|Functional nasolacrimal duct obstruction|
|Partial nasolacrimal duct obstruction|
|Congenital nasolacrimal duct obstruction (after failed probing)|
|After removal of lesion overlying punctum|
|For reconstruction of the eyelid after removal of the proximal lacrimal system from cancer surgery|
|To promote healing of the lacrimal system after repair of eyelid laceration including the canalicular system|
|Prophylaxis against canaliculus stenosis while on chemotherapy (docetaxel)|
|Detailed history of tearing – frequency, mucoid discharge, dacryocystititis|
|Medication history – chemotherapy for breast cancer (docetaxel), radioactive iodine for thyroid carcinoma, glaucoma medications, anti-herpes simplex/zoster virus drops|
|History of prior lacrimal surgery – nasolacrimal duct probing, stent placement, DCR (external/endonasal)|
|Probing and irrigation of canaliculi|
|Presence of punctal stenosis|
|Presence of lower eyelid malposition – ectropion, entropion, punctal ectropion, eyelid retraction|
|Work-up for dry eye (pseuoepiphora)|
Silicone stent intubation of the nasolacrimal duct has a role in both children and adults and each warrants a separate discussion. In children, a membranous lining over the valve of Hasner is associated with congenital nasolacrimal duct obstruction. The vast majority of these cases resolve spontaneously as this membrane perforates. Initial management of congenital nasolacrimal duct obstruction includes digital massage over the lacrimal sac with occasional topical antibiotics for the associated mucoid discharge. Probing of the nasolacrimal duct is considered between 9 and 12 months and has a high rate of success. After failed probing, nasolacrimal duct intubation can be considered. This is often performed in conjunction with fracturing of the inferior turbinate towards the nasal septum. The stent is left in place for a minimum of 3 months. If tearing recurs after stent removal, then dacryocystorhinostomy may be the only remaining option ( Chapter 53 , Chapter 54 , Chapter 55 , Chapter 56 , Chapter 57 , Chapter 58 ).
In adults, there are several indications for stenting of the nasolacrimal duct. Any trauma to the lower eyelid involving the canaliculus requires early stenting to prevent scarring of the proximal lacrimal drainage apparatus. Similarly, lesions that occlude the punctum may be removed, followed by silicone stenting. An alternative to bicanalicular intubation with unilateral pathology is the monocanalicular stent.
Lacrimal obstruction can also occur by iatrogenic causes as well. Extended treatment with docetaxel for breast carcinoma is associated with proximal lacrimal obstruction and prophylactic stenting is advised in such cases. Short-term treatment with docetaxel is not primarily indicated. Radioactive iodine for the treatment of thyroid carcinoma has also been associated with nasolacrimal duct obstruction and stenting may be considered in select cases.
Silicone stent intubation for epiphora remains the most common indication. Partial and functional nasolacrimal duct obstruction on lacrimal irrigation may be considered for stenting. Failed stenting for partial or functional nasolacrimal duct obstruction should proceed to dacryocystorhinostomy.
Silicone stenting of the nasolacrimal system is typically performed in the operating room with intravenous sedation or general anesthesia, with the latter a requirement in children. An infraorbital block ( Chapter 1 ) can be performed to minimize discomfort. Local anesthetic is infiltrated around the upper and lower punctum as well as the lateral vestibule of the naris. Oxymetazoline and 2% lidocaine can be mixed and used for nasal packing for decongestion and anesthesia. The stent is left in the nasolacrimal system for a variable amount of time but generally for at least 2 months’ duration.