Probing

When nasolacrimal probing is to be performed in the operating room, placement of an oxymetazoline-soaked pledget beneath the inferior turbinate before surgery may decrease intraoperative bleeding. The initial step in nasolacrimal probing is dilation of the puncta and proximal canaliculi. Punctal membranes and atretic canaliculi are sometimes not recognized until surgery. Their management is discussed earlier in this chapter. Because the lacrimal system cannot be visualized beyond the puncta, knowledge of the anatomy and normal course of the lacrimal excretory system is essential for passing lacrimal probes properly. The probes are initially inserted in the puncta, perpendicular to the eyelid. Within 1–2 mm of the eyelid margin, the canaliculi turn approximately 90°; the probes are therefore turned almost immediately and passed along the course of the canaliculi until the nasal bone is encountered on the medial side of the lacrimal sac. The probes are held flat on the patient’s face and rotated and passed gently into the distal duct (Fig 19-6A). With simple CNLDO, most surgeons feel a slight popping sensation as the probe passes through the membrane causing the obstruction. With complex CNLDO (see the following section), the surgeon’s probe may encounter a firmer obstruction or a tight passage throughout the length of the NLD.

A wide variety of techniques are used for probing in NLDO. Most surgeons begin with a size 0 or 1 Bowman probe, and some pass successively larger probes to enlarge the distal duct. Introducing a second metal probe into the nares and making direct contact with the previously placed lacrimal probe verifies the position of the latter (Fig 19-6B). Alternatively, direct inspection with a nasal speculum and headlamp or with a nasal endoscope can precisely determine the position of the probe. Irrigation may be performed following probing in order to verify that the system is patent. Infracture of the inferior turbinate may be used to widen the area where the fluid drains beneath the inferior turbinate. The surgeon accomplishes this by placing a small periosteal elevator beneath the turbinate or by grasping it with a hemostat and then rotating the instrument.

Figure 19-6 Probing for NLDO. A, The probe is advanced through the lacrimal sac and NLD, in this instance via the lower canaliculus. B, A second probe introduced into the nares is used to verify the position of the probe tip.

(Courtesy of Edward L. Raab, MD.)

Postoperatively, minor bleeding from the nose or into the tears commonly occurs and usually requires no treatment. Optional postoperative medications include antibiotic drops, corticosteroid drops, or both instilled 1–4 times daily for 1–2 weeks. Phenylephrine or oxymetazoline nasal spray may be used to control nasal bleeding or congestion. Because transient bacteremia can occur after probing, systemic antibiotic prophylaxis should be considered for patients with cardiac disease.

Resolution of signs after probing may not occur until 1 week or more postoperatively. Recurrence after unsuccessful probing is usually evident within 1–2 months. The success rate of properly performed initial probing for CNLDO exceeds 80% in infants younger than 15 months.

Significant complications of probing are rare. In some patients, mild epiphora occurs occasionally, particularly outdoors in cold weather or in conjunction with an upper respiratory tract infection. This epiphora is probably attributable to a patent but narrow lacrimal drainage channel. Usually no additional treatment is required.

Patients with complex CNLDO or persistent symptoms after initial probing

A variety of treatment options are available for patients with complex CNLDO (usually discovered at the time of initial surgery) or those with symptoms that persist following initial probing. Some surgeons may choose to perform balloon dacryoplasty or NLD stenting as the initial procedure in patients they believe are at risk for recurrence of CNLDO. Recurrent NLDO is more likely in persons with chronic rhinitis, those older than 36 months, or patients with complex CNLDO. Balloon dacryoplasty or intubation is more successful than probing alone for persistent NLDO after initial probing. The selection of intubation or balloon dacryoplasty is based on surgeon preference. Infracture of the inferior turbinate has not been shown to improve surgical outcomes. Perioperative systemic antibiotics and steroids may be beneficial in children at risk for recurrence.

• Pediatric Eye Disease Investigator Group. Balloon catheter dilation and nasolacrimal duct intubation for treatment of nasolacrimal duct obstruction after failed probing. Arch Ophthalmol. 2009;127(5):633–639.

• Silbert DI, Matta N. Congenital nasolacrimal duct obstruction. Focal Points: Clinical Practice Perspectives. San Francisco: American Academy of Ophthalmology; 2016, module 6.

Intubation

Intubation of the lacrimal system is usually recommended when probing or balloon dacryoplasty has failed. Several methods of intubation are available. Bicanalicular intubation is performed by passing stents through the upper and lower canaliculi and recovering them in the nares. Most surgeons secure the stents in the nares by using a bolster or by suturing the stents to the nasal mucosa. Monocanalicular stents are placed by passing them through either the upper or lower canaliculus or sometimes by passing separate stents through both canaliculi.

Figure 19-7 Balloon dacryoplasty. A, Passing the balloon into the NLD. B, Inflated balloon, endoscopic view.

(Part B courtesy of Eric Paul Purdy, MD.)

Complications associated with stents include elongation of the lacrimal puncta, dislodging and protrusion of the stents, and corneal abrasions. In some cases, the stent can be repositioned, but early removal may be necessary.

Stents are usually left in place for 2–6 months, but shorter periods can be successful. The technique used for stent removal depends on the age of the patient, the measure employed to secure the stent, and the position of the stent (in place or partially dislodged).

Older children with NLDO

There is some controversy in the literature regarding success rates for NLD surgery in older children. The Pediatric Eye Disease Investigator Group (PEDIG) found a high success rate for simple probing in children up to 36 months of age. Many older children have simple NLDO; they have the same membranous obstruction of the distal duct found in younger children with NLDO (see Fig 19-4A). As previously mentioned, this obstruction is identified by a distinct popping sensation as the probe is passed into the distal duct. Probing in older patients with this finding has a success rate similar to that in younger children. Because probing is less likely to be successful in complex NLDO, particularly in older children, balloon dacryoplasty or stent placement should be considered as the initial surgical procedure.

• Pediatric Eye Disease Investigator Group; Repka MX, Chandler DL, Beck RW, et al. Primary treatment of nasolacrimal duct obstruction with probing in children younger than 4 years. Ophthalmology. 2008;115(3):577–584.

Dacryocystorhinostomy

Dacryocystorhinostomy involves creation of a new opening between the lacrimal sac and the nasal cavity. It is an option when the procedures described in the preceding sections are unsuccessful and NLDO persists or recurs. The decision of when to perform this procedure is affected by the severity of the signs and symptoms of obstruction. See BCSC Section 7, Oculofacial Plastic and Orbital Surgery, for further discussion of this procedure.

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.