Indications/contraindications
Indications
- The primary assessment of the patient with tearing and epiphora; performed to identify and characterize a potential lacrimal outflow obstruction
Possible contraindication: acute infection
- Higher risk of false passage creation in friable infected tissue
- Potentially more painful to patient
- Potential spread of infection
Exam
- External observation for epiphora (tears onto cheek)
- Assess presence, position, and patency of all four lacrimal puncta
- Punctal "pouting" or discharge (as in canaliculitis)
- Canalicular erythema
- Presence of dacryocystocele or dacryocystitis
- Elevated tear meniscus (increased tear lake)
- Assess eyelid position, tone, blink to assess "lacrimal pump" function (Figure 1)
- Lateral canthus should be slightly higher than medial canthus
- "Snap-back" test: following distraction and release lid should snap-back to globe; requirement of blink to return lid to globe indicates significant eyelid laxity
- Eyelid distraction test: lid should not be able to be distracted from globe more than 5-6mm – a larger amount indicates significant eyelid laxity
- Delayed fluorescein dye disappearance test (Figure 2)
- Assessment of ocular surface for underlying dryness or poor tear quality
Figure 1. Lacrimal pump. (A) In the relaxed state, the puncta lie in the tear lake. (B) With eyelid closure, the orbicularis contracts. The pretarsal orbicularis squeezes and closes the canaliculi. The preseptal orbicularis, which inserts into the lacrimal sac, pulls the lacrimal sac open, creating a negative pressure that draws the tears into the sac. (C) With eyelid opening, the orbicularis relaxes, and the elastic forces create a positive pressure in the sac that propels the tears down the duct. Illustration by Christine Gralapp.
Figure 2. Dye disappearance test. Image courtesy Andrew Harrison, MD.
Basic secretion test
- Evaluates tear production with minimal ocular surface stimulation
- Topical anesthetic instilled in eye
- Conjunctival cul-de-sac dried with tissue paper
- Filter paper strip placed in inferotemporal fornix for 5 minutes
- Normal tear production > 15 mm
- Less than 10 mm indicative of relative hyposecretion: Patient's symptoms likely to respond to artificial tear drops if applied on a regular basis (e.g. QID)
Schirmer I
- Evaluates tear production but variable response due to irritation by filter paper
- No topical anesthetic
- Dry conjunctival cul-de-sac with tissue paper
- Filter paper strip placed in inferotemporal fornix for 5 minutes
- Normal tear production greater than 15 mm
- Patients with less than 15 mm might have positive response to regular use of artificial tear drops
Schirmer II
- Evaluates potential for any tear production in patients with severe dry eyes (e.g., Sjogren syndrome)
- This test is only done in patients with a significantly decreased Schirmer 1 test
- No topical anesthetic
- Dry conjunctival cul-de-sac with tissue paper
- Filter paper strip placed in inferotemporal fornix for 5 minutes
- A cotton applicator is used to irritate the inside of the nose and stimulate tearing
- A moistened filter paper represents some ability of the main lacrimal gland to respond to a noxious stimulus
Tear breakup time
- This test is used to qualitatively assess the quantity and quality of tears produced
- Fluorescein is instilled in the affected eye
- At the slit lamp, the tear film is assessed
- Patient is asked to blink and then stare
- Initial lack of corneal tear coating with blink might indicate a general deficiency of tear production
- If initially smooth coating of cornea occurs, but breaks up after 15 seconds, this is likely normal
- If tear film breaks up in less than 10 seconds, this might represent a deficiency of mucin or lipid components of tears
Procedure alternatives
- Lacrimal irrigation without probing — although probing of upper lacrimal system is generally performed concurrently with cannula used for irrigation
- Physiologic patency of the lacrimal excretory system might include dye disappearance test and intranasal exam, either via nasal speculum and headlight or by formal nasal endoscopy.
Jones testing
- Jones 1
- Drop of fluorescein is instilled in cul-de-sac and a cotton-tipped applicator is placed into the inferior meatus.
- If dye is detected after 5 minutes, the system is patent and functioning.
- If no dye, proceed to Jones 2.
- Jones 2
- The cul-de-sac is cleared of remaining fluorescein and then lacrimal irrigation is performed.
- If dye is detected in the nose, it suggests that on initial testing (Jones 1), some dye entered the lacrimal sac, but could not proceed down the nasolacrimal duct, suggesting duct stenosis or blockage.
- If no dye is detected, it suggests no dye entered the lacrimal sac during Jones 1 and there is punctal or canalicular stenosis or a tear pump deficiency.
Specialized radiographic assessment of lacrimal drainage system
- CT scan of facial bones can be obtained in cases of suspected trauma or tumor (palpable mass, bleeding, etc.).
- Dacryocystography (DCG)
- To assess the anatomy of the lacrimal drainage system, e.g., fistula, diverticulum, stone/dacryolith, mass
- Nonphysiologic test: Radiotracer dye is injected under pressure via punctum and canaliculus followed by radiography.
- Considered when suspicion for any of the above or in some cases of "functional" nasolacrimal duct obstruction, e.g., patent system to irrigation, but symptomatic epiphora in absence of other causes.
- DCG shows greater anatomical detail of the lacrimal drainage apparatus than DSG.
- Specialized forms of DCG (CT-based and MR-based) exist, but are used less frequently.
- Dacryoscintigraphy (DSG)
- Physiological visualization of the function of the lacrimal drainage system
- Radiotracer eye drops applied followed by serial imaging to depict the natural "physiologic flow" of tracer through system
- Also reserved for "atypical" cases of epiphora/functional nasolacrimal obstruction, e.g., a patient patent to lacrimal irrigation but with dacryoscintigraphic evidence of limitation of dye flow past sac/duct junction (preductal delay) might benefit from DCR surgery.
- Presac retention (tracer does not enter the lacrimal sac) suggests a lacrimal pump or canalicular dysfunction.
- Despite differences in technique, sensitivity of detecting a lacrimal outflow apparatus abnormality is relatively similar between DCG and DSG (93% and 95%, respectively) (Wearne, Br J Ophthalmol 1999).
Instrumentation and technique of lacrimal probing and irrigation
Anesthesia
- Adults
- Topical anesthesia
- Proparacaine or tetracaine eye drops followed by cotton pledget soaked in 4% lidocaine solution applied to the area of the punctum/canaliculus for two to five minutes.
- Infants: usually general anesthesia
Technique (Figure 3)
- Lateral traction on eyelid
- Punctal dilation
- Gentle probing of punctum and canaliculus with a Bowman lacrimal probe (generally begin with smaller size probe such as "00").
- This part of the procedure can also be performed with the cannula used for lacrimal irrigation.
- Note length of probe that can be inserted prior to resistance ("soft stop") to measure location of a canalicular obstruction, or successful passage of probe into lacrimal sac with contact with bone ("hard stop") indicating normal and patent canaliculus.
- When a soft-stop is encountered:
- The probe is gently withdrawn.
- Care is taken to ensure adequate lateral eyelid traction is maintained and that the probe is aimed along the correct trajectory.
- An attempt is made to pass the probe again through to a hard stop.
- Irrigation is performed with a lacrimal cannula on a 3‑cc syringe with sterile saline.
- The cannula is withdrawn from the hard stop so that the tip of the cannula is intracanalicular and not all the way to the lacrimal sac.
- Gentle irrigation is then performed and an assessment made for ease of injection, reflux around the injected punctum and canaliculus, reflux from the opposite punctum (e.g. upper punctum reflux from lower punctum irrigation).
- Irrigation should also be attempted in the presence of a canalicular "soft-stop" because this maneuver will help differentiate a complete canalicular obstruction from a partial or stenosed segment.
Figure 3. Lacrimal probing technique. Illustration by Christine Gralapp.
Potential complications of the procedure
- Tearing of lacrimal punctum by over-aggressive dilation — expected to heal spontaneously without sequelae
- False passage creation prevented by gentle probing technique and care to maintain the probe along the expected canalicular trajectory while maintaining lateral eyelid traction during the procedure
- Generally no treatment required because the false passage is expected to spontaneously heal
Interpretation (Figure 4)
Soft stop identifies the presence and position of canalicular obstruction.
Hard stop (lacrimal bone of lacrimal sac fossa) demonstrates a patent canaliculus/common canaliculus into the lacrimal sac.
A stenotic portion of the canaliculus can be identified and localized with gentle probing and measuring distance from punctum to end of probe at obstruction.
Irrigation of saline to the nose indicates a grossly patent system.
Resistance to irrigation with some flow of saline to nose and some reflux indicates a stenotic nasolacrimal duct.
Complete reflux from the same punctum indicates improper cannula position or canalicular/common-canalicular obstruction.
Complete reflux from opposite punctum indicates complete nasolacrimal duct obstruction if previously able to advance to a hard stop or obstruction of the common canaliculus if not able to advance fully to a hard stop.
Figure 4. Interpretation of lacrimal irrigation results. Illustration by Cyndie C. H. Wooley.