Opthalmology Flashcards
Changes seen in ARMD vs diabetic vs hypertensive retinopathy?
ARMD: drusen, choroidal neorevascularisation (wet AMD - 10% of cases), geographic atrophy (dry AMD - 90% of cases)
Diabetes: microaneurysm, dot & blot and flame haemorrhages
HTN: copper wiring, AV nipping, dot, blot and flame haemorrhages, cotton wool spots, papilloedema
tx of chronic open angle glaucoma
360 selective laser trabeculectomy if pressure >24mmHg
prostaglandin analogue (latanoprost)
beta-blocker eye drop (timolol)
carbonic anhydrase eye drop (bitanoloprost, brinzolamide)
sympathomimetic eye drop (pilocarpine, brimonidine)
Tx of acute closed angle glaucoma
IV acetazolamide
Topical pilocarpine
Surgical or laser iridotomy
difference between pterygium and pinguecula?
Pterygium: go beyond cornea
Pinguecula: doesn’t reach cornea
Both: are benign growths of conjunctiva that comes from the nasal side. wedge shapes and moves towards the centre as it is a continuation of the conjunctival epithelium.
differences between:
central scotoma
arcuate scotoma
centrocaecal scotoma
ring scotoma
central: cannot see the centre of visual field. seen in diseases affecting the macula - eg age-related maculopathy
arcuate: cannot see one part of the visual field - seen in glaucoma
centrocaecal: cannot see from the centre and it radiates out (like a caecum). it often involves the macula and the blind spot. seen in toxic/nutritional deficiencies (eg vit B12) or leber’s optic neuropathy.
ring: cannot see the area in a ring-like pattern (but can still see the centre of visual field). seen in retinitis pigmentosa.
when looking at differences in symptoms between orbital cellulitis OC and preseptal cellulitis PC, which symptom presents in OC but not PC?
proptosis
visual changes
pain on eye movement
restriction of eye movement
RAPD
(but they both contain these:) swelling or erythema of eyelid, periorbital oedema, ptosis
warm or cold compress for
- stye/hordeolum (hair follicle)
- blepharitis
- chalazion/meibomian cyst (blocked gland)
warm compress
a curtain or dark shadow moving across vision towards the centre -?diagnosis
transient loss of vision (TVL) aka amaurosis fugax
usually due to ischaemic or non-ischaemic cause:
- ischaemic: GCA, CVA, retinal arteriolar emboli (if affect one eye: likely anterior circulation affected such as carotid artery. if affect both eyes, consider posterior circulationn affected such as basilar artery/vertebral artery)
- non-ischaemic: dry eyes, migraine
which topical antibiotic should be avoided for pregnant lady with conjunctivitis?
chloramphenicol
(there may be a risk of ‘neonatal grey baby syndrome’ with oral use in 3rd trimester but no studies for topical use)
what is:
- hard exudate
- soft exudate
Hard: well defined yellow-white deposits like ring. Due to lipoprotein leaking out of blood vessel. Seen in diabetes & HTN.
Soft: like cotton-wool. Occur in infarcted retina. Due to swelling of the axons in the nerve fibre of the retina.
red eye that improves with topical phenylephrine
episcleritis
what eye pathology is linked with connective tissue disease such as ehler’s danlos and marfan syndrome?
lens dislocation (upwards for Marfan)
Keratoconus
tx of allergic conjunctivitis
topical antihistamine (eg diphenhydramine)
systemic antihistamine
topical mast cell stabilisers: sodium chromoglycate, nedocromil
4 features of retinal detachment
4F’s
floaters
flashing lights (photopsia)
field loss
fall in visual acuity
keith-wagener-barker classification
for HTN-retinopathy
Grade 1 - arteriolar narrowing
Grade 2 - plus AV nipping
Grade 3 - plus microaneurysm, dot-blot haemorrhages, flame shaped haemorrhage, cotton-wool spots and hard exudate
Grade 4 - plus optic disc swelling
tx of orbital cellulitis
ABX
- Penicillin or cephalosporin
- if pen allergic: cefuroxome & clarithryomycin IV OR clindamycine and ciprofloxacin IV
Uveitis - usually linked with what diseases?
Anterior uveitis: usually ank spon and reactive arthritis
Posterior uveitis & usually bilateral & chronic: psoriatic arthritis and IBD
different stages of diabetic retinopathy
background: blot haemorrhages, microaneurysm, hard exudate
pre-proliferative: cotton wool spots, intraretinal microvascular anomalies
proliferative: new vessels and fibrosis - can cause retinal detachment or vitreous haemorrhage
signs/symptoms of CNIII palsy
ptosis
diplopia
pupils out and down
mydriasis
Holmes Adie pupil -what is it?
parasympathetic denervation of the afflicted pupil
- dilated at rest initially and then become small chronically
- poor/sluggish response to bright light and NORMAL (not slow!) accommodation
- deep tendon reflexes
Argyl Robinson pupil
reacts poorly to light BUT quick to accommodation
- seen in neurosyphilis
bilateral tonically small pupils that reats poorly or not at all to light but briskly to accommodation (light-near dissociation)
Marcus Gunn pupil
RAPD
unilateral dysfunction of optic nerve or retina
relative weakness of the afferent limb of the pupillary light reflex compared to the other eye
what is tobacco-alcohol amblyopia?
defective vision arises as the anterior visual pathway is susceptible to damage from toxins or nutritional deficiency
?cyanide toxicity or undernutrition
central loss of vision for colours, optic atrophy
blurred vision, painful and loss of colour vision
?diagnosis
optic neuritis - need to rule out MS
sudden onset periorbital pain with reduced visual acuity, conjunctival injection, mid-dilated pupil and non-reactive pupil
?diagnosis
acute CLOSED angle glaucoma
sudden onset eye pain and discomfort with irregular small pupil. photophobia present. blurred vision with red eye.
?diagnosis
anterior uveitis
most common organism for conjunctivitis
viral: adenovirus
bacterial: strep penumonia, staph aureus, haem influenza
for opthalmia neonatorum (within 4 weeks of life)- chlamydia trachomatis is most common. other causes: neisseria gonorrhoea, haemophilus, strep & staph, e.coli, pseudomonas, adenovirus, H. simplex
red flags for conjunctivitis
reduced visual acuity
marked eye pain, headache, photophobia
red sticky eye in neonate
history of trauma
copious rapidly progressive discharge
herpes infection
soft contact lens use with corneal symptoms (photophobia and watering)
cannot close eyes post-blepharoplasty operation -? complication
lagophthalmos (inability to close eye fully due to too much excess skin/fat removed in surgery)
how does anterior VS posterior uveitis present?
Anterior: painful red eye, photophobia, blurred vision. no mucopurulent discharge -just watery one. pupils are equal and reactive to light.
Posterior: blurred vision, floater
treatment of retinitis pigmentosa
supportive
fat soluble vitamins (A, E) ascorbic acid
calcium channel blockers (diltiazem)
carbonic anhydrase inhibitors (acetazolmaide)
AVOID THESE MEDICATIONS: viagra, isotretinoin, high dose vitamin E
diagnosis and treatment of 1-day history of blistering rash around the eye with normal visual acuity
Herpes Zoster opthalmicus
Oral aciclovir 800mg five times a day for 7/7
cataract is associated with what diseasese?
diabetes
myotonic dystrophy
hpoparathyroidism
rubella
what are the 2 causes of retinal artery occlusion?
atherosclerosis - 80% (out of this HTN accounts for 60% and diabetes - 25%)
embolism - 2nd main cause
most common cause of blindness in 45-64yo is….?
diabetic retinopathy
most common cause of irreversible vision loss in the world is….?
ARMD
