Ophthalmology Flashcards
(38 cards)
Which 2 of the following play a role in upper eyelid elevation: Facial (seventh/VII) cranial nerve Oculomotor (third/III) cranial nerve Parasympathetic nervous system Sympathetic nervous system Trochlear (fourth/IV) cranial nerve
Elevation of upper eyelid controlled by levator palpebrae suprioris, supplied by oculomotor CN, and Muller’s muscle, supplied by sympathetic nervous system.
The eyelids are closed by the action of which muscle, supplied by which nerve?
Orbicularis oculi supplied by facial (VII) CN.
Give 3 causes of ptosis?
Myasthenia gravis Horner's syndrome Third nerve palsy, Age Myopathy e.g. chronic progressive external ophthalmoplegia
A 25 year woman has three days of mild pain in the right eye, worse on eye movements. In her right eye, her vision is blurred and colours also appear faded. Her vision gradually worsens in her right eye over one week. She has no systemic symptoms.
This is a typical history of?
Optic neuritis
Pain on eye movement can occur in optic neuritis and scleritis. What are two differences to differentiate scleritis?
Scleritis more severe pain and not associated with reduction of colour vision.
An afferent pupillary defect implies a defect in the contralateral or ipsilateral optic nerve?
Ipsilateral
What are the 3 most common causes of an abnormally large pupil?
Pharmacological, third nerve palsy and acute glaucoma
What treatment would you offer a patient with optic neuritis: Aspirin Beta Interferon IVIG (intravenous immunoglobulin) No pharmacological treatment Steroids?
No pharmacological treatment
Steroids will speed up recovery, but have no impact on the final vision, and do not modify the disease process.
Which nerve is involved in herpes zoster ophthalmicus? (Specific branch)
V1= ophthalmic branch of trigeminal nerve
Name 3 ophthalmic complications of herpes zoster ophthalmicus
Conjunctivitis Keratitis Uveitis Extraocular muscle palsy Corneal ulcer
A patient presents after their partner noticed their eye had turned red. On examination, you find a confluent redness of the white of the right eye. The patient has reported no pain.
What is the most likely diagnosis?
Investigations and management?
Subconjunctival haemorrhage
No investigations necessary (unless it’s recurrent or there are signs of bruising/bleeding elsewhere)
Management= none required, it will settle like a bruise.
True/false: hypermetropia is a risk factor for acute angle closure glaucoma.
True
The following signs: Mydriasis General corneal haze Eye feels rock hard when (gently) palpated are seen in what condition?
Acute angle closure glaucoma
Name 3 agents given to lower IOP in acute ACG?
- IV acetozolamide
- Topical prostaglandin analogues
- Topical beta blockers
- Sometimes IV mannitol
Other than IOP lowering therapies, what are 3 other components involved in managing acute angle closure glaucoma?
- Pilocarpine drops to cause miosis
- Topical steroids for inflammation
- Laser peripheral iridotomy to prevent recurrence
Give 3 causes of an acute red eye
Bacterial keratitis Acute angle closure glaucoma Endophthalmitis Conjunctivitis Iritis
As a general rule, if there is a hypopyon, what is the diagnosis?
Endophthalmitis- urgent treatment needed, until proven otherwise
What investigation is required in bacterial keratitis?
Urgent ophthalmology review in order to do a corneal scrape for Gram stain and cultures + sensitivities
What is the management of bacterial keratitis?
- Intensive antimicrobial eye drops (start before results of cultures come back)
- May need admission to ensure drops are given hourly
- Analgesia
What are the 2 most common causes of infected corneal ulcers?
Contact lenses and trauma
Which of the following microorganisms is not recognised as a causitive organism of bacterial keratitis? Acanthamoeba Clostridium perfringens Gonococcus Pseudomonas aeruginosa Staph. Aureus
Clostridium perfringens (commonly causes food poisoning)
What is the most common cause of unilateral or bilateral proptosis?
Thyroid eye disease
Chemosis and pulsatile proptosis with an audible bruit point towards what diagnosis?
Caroticocavernous fistula
A patient has a smaller pupil on the same side as a ptosis. Which investigations would be appropriate, and describe why?
- Abdominal CT
- Angiography of the head and neck (MRI or CT)
- Chest x-ray
- Intraocular pressure
- Orbital x-ray
Angiography of head and neck, and CXR
Horner’s syndrome is due to an interruption of the sympathetic supply to the eye. The sympathetic supply to the eye starts in the brainstem and takes a long scenic route to the eye, descending as far as the apex of the lung, then ascending with the carotid artery. Any lesion along this course can potentially cause a Horners syndrome. Two causes are particularly worth remembering:
Pancoast’s tumour, i.e. a lung tumour in the lung apex, which chest imaging (chest x-ray or CT) may demonstrate
Carotid artery dissection, occurring for example after severe whiplash injuries of the neck or after prolonged neck extension. Angiography (MRA or CTA) is the gold standard test to exclude or detect carotid artery dissection.
