Lacrimal glands Flashcards
Diseases of the Lacrimal system
Abnormal tear film
- Aqueous layer deficiency: Keratoconjunctivitis sicca
- Lipid and mucin layer deficiency
- Eyelid abnormalities
- Ocular surface abnormalities
Lacrimal drainage apparatus abnormalities
- Obstruction
- Acute Dacryocystitis
- Chronic Dacryocystitis
- Trauma
Aqueous layer deficiency: Keratoconjunctivitis sicca
causes
clinical
Treatment
Causes:
- Idiopathic
- Postmenopausal woman
- Associated with dryness of mouth and genitals - Injury of Lacrimal gland
- Infection
- Surgery
- Autoimmune
- CT disorders: RA - Occlusion of draining system: cicarticial conjunctival diseases:
- Chemical burns
- Trachoma
- Stevens-Johnsons syndrome
Clinical:
- Burning and scratching eyes (> wind and aircon)
- Dryness
- Corneal vascularization
- Opacification
- Keratinization
- Secondary infection (< antibacterial activity of tear film and ep damage)
Treatment:
- Avoid triggers
- Artificial Tears: Used reguraly, Try different products, try different application frequency
- Preservative free cartridges for one day use –> these avoid the problems of preservative sensitivity and irritation.
- Gels @ night: greater relief, but interfere with vision
- Ointments only in severe cases: cause blurring of vision and feel unpleasant in the eye.
Lipid and mucin layer deficiency
Causes
Clinical picture
Treatment
Causes:
- Blepharitis: < in the lipid layer secreted by the tarsal glands.
- Condition that leads to > destruction of mucous secreting conjunctival goblet cells will cause a mucin deficiency.
(a) Cicatricial conjunctival diseases such as chemical burns, trachoma and Stevens-Johnson syndrome.
(b) Xerophthalmia (vitamin A deficiency).
Clinical picture:
- Dry eye
- Burning and scratching eyes
- Paradoxical symptom of tearing.
- Dry spots: Tear film instability–> irritation and reflex aqueous tear secretion by the lacrimal gland to produce an excessive volume of fluid in the eye despite the dryness.
- Corneal vascularisation, opacification and even keratinisation. (severe)
Eyelid abnormalities
Consequences
Causes
Treatment
Consequences:
- Inadequate wetting of parts of the cornea. 2. Keratitis
- Initially damage is confined to the epithelium–> vascularisation, opacification and eventually keratinisation.
Causes: 1 Abnormal eyelid contour (a) Trauma (b) Trachoma (c) Tumour 2 Disruption of eyelid movements (a) Lagophthalmos (incomplete eyelid closure): VII paralysis. (b) Symblepharon (adhesion between palpebral and bulbar conjunctiva): trauma, trachoma, Stevens-Johnson syndrome.
Ocular surface abnormalities
Causes
Pathophysiology
Treatment
Causes:
- abnormal contour
- abnormal epithelium: pterygium or scarring.
Pathophysiology:
Abnormal contour or epithelium–> tear film turbulence/resist mucin adhesion–> unstable tear film–> formation of dry patches.
Obstruction in neonates and infants Physiology Incidence Pathophysiology Clinical picture Complications Treatment Prognosis
Physiology: Obstruction to tear outflow –> tears collecting in the conjunctival sac–> flowing over the lid margin. This is called epiphora.
Obstruction causes stasis which predisposes to acute and chronic infections of the lacrimal sac.
Incidence: 5% of neonates
Pathophysiology: thin membrane occludes the nasal orifice of the nasolacrimal duct
Clinical picture: tearing and discharging eyes
Complications: Acute dacryocystitis
Prognosis: 90% of cases the tearing clears spontaneously by about 12 months of age.
Treatment:
1. Massaging the lacrimal sac twice a day,
2. Probing: If the problem is not resolved by 12 months of age
Acute Dacryocystitis
path
clinical
treatment
Pathophysiology:
Obstruction of tear film distal to lacrimal sac–> stasis–> secondary infection –> Lacrimal duct fills with puss–> Cellulitis
Clinical
- Epiphora
- Pain
- Redness of lacrimal sac
- Swelling of lacrimal sac
- Abcess with discharge
Treatment:
- AB local and systemic
- Abcess drainage
- Dacryocystorhinostomy when infection cleared: Opening from lacrimal sac to nasal opening
Chronic Dacryocystitis
path
clinical
Pathophysiology:
Obstruction of tear flow distal to lacrimal sac–> Stasis–> secondary infection–> lacrimal sac fills with material–> chronic irritation of eye
Clinical -Epiphora -Mucopurulent discharge - Swelling over Lacrimal sac Pressure on Lacrimal sac causing mucopurulent material expressed from puncta
Treatment:
1. Dacryocystorhinostomy
Trauma
Path
clinical
treatment
Path: Canalicular injury
Clinical: lower and upper across each other–> if shifted–> abnormal
Treatment: Surgical Repair
Anatomy of Lacrimal system: Tear film
3 layers of tear film:
- Outer lipid layer
- secreted: Tarsal glands
- function: Retards evaporation of the aqueous layer
Prevent tears from spilling over the edge - Middle Aqueous layer
- secreted: Lacrimal glands - Inner Mucin layer
- secreted: Conjunctival goblet cells
- function: Hydrophilic surface on which aqueous layer can be spread
Physiology of Lacrimal system: tear film
Structure unstable–> stabilized by methods:
- renewed by blinking- need normal 3 layers of tear film
- Corneal epithelium surface must be smooth and normal
- Good eyelid apposition
- Good contact of eyelids and anterior surface of eye
Irregular areas–> unstable tear film–> dry spots
- tear film turbulence–> mixing of layers
- mucin adhesion
Lacrimal drainage system anatomy
- Lacrimal sac
- Inferior punctum
- Inferior canaliculus
- Inferior turbinate
- Nasalacrimal duct
Lacrimal drainage system physiology
Blinking–> tears to flow to the medial canthus –> siphoned into the canaliculi–> squeezed into the lacrimal sac–> They flow down the nasolacrimal duct and into the nose.
Lacrimal drainage system anatomy
- Lacrimal sac
- Inferior punctum
- Inferior canaliculus
- Inferior turbinate
- Nasalacrimal duct
Lacrimal drainage system physiology
Blinking–> tears to flow to the medial canthus –> siphoned into the canaliculi–> squeezed into the lacrimal sac–> They flow down the nasolacrimal duct and into the nose.
