Mucoceles may form within the lacrimal sac or within the nasal cavity as a consequence of congenital NLDO. The type of mucocele involved in lacrimal sac distention has been termed a dacryocystocele, and it may be present at birth or may develop within 1 to 4 weeks after birth. It occurs when mucus (secreted by lacrimal sac goblet cells) is trapped in the tear sac because of a functional block above the sac (valve of Rosenmüller) and obstruction at the distal end (valve of Hasner) of the NLD. The dacryocystocele is initially sterile and may respond to conservative management with prophylactic topical antibiotics and digital compression of the lacrimal sac. When there is minimal improvement or infection develops, probing of the lacrimal drainage system may be necessary to address the disorder. Extension of the dacryocystocele cyst into the nasal cavity at the level of an occluded valve of Hasner may also occur. The intranasal cystic portion often extends inferiorly under the inferior turbinate, where it can be observed during nasal examination (Fig 15-4). Intranasal examination and urgent treatment are needed if the condition is bilateral and causes airway obstruction, as infants are obligate nasal breathers.
In most patients, dacryocystoceles demonstrate expansion inferior to the medial canthal tendon. Congenital swelling above the medial canthal tendon suggests alternative etiologies, such as a dermoid cyst or meningoencephalocele. Computed tomography (CT) or magnetic resonance imaging (MRI) is useful in evaluating the patient for these more complex diagnoses.
Figure 15-4 Congenital dacryocystocele. A, Left congenital dacryocystocele (arrow) 1 week postpartum. B, Computed tomography (CT) scan of a congenital dacryocystocele. C, Endoscopic view of a left dacryocystocele (red arrow) prolapsing under the inferior turbinate (yellow arrow).
(Parts A and B courtesy of Pierre Arcand, MD; part C courtesy of Pete Setabutr, MD.)
Probing and irrigation
Probing is a delicate procedure that is facilitated by immobilization of the pediatric patient and by constriction of the nasal mucosa with a topical vasoconstrictor, usually oxymetazoline hydrochloride. Punctal dilation is often needed to safely introduce a size 00 Bowman lacrimal probe. The probe is initially inserted into the punctum perpendicular to the eyelid margin and then turned parallel to the eyelid margin as it is advanced down the canalicular system, toward the medial canthal tendon (Fig 15-5). Manual lateral traction of the eyelid with the opposite hand straightens the canaliculus, decreasing the risks of damage to the canalicular mucosa and creation of a false passage.
Resistance to passage of the probe—along with medial movement of the eyelid soft tissue (“soft stop”), causing wrinkling of the overlying skin—may signify canalicular obstruction. More commonly, resistance is simply due to a kink in the canaliculus created by bunching of the soft tissues in front of the probe tip. If kinking is encountered, the probe is withdrawn and reinserted while lateral horizontal traction is maintained (Fig 15-6). If the probe advances successfully through the common canalicular system and across the lacrimal sac, the medial wall of the lacrimal sac and adjacent lacrimal bone will be encountered, resulting in a tactile “hard stop.”
Figure 15-5 Punctal dilatation. A, Initial insertion of the punctal dilator is perpendicular to the eyelid margin. B, Next, with lateral countertraction on the eyelid, the dilator is directed horizontally into the canaliculus.
(Courtesy of Eric A. Steele, MD.)
Figure 15-6 Proper technique for canalicular probing. A, Bowman probe in the right upper horizontal canaliculus with lateral traction on the eyelid. B, When canalicular obstruction is present or when the probe is not in the correct position, resistance to passage of the probe (“soft stop”) with wrinkling of the overlying skin is encountered.
(Illustration by Christine Gralapp.)
Figure 15-7 Irrigation of the nasolacrimal system. Dye is injected from the syringe, and patency of the system is confirmed by suctioning the dye from the inferior meatus of the nose.
(Illustration by Christine Gralapp.)
The probe is then rotated 90° superiorly toward the brow until it lies adjacent to the supraorbital notch. The probe is directed posteriorly and slightly laterally as it is advanced down the NLD. Creation of a false passage makes it difficult to redirect the probe back into the native lacrimal system. Therefore, if resistance is encountered and the surgeon is uncertain whether the probe is in the natural pathway, the probe is repositioned and passage attempted again. At some points of narrowing, particularly at the distal end of the NLD, gentle pressure may be necessary to push through the blockage. The probe tip can be visualized along the lateral wall of the nose under the inferior turbinate, approximately 2 cm back from the nostril, using an endoscope or a nasal speculum with a fiber-optic headlight. Alternatively, patency of the duct can be confirmed by metal-on-metal contact with another probe inserted through the naris or by irrigation with saline mixed with fluorescein (Fig 15-7). The fluorescein can be retrieved from the inferior meatus and visualized with a transparent suction catheter. A single lacrimal probing successfully resolves congenital NLDO in 90% of patients who are 13 months or younger.
Intubation with a lacrimal stent is indicated for children who have recurrent epiphora following nasolacrimal system probing and for older children in whom initial probing reveals significant stenosis or scarring. Intubation is also useful for the treatment of upper-system abnormalities such as canalicular stenosis, trauma, and agenesis of the puncta. Nasolacrimal intubation after failed probing has a reported success rate greater than 70%.
Figure 15-8 Crawford stent and hook. A, Hook engaging the “olive tip” of the stent. B, Intranasal view of the engaged hook retrieving the stent.
(Reproduced with permission from Nerad JA. Oculoplastic Surgery: The Requisites in Ophthalmology. Philadelphia: Mosby; 2001:233.)
There are many intubation techniques and types of intubation sets. Figure 15-8 illustrates one of the more commonly used stents (ie, the Crawford stent). Keys to successful intubation include shrinkage of the nasal mucosa with a topical vasoconstrictor and adequate lighting with a fiber-optic headlight. In more difficult cases, an endoscope can be used, and medialization of the inferior turbinate is sometimes performed. The lacrimal stent can be secured with a simple square knot, which allows removal of the stent through the canalicular system in a retrograde fashion. Alternatively, the lacrimal stent may be directly sutured to the lateral wall of the nose (without tension), or the limbs of the stent can be secured by passing them through either a silicone band or a sponge in the inferior meatus of the nose.
A self-retaining bicanalicular lacrimal stent comes preloaded with a rigid inserter and does not require intranasal retrieval or fixation (Fig 15-9A). Alternatively, a monocanalicular stent is useful for patients with only one patent canaliculus (Fig 15-9B). This type of stent is passed through a single punctum to the nasal cavity, where the end of the stent is allowed to retract loosely into the nose. The proximal end has a punctal plug and is self-secured at the punctum.
Figure 15-9 Lacrimal intubation stents. A, Self-retaining bicanalicular lacrimal stent with a rigid insertion device. B, Monocanalicular stent with a soft barb and collarette, which secure the stent within the punctum.
(Part A courtesy of Bobby S. Korn, MD, PhD; part B courtesy of Roberta Gausas, MD).
Balloon catheter dilation of the nasolacrimal canal has been used successfully in patients with congenital nasolacrimal obstruction. A collapsed balloon catheter is placed in a manner similar to probing and is inflated inside the duct. The role of this modality remains undefined, in part because the necessary catheter equipment is expensive, and because simple probing has a high success rate, obviating the need for further procedures.
If the inferior turbinate appears to be lateralized against the NLD at the time of probing and irrigation, medial infracture of the inferior turbinate should be performed. The blunt end of a periosteal elevator is placed within the inferior meatus along the lateral surface of the inferior turbinate. The inferior turbinate is then rotated medially toward the septum. Fracturing the turbinate at its base significantly enlarges the inferior meatus and permits direct visualization of the lacrimal probe tip.
Dacryocystorhinostomy (DCR) is usually reserved for children who have persistent epiphora following intubation and/or balloon dacryoplasty, children who experience recurrent dacryocystitis, and patients with extensive developmental abnormalities of the nasolacrimal drainage system that prevent probing and intubation. DCR is more fully discussed later in this chapter in the section Acquired Nasolacrimal Duct Obstruction.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.