Opthalmology Flashcards
Where is the leison in RAPD?
Ipsilateral Optic nerve / severe retinal disease
Describe the afferent and efferent pathways for pupillary light reflex
afferent: retina → optic nerve → lateral geniculate body → midbrain
efferent: Edinger-Westphal nucleus (midbrain) → oculomotor nerve
How do prostaglandin analogues and miotics work in glaucoma mx? examples?
Prostaglandin analogue - Latanoprost
Miotic - Pilocarpine (muscarinic receptor agonist)
They increase uveoscleral outflow
What are flashes and floaters in vision suggestive of?
Vitreous / retinal detachment - requires urgent referral to opthalmologist
What is the issue in open angle glaucoma?
imbalance between aqueous production and drainage
how does latanoprost work?
prostaglandin analog used in glaucoma. - These are 1st line
It works by increasing uveoscleral outflow
(can lead to brown pigmentation of iris and increased eyelash length)
How do BB work in open angle glaucoma?
Reduces aqueous production
How do sympathomimetics work in open angle glaucoma? example and when to avoid?
Sympathomimetics (e.g. brimonidine, an alpha2-adrenoceptor agonist) - Reduces aqueous production and increases outflow
Avoid if taking MAOI or tricyclic antidepressants
Adverse effects include hyperaemia
How do carbonic anhydrase inhibitors work in open angle glaucoma and examples?
Carbonic anhydrase inhibitors (e.g. Dorzolamide) -> Reduces aqueous production
How do mitotics work in open angle glaucoma and examples? adverse effects?
Miotics (e.g. pilocarpine, a muscarinic receptor agonist) -> Increases uveoscleral outflow
Adverse effects included a constricted pupil, headache and blurred vision
When should 360 SLT be used in open angle glaucoma?
offer 360° selective laser trabeculoplasty (SLT) first-line to people with an IOP of ≥ 24 mmHg
360° SLT can delay the need for eye drops and can reduce but does not remove the chance they will be needed at all
a second 360° SLT procedure may be needed at a later date
When is trabeculectomy used in open angle glaucoma? what does this do?
surgery in the form of a trabeculectomy may be considered in refractory cases - this opens up drainage pores
What is cause of sudden painless loss of vision, that is characterised by a dense shadow starting peripherally and progressing centrally?
Retinal detachment
Most common causes of sudden painless loss of vision?
ischaemic/vascular (e.g. thrombosis, embolism, temporal arteritis etc). This includes recognised syndromes e.g. occlusion of central retinal vein and occlusion of central retinal artery
vitreous haemorrhage
retinal detachment
retinal migraine
What is a RF for retinal detachment?
Myopia - short sightedness
Features and causes of central retinal vein occlusion? fundoscopy?
A cause of sudden paniless vision loss, incidence increases with age, more common than arterial occlusion
causes: glaucoma, polycythaemia, hypertension
severe retinal haemorrhages are usually seen on fundoscopy
Features and causes of Central retinal artery occlusion?
A cause of sudden paniless vision loss due to thromboembolism (from atherosclerosis) or arteritis (e.g. temporal arteritis)
features include afferent pupillary defect, ‘cherry red’ spot on a pale retina
Flashes of light (photopsia) - in the peripheral field of vision
Floaters, often on the temporal side of the central vision
These are features of which sudden onset painless cause of vision loss?
Posterior vitreous detachment
What are the features + causes of vitreous haemorrhage?
causes: diabetes, bleeding disorders, anticoagulants
Large bleeds cause sudden visual loss
Moderate bleeds may be described as numerous dark spots
Small bleeds may cause floaters
night blindness + tunnel vision is suggestive of what? Fundoscopy findings?
Retinitis pigmentosa - inherited retinal disorder leading to progressive degeneration of retina
fundoscopy: black bone spicule-shaped pigmentation in the peripheral retina, mottling of the retinal pigment epithelium
Herpes zoster ophthalmicus sign suggestive of ocular involvement?
Hutchinson’s sign: rash on the tip or side of the nose. Indicates nasociliary involvement and is a strong risk factor for ocular involvement
Mx of Herpes zoster ophthalmicus?
oral antiviral treatment for 7-10 days (within 72h) - IV if severe / immunocompromised
Topical corticosteroids for any secondary inflammation
Ocular involvement - urgent ophthal review
How can you distinguish between location of leison causing Horners syndrome?
Horner’s syndrome - anhydrosis determines site of lesion:
> head, arm, trunk = central lesion: stroke, syringomyelia, MS, Tumour and encephalitis
> just face = pre-ganglionic lesion: Pancoast’s, cervical rib, trauma + thyroidectomy
> absent = post-ganglionic lesion: carotid dissection / aneurysm, cavernous sinus thrombosis, cluster headache
presentation of severe ocular pain, redness, nausea, vomiting and decreased visual acuity
is suggestive of?
Acute angle closure glaucoma
Mx of acute angle closure glaucoma?
combination of eye drops, for example direct sympathomimetic (pilocarpine), BB (timolol), a2 agonist (apraclonidine)
IV acetazolamide - reduce aqueous secretions
can also give topical steroids for inflammation
Definitive mx - laser peripheral iridotomy
Keith-Wagener classification of hypertensive retinopathy?
I Arteriolar narrowing and tortuosity, Increased light reflex - silver wiring
II Arteriovenous nipping
III Cotton-wool exudates, Flame and blot haemorrhages, These may collect around the fovea resulting in a ‘macular star’
IV Papilloedema
Pilocarpine MoA?
Pilocarpine is a muscarinic receptor agonist - increases uvoscleral outflow via constriction of pupil
Leison in RAPD?
Severe retinal disease / optic nerve in dilated eye when light shines into it
What are the features of optic neuritis?
gradual loss of visual acuity, painful eye movements, a relative afferent pupillary defect and evidence of a central scotoma
impairment of colour vision and red desaturation of images
Causes of optic neuritis?
multiple sclerosis: the commonest associated disease
diabetes
syphilis
Why do pts with orbital cellulitis need urgent abx?
risk of cavernous sinus thrombosis and intracranial spread
How to distinguish between orbital and preseptal cellulitis?
reduced visual acuity, proptosis, ophthalmoplegia/pain with eye movements are NOT consistent with preseptal cellulitis
application of fluorescein demonstrates a dendritic pattern of staining in affected eye
What is this suggestive of? mx?
epithelial / dendritic corneal ulcer which is a common presentation of HS keratitis
Mx - topical aciclovir
What can percipitate acute angle closure glaucoma?
use of mydriatic drops, dilating pupil -> the peripheral iris to bunch up and block the drainage angle of the anterior chamber
eg using atropine, tropicamide, cyclopentolate
What is an argyll robertson pupil and when is this seen?
constricted pupil that does not respond to light but responds to accommodation
Usually bilateral and seen with neurosyphilis
When is a ciliary flush seen in the eye?
Anterior uveitis
What are the differences between acute glaucoma and uveitis?
Both present with red eyes
glaucoma: severe pain, haloes, ‘semi-dilated’ pupil
uveitis: small, fixed oval pupil, ciliary flush
sudden painless loss of vision, severe retinal haemorrhages on fundoscopy is suggestive of?
central retinal vein occlusion
Mx of blepheritis?
Hot compresses + mechanical removal of lid debris (lid hygiene)
How can proliferative diabetic retinopathy be managed? issues with this?
panretinal laser photocoagulation - 50% have noticable reduction in visual acuity due to scarring of peripheral retinal tissue, decrease in night vision (rods responsible for night vision are peripheral)
Intravitreal VEGF inhibitors eg ranibizumab - used in combination with the above, slow progression + improve
Ophthalmoscopy features of a Weiss ring is suggestive of what condition? What symptoms are often seen?
Posterior vitreous detachment which commonly causes flashes and floaters
What are angioid retinal streaks and what can cause this?
These are irregular dark red streaks radiating from the optic nerve head seen on fundoscopy
Causes include:
SPACE
Sickle-cell anaemia
Paget’s disease, Pseudoxanthoma elasticum
Acromegaly
Calcification and breaks in Bruch’s membrane .
Ehler-Danlos syndrome
Most common ocular manifestation of RA?
keratoconjunctivitis sicca
can also get episcleritis and scleritis
How can you distinguish between episcleritis and scleritis?
episcleritis (erythema)
scleritis (erythema and pain)
reduced visual acuity and blurred vision, along with the presence of drusen on fundoscopy
Suggestive of what condition?
Dry age-related macular degeneration (AMD)
Drusen = Dry macular degeneration
Drusen are yellow deposits that accumulate under the retina and can lead to gradual loss of central vision
Wet v Dry age related macular degeneration
Dry is slower and better prognosis
Ix of age related macular degeneration?
slit-lamp microscopy is the initial investigation of choice
fluorescein angiography is utilised if neovascular ARMD - feature of wet ARMD
optical coherence tomography
Drugs which may precipitate acute glaucoma?
anticholinergics and tricyclic antidepressants
red eye: SURFACE pain and erythema
photophobia
foreign body, gritty sensation
hypopyon may be seen
Suggestive features of what?
Keratitis - anterior uveitis is similar but DEEP pain
Mx = topical abx + cycloplegic for analgesia
What can be seen in congenital Horners syndrome?
heterochromia (difference in iris colour) is seen in congenital Horner’s
RFs for ARMD?
advancing age itself is the greatest risk factor for ARMD
smoking
family history is also a strong risk factor for developing ARMD
ischaemic cardiovascular disease, such as hypertension, dyslipidaemia and diabetes mellitus.
What is dacryocystitis and how does it present?
Dacryocystitis is infection of the lacrimal sac
Presents w watering eye - epiphora + swelling + erythema at inner canthus of eye
