Lacrimal Apparatus and Dacryocystitis

The lacrimal apparatus has two halves: a secretory part that makes the aqueous layer of the tear film, and an excretory (drainage) part that carries tears from the eye into the nose. Most exam questions on watering eyes are really questions about which half has failed. Too much production gives reflex tearing; a blocked outflow gives epiphora — tears spilling over the lid because they cannot drain.

The main lacrimal gland sits in the superolateral orbit and is divided into an orbital lobe and a palpebral lobe, joined by interlobular ducts. Tear fluid from both lobes is secreted into the upper conjunctival fornix. Beyond lubrication, the gland has an immune role: it secretes IgA and IgG antibodies into the tear film.

Aqueous secretion responds to parasympathetic (secretomotor) and sympathetic stimulation. The secretomotor pathway is a favourite anatomy question because it crosses several named nerves and one ganglion before reaching the gland.

1. Preganglionic fibres arise in the lacrimatory nucleus of the facial nerve in the pons.
2. They travel with the facial nerve to the region of the geniculate ganglion and leave as the greater petrosal nerve.
3. The greater petrosal nerve joins the deep petrosal nerve (sympathetic fibres from the superior cervical ganglion) to form the nerve of the pterygoid canal.
4. Parasympathetic fibres synapse in the pterygopalatine ganglion.
5. Postganglionic fibres run in the zygomatic and zygomaticotemporal nerves and reach the gland with the lacrimal nerve.

Tears collect at the medial canthus and drain in a fixed order: upper and lower puncta → canaliculi → common canaliculus → lacrimal sac → nasolacrimal duct → inferior meatus of the nose. The duct opens through a mucosal flap called the valve of Hasner, and this distal end is where congenital obstruction usually sits.

Congenital nasolacrimal duct obstruction (CNLDO) is the most common cause of persistent watering in infants. The commonest cause is a persistent membrane at the distal end of the duct; a narrow bony canal or inferior meatal stenosis can also be responsible. In a British cohort of 4,792 infants, epiphora affected 20% in the first year of life, and bilateral involvement is reported in 14% to 34% of cases.

The natural history is favourable. Spontaneous resolution has been reported in up to 95% of children by 13 months; one prospective series showed resolution in 45% by 6 months and 93% by 12 months. Management is therefore stepwise and age-based rather than surgical at presentation.

1. Lacrimal sac massage (Crigler technique) — first-line for all children at presentation; caregivers are taught the technique under supervision. Topical antibiotics are reserved for infective discharge.
2. Probing with Bowman probes — generally recommended for persistent symptoms after 12 months of age, usually under general anaesthesia. Recurrence after failed probing typically appears within 4 to 8 weeks, and repeat probing may follow.
3. Probing with silicone intubation or balloon catheter dilatation — after one or more failed probings; silicone stents are generally removed after 2 to 6 months.
4. Dacryocystorhinostomy — for persistent obstruction, bony obstruction, dacryocystocele or dacryocystitis.

Probing success falls with age: one prospective study of 343 children reported success of 85% at 2 to 3 years, 63% at 3 to 4 years and 50% at 4 to 5 years. The fluorescein dye disappearance test can be read at 5 minutes but gives false results in infants, so the diagnosis rests mainly on history and discharge.

Dacryocystitis is inflammation of the lacrimal sac, usually caused by obstruction of the nasolacrimal duct with stagnation of tears in the sac. It is the most commonly encountered disease of the lacrimal drainage system. A history of less than 3 months is classed as acute; incomplete resolution with persistent infection is called subacute.

Acute disease is treated with systemic antibiotics covering gram-positive cocci — amoxicillin-clavulanate, cefuroxime or ciprofloxacin depending on local sensitivity — plus analgesics and topical antibiotics. Syringing and lacrimal probing are contraindicated during acute inflammation. The acute episode typically settles in 3 to 7 days, but watering persists because the duct remains blocked, so flare-ups recur.

If an abscess ruptures spontaneously it forms an acquired lacrimal fistula at the most dependent part of the abscess, below the medial canthus on the lower lid. Chronic dacryocystitis has been staged as catarrhal, mucocele, chronic granulation and complicated disease. Acquired primary obstruction (PANDO) shows a female predisposition, with nearly 75% of cases in women.

ROPLAS stands for regurgitation on pressure over the lacrimal sac area. Pressing over the sac squeezes mucopurulent material back out through the upper and lower puncta. A positive test means the sac is distended with contents that cannot pass down the duct — the classic sign of chronic dacryocystitis or mucocele.

• Syringing — saline injected through the punctum; free passage into the throat means a patent system, regurgitation through the opposite punctum suggests a block at or below the common canaliculus.
• Probing — localises proximal, distal or common canalicular blocks in millimetres; done under topical anaesthesia in adults.
• Fluorescein dye disappearance test — dye retained in the tear film suggests impaired outflow.
• Jones 1 test — fluorescein instilled in the eye and its presence in the nose checked after 5 minutes; now used less often.

Dacryocystorhinostomy (DCR) creates a functional pathway from the canaliculi into the nose by making a bony osteotomy and opening the lacrimal sac into the nasal cavity. It bypasses the blocked duct and restores drainage, so it treats both the infection and the watering. Toti described the first definitive DCR in 1904. It can be done by an external skin approach or an endonasal (endoscopic) approach; endonasal DCR is as successful as external surgery when proper technique is used.

Dacryocystectomy (DCT) is complete excision of the lacrimal sac. It removes the infected reservoir but does not create a new drainage route, which is why DCR is the default operation for nasolacrimal duct obstruction. DCT remains the standard for suspected or confirmed lacrimal sac malignancy, and other indications include chronic dacryocystitis with severe dry eye, bleeding tendency and nasal inflammatory disease such as granulomatosis with polyangiitis.