Ophthalmology - Other Flashcards
(50 cards)
What is the function of eyelids?
Prevent the eye from drying out.
Protect the eye from foreign bodies and excessive light.
What is the function of meibomian glands?
Modified sebaceous glands that produce the lipid outer layer of tear film.
What is blepharitis?
Inflammation of the eyelid, causing dry eye disease.
Aetiology of blepharitis.
Congestion and inflammation of eyelash follicles and meibomian glands.
Presentation of blepharitis.
Bilateral symptoms:
- ocular irritation
- foreign body sensation
- burning
- redness
- crusting
- watering of the eye
Treatment and prevention of blepharitis.
Lid hygiene:
- warm compression of eyelids
- eyelid massage
- cleaning eyelids with cotton wool
Topical antibiotic ointment can be applied to reduce bacterial colonisation.
Aetiology of a stye.
Staphylococcal infection of an eyelash follicle.
Presentation of a stye.
Tender, red eyelash follicle swelling.
Management of stye.
Often resolves spontaneously; encourage lid hygiene:
- warm compression of eyelids
- eyelid massage
- cleaning eyelids with cotton wool
Other treatments may include:
- removal of eyelash
- incisional drainage
- topical antibiotics
What is chalazion?
Granulomatous inflammatory lesion forming in an obstructed meibomian gland.
NOT infective.
Presentation of chalazion.
PAINLESS red eyelid cysts, in the internal eyelid.
Management of chalazion.
Often resolves spontaneously; encourage lid hygiene:
- warm compression of eyelids
- eyelid massage
- cleaning eyelids with cotton wool
What is entropion?
Age-related inward turning of the eyelid.
Inward-turning eyelashes may irritate the cornea, causing ulceration and risking sight loss.
Management of entropion.
- examination for corneal abrasion / keratitis
- frequent lubrication eyedrops
- referral to ophthalmology for surgical correction
What is ectropion?
Age-related outward turning of the eyelid*.
This causes a disruptive tear drainage, resulting in a sore and watery red eye.
*associated with CNVII palsy (Bell’s palsy)
Management of ectropion.
- lubricating eye drops
- taping the eyes shut
What is trichiasis?
Eyelashes grow inwards due to damage eyelash follicles, irritating the cornea:
- corneal ulceration (keratitis)
- sight loss
Management of trichiasis.
Often resolves spontaneously; encourage lid hygiene:
- warm compression of eyelids
- eyelid massage
- cleaning eyelids with cotton wool
Electrolysis or laser ablation can destroy the lash follicle and may provide a permanent solution.
What is the purpose of topical mydriatics?
Dilating eye drops to facilitate examination of the eye with an ophthalmoscope or slit lamp.
Which topical mydriatics are used most commonly?
Tropicamide and phenylephrine - dilatory effects wear off sooner.
What is the purpose of fluoresceine sodium 1% eyedrop?
Fluorescent dye applied in slit-lamp examination to allow visualisation of corneal defects.
What is the purpose of anaesthetic eyedrops?
- ophthalmic surgery
- intraocular pressure measurement (Goldmann applanation tonometer)
- examination of eye
What classes of medications are used to reduce intra-ocular pressure in the context of glaucoma?
- alpha agonists
- beta-blockers
- carbonic anhydrase inhibitors
- prostaglandin analogues
- cholinergics
Alpha agonist eye drops.
a) examples
b) MOA
c) side effects
a) iodipine
b) decrease production of aqueous humour in anterior chamber, reducing IOP.
c) headache; dry mouth; dry nose