrigated into the sac through that punctum, and then the palpebral conjunctiva of the upper and lower lids are examined for retrograde flow of dye into the abnormal canaliculus.
If both puncta are absent but there is evidence of a lacrimal papilla, then consideration can be given to a percutaneous injection of dilute methylene blue solution into the lacrimal sac (Figs. 29.5 and 29.6). After injection, the surgeon applies pressure over the lacrimal sac area, then the conjunctival surface of the lid margin can be examined for retrograde flow of methylene blue. Of note, if there is no definite lacrimal papilla, the percutaneous injection of methylene blue is not recommended. Even with the presence of a papilla, there is a very low success rate (10%).
If the dye is not seen on external exam after irrigation or injection, an incision can be made in the lid margin at the lateral edge of the lacrimal papilla. If the dye is noted in the cutdown area, then a mucosal lined canaliculus is presumed to be present nearby.
If the dye can be suctioned from the nose after injection or irrigation into the upper system, this indicates that the sac and duct are at least partially patent. In this case, a silicone stent tube can be placed through the nasolacrimal system for persistent dacryostenosis. Alternatively, if there is significant obstruction in the lower system, then a DCR is required.
Congenital absence of both puncta on the left side
Repair of punctal and partial canalicular agenesis . (a) Methylene blue injected through the medial canthal tendon to the area of presumed lacrimal sac in same patient. (b) If pressure placed on the sac does not show dye on the lid margin, a cutdown is done over the lacrimal papilla or approximately 8 mm lateral to the canthal angle to search for possible patent canaliculus. (c) Probing of the cutdown shows a canaliculus that is patent to the lacrimal sac, as evidenced by methylene blue being seen in the cutdown site when pressure is placed on the sac. (d) The lower system is open as shown by the methylene blue collected from the nose. When the lower system is open, only Silastic intubation of the system through the nasolacrimal duct is required. (e) After Silastic tubing was in place for 3 months, the punctum remains patent at 1-year follow-up (From Katowitz and Low ; with permission)
A Single Canaliculus is Patent
Under typical conditions, a normal patent superior canaliculus will drain ~15% of tears, while a normal inferior canaliculus drains the other ~85%. When one canaliculus is impeded, drainage through the remaining canaliculus may increase to meet the demand. Thus, even with one absent punctum or canaliculus, it is possible for a patient to be asymptomatic and require no intervention.
If a patient with a single patent canaliculus does have epiphora, it may be due to insufficient drainage through the upper or the lower nasolacrimal system (dacryostenosis). To assess for a lower system blockage, probing and irrigation should be done through the patent canaliculus. If lower obstruction is identified, then a monocanalicular silicone stent can be placed, such as the Monoka (FCI, Mansfield Hills, MA) (Fig. 29.7).
Agenesis of the upper punctum . (a) Absent upper punctum with normal inferior punctum and canaliculus. (b) After simple probing of nasolacrimal duct unsuccessful in the same patient, a monocular stent is inserted (Monoka, FCI Ophthalmics, Marshfield Hills, MA). (c) Normal position of Monoka stent with 4-mm collar
There are multiple methods to restore or establish bicanalicular flow in a patient with only one patent canaliculus. One method involves retrograde probing through a DCR incision . After opening the lacrimal sac, an attempt is made to visualize a common internal punctum. A blunt right-angle (Werb) probe or an angled #00 Bowman probe can be passed from the sac toward the lid in an effort to identify the length of any patent canaliculus. A sharp Werb probe can then be used to puncture up through the lid margin from the inside, creating a pseudo-punctum on the lid margin connecting to the patent canaliculus. An alternative is to puncture the lid margin externally and then introduce an 18- or 19-gauge Teflon intravenous catheter to create a new channel from the lid margin into the sac. The new passage can then be threaded with Silastic tubing to create a new common internal punctum [12–15].
Neither Canaliculus Is Patent
If both puncta are absent, then surgical exploration of the internal common puncta within the lacrimal sac opening in the setting of DCR may permit retrograde probing to deliberately create a false passage out to the eyelid margin [11, 13, 14]. In our experience, success requires a sufficient length of preexisting patent canaliculus. Unless the naturally patent segment extends to midcanaliculus (within 4 mm of punctum), such false passages will not usually remain patent. As a general rule, if there is an absence of normal puncta and canaliculi in both the upper and lower lid, then a conjunctivodacryocystorhinostomy (CJDCR) will be necessary (see Chap. 30).
Distal or Common Canalicular Agenesis
Blockages in the distal canalicular system require a bypass procedure, consisting of either a CJDCR (see Chap. 30) or a canaliculodacryocystorhinostomy (CLDCR). The CJDCR creates a new passage from the ocular surface near the caruncle, directly through a lacrimal fossa osteotomy into the nose, and then holds the passage patent with a glass tube (Jones tube) through which drainage can flow. In contrast, CLDCR involves excision of the blocked distal canaliculus followed by microsurgical anastomosis of the patent canalicular segment directly to the nasolacrimal sac, in an effort to retain usage of the canalicular drainage pathway .