Opthalmology Flashcards
Opthalmoscopy: what must you do first.
- what kind of agent
- warning
- C.I.
Dilate the pupil with parasympathomimetic (Tropicamide - lasts for 20 min - 12h)
Warn about driving as affects ciliary muscles inhibiting accommodation for near vision
Head injury (require pupil reflex)
Risk of closed angle glaucoma
4 C of normal Optic disc
Colour - yellow/orange
Contour - well defined, flat
Cup - small depression in centre of optic disc. less than 0.5 of disc diameter. No vessels or nerve fibres
Circulation - not tortuous, not attenuated (reduced)
What is red reflex
reflection from orange retina
Sign of cataract or central tumour
Pale disc?
optic atrophy - prev damage to nerve
Elevated/swollen disc
papilloedema
Large cup
If over 50% of dis diameter -> chronic glaucoma
Attenuated (reduced vessels)
Central retinal artery occlusion
What is the optic disc?
The blind spot.
This is point of entry of BV and Optic nerve
What is Macula and Fovea
Area where visual acuity is the highest. Just temporal to Optic disc. No vessels.
Centre is Fovea - Just Cone (colour and acuity) receptors
Retina
- What
- abnormal signs
Layer at the back of eyeball with photoreceptors
Haemorrhages, Exudates, Drusen (lipid deposits), Scarring, Retinitis Pigmentosa (loss of photoreceptors - black deposits)
Signs of vascular disease in Retina
Flame haemorrhages: superficial (Retinal vein occlusion)
Blot haemorrhages: deeper (Diabetic)
Dot haemorrhage: micro aneurysms (Diabetic)
Preretinal (boat shaped) haemorrhages (Diabetic, SAH)
Hard Vs Soft exudate
Hard (true exudate) = leakage of fluid into retina
Soft = micro infarcts & cotton wool spots (fluffy/white)
What are drusen
Lipid deposits - Pale, Round, Grey spots seen at the macula
Seen in elderly, age related macula degeneration
What is retinitis Pigmentosa?
What is seen
Inherited retinal degeneration, spidery black pigmentation in peripheral retina
Tunnel vision and night blindness
Scotoma (relative & absolute)
Quadra/Hemianopia
Scotoma = blind spot
- Relative = decrease
- Absolute = total
Quarter loss /
Half loss
What is meant my congruity?
How well formed the shape of the defect is. gets better closer to visual cortex
Bitemporal hemianopia
- Cause
- diagnosis
compression of the optic chiasm
upper more than lower = pituitary tumour
lower more than upper = craniopharyngioma
Remember this as UP London City
Homonymous quadrantanopia
superior homonymous quadrantanopia = lesion in temporal lobe
inferior homonymous quadrantanopia = lesion in the parietal lobe
PITS - parietal inferior temporal superior
incongruous = optic tract
congruous = the optic radiation/cortex
Homonymous hemianopia (ssam e.g. left field in both eyes)
Brain lesion (Bleed or tumour) on Contralateral side to lesion
Central scotoma
Lesion in Optic nerve -> Optic neuritis
e.g demyelination in MS, toxins like methyl-alcohol
What is slit lamp for
Visualising Anterior segment of eye (vitreous body/lens)
Slit lamp signs
Flare = inflammation
Cells in vitreous (tobacco dust) = retinal tear
Outer layer of eye
Cornea over lens, sclera over rest
Anterior segment
- where
- what humor
Anterior to lens
Contains aqueous humor
Posterior segment
- where
- layers
- Humor
Behind lens
Sclera (outer), choroid, Retina
Vitreous humour
What adjusts the lens
Ciliary muscles and fibres
What is Macula and fovea.
Macula is thickest part of retina with high conc of cones (c for colour)
Small depression in centre of macula
Photoreceptor types
Cones: Colour vision and acuity, central retina
Rods: night vision, outer retina
Referral for:
- Sudden loss of vision
- Sudden diplopia
- Gradual loss of vision
Urgent telephone to Opthal for sudden acute changes
Gradual = optometrist
Cause of Gradual visual loss
Cataract, Glaucoma, Age-related Macula degeneration (chronic + degenerative)
What is used for visual acuity
Snellen chart
- Do test at 6m
- Top line is what can be done at 60m (6/60 if can read)
second from bottom is what should be read at 6m. This is aim (6/6)
White discolourations of pupil?
Cataract
What is cataract
RF
Clouding in lens. progressive
Aging, Downs, sunlight, smoking
Job of lens
Accommodation to focus vision
Presentation of Cataract
Change in vision - Myopia (short-sightedness) - Blurred vision - glare - double vison - poor vision in bright light - Loss of colour vision Changing astigmatism
Cataract surgery
- when
- anaesthesia
- what is done
Opacity impacts everyday life
Local
Lens is remover through small incision and intaocular lens inserted
Cataract surgery complications
Vitreous prolapse/rupture
Intraocular haemorrhage
Post-op: inflammation, lens dislocation, infection
What is the optic ‘angle’
Space between the posterior surface of cornea and anterior surface of Iris (coloured bit) where aqueous humour leaves the eye
Glaucoma classifications
- angle
- cause
- onset
Open Vs closed angle
Primary Vs Secondary
Acute Vs Chronic
Aqueous production + function
- note don’t confuse with vitreous
Made by the ciliary body
Circulates and nourishes lens
Leaves via angle and enters episcleral veins
Intra-ocular pressure
Balance between aqueous production and drainage
normal 21mmHg
Chronic open angle glaucoma (most common glaucoma)
- def
- type of visual loss
Chronic, progressive changes in optic nerve causing visual field loss
Peripheral loss (Tunnel vision)
Triad of signs/sympt in Glaucoma
1) Raised IOP - over 21mmHg (Eye ache)
2) Abnormal disc (inc cup, haemorrhage, loss of neurones)
3) VF defect (tunnel)
Chronic may be asymptomatic
Chronic open angle glaucoma pathophys
alteration of trabecular meshwork in angle impairing outflow of aqueous
Chronic open angle glaucoma RF
Age over 40 Afro-Caribbean FH Steroids Vascular disease (HTN, DM. Thought to be possible cause for trabecular dysfunction)
Optic disc in Chronic open angle glaucoma
Severe cupping of optic disc (over 0.5 of optic disc)
Vision loss in Chronic open angle glaucoma.
- Pattern
- When
Progressive into tunnel pattern of vision
Asymptomatic/Acuity preserved until late.
Screening methods for Chronic open angle glaucoma
IOP - inc (using tonometry)
VF testing - reduced
Fundoscopy - cupping
All 3 to reduce false +ve rate
Chronic open angle glaucoma management (*note, observe is done 1st)
Drops:
- PG analogues (latanoprost) 1st line
- Beta block (timolol)
Laser therapy (target ciliary body)
Surgical trabeculaectomy
Management strategy in Chronic open angle Glaucoma
Counsel (life long Tx, driving)
Target 20% reduced IOP
PG agonist/BB 1st line
Review 6 weekly
Prostagalndin analogue mechanism
Increase trabecular (uveoscleral) outflow
E.G Latanoprost
Beta blocker mechanism
Decrease aqueous prod by blocking symp fibres in Ciliary body
E.G Timolol
SE: bradycard, hypotension, bronchospasm
CI: Heart block, COPD, Asthma
Carbonic anhydrase inhibitors mechanism
Decrease aqueous production
E.G: Dorzolamide
CI: renal & liver failure
Age related macular degeneration types
Retinal atrophy (dry) - slow progression/deterioration ATROPHIC
New vessel growth under Retina (wet) - fast degeneration NEOVASCULARISATION
What does visual acuity rely on
1) Functional photoreceptors (Rods/cones)
2) Healthy retinal pigment epithelium
3) Perfusion of Choroid (capillary layer)
What is 1st sign of Age related macular degeneration & what is it
Drusen
Lipid waste material from photoreceptors accumulating in and below Retinal Pigment Epithelium (white deposits)
Dry AMD
- Features
- Progression
Ophthalmoscope: Atrophy of retinal pigment epithelium (can see choroidal arteries underlying)
Visual field loss: central scotoma, preserved peripheral vision
Frequently deteriorate, Require vision aids
Not much can be done to Tx
Wet AMD
- Features
- Management
Opthalmoscope:
- Leaking vessels below retina
- Exudates, haemorrhages and scarring
Visual Field loss
- localised retinal detachment = distorted central vision
- eventual central scotoma
Intravitreal anti-TNF-beta, anti-VEGF
Age related macular degeneration RF
sunlight, smoking, older, fam Hx
STOP SMOKING!!!
Sudden visual loss causes
Tend to be
Vascular:
- Branch/Central retinal artery/vein occlusion
- Anterior ischemic optic neuropathy
Inflammatory:
- Optic neuritis (multiple sclerosis)
Retinal detachment
Blood supply to eye
From internal carotid and also middle meningeal
Opthalmic artery is branch of internal carotid. Central retinal comes off this
Branch and Central retinal artery occlusion
- Presentation
- Cause
- Management
Sudden total loss of vision (central) or loss of top/bottom half (branch)
Relative afferent pupil defect (Marcus Gunn - swinging flashlight)
Embolic (carotid atheroma, cardiac origin)
GCA
Thrombophilic conditions
Cant be improved. Secondary prevent: aspirin, smoking, HTN, Cholesterol, AF
Branch and Central retinal artery occlusion Opthalmoscopy
Embolus visible at optic disc
Thin (attenuated) Retinal arteries
Retinal oedema (pallor temporal to disc)
After 3 months disc becomes pale (necrosis)
Investigation retinal emboli
Carotid doppler (stenosis over 70% needs stent)
Fasting serum lipids (cholesterol)
± Clotting screen, CT head
Transient monocular visual loss =
Pres
Investigate
Tx
Amaurosis Fugax (ocular TIA)
Curtain over vision for around 30 mins
Carotid doppler, USS
Aspirin, Clopidogrel
Micro-aneurysm complication
Tx of microaneurysm and management of complication
vitreal leak = reduced vision
Laser around margin, investigate source: HTN, emboli
Watch/wait, vitrectomy (remove vitreous from eye)
Branch retinal vein occlusion
- Pres
- Cause
- Opthalmoscope
Sudden Visual blurring, Visual field defect (blood leak)
Athero, HTN, DM, Smoking, Thrombophilias
Flame haemorrhages, leaking veins.
Arteries are INTACT
Branch retinal vein occlusion Tx
Laser photocoagulation
Minimally invasive destroy/seal leaking blood vessels in retina (esp helpful if neovascularisation - can destroy)
Causes of intravitreal haemorrhage
Retinal vein (branch/central) occlusion, Diabetic retinopathy, juxtafoveal telangiectasia, Microaneurysm/Macroaneurysm
Central retinal vein occlusion
- Presentation (symptoms)
- Opthalmoscopy (signs)
- Prognosis
Mild/Severe loss of vision
Marcus-Gunn pupil, Rubeosis (neovascularisation of the iris)
Flame haemorrhages, Swollen optic disc, dilated/tortuous veins, blot haemorrhages, macular oedema
1/3 progress to retinal ischaemia
Rubeosis def + causes
Neovascularisation on iris
Diabetic retinopathy, CRVO, ocular ischaemia, retinal detachment
Immediate
AGGRESSIVE PRP (panretinal photocoagulation) +/- vitrectomy
Anterior ischaemic optic neuropathy
- Assoc
- Presentation
- Investigations
- Fundoscopy
- Treatment
GCA
Sudden onset profound loss of vision ± Marcus-Gunn
ESR, CRP, FBC (may want biopsy of temporal artery if GCA suspected as cause)
Pale, swollen optic disc
High dose steroids
Optic neuritis:
- Assoc
- Ophthalmoscopy
- Recovery
Multiple sclerosis
May appear normal
Swollen, hyperaemic optic nerve (excess blood vessels)
Spontaneous 6-8 weeks recovery (Steroid Tx may speed recovery)
Retinal detachment
- pathophys
- cause
- presentation
- treatment
Potential space between photoreceptors and retinal epithelium fills with fluid causing detachment
Normally due to retinal tear.
Flashes, Floaters, field loss
Requires surgery to stop complete detachment
Causes of retinopathy
HTN
DM
HTN retinopathy on ophthalmoscopy (Think what high BP will do)
Microinfarct (cotton wool spots)
Arteriovenous nipping (vein disappears under artery)
Flame/blot haemorrhage
Microaneurysms
Exudate
Papilloedema (disc swelling)
Malignant HTN retinopathy
Microinfarct
Tortuous veins
Hyperaemic, swollen disc
Elsching’s spots (choroidal infarct)
Macular exudate star
Accelerated/malignant HTN
- Causes
Exacerbated essential HTN
Renal artery stenosis
Phaeo, Cushing’s, Conns
Accelerated/malignant HTN
- Causes of poor vision
- Treatment complications
Acute optic nerve damage
Macular oedema
Retinal artery closure
Choroidal detachment
dropping BP too fast = ischaemic neuropathy + blindness
Flame Vs Blot haemorrhages
Haemorrhages are flame or blot shaped depending on depth in retina
Diabetic retinopathy
- def
- pathology
The retinal consequences of microvascular leaked and occlusion
hyperglycaemia = inc viscosity of blood, loss of antithrombogenic endothelium = ischaemia/thrombus
Pericyte loss/damage by hyperglycaemia = capillary leakage
Ischaemia = inc VEGF promoting novasc, inc capillary permeability (Proliferative Diabetic retinopathy = sight threatening)
Diabetic retinopathy RFs
Poor glycemic control HTN Carotid stenosis Pregnancy Renal disease Anaemia
Diabetic retinopathy
- symptoms
- signs
Dark blots in vision (moderate disease)
Blurred vision
Floaters
Vision loss
Microaneurysms (seen in mild)
Cotton wool spots, lipid exudates (moderate)
Retinal haemorrhages (flame/dot/blot)
Proliferative DR: Neovascularisation of retina/optic disc.
Proliferative Diabetic retinopathy pathophys
Neovascularisation of retina or optic disc.
New vessel fragile and prone to haemorrhage -> sudden vision loss
Inc in fibrosis -> retinal detachment vision loss
What causes cotton wool spots
Poor perfusion/ischaemia
How is severity rate in DR
Number of quadrants affected
Is there intra-retinal bleeding (none in mild - just micro aneurysms)
HTN retinopathy
- Triad
1) High BP
2) Visual disturbance
3) optic disc swelling/piplloedema
Diabetic retinopathy Tx
- Anti-VEGF (ranibizumab_
- Macular laser therapy (burns/reduces leaking BV under the macula)
- Pan-retinal Photocoagulation therapy (controlled destruction of retina)
Screening in Diabetic retinopathy
Onset over 30 -screen 5 yearly
Onset under 30 screen annually
Red eye Red flag
Impaired vision
Pain/Photophobia
Lack of ocular discharge
Red eye causes over view:
Inflammation:
- sclera: scleritis
- intraocular: uveitis
Intraocular infection: Endopthalmitis
Raised IOP: Acute Glaucoma
Blephritis
- Pres
- Signs
- Tx
Gritty, irritable eyes
Watery discharge
Foreign body sensation eyelid
Loss of eyelashes, poor tear film, notched upper lid, ingrowing eyelash
Lubrincants (poor tear film), lid hygiene and topical Abx if needed
Stye Vs Chalazion
Tx
Granuloma of Meibomian glands (hard non-tender)
Infected lash follicle = Stye (red, tender)
Hot spoon bathing
Herpes Zoster (shingles) Opthalmaticus
- Pathophys
- Signs
- Tx
Opthalmic division of trigeminal.
If tip of nose affected normally so is eye (nasocilliary nerve)
Severe corral inflammation, clouding and thinning
Oral&Topical Acyclovir
What can cause Conjuctivitis?
Infection: Viral, Bacterial.
Allergy
Chemical irritation (pH imbalance)
Symptoms of Conjuctivitis
Red eye, swollen lid.
Discharge
- Watery: viral, allergic
- Purulent: bacterial
Conjuctivitis
- Viral cause
- Bacterial cause
- Neonatal potential cause
- Allergic causes
Adenovirus commonly
Staph, Strep
Chlamydial (risk chlamydial pneumonitis)
Topical NSAID/Steroids, Eye drops
Treatment of Bacterial Conjuctivitis
Chloramphenicol eye drops
Fusidic acid
Chlamydia Conjuctivitis
- Complication
- Tx
Corneal scarring - blindness
Neonates - birth
Adults - unwashed hands
Systemic erythromycin
Opthalmia neonatorum:
- Def
- Causes
Defined as conjunctivitis in first 3 weeks of life (from birth canal)
Chlamydia
Gonorrhoea
S-Aureus
Herpes simplex
Chronic conjuncatavitis
Assoc with?
Risk of?
Tx?
Atopy
Corneal ulceration
Topical steroids
Corneal disorders
Trauma
Infective (Viral, Bacterial)
Allergic
Corneal infection (Keratitis)
- Viral cause + signs + tx
- Bacterial cause and signs + tx
Herpes simplex, foreign body sensation, watery discharge, Topical acyclovir
Staph/Pseudomonas, Red eye, Loss of vision, hazy cornea, Specialist Tx with intense ABx
What makes up the Uvea?
Iris
Ciliary body
Choroid
Anterior Uveitis: Assoc diseases
Seroneg (HLAB27) arthropathies
- IBD
- Psoriatic
- Ankylosing Spondylitis
Sarcoidosis, Syphilis, Behcet’s (vasculitis)
Anterior Uveitis
- Pres
- clinical signs
- What should be checked for
Acute & Unilateral
Pain
Red eye
Photophobia
Small pupil
Normal/Decreased acuity
Intense redness of globe
Systemic dises: Joint, Chest (sarcoid), skin disease symptoms
Episcleritis:
- where is this
- pres
- Tx
Vascular layer between sclera and conjunctiva
Irritation/localised redness, no discharge/LOV
NSAIDs helpful
Scleritis
- Assoc
- Pres
Rare and serious assoc with vasculitis & RA (thinning of sclera -> blue)
Very painful
Assoc with LOV
Acute angle-closure glaucoma
- Who
- Sign
- Pres
Often elderly, Female, Long-sighted
Very high IOP
Unilateral, Painful, Red eye, Profuse LOV, Photophobia
Nausea + vomiting
Normal Aqueous flow
Aq prod n ciliary body and flows between lens/iris through pupil into anterior chamber
Leaves eye at angle to canal of Schlemm through trabecular meshwork
Acute angle-closure glaucoma mechanism
If pupil is dilated (e.g. dark room) Iris is pushed against the cornea and angle closes
Rapid build up of pressure
In long sighted, the lens shape pre-desposes to Acute angle-closure glaucoma (impairs Aq flow out of pupil)
Acute angle-closure glaucoma symptoms
Very red eye
Corneal oedema
Mid-dilated pupil
Poor vision
Very red eye Corneal oedema Mid-dilated pupil Poor vision investigations
Gonioscopy (examination anterior angle) - trabecular meshwork not visible
Slit-lamp - shallow anterior chamber, signs of glaucoma (large cup + nerve fibre loss)
Acute angle-closure glaucoma
1) lower pressure: Topical carbonic anhydrase inhibitors (acteazolamide)/Beta-blockers (Timolol)
2) Constrict pupil: colinergic agonists - Pilocarpine
3) Prevent recur: laser surgery to provide bypass
Discharge Ddx:
- Watery eye
- Purulent/mucus
- Bloody
Inc lacrimation (foreign body in cornea), blocked tear duct
Infection, allergy
Severe infection, Tumour
Severe pain Ddx
Acute glaucoma
Scleritis
May also be seen in migraine, cluster headache
Vision loss Ddx (always serious)
Transient Profoud Rapid Slow Central Peripheral Loss colour Bilateral
Transient: Retinal emoli (Amourosis fugax)
Profound:
GCA
Rapid:
Vascular (haemorrhage), Retinal detachment
Slow:
Dry macular degeneration
Central:
Optic nerve disease (neuritis in MS), DR
Peripheral:
Glaucoma, CVD
Loss of colour:
Optic neuritis
Bilateral:
Glaucoma
What serious eye diseases are asymptomatic in early stages
Chronic glaucoma
Diabetic retinopathy
HTN
Papilloedema
What controls pupil size (muscle, ANS)
Constrict:
- Sphincter pupillae muscle
- CN3
- parasympathetic tone controls size
Dilate:
- Dilator pupillae
- sympathetic nNS
Small pupil (Miosis) causes
Opiates, pontine haemorrhage, topical pilocarpine (pressure - glaucoma)
Mydriasis (dilated pupils) causes
Sympathomimetics (amphetamine, cocaine), anticholinergics, topical mydriatics
What is Horner’s triad
Causes
Miosis (constriction), Anhidrosis, partial ptosis
Brainstem: stroke, carotid dissection
Pancoast’s tumours
What is seen in CNIII palsy
Causes
Large pupil
Ptosis
Down and out eye
Aneurysm to posterior communicating artery, uncle herniation post truma - send for neurosurgical review
Eye + Pupil in acute glaucoma
Bilateral large pupils and red eyes
Pupil in anterior uveitis
small in affected eye and red eye
pupil can become unreactive and stuck to lens
Pupil 3 reflexes
Light: constrict/miosis
Dark: dilate/mydriasis
Near: Miosis, accommodation (ciliary focusing of lens)
Normal light response
R optic nerve problem (afferent: retina -> brain)
Shine light into R. Both pupils constrict. R by direct. L by consensual
Neither pupil responds when affected eye stimulated. Both pupils respond when light shone into L.
Marcus-Gunn pupil
What is it?
Underlying cause?
Relative afferent pupillary defect
Swinging flashlight test. When shone in normal eye both will constrict (efferent pathways fine), when shone in affected eye (afferent lesion) there is dilation
Partial injury to one optic nerve caused by large retinal lesions (detachment, central artery/vein occlusion optic neuritis, advanced glaucoma
Causes of central scotoma
Macular disease
Optic neuritis
Optic nerve ischaemia (GCA - part of optic nerve loses blood supply
Visual field loss in glaucoma
1) nasal and peripheral
2) tunnel vision as superior and inferior defects join
Chiasmal compression visual field
Bitemporal hemianopia
Pituitary - from below = upper field affected more
Craniopharyngioma - compress from above = lower quadrantanopia
PITS
Parietal lesion = inferior quadrantanopia
Temporal lesion = superior quadrantanopia
Horizontal conjugation
How is this achieved
What can cause intranuclear ophthalmoplegia
Communication between CNIII and CNVI means allows confluent horizontal gaze
Via medial longitudinal fasicululus (jerky nystagmus if damaged)
Retinitis pigmentosa:
What is it?
Pres
Onset
Management
Hereditory, progressive dystrophy of photoreceptors in retina
Ring scotoma, night vision problems. central vision is spared until late
Onset 10-30yrs
Manage to slow progress
- refer to Opthal
- DVLA inform
- Acetazolomide (oral carbonic anhydrase inhibition’s) + Beta Carotene
Dry eyes:
Causes
Aging
Medication (diuretics, antidep, antihist, beta blockers)
Systemic illness (RA, SLE, Sjogren’s - hyposecretive)
Increased evaporation (low humidity, low blink rate, allergic conjunctivitis)
Treatment of dry eyes
Artificial tears
When to inform DVLA
Decreased acuity
1st unprovoked seizure (6M), Serious head injury (1M)
TIA (3M), ACS/CABG 1M
Causes of sudden painless vision loss:
flashes of light or floaters
sudden visual loss, dark spots, Cheese and Tomato Pizza look
afferent pupillary defect, ‘cherry red’ spot on a pale retina
severe retinal haemorrhages are usually seen on fundoscopy
retinal detachment
vitreal haemorrhage
central retinal vein occlusion
central retinal artery occlusion
Other causes: Ischemic optic neuritis (atherosclerosis, GCA),
Open angle glaucoma Vs Closed angle Glaucoma
In open angle the iris is clear of the trabecular meshwork, in closed angle it is over the meshwork (e.g. when pupil is dilated)
Anterior Uveitis
- Onset
- what is felt
- visual efects
- pupil
acute onset
pain
blurred vision and photophobia
small, fixed oval pupil, ciliary flush
Sudden Red painful eye, Dilated pupil
What is likely diagnosis
Acute angle closure glaucoma
What is Pilocarpine and what are SE
Miotic (pupil constrictor)
Constricted pupil, headache and blurred vision
What is Prostitutes pupil?
Argyll Roberston
Neurosyphilis giving a constricted pupil (non-reactive to light)
Also seen in Diabetic neuropathy
