Diseases of the Lacrimal Apparatus
The lacrimal apparatus includes the lacrimal glands, puncta, canaliculi, lacrimal sac, and nasolacrimal duct. Its primary function is to produce, distribute, and drain tears. Disorders of the lacrimal apparatus can lead to discomfort, infections, and visual disturbances. Below is a detailed explanation of key lacrimal diseases for ophthalmology and optometry students.
1. Dacryocystitis
Definition:
Dacryocystitis is the inflammation or infection of the lacrimal sac, usually due to obstruction of the nasolacrimal duct.
Causes:
- Congenital: Developmental anomalies causing nasolacrimal duct obstruction.
- Acquired:
- Primary: Idiopathic stenosis of the duct.
- Secondary: Trauma, nasal polyps, infections, or tumors compressing the duct.
Signs and Symptoms (s/s):
- Pain, swelling, and redness over the medial canthus.
- Epiphora (excessive tearing).
- Mucopurulent discharge on pressure over the lacrimal sac area.
- Fever in acute cases.
Investigations:
- Dye disappearance test: Evaluates tear drainage.
- Dacryocystography: X-ray of the nasolacrimal duct.
- Culture and sensitivity: To identify causative organisms.
Management:
Acute dacryocystitis:
- Antibiotics (oral or IV for severe cases).
- Warm compresses.
- Incision and drainage if an abscess forms.
Chronic dacryocystitis:
- Definitive treatment: Dacryocystorhinostomy (DCR) surgery.
- Probing or intubation for congenital cases.
2. Lacrimal Tumors
Definition:
Lacrimal gland tumors can be benign or malignant growths involving the lacrimal gland.
Causes:
- Benign: Pleomorphic adenoma.
- Malignant: Adenoid cystic carcinoma, lymphoma.
Signs and Symptoms:
- Gradual or rapid onset of painless swelling in the superotemporal region.
- Proptosis (eye displacement forward).
- Diplopia (double vision).
- Decreased ocular motility.
- Pain in malignant cases.
Investigations:
- Imaging: CT or MRI to assess the extent of the lesion.
- Biopsy: Histopathological examination for definitive diagnosis.
Management:
- Benign tumors: Complete surgical excision.
- Malignant tumors: Surgery followed by radiation or chemotherapy, depending on the tumor type and stage.
3. Dry Eye Disease (Keratoconjunctivitis Sicca)
Definition:
A multifactorial disease of the tears and ocular surface, leading to discomfort, visual disturbance, and tear film instability.
Causes:
- Decreased tear production: Sjögren’s syndrome, aging, medications (antihistamines, diuretics).
- Increased tear evaporation: Meibomian gland dysfunction, environmental factors.
Signs and Symptoms (s/s):
- Burning, stinging, and gritty sensation in the eyes.
- Redness and photophobia.
- Stringy mucus discharge.
- Blurred vision, worsening with prolonged visual tasks.
Investigations:
- Schirmer test: Measures tear production.
- Tear breakup time (TBUT): Assesses tear film stability.
- Ocular surface staining: Fluorescein, rose bengal, or lissamine green.
Management:
- Artificial tears and lubricating ointments.
- Warm compresses and lid hygiene for meibomian gland dysfunction.
- Punctal plugs or surgery for severe cases.
- Medications: Cyclosporine eye drops, omega-3 fatty acid supplements.
4. Watering of the Eye (Epiphora)
Definition:
Excessive tearing due to overproduction of tears or obstruction of tear drainage.
Causes:
- Overproduction: Ocular irritation (allergies, infections, foreign bodies).
- Drainage obstruction:
- Lacrimal punctum/canaliculi stenosis.
- Nasolacrimal duct obstruction.
Signs and Symptoms (s/s):
- Persistent tearing.
- Discharge in infectious causes.
- Associated symptoms like redness, pain, or photophobia.
Investigations:
- Lacrimal irrigation: To detect blockage.
- Jones test: Determines the level of obstruction.
- Dacryocystography: Visualizes tear drainage anatomy and obstruction sites.
Management:
- Treat underlying causes (e.g., infection, inflammation).
- Surgery: DCR or canaliculoplasty for obstruction.
Summary of Key Lacrimal Investigations
- Dye disappearance test: Assesses tear drainage efficiency.
- Schirmer test: Measures tear production.
- Tear breakup time (TBUT): Evaluates tear film stability.
- Imaging (CT/MRI): For lacrimal gland tumors.
- Dacryocystography: Visualizes tear drainage anatomy and obstruction sites.
Conclusion
Understanding the lacrimal apparatus's anatomy and physiology is critical for diagnosing and managing these diseases. Comprehensive clinical evaluation, relevant investigations, and timely management can prevent complications and restore normal tear function.