Anterior segment problems Flashcards
how do tears drain
via the lacrimal puncta, canaliculi, lacrimal sac, lacrimal duct, inferior meatus into nasal passage
what can dry eyes be due to
insufficient tear production- deficiency in one of 3 components of the tear film
what is keratoconjunctivitis sicca
uncommon but severe cause- aqueous tear deficiency
pure kerato sicca what does it involve
lacrimal gland alone
lacrimal gland dysfunction
usually inflammation- autoimmune; scaring of secretory ducts; excision of the gland
if salivary and other glands are involved what is this
Sjogrens
what is mucin deficiency
xerophthalmia- when large numbers of goblet cells are damaged by extensive conjunctival scarring.
clinical features dry eyes
poor tear film quality, persistent irritation with a feeling of dryness.
signs dry eyes
slit lamp examination. fluorescin dye.
what is Schirmers test
for dry eyes- measures the wetting of a strip of filter paper
what can severe dry eye lead to
corneal epithelial loss, scarring, vascularisation
management dry eye
tear supplement. lacrimal punctal occlusion
what can watery eyes be due to
failure of lacrimal gland drainage system, or over secretion of tears
causes watery eye
emotion, corneal injury/FB, entropion, conjunctivitis, iritis, acute glaucoma
what is the name given to improperly drained tears
epiphora
what can cause obstruction to drainage in watery eye
ectropion, drainage system blockage, congenital- incomplete development of nasolacrimal duct. punctual stenosis
treatment watery eye
dacryocystorhinstomy for nasolacrimal duct obstruction, surgery for other causes
cause of oversecretion tears
ocular irritation eg by eyelashes
what is entropion
inwards turning of lid margin
causes of entropion
ageing (involutional), conjunctival scarring, spasm orbicular oculi
what happens due to the entropion
eyelashes rub against eyeball- FB sensation and reflex watering. may cause corneal abrasion
management entropion
botulinium toxin injection. surgery. conjunctival scarring hard to treat
what is ectropion
turning outwards of eyelid margin- lower lid
causes of ectropion
involutional (ageing), facial nerve palsy, eyelid skin scarring, bulky eyelid tumours
what does ectropion cause
irritation, watering, exposure keratitis
management ectropion
surgery. if cornea is at risk- eyelids sutured together- temporary lateral tarsorraphy
what is blepharitis
lid inflammation eg from staphs, seborrheoic dermatitis, rsacea
features blepharitis
burning itching red margins, scales on the lashes
treatment blepharitis
clean crusts off lashes +-tears natural, fusidic acid, steroid drops
