Lacrimal passage obstruction (stenosis/occlusion) causing tearing is called lacrimal duct obstruction. Among these, obstruction at or beyond the entrance of the nasolacrimal duct is termed nasolacrimal duct obstruction (NLDO).
Slit-lamp examination may show a high tear meniscus, and delayed clearance of fluorescein staining suggests lacrimal duct obstruction. Diagnosis is confirmed by lacrimal irrigation test.
Based on the site of obstruction, it is broadly classified into the following four types.
Punctal occlusion
Definition: A condition in which the upper and lower lacrimal puncta are stenosed or closed.
Main causes: Scarring after burns or chemical corrosion, Stevens-Johnson syndrome, ocular pemphigoid.
Drug-induced: Glaucoma eye drops such as timolol, dorzolamide, pilocarpine; IDU (antiviral drug); S-1 (TS-1®).
Canalicular obstruction
Definition: A condition in which the lacrimal canaliculi (upper and/or lower) are obstructed.
Yabe-Suzuki classification: Grade 1 (common canalicular obstruction with communication), Grade 2 (no communication between upper and lower, insertion possible 7–8 mm or more), Grade 3 (more proximal obstruction than Grade 2).
Features: Anticancer drug-related cases are often bilateral and involve both upper and lower canaliculi simultaneously.
Common canalicular obstruction
Definition: A condition in which the common canaliculus (junction of the upper and lower canaliculi) is obstructed.
Treatment strategy: Recanalization by DEP or SEP is the basic approach but is technically challenging; if not possible, CDCR (conjunctivodacryocystorhinostomy) is considered.
Nasolacrimal duct obstruction
Definition: A condition in which the nasolacrimal duct from the lacrimal sac to the opening in the inferior meatus is obstructed.
Most common site: Obstruction at the entrance of the nasolacrimal duct is the most frequent.
Curative treatment: DCR (dacryocystorhinostomy) is the first choice.
Since lacrimal endoscopy was covered by insurance in 2018 1), it has become possible to observe the degree of fibrosis and mucosal inflammation at the obstruction site, improving the accuracy of differentiating between common canaliculus and nasolacrimal duct obstruction. The concordance rate between obstruction site estimation by irrigation and lacrimal endoscopic findings is about 70% 1), highlighting the significance of direct endoscopic observation.
Epiphora includes not only lacrimal passage obstruction but also hypersecretion of tears (e.g., reflex tearing due to dry eye). If reflux occurs during lacrimal irrigation, obstruction can be diagnosed. Evaluate tear secretion with BUT measurement or Schirmer test to differentiate.
Punctal and canalicular obstruction occurring during anticancer treatment with S-1 (tegafur/gimeracil/oteracil potassium combination, TS-1®) often becomes severe. Early tube insertion is recommended. Among anticancer drug-related lacrimal duct obstructions, punctal and canalicular disorders account for about 60% 1). If the tube is removed during anticancer drug use, reobstruction is likely, so it is desirable to continue tube placement during treatment 1).
The Yabe-Suzuki classification is used as a severity classification for canalicular obstruction 1).
| Grade | Definition | Treatment approach |
|---|---|---|
| Grade 1 | Bougie can be inserted ≥11 mm; communication between upper and lower puncta present (common canalicular obstruction) | DEP/SEP, tube placement for 2–10 months |
| Grade 2 | No communication between upper and lower puncta; bougie can be inserted ≥7–8 mm | DEP/SEP (high difficulty); consider CDCR |
| Grade 3 | Obstruction more proximal than Grade 2 | DEP/SEP difficult; attempt with metal bougie; consider CDCR |
Nasolacrimal duct obstruction is the most common cause of adult epiphora. It is more common in women and the elderly, and anatomical narrowing of the nasolacrimal duct is considered a contributing factor. Cone-beam CT dacryocystography analysis has shown that the angle between the superior orbital rim, the internal common punctum, and the nasolacrimal duct opening is anteriorly flexed in 92% of cases 3), and this morphological characteristic is thought to contribute to the risk of obstruction.
Causes of nasolacrimal duct obstruction include chronic inflammation, age-related changes, as well as Stevens-Johnson syndrome, ocular cicatricial pemphigoid, and drug-induced causes (glaucoma eye drops, antiviral drugs, anticancer agents).
| Examination | Information Detected | Invasiveness | Insurance Coverage |
|---|---|---|---|
| Lacrimal irrigation (syringing) | Presence of obstruction and direction of reflux | Low | Yes |
| Dye disappearance test | Decreased tear clearance | Low | Yes |
| Dacryocystography | Obstruction site, lacrimal sac enlargement, contrast cutoff | Moderate | Yes |
| Lacrimal endoscopy | Direct observation of obstruction, fibrosis, mucosal inflammation | Moderate | Since 2018 |
| Orbital and sinus CT | Lacrimal sac fossa, nasal cavity shape, sinusitis, mass | Moderate | Yes (preoperative) |
Dacryoendoscopy was covered by insurance in 2018 1) and is useful for diagnosing the degree of fibrosis at the obstruction site, mucosal inflammation, and intralacrimal masses. If extralacrimal pathology is suspected, CT or MRI is used in combination.
Dacryocystography may be ambiguous in determining whether contrast reaches the obstruction site 1), and its role is largely complementary to direct observation with dacryoendoscopy.
The causes of epiphora are broadly divided into “lacrimal passage obstruction (normal secretion but inability to drain)” and “hypersecretion of tears (increased tears due to stimulation).” Lacrimal duct obstruction is the most common cause, but reflex epiphora due to dry eye, conjunctivitis, and keratitis can also cause tearing. Differential diagnosis is made by evaluating tear secretion with BUT measurement and Schirmer test, and checking for passage obstruction with lacrimal irrigation.
It has been covered by insurance since 2018. Lacrimal endoscopy allows direct observation of the obstruction site and is useful for diagnosing the degree of fibrosis, mucosal inflammation, and intralacrimal tumors. It is particularly helpful for detailed classification of obstruction sites that are difficult to estimate with irrigation tests (e.g., distinguishing between common canalicular obstruction and nasolacrimal duct obstruction, and differentiating between lacrimal sac-nasolacrimal duct junction obstruction and lower membranous nasolacrimal duct obstruction).
Treatment is selected according to the site of obstruction, severity, and patient preference.
The following are performed as acute phase/initial management:
Under topical anesthesia, the punctum is incised and dilated using a punctal dilator or sharp blade. A punctal plug is placed for 2–4 weeks and then removed; if reocclusion occurs, a silicone tube is placed in the canaliculus for 1–2 months and then removed.
Gradual punctal dilation (from thin to thick) followed by lacrimal tube placement can prevent reocclusion. The indwelling period is 1–7 months, and the success rate 3–12 months after tube removal is reported to be 81.8–100% 1).
After performing intralacrimal anesthesia with 4% lidocaine hydrochloride solution, the canaliculus is sufficiently dilated with a punctal dilator. A nunchaku-type or catheter-type silicone tube is carefully inserted from the punctum while confirming the sensation of the obstruction site, and removed after 1–2 months of indwelling.
The obstruction is perforated using DEP (direct endoscopic probing) or SEP (sheath-guided endoscopic probing) 1).
The tube indwelling period is 2 to 10 months. The patency rate at 878 days postoperatively by the Kaplan-Meier method is reported to be 94%1).
The difficulty level is significantly higher. If perforation is difficult with DEP/SEP, a thin metal bougie is used to attempt perforation1). If neither the upper nor lower canaliculus can be opened, CDCR (conjunctivodacryocystorhinostomy) is considered.
The obstruction is perforated with DEP or SEP, and a tube is inserted using SGI (sheath-guided intubation) or G-SGI1).
Direct tube insertion has a reported 22% rate of submucosal misinsertion1), so the SGI/G-SGI method is recommended. The tube indwelling period is 2 to 12 months. The surgical success rate at 1 year after tube removal is 70–87%1). The success rate of DSI (direct silicone intubation) is low at about 52.5% (8–30 months after tube removal)1), and the patency rate at 3,000 days after tube removal is 64%, with long-term recurrence risk reported1). Risk factors for recurrence include history of dacryocystitis, long disease duration, long obstruction length, and male sex1).
Indicated for patients with long-standing symptoms of epiphora and discharge who desire surgery. In acute dacryocystitis, surgical planning is done after incision and drainage and antibiotics to control inflammation. For patients who do not desire radical surgery, bougie or tube placement can delay surgery, but it should be fully explained in advance that the outcomes of tube placement for nasolacrimal duct obstruction are not favorable.
Procedure for external DCR:
The success rate of external DCR is 90–99% 1), and many reports indicate a reocclusion rate of less than 10%. Some reports suggest that the endoscopic (intranasal) DCR has slightly inferior outcomes due to the smaller bone window.
| Procedure | Success rate | Stent/patency duration | Main indications |
|---|---|---|---|
| Direct silicone intubation (DSI) | Approximately 52.5% (at 8–30 months) | Stent left in place for 2–12 months | Nasolacrimal duct obstruction (mild) |
| Lacrimal endoscopic tube insertion (DEP/SEP+SGI) | 70–87% (at 1 year) | Indwelling for 2–12 months | Nasolacrimal duct obstruction / canalicular obstruction |
| External DCR | 90–99%1) | — | Nasolacrimal duct obstruction (curative) |
| DEP/SEP (Grade 1 canalicular obstruction) | Patency rate 94% (at 878 days) | Indwelling for 2–10 months | Total canalicular obstruction |
The main complications associated with lacrimal endoscopic surgery and lacrimal tube intubation are listed below1).
Broadly, there are two types: “endoscopic lacrimal intubation” and “DCR (dacryocystorhinostomy).” Intubation is less invasive, with a success rate of 70–87% at 1 year after removal, but has a long-term recurrence risk. External DCR is curative with a success rate of 90–99% and a reocclusion rate below 10%. The choice depends on symptom severity, disease duration, and patient preference.
Lacrimal obstruction caused by S-1 (TS-1®) often occurs at the punctum and canaliculus and tends to be severe, so early silicone tube intubation is recommended. If the tube is removed during chemotherapy, reocclusion is likely, so it is advisable to maintain tube placement during ongoing treatment. If you notice symptoms, consult an ophthalmologist promptly.
It depends on the site of obstruction and the surgical technique. Punctal tube placement: 1–7 months; endoscopic lacrimal treatment of the canaliculus (DEP/SEP): 2–10 months; nasolacrimal duct intubation: 2–12 months. Optimal timing for tube removal based on endoscopic findings is expected in the future.
Obstruction at the entrance of the nasolacrimal duct is most common. Chronic inflammation, age-related changes, and anatomical narrowing are involved in combination.
When obstruction occurs, tears and secretions accumulate proximal to the blockage (lacrimal sac side). The accumulated mucus becomes a culture medium for bacteria, leading to overgrowth of Moraxella lacunata, S. mitis, Pseudomonas aeruginosa, alpha-hemolytic streptococci, etc., and progression to chronic dacryocystitis1). Reduced tear clearance also contributes to chronic changes in the cornea and conjunctiva.
A report analyzing lacrimal duct morphology using cone-beam CT dacryocystography found that the angle between the superior orbital rim, the internal common punctum, and the nasolacrimal duct opening is anteriorly flexed in 92% of cases 3), and this morphological characteristic is thought to influence the difficulty of instrument insertion into the nasolacrimal duct and the formation of obstructions.
Lacrimal endoscopes come in two types: a specification with an outer diameter of 0.9 mm and 10,000 observation pixels (2012 improved version), and an operability-priority type with an outer diameter of 0.7 mm and 3,000 pixels 1). In 2020, the depth of focus was improved to accommodate observation distances of 1.5 to 7 mm. A bent type with a 27° upward bend at the distal 10 mm is mainly used, and straight and double-bent types are selected according to the case 1).
Lacrimal sac stones are formed by chronic inflammation and retention of secretions 4). Intracanalicular tumors are sometimes discovered by lacrimal endoscopy, and reports include malignant melanoma, papilloma, and granuloma 1). Since malignant tumors are found in about 1.0% (69% of all tumors) of pathological examinations during DCR, histopathological examination of surgical specimens is recommended 5).
