Chronic infection of the lacrimal sac in adulthood.
A. Predisposing factors (causes of acquired NLD obstruction):-
I. In the lumen:
- Concretions (collection of Ca or fungal colonies around foreign bodies as lashes).
II. In the wall:
- Congestion because the lower end of the wall has an erectile tissue. It becomes congested due to hormonal disturbances in females about menopause.
- Tumours or polypi of NLD.
III. Pressure from outside by fractures or tumours of the maxillary sinus.
IV. Obstruction at the nasal end of NLD for example by deviated septum and nasal polyps.
B. Causes of infection (precipitating factors):
As congenital dacryocystitis.
- Watering of the eye especially in cold or dusty atmosphere.
- Swelling below the MPL.
- As congenital dacryocystitis.
- Exclusion of other causes of lacrimation and epiphora should be done as the presence of ectropion and orbicularis paresis.
A. To confirm the presence of obstruction:
1. Fluorescein clearance test: A drop of fluorescein should normally disappear from the conjunctival sac within 5 minutes.
2. John's dye test: If a piece of cotton is put in the inferior meatus of the nose and a fluorescein drop in the eye, the piece of cotton should normally receive fluorescein within 5 minutes.
B. To identify the site and cause of obstruction:
1. Probing: The punctum is dilated by a punctal dilator, then a probe is introduced into the sac. If > 8 mm of the probe can pass inside, thus there is no canalicular obstruction. If only less than 8 mm, thus there is canalicular obstruction.
2. Lacrimal irrigation with saline: Saline is injected into the lacrimal passages by a special blunt angulated needle. If could reach the nose under pressure, thus there is partial obstruction.
3. Lacrimal irrigation with saline and adrenaline: A diluted solution of adrenaline is injected. If it could reach the nose, thus the cause of obstruction is congestion of NLD. If it could not, the cause is stricture.
i. Plain X - ray to show bone lesions as malunion of maxillary fractures.
ii. Dacryocystography: A dye is injected into the lacrimal passages and serial X - ray films are taken. It may show:
* Abrupt NLD obstruction in cases of tumours.
* Rat tail appearance in cases of stricture of NLD.
* No obstruction, but delayed emptying of lacrimal sac in cases of functional lacrimal obstruction. It occurs due to paralysis of the lacrimal portion of O.O..
* The dye can not enter the sac in cases of canalicular obstruction.
iii. Lacrimal scintillography:
* Radioactive eye drops are instilled and its movement through the lacrimal passages is monitored (very accurate).
5. ENT examination: It is important for:
i. To find nasal causes of NLD obstruction.
ii. To find contraindications of DCR operation.
C. Culture and sensitivity to identify the causative organism.
As congenital dacryocystitis.
1. Dacryo-cysto-rhinostomy (DCR):
* Idea: a permanent artificial canal is made between the lacrimal sac and nose through the nasal bone. It is the operation of choice because it solves both the problems of obstruction and infection.
* Absolute contraindications of DCR:
i. Causes in the sac:
- Malignancy of the sac.
- Specific dacryocystitis as TB & syphilis.
ii. Causes in the nose:
- Malignancy of nose.
- Specific rhinitis as rhinoscleroma.
- Atrophic rhinitis.
iii. Causes in the nasal bone as periostitis.
* Relative contraindications:
- Extremes of age.
- Mucocele and lacrimal fistula.
NB. Modifications of DCR:
a. With lacrimal fistula we do DCR + fistulectomy.
b. For mucocele and pyocele we do DCR + silicon intubation of the canaliculi (canaliculo-dacryo-cysto-rhinostomy CDCR).
- In this operation we excise the lacrimal sac.
- It solves the problem of infection, but epiphora remains forever.
- It is indicated when DCR is contraindicated.