Ophthalmology Flashcards
What is the most common cause of blindness?
Age related macular degeneration
What are the risk factors for age related macular degeneration?
Advanced age Family history smoking obesity cardiovascular disease
What are the two types of AMD?
Dry AMD - nonexudative AMD or atrophic AMD - slow progressive atrophy
characterised by drusen - yellow round spots in Bruch’s membrane
Wet AMD - exudative AMD - sudden localised elevation of the macula
leakage of serous fluid and blood can subsequently result in a rapid loss of vision
What are the symptoms of AMD?
- A reduction in visual acuity, particularly for near field objects
- Difficulties in dark adaptation with an overall deterioration in vision at night
- Fluctuations in visual disturbance which may vary significantly from day to day
- They may also suffer from photopsia, (a perception of flickering or flashing lights), and glare around objects
What are the factors pre-disposing patients o acute angle closure glaucoma?
- Hypermetropia (long-sightedness)
- Pupillary dilatation
- Lens growth associated with age
What are the features of acute angle glaucoma?
- severe pain: may be ocular or headache
- decreased visual acuity
- symptoms worse with mydriasis (watching TV in dark room)
- hard, red eye
- halos around lights
- semi dilated non-reacting pupils
- corneal oedema - dull or hazy cornea
What is the first line treatment for AACG?
urgent referal to an ophthalmologist
combination of eye drops -
- direct parasympathomimetic - pilocarpine - causes contraction of the ciliary muscle –> opening the trabecular meshwork
- beta blocker - timolol - decreases aqueous humour production
- an alpha -2 agonist - apraclonidine - decreasing aqueous humour production and increasing
IV acetazolamide- reduces aqueous secretions
What is the definitive management of AACG?
Laser peripheral iridotomy - creates a tiny hole in the peripheral iris –> aqueous humour flowing to the angle
What conditions are associated with anterior uveitis?
- Ankylosing spondylitis
- Reactive arthritis
- Ulcerative colitis, Crohn’s disease
- Behcet’s disease
- Sarcoidosis: bilateral disease may be seen
What is the management of iritis/anterior uveiitis?
Urgent review by ophthalmology
- cycloplegics - dilates the pupil which helps to relive pain and photophobia - atropine, cyclopentolate
- steroid eye drops
What are the features of herpes zoster ophthalmicus?
- Vesicular rash around the eye, which may or may not involve the actual eye itself
- Hutchinson’s sign - rash on the tip or side of the nose. indicates nasociliary involvement
What are the complications of herpes zoster opthalmicus?
- Ocular - conjunctivitis, keratitis, episcleritis, anterior uveitis
- Ptosis
- Post -herpetic neuralgia
What is the management of herpes zoster ophthalmicus?
- oral antiviral treatment for 7-10days
Ideally started within 72 hours
IV antivirals - if very severe infection or if the patient is immunocompromised
- Topical antiviral treatment is not given in HZO
- Topical corticosteroids - used to treat any secondary inflammation of the eye
What is seen during fundoscopy of AACG?
Cupping of the optic disc
What is the common presentation of orbital cellulitis?
- Redness and swelling around the eye
- Severe ocular pain
- visual disturbance
- proptosis
- eyelid oedema and ptosis
- Drowsiness +/- Nausea/vomiting in meningeal involvement (Rare)
How do you differentiate periorbital cellulitis from orbital cellulitis?
reduced visual acuity, proptosis, ophthalmoplegia/pain with eye movements are NOT consistent with preseptal cellulitis
What are the investigations to be ordered if orbital cellulitis is suspected?
- FBC
- CT with contrast
- Blood cultures and microbiological swab
What is the triad seen in horner syndrome?
Ptosis + constricted pupil - miosis and anhydrosis
Causes of papilloedema?
- Space-occupying lesion, neoplastic, vascular
- Malignant hypertension
- IIH
- Hydrochephalus
- Hypercapnia
What are the causes of optic neuritis?
- Multiple sclerosis
- Infections - Tb, syphilis, Lyme disease
- Toxic - ethambutol and methanol poisioning
What are the features of optic neuritis?
- unilateral decrease in visual acuity over hours or days
- poor discrimination of colours - red desaturation
- pain worse on eye movement
- RAPD
- central scotoma