Common Disease Of Lacrimal System Flashcards
What are the 2 parts of the main lacrimal gland?
- Orbital part = larger, located in lacrimal fossa of frontal bone
- Palpebral part = smaller, consists of 1-2 lobules, continuous with orbital part
Where do the lacrimal gland ducts open?
- 10-12 ducts open into lateral sup. fornix
- 1-2 ducts open into lateral inf. fornix
What are the accessory lacrimal glands?
- Glands of Krause = 42 in upper fornix, 6-8 in lower fornix
- Glands of Wolfring = near sup. tarsal plate & inf. tarsus
What is the blood supply of lacrimal gland?
Lacrimal artery (branch of ophthalmic artery)
What is the nerve supply of lacrimal gland?
Sensory = lacrimal nerve (branch of ophthalmic division of CN V)
Sympathetic = carotid plexus of cervical sympathetic chain
What is dry eye disease?
A multi factorial disease characterized by loss of homeostasis of tear film causing tear film instability, hyperosmolality & ocular inflammation.
What are the layers of tear film (structure of fluid covering cornea) from post. to sup.?
- Mucous layer
- Aqueous layer
- Lipid/oily layer
What are the symptoms of dry eye disease?
- Irritation, foreign body (sandy) sensation
- Dryness, itching, sore eyes
- Discomfort despite using eye drops
What are the tear film signs in dry eye disease?
- stringy mucous
- marginal tear strip reduced/absent
- froth at lid margin (meibomian gland dysfunction)
What are the conjunctival signs in dry eye disease?
- lusterless, mild congestion, keratinization
- Rose bengal or Lissamine green staining +ve
What are the corneal signs in dry eye disease?
- Punctate erosion, filaments and mucus plaque
- cornea loose lustre
What are the causative diseases in dry eye disease?
- Posterior Blepharitis
- Conjunctival scarring diseases = trachoma, Steven Johnson’s, chemical burns, ocular pemphigoid
What are the complications of dry eye diseases?
- threatens vision
- epithelial breakdown
- corneal perforation, ulceration, melting
Describe TBUT (tear film break up time) test
(dry eye disease)
- interval btwn complete blink & appearance of first dry spot on the cornea
- noted after instilling drop of fluorescein & examining in cobalt blue light of slit lamp
- normal = 15-35 sec
- unstable tear film = <10 sec
Describe Schirmer-l test
(dry eye disease)
- measure total tear secretion
1. strip of whatman-41 filter paper folded 5mm from one end
2. Kept in lower fornix at junction of lat 1/3rd and medial 2/3rd
3. Ptn asked to look up and not blink/close eyes
4. After 5 mins, wetting of filter paper strip from bent end measured
> 15mm = normal
- 5-10 mm = mild/moderate keratoconjunctivitis sicca
<5 mm = severe KCS
Describe rose bengal staining
To detect mild cases of KCS
Mild (C) = fine punctate stains
Moderate (B) = extensive staining
Severe (A) = confluent staining of conjunctiva/cornea
What are the treatments for dry eye disease?
- Tear substitutes
- Anti-inflammatory agents (topical steroids, cyclosporine)
- Mucolytics (5% acetylcysteine)
- Reduce evaporation & draining
What is Sjögren’s syndrome?
Chronic autoimmune inflammatory disease affecting lacrimal & salivary glands
- F>M (40-50 yrs)
What is primary Sjögren’s syndrome?
present with sicca complex (combination of KCS and xerostomia)
What is secondary Sjögren’s syndrome?
dry eye and/or dry mouth
- associated with an autoimmune disease (ex. rheumatoid arthritis)
What is watering eye disease?
Overflow of tears from the conjunctival sac
Watering eye is due to
- Hyperlacrimation = excessive secretion of tears
- Epiphora = inadequate drainage/outflow of normally secreted tears
What is primary hyperlacrimation?
- due to direct stimulation of lacrimal gland
Ex. early stage gland tumor, cyst
parasymphathomimetic drugs
What is reflex hyperlacrimation?
Stimulation of sensory branches of 5th nerve due to irritation of cornea/conjunctiva
- ex. affection of lid, conjunctiva, cornea, sclera
Acute glaucoma, endopththalmitis, orbital cellulitis
