Ophthalmology Flashcards
Increased UV exposure is a risk factor for what 3 eye conditions
- Cataracts
- Pterygium
- Cancers of the eyelid (commonly BCC)
What is tropicamide used for
Pupil dilation (e.g. before fundoscopy of slit lamp examination)
How many layers does the cornea have
5
How can you distinguish between episcleritis and scleritis
- Episcleritis blood vessels will blanch with admission of phenlephrine/cotton bud
- Episcleritis engorged vessels in cone/wedge shape (thin towards pupil) that can be moved - superficial veins
- Actuity unaffected in episcleritis
- Scleritis is associated with underlying chronic disease, can be sight treatening as needs urgert referal if posterior scerlitis/if necrotising changes present
- Scleritis is painful with eye movement as extraocular muscles insert into sclera
Phenylephrine uses and mechanism of action
Symphatomimetic, acts on alpha1 ADRs
dilates eyes (also used as decongestant & to relieve heamorroid for vasocontrictive action via vasocontriction mediated by a1 activation, increases BP)
Proliferative diabetic retinopathy is a risk factor for what cause of sudden painless vision loss
Vitreous heamorrage (over 50% of vireous heamorage is caused by proliferative diabetic retinopathy as the new blood vessels grow into the vitreous, are weak and prine to shearing - presenting as floaters)
Characteristic of grade 4 hypertensive retinopathy
Papiloedema
Cotton wool exudates and flame heamoorrages indicate what grade of hypertensive retinopathy
Grade 3
What type of organism can cause infections/corneal ulcers in contact lense wearers
Protozoa - acanthamoebae (common in soil and even tap water)
Four features of horners syndrome
LOSS OF SYMPATHETIC TRUNK
- Miosis
- Anhydrosis
- Ptosis
- Enopthalomos
Feature that would indicate congenital horners syndrome
Heterochromia of eyes
Name two types of carbonic anhydrase drops that can be used in treatment of acute closed angle and open angle glaucoma
Acetozolamide
Dorzolamide
What is a relative afferent pupillary defect
If you don’t know this look it up, it’s conceptual
What is a Marcus Gunn pupil
Pupil with a RAPD (abnormal direct and consensual response to light shining in it due to defect in the afferent - optic nerve to pretectal nucleas bilateral innervation of edinger westphal - pathway of the light reflex)
What is an Argyll - Robinson pupil and in what conditions is it found
aka postitues pupil - accomdates but doesn’t react
small pupil, accomodates, no light response
syphillis and diabetes mellitus
What is a Holmes-Aidie pupil
Fixed dialated pupil, poor accomdation and poor light response but light is better than accomodation.
Damage to parasympathetic innervation (via ciliary body and short cilary nerve hitchhiking on CN3)
What is Hutchinson’s pupil and what underlying pathology does it indicate?
Fixed dialated pupil, unresponsive to light, due to compression of oculomotor nerve by a same-sided intracranial mass
Whats the proportion of dry to wet ARMD and treatment of both
dry to wet - 90% and 10%
Dry - zinc and anti oxidative vitamens ACE to slow disease progresssion
Wet - Anti-VEGF injections (ranibizumab) also laser photocoagulation
What are the deposits called in dry ARMD
Drusen
Investigations used in ARMD
Slit lamp examination to visualised deposits/neovascularisation
OCT to obtain 3D image of areas unable to be visualised
Angiography (fluorcsin or indocyanine green) to visulaise neovascularisation and guide anti-VEGF therapy if wet ARMD
Amsler grid testing - distortion of grid & fundoscopy
Risk factors of ARMD
Age
Smoking
Family history
What autoimmune condition is episcleritis and scleritis linked to
Rheumatoid arthritis
Management of anterior uveitis and what disease is it associated with
- Urgent ophthal review
- Cycloplegic drugs (e.g. atropine, cyclopentolate) to minimise pain and photophobia
- steroid eye drops
Appearance of anterior uveitis
Small, irregular pupil
Red, painful eye
Photophobia
‘snow storm’ of inflammatory cells seen in anterior chamber on examination
What do cytoplegic drugs do, how do they work and list 3 with their different uses and why they are used for those
Dialate the eye
By opposing parasympathetic constriction by blocking M3 receptors
MUSCARINIC ANTAGONISTS
Tropicamide - fundoscopy, only lasts a few hours
Atropine & cyclopentolate - last longer therefore as an adjunct to treat anterior uveitis
What is synechia
Attachment of the iris to surrounding structions - e.g. anterior synechia is iris attachment to cornea - precipitating ACA glaucoma, or posterior synechia - attachment to lens
What is a chalazion
AKA Meibomina cyst
Initial painful internal stye (aka hordeolum internum) affecting meibonian glands, resolves to leave painless cyst, only needs to be treated if big via surgical drianage or if conjuncivitis
Give an example of a prostaglandin analogue, how it works in glaucoma treatment, when you would give it specifically and a potential side effect
Latanoprost
Increases uveoscleral outflow in glaucoma
First line for open angle glaucoma treatment, especially if asthma contraindicated B blockers such as timolol
Pigmentation of retina & growth of eyelashes is a side effect
Two catagories of strabismus, names of the four axis in which there can be a convergence/deviation, test to identify and treatment
Paralytic (rare, paralysis of extraocular muscles) or concomitant (imbalance of extraocular muscles)
Esotropia - convergence towards nose/midline
Exotropia - deviation towards temporal area
Hypertropia - upwards
hypotropia - downwards
Cover test
Eye patch, referral to secondary care, corrective surgery is an option
5 features of optic neuritis and a common condition it’s seen in
- red desaturation
- central scotoma
- painful eye movements
- RAPD
- unilateral decrease in visual acuity
MS, DM, syphilis
Management of optic neuritis, recovery time and extra test + prognosis
High dose steroids (3 days) recovery 4-6 weeks MRI scan (>3 lesions, 5 yr MS risk is 50%)
5 causes of cataracts
- Down’s syndrome
- Corticosteriods (subcasular cataracts)
- Hypocalcaemia
- Uvietis
- Diabetes
