How does the lacrimal apparatus work?
The lacrimal gland constantly produces a small amount of fluid, which, when blinking, is distributed over the surface of the eye and nourishes the cornea. The spent tear collects at the inner corner and goes through two small lacrimal puncta on the eyelids into the lacrimal sac, and from there along the nasolacrimal duct into the nasal cavity. This is why your nose runs when you cry. A failure in any part of this system - from a loose eyelid to a narrowing of the canal - leads to the fact that a tear remains on the eye and flows down the cheek.
- Lacrimal gland - production of tears
- Tear film - protection and nutrition of the cornea
- Lacrimal puncta and canaliculi are the entrance to the drainage tract
- Lacrimal sac - accumulation
- Nasolacrimal duct - exit to the nasal cavity
Possible reasons
In adults, two reasons lead. The first is dry eye syndrome: the tear film is unstable, the eye is irritated, and tears flow in fits and starts, especially in the wind and when working behind a screen. The second is a violation of the outflow: narrowing of the lacrimal punctum, obstruction of the nasolacrimal duct, chronic inflammation of the lacrimal sac. Contributions include blepharitis and dysfunction of the meibomian glands, allergies, ectropion or entropion of the eyelid with age, and the consequences of nasal injuries and sinus surgeries. In infants, a common cause is an unopened film in the nasolacrimal duct.
- Dry eye syndrome
- Blepharitis and inflammation of the eyelid margins
- Allergic conjunctivitis
- Narrowing or obstruction of the nasolacrimal duct
- Dacryocystitis - inflammation of the lacrimal sac
- Eversion or inversion of the eyelid, abnormal eyelash growth
- Foreign body and corneal erosion
Tearing in babies
In newborns, lacrimation on one or both sides is common: the outlet of the nasolacrimal duct is closed by a thin film that has not resolved by birth. This usually goes away on its own by one year. The pediatrician or ophthalmologist shows parents how to massage the lacrimal sac area and explains how to care for the eye. If lacrimation persists after 9–12 months or is accompanied by purulent discharge and swelling, probing and rinsing of the nasolacrimal canal is performed - a short procedure with a good result.
- A common cause is an unopened canal film.
- Massage of the lacrimal sac according to the technique indicated by the doctor
- Toilet eyes with clean wipes
- Follow-up up to 9–12 months
- Probing the channel in the absence of effect
- Urgent examination for pus and swelling at the corner of the eye
Diagnostics
The ophthalmologist examines the eyelids and the position of the lacrimal openings, evaluates blinking and the condition of the eyelid margins, examines the eye at the slit lamp, and checks the stability of the tear film. The patency of the passages is assessed by lavage: if the fluid flows freely into the nose, the outflow is preserved. Additionally, a staining test is used. If pathology of the nose and sinuses is suspected, an ENT doctor is connected, and before surgery on the lacrimal ducts, an X-ray or CT scan with contrast may be required.
- Examination of eyelids and lacrimal openings
- Slit lamp biomicroscopy
- Tear film assessment and dryness test
- Lacrimal duct rinsing
- Colored nasolacrimal test
- Consultation with an ENT doctor, CT scan if indicated
Treatment
Treatment depends on the cause, so blindly "anti-tear drops" don't work. For dry eyes, tear substitutes without preservatives, warm compresses and eyelid hygiene are prescribed, and screen time is adjusted. For allergies, antiallergic drugs are added, for blepharitis - regular hygiene of the eyelid edges. The impaired outflow is restored by washing, bougienage or probing, and in case of persistent obstruction and recurrent dacryocystitis, dacryocystorhinostomy is performed - the creation of a new outflow path. Eversion of the eyelid and abnormal eyelash growth are corrected surgically.
- Tear substitutes without preservatives
- Warm compresses and eyelid hygiene
- Allergy treatment
- Rinsing and probing of lacrimal ducts
- Surgery for persistent obstruction
- Correction of eyelid position
- Breaks and humidification when working behind a screen
