Opthalmology Flashcards
Afferent Defect of Pupils
No direct response but intact consensual response
Cannot initiate consensual response in contralateral eye.
Dilatation on moving light from normal to abnormal eye
Total CN2 Lesion
Relative Afferent Pupillary Defect
Features
- minor constriction to direct light
- dilated on moving light from normal to abn eye
- marcus gunn pupil
Causes
- optic neuritis
- optic atrophy
- retinal disease
Efferent Defect
Dilated Pupil does not react to light
- initial consensual response in contralateral pupil
- opthalmoplegia + ptosis
Cause
3rd nerve palsy
The pupil is often spared in a vascular lesion (e.g.
DM) as pupillary fibres run in the periphery.
DDx of fixed dilated pupil
Mydriatics (tropicamide etc)
Iris trauma
Acute glaucoma
CN3 compression (tumour, coning)
Holmes-Adie Pupil
Features
Young woman sudden blurring of near vision
Initially unilateral and then bilateral pupil dilatation
Dilated pupil has no response to light + sluggish
response to accommodation.
A “tonic” pupil
Ix
Iris shows spontaneous wormy movements on slit-lamp
examination (Iris streaming)
Cause - damage to postganglionic parasympathetic fibres
idiopathic - may have viral origin
Holmes Adie syndrome
Tonic Pupil
absent knee/ankle jerks
low blood pressure
Horner Syndrome
PEAS Ptosis Enopthalmos Anhydrosis Small pupil
Causes
- Central - MS, Wallenberg’s Lateral Medullary Syndrome
- Pre-ganglionic (neck)
Pancoast’s tumour: T1 nerve root lesion
Trauma: CVA insertion or CEA
Post-ganglionic
Cavernous sinus thrombosis
Usually 2ndary to spreading facial infection via the ophthalmic veins
CN 3, 4, 5, 6 palsies
Argyll Robertson Pupil
Features
- small, irregular pupils
- accommodate but doesn’t react to light
- atrophied + depigmented iris
Cause
- DM
- Quaternary syphilis
Optic atrophy/neuropathy
Features
↓ acuity ↓colour vision (esp. red) Central scotoma Pale optic disc RAPD
Optic Atrophy/neuropathy
Causes
CAC VISION
- commonest MS + glaucoma
Congenital Leber’s hereditary optic neuropathy HMSN / CMT Friedrich’s ataxia DIDMOAD Retinitis pigmentosa
Alcohol + other toxins
Ethambutol
Lead
B12 deficiency
Compression
Neoplasia: optic glioma, pituitary adenoma
Glaucoma
Paget’s
Vascular: DM, GCA or thromboembolic
Inflammatory: optic neuritis –MS, Devic’s, DM
Sarcoid / other granulomatous
Infection: herpes zoster, TB, syphilis
Oedema: papilloedema
Neoplastic infiltration: lymphoma, leukaemia
Red eye History
Vision
- blurred
- distorted
- diplopia
- field defect/scotoma
- floaters, flashes
Sensation
- irritation
- pain
- itching
- photophobia
- FB
Appearance
- red ?distribution
- lump
- puffy lids
Red eye key examination questions
Inspect from anterior to posterior
is acuity affected?
is the globe painful?
Pupil size + reactivity
Cornea - intact, cloudy? Use fluorescein
Sign of serious disease
Photophobia
Poor vision
Corneal fluorescein staining
Abnormal pupil
Acute closed angle glaucoma
Blocked drainage of aqueous from anterior chamber via canal of schlemm
Pupil dilatation worsens with blockage)
IOP rises from 15-20 to over 60mmHg
Acute closed angle glaucoma
RF
Hypermetropia - long sitedness Shallow ant. chamber Female FH ↑age
Drugs Anti-cholinergics Sympathomimetics TCAs Anti-histamines
Acute closed angle glaucoma
Sx
O/E
Ix
Sx
- prodrome - rainbow haloes around lights at night
- severe pain w n/v
- decrease acuity + blurred vision
O/E
- Cloudy cornea w circumcorneal infection
- Fixed dilated irregular pupils
- ^IOP - eye feels hard
Ix
- Tonometry (^^IOP - usually 40+)
Acute closed angle glaucoma
Acute Mx
subsequent Mx
Acute Mx - refer to cardiologist
Pilocarpine 2-4% drops stat: miosis opens blockage
Topical β-B (e.g. timolol): ↓ aqueous formation
Acetazolamide 500mg IV stat: ↓ aqueous formation
Analgesia and antiemetics
Subsequent Mx
- Bilateral YAG peripheral iridotomy once IOP decreses medically
YAG is Yttrium-Aluminum Garnet
Anterior Uveitis/Acute Iritis
Uvea is pigmented part of eye and included: iris, ciliary
body and choroid.
Iris + ciliary body = anterior uvea
Iris inflammation involves ciliary body too.
Sx
- acute pain + photophobia
- blurred vision
Anterior Uveitis/Acute Iritis
O/E
Small pupil initially, irregular later Circumcorneal injection Hypopyon: pus in anterior chamber White (keratic) precipitates on back of cornea Talbots test: ↑pain on convergence
Anterior uveitis/acute iritis Associations
Seronegative arthritis: AS, psoriatic, Reiter’s
Still’s / JIA
IBD
Sarcoidosis
Behcet’s
Infections: TB, leprosy, syphilis, HSV, CMV, toxo
Anterior uveitis/acute iritis
Mx
Refer to ophthalmologist
Prednisolone drops
Cyclopentolate drops: dilates pupil and prevents
adhesions between iris and lens (synechiae)
Episcleritis
inflammation below conjunctiva in episclera
Presents
Localised reddening: can be moved over sclera
Painless / mild discomfort
Acuity preserved
Causes
Usually idiopathic
May complicate RA or SLE
Rx: Topical or systemic NSAIDs
Scleritis
vasculitis of sclera
Presents
- severe pain, worse on eye movement
- generalised scleral inflammation (vessels won’t move over sclera)
- conjunctival oedema (chemosis
Causes
- Wegener’s
- RA
- SLE
- Vasculitis
Mx
- refer to specialist
- most need corticosteroids or immunosuppressants
Complications - scleromalacia (thinning) > globe perforation
Conjunctivitis Presents
- Often bilateral ¯c purulent discharge
Bacterial: sticky (staph, strep, Haemophilus)
Viral: watery
Discomfort
Conjunctival injection
Vessels may be moved over the sclera
Acuity, pupil responses and cornea are unaffected.
Conjunctivitis Causes/Rx
Causes
Viral: adenovirus
Bacterial: staphs, chlamydia, gonococcus
Allergic
Rx
Bacterial: chloramphenicol 0.5% ointment
Allergic: anti-histamine drops: e.g. emedastine
Corneal Abrasion
Epithelial breech w/o keratitis
Cause: trauma
Symptoms
Pain
Photophobia
Blurred vision
Ix
Slit lamp: fluorescein stains defect green
Rx
Chloramphenicol ointment for infection prophylaxis
Corneal Ulcer + Keratitis (Causes)
Causes: bacterial, herpetic, fungal, protozoa, vasculitic (RA)
Dendritic ulcer = Herpes simplex
Acanthamoeba: protazoal infection affecting contact
lens wearers swimming in pools.
Corneal Ulcer + Keratitis (Presentation + RF)
Pain photophobia
Conjunctival hyperaemia (XS blood vessels)
decreased acuity
white corneal opacity
RF - contact lense wearers
Corneal Ulcer + Keratitis (Ix + Rx + complications)
Ix - green w fluorescin on slit lamp
Rx - refer immediately to specialist
Take smears and cultures
Abx drops, oral/topical aciclovir
Cycloplegics/mydriatics ease photophobia
Steroids may worsen symptoms: professionals only
Complications
- scarring + visual loss
Opthalmic Shingles
Pain in CNV1 dermatome precedes blistering rash
40% → keratitis, iritis
Hutchinson’s sign
Nose-tip zoster due to involvement of nasociliary
branch.
↑ chance of globe involvement as nasociliarry
nerve also supplies globe
Opthalmic involvement
- Keratitis + corneal ulceration (fluorescin stains)
- +/- iritis
Sudden Loss of vision
Key Questions
Headache associated: GCA
Eye movements hurt: optic neuritis
Lights / flashes preceding visual loss: detached retina
Like curtain descending: TIA, GCA
Poorly controlled DM: vitreous bleed from new vessels
Anterior Ischaemic Optic Neuropathy (AION)
optic nerve damaged if posterior cilliary arteries blocked (inflammation or atheroma)
Pale swollen optic disc
Causes
- Arteritic AION - giant cell arteritis
- Non-arteritic AION - HTN, DM, hyperlipidaemia, smoking
Optic neuritis
Sx + Signs
Sx - unilateral loss of acuity over hrs - days
- ↓ colour discrimination (dyschromatopsia)
- eye movements may hurt
Signs ↓ acuity ↓ colour vision Enlarged blind-spot Optic disc may be: normal, swollen, blurred Afferent defect
Optic neuritis
Causes + Rx
Causes Multiple sclerosis (45-80% over 15yrs) DM Drugs: ethambutol, chloamphenicol Vitamin deficiency Infection: zoster, Lyme disease
Rx
High-dose methyl-pred IV for 72h
Then oral pred for 11/7
Vitreous Haemorrhage
Source
New vessels: DM
Retinal tears / detachment / trauma
Presentation
Small bleeds → small black dots / ring floaters
Large bleed can obscure vision → no red reflex, retina
can’t be visualised
Ix
May use B scan US to identify cause
Mx
VH undergoes spontaneous absorption
Vitrectomy may be performed in dense VH
Central Retinal Artery Occlusion
Presents
- Dramatic unilateral vision loss in seconds
- Afferent pupil defect (may precede retinal changes)
- Pale retina w cherry-red macula
Causes
- GCA
- Thromboembolism: clot, infective, tumour
Rx - if seen w/i 6h aim is to ^retinal blood flow by decreasing IOP >occular massage > Surgical removal of aqueous > antihypertensives (local + systemic)
Central Retinal Vein Occlusion
Commoner than arterial occlusion
Causes: arteriosclerosis, ↑BP, DM, polycythaemia
Pres: sudden unilat visual loss w RAPD (relative afferent pupillary defect)
Fundus: Stormy Sunset Appearance
Tortuous dilated vessels
Haemorrhages
Cotton wool spots
Complications
Glaucoma
Neovascularisation
Prognosis: possible improvement for 6mo-1yr
Branch Retinal Vein Occlusion
Presents - unilateral visual loss
Fundus - segmental fundal changes
Comps - retinal ischaemia > VEGF release + neovascularisation
Rx - laser photocoagulation
Retinal Detachment
Holes/tears in retina allow fluid to separate sensory retina from retinal pigmented epithelium
May be 2ndary to cataract surgery, trauma, DM
Presentation 4 Fs - Floaters - numerous acute onset spider web - Flashes - Field loss - Fall in acuity painless
Fundus - grey, opalescent retina, ballooning forwards
Retinal detachment Rx
Urgent surgery
Vitrectomy + gas tamponade w laser coagulation to secure retina
Causes of transient visual loss
Vascular: TIA, migraine
MS
Subacute glaucoma
Papilloedema
Gradual Visual Loss
Causes
Common Diabetic retinopathy ARMD Cataracts Open-angle Glaucoma
Rarer
Genetic retinal disease: retinitis pigmentosa
Hypertension
Optic atrophy
Age Related Macular Degeneration
Commonest cause of blindness 60+
RF - smoking, age, genetics
Presentation - elderly, central visual loss
Dry and Wet
Ix Optical Coherence Tomography
- high resolution images of retina
Dry AMD
Geographic Atrophy
Drusen - fluffy white spots around macula
Degeneration of macula
Slow visual decline over 1-2 years
Wet AMD
Subretinal Neovascularisation
Abberrant vessels grow into retina from choroid + haemorrhage
Rapid visual decline (sudden/days/weeks) w distortion
Fundoscopy - macular haemorrhage > scarring
Amsler grid detects distortion
Mx of Wet AMD
Photodynamic therapy
Intravitreal VEGF inhibitor
- Bevacizumab (Avastin)
- Ranibizumab (Lucentis)
Antioxidant vitamins (C,E) + zinc may help early AMD
Tobacco-Alcohol Amblyopia
Due to toxic effects of cyanide radicals when combined
with thiamine deficiency.
Pres: Optic atrophy, loss of red/green discrimination,
scotomata
Rx: vitamins may help
Chronic Simple (open-angle) Glaucoma
Pathogenesis
Pathogenesis depends on susceptibility of pt retina + optic nerve to ^IOP damage
IOP >21mmHg > decreased bloow flor + damage to optic nerve > optic disc atrophy (pale) + cupping
Chronic Simple (open-angle) Glaucoma
Presentation
Peripheral Visual field defect (superior nasal first)
Central field intact - acuity maintained until late
> presentation delayed until optic N damage is irreversible
Chronic Simple (open-angle) Glaucoma
Screen if high risk (RF)
>35y Afrocaribbean FH Drugs - steroids Co-morbidities - DM, HTN, Migraines Myopia
Chronic Simple (open-angle) Glaucoma
Ix Mx
Ix
- Tonometry - IOP 21+ mmHg
- Fundoscopy - cupping of optic disc
- visual field assessment - peripheral loss
Chronic Simple (open-angle) Glaucoma
Mx
Lifelong follow/up
Eye-drops to lower IOP to baseline
1st line: β-blockers
Timolol, betaxolol
↓ aqueous production
Caution in asthma, heart failure
Prostaglandin analogues
Latanoprost, travoprost
↑ uveoscleral outflow
α-agonists
Brimonidine, apraclonidine
↓ aqueous production and ↑ uveoscleral outflow
Carbonic anhydrase inhibitors
Dorzolamide drops, acetazolamide PO
Miotics
Pilocarpine
Non-medical options
- laster trabeculoplasty
- Surgery (trabeculectomy) if drugs fail > new channel allows aqueous to flow into conjunctival bleb
Commonest Causes of Blindness Worldwide
Trachoma Cataracts Glaucoma Keratomalacia: vitamin A deficiency Onchocerciasis Diabetic Retinopathy
The eye in DM
DM is leading cause of blindness up to 60yrs
30% have ocular problems @ presentation
BP < 130/80 and normoglycaemia → ↓ diabetic retinopathy
Eye in DM pathogenesis
Cataract
- DM accelerates formation of cataract
- Lens absorbs glucose, converted to sorbitol by aldose reductase
Retinopathy
- Microangiopathy > occlusion
- Occlusoin > ischaemia > new vessel formation in retina
Bleed → vitreous haemorrhage
Carry fibrous tissue w them → retinal detachment
- occlusoin also > cotton wool spots (ischaemia)
- vascular leakage > oedema + lipid exudates
- rupture of microaneurysms > blot haemorrhages
Eye in DM fundoscopy findings
Background Retinopathy: Leakage
Dots: microaneurysms
Blot haemorrhages
Hard exudates: yellow lipid patches
Pre-proliferative Retinopathy: Ischaemia Cotton-wool spots (infarcts) Venous beading Dark Haemorrhages Intra-retinal microvascular abnormalities
Proliferative Retinopathy
New vessels
Pre-retinal or vitreous haemorrhage
Retinal detachment
Maculopathy
Caused by macular oedema
↓ acuity may be only sign
Hard exudates w/i one disc width of macula
Eye in DM Ix Mx
Ix - fluorescein angiography
Mx
- good BP and glycaemic control
- Rx concurrent disease (HTN, dyslipidaemia, renal disease, smoking, anaemia
- Laser photocoagulation
Maculopathy: focal or grid
Proliferative disease: pan-retinal (macula spared)
CN palsies in DM (eye)
CNIII and CNVI palsies may occur
in diabetic CNIII palsy, pupil may be spared as nerve fibres run peripherally + receive blood from pial vessels
Cataracts Presentation
Increasing myopia
Blurred vision → gradual visual loss
Dazzling in sunshine / bright lights
Monocular diplopia
Cataracts causes
↑Age: 75% of >65s DM Steroids Congenital Idiopathic Infection: rubella Metabolic: Wilson’s, galactosaemia Myotonic dystrophy
Cataracts Ix
Visual acuity
dilated fundoscopy
tonometry
blood glucose to exclude dM
Cataracts Mx
Conservative
- glasses
- mydriatic drops + sunglasses may give relief
Surgery
- consider if Sx affect lifestyle or driving
- day case under local - phacoemulsion + lens implants
-1% risk serious complications
Anterior uveitis / iritis
VH
Retinal detachment
Secondary glaucoma
Endophthalmitis (→ blindness in 0.1%)
- post-op capsule thickening common
- post-op eye irritation common + requires drops
Retina
outer pigmented layer in contact w choroid
inner sensory layer in contact w vitreous
at centre - fovea
Optic disc
Colour - pale pink, paler optic atrophy
Contour - margins blurred in papilloedema + optic neuritis
Cup
- physiological cup lies centrally + should occupy 1/3 of disc diameter
- Cup widening + deepening in glaucoma
Retinitis Pigmentosa
Most prevalent inherited degeneration of macula
Presentation
Night blindness
↓↓ visual fields → tunnel vision
Most are registrable blind (<3/60) by mid 30s
Fundoscopy
- Pale optic disc - optic atrophy
- peripheral retina pigmentation - spares macula
assw Friedrich's ataxia Refsum's disease Kearns-Sayre Syndrome Usher's syndrome
Retinoblastoma
commonest intraocular tumour in children
- AD mutation in RB gene
- can be non-hereditary
- pt typically have 1 mutant allele in every retinal cell, if other allele mutates > TB
Assw osteosarcoma, rhabdomyosarcoma
Signs - stabismus (eyes not aligned properly
- leukocoria (white pupil) - no red reflex
Rx - depends on size
- chemo, radio, enuclreation
Stye or hordeolum externum
abscess/infection in lash follicle which points outwards
Rx - local abx - fusidic acid
Chalazion or hordeolum internum
abscess of meibomian glands which point inwards onto conjunctiva
- sebacious glands of eyelid
Blepharitis
common inflammation of eyelid
Causes - seborrhoeic dematitis, staph
Features
- red eyes
- gritty/itchy sensation
- scales on lashes
- oft assw rosacea
Rx
- clean cursts w warm soaks
- may need fusidic acid drops
Entropion
lid inversion > corneal irritation
degeneration of lower lif fascia
Ectropion
lower lid eversion > watering + exposure keratitis
assw ageing + facial nerve palsy
Ptosis
True ptosis is intrinsic Levator Palpebrae Superioris msucle weakness
Bilateral
- congen, senile, MG, Myotonic dystrophy
Unilateral
- 3rd nerve palsy
- Horner’s syndrome
- Mechanical - xanthelasma , trauma
Lagopthalmos
difficulty in lid closure over globe may > exposure keratitis
Causes - exopthalmos, facial palsy, injury
Rx - lubricate eyes w liquid paraffin ointment
- Temporary tarsorrhaphy may be needed if cornreal ulcer develops
Pinguecula
yellow vascular nodules either side of cornea
Pterygium
Similar to pinguecula but grows over the cornea → ↓
vision.
Benign growth of conjunctiva
Assoc. c¯ dusty, wind-blown life-styles, sun exposure
Orbital Cellulitis
infection spreads locally (from paranasal sinuses, eyelid or external eye)
- staph, pneumococcus, GAS
Presentation
- usually child w inflammation of orbit + lif swelling
- pain and decreased ROM of eye movement
- exopthalmos
- systemic signs - fever
- +/- tenderness over sinuses
Rx - IV Abx - cefuroxime (20mg/kg/8h IV)
Complication
- local extension > meningitis and cavernous sinus thrombosis
- blindness due to opitc N pressure
Carotico-Cavernous fistula
May follow carotid aneurysm rupture w reflux of blood
into cavernous sinus.
Causes: spontaneous, trauma
Presentation Engorgement of eye vessels Lid and conjunctival oedema, Pulsatile exophthalmos Eye bruit
Rx - oral antivirals - famciclovir, aciclovir
Exopthalmos/Proptosis
protrusion of one or both eyes
Common cause
- Grave’s (retroorbital inflam + lymphocyte inflammation > swelling)
- orbital cellulitis
- trauma
Other causes - idiopathic (orbital inflammatory disease) - vasculitis - wegener's - carotico-cavernous fistula - Neoplasm Lymphoma Optic glioma: assoc. c¯ NF-1 Capillary haemangioma Mets
Myopia
short sightedness
- eye too long
- distant objects focused too far forward
Causes
- genetic
- XS close work in early decades
Solution
- concave lenses
Astigmatism
cornea or lens not same degree of curvature in horizontal + vertical planes
- image of object is distorted longitudinally or vertically
Solution - correcting lenses
Hypermetropia: long-sightedness
eye too short
- when eye relaxed + not accommodating, objects focussed behind retina
- contraction of ciliary muscles to focus image > tiredness of gaze + possibly convergent squint in children
Solution - convex lenses
- convex lenses
Presbyopia
w age lens becomes stiff + less easy to deform
start 40 completed by 60
use convex lenses
Esotropia
convergent squint
Commonest type in children
May be idiopathic or due to hypermetropia
Exotorpia
divergent squint
Older children
Often intermittent
Non-paralytic Squint
Diagnosis
- Corneal reflection - should fall centrally + symmetrically on each cornea
- Cover test - movement of uncovered eye to take up fixation demonstrates manifest squint
Management of 3Os
- optical - correct refractive errors
- orthoptic - patching good eye encourages use of squinting eye
- Operations - resection and recession of rectus muscles - help alignment + cosmesis
Paralytic Squint
Diplopia most on looking in direction of pull of paralysed muscle
eye won’t fixate on covering
cover each eye in turn
- whichever sees outer image is malfunctioning
CNIII Paralytic Squint
Ptosis (Levator palpebrae superioris)
Fixed dilated pupil (no parasympathetic)
Eye looking down and out
Causes
- Medical - DM, MS, infarction
- Surgical - ^ICP, cavernous sinus thrombosis, posterior communicating artery aneurysm
CNIV Paralytic Squint
Diplopia esp on going downstairs
- head tilt
Test - can’t depress in adduction
Causes
- peripheral - DM, trauma, compression
- Central - MS, vascular, SOL
CNVI
eye medially deviated and cannot abduct
- diplopia in horizontal plane
Cause
- peripheral - DM, compression, trauma
- Central - MS, vascular, SOL
Rx- botulinum toxin - can eliminate need for surgery
Eye trauma if unable to open injured eye -
instill LA
Foreign Bodies
XR orbit if metal FB suspected
- fluorescein may show cornreal abrasions
Mx - Chloramphenicol drop 0.5% prevent infection > usually coagulase negative staph - eye patch - cycloplegic drops may decrease pain
Intra-ocular haemorrhage
blood in anterior chamber = hyphaemia
small amounts clear spontaneously - some may need evacuation
complicated by corneal staining + glaucoma (pain)
keep IOP low + monitor
Orbital Blowout Fracture
Blunt injury > sudden ^ IOP w herniation of orbital contents into maxillary sinus
Presents
- Opthalmoplegia + Diplopia - tethering of inferior rectur + inferior oblique
- Loss of sensation to lower lid skin - infraorbital nerve injury
- Ipsilateral epistaxis - damage to anterior ethmoidal artery
- decreased acuity
- irregular pupil reacting slowly to light
Mx - Reduction and muscle relesae necessary
Chemical Injury to eye
Alkaline solutions are particularly damaging
Mx
Copious irrigation
Specialist referral
Floaters (eye)
small dark spots in visual field
Sudden showers of floaters can be due to blood or retinal detachment
Causes
- Retinal detachment
- VH
- diabetic retinopathy/HTN
- Old retinal branch vein occlusion
- snresis (degenerative opacities in vitreous)
Flashes (Photopsia)
either intraocular or intracerebral pathology
Headache N/V migraine
Flashes and floaters - retinal detachment
Haloes (eye)
usually diffractive phenomena
may be caused by hazy ocular media - cataract, corneal oedema, acute glaucoma
Haloes + eye pain - acute glaucoma
jagged haloes which change shape - usually migraine
Seasonal Allergic Conjunctivitis
50% allergic eye disease
small papillae on tarsal conjunctivae
Rx
- antzoline - antihistamine drops
- cromoglycate - inhibits mast cell degranulation
Perennial allergic conjunctivitis
Sx all year w seasonal exacerbations
small papillae on tarsal conjunctivae
Rx - olopatadine (antihistamine + mast cell stabiliser)
Giant Papillary Conjunctivitis
Iatroenic FBs - contact lenses, prostheses sutures
giant papillae on tarsal conjunctivae
Mx or Allergic eye disorders
1 Remove allergen responsible where possible
2 General measures
- cold compress
- artificial tears
- oral antihistamines - loratadine 10mg/d PO
3 eye drops
- antihistamines - antazoline , azelastine
- mast cell stabilisers - cromoglycate, lodoxamide
- steroids - dexamethasone (beware inducing glaucoma)
- NSAIDs - diclofenac
Trachoma
Caused by Chlamydia trachomatis
spread by flies
inflammatory reaction under lids > scarring > lid distortion > entropion > eyelashes scratch cornea > ulceration > blindness
Rx - tetracycline 1% ointment +/- PO
Prevention - good sanitation, face washing
Onchocerciasis (river blindness)
Caused by microfilariae of nematode Onchocerca volvulus
- spread by flies
- fly biets > microfillariae infection > invade eye > inflammation > fibrosis > corneal opacities + synechiae
Rx - Ivermectin
Xeropthalmia + Keratomalacia
Vit A deficiency
Presents
- night blindness + dry conjunctivae (xerosis)
- corneal ulceration + perforation
Rx - vit A/palmitate reverses early corneal changes
hypertensive retinopathy
Keith-Wagener Classification
- Tortuosity and silver wiring
- AV nipping
- Flame haemorrhages and soft / cotton wool spots
- Papilloedema
Grades 3 and 4 = malignant hypertension
Granulomatous Disorders (eye signs)
TB, sarcoid, toxo, leprosy, brucella
Uveitis (ant/post) and choroidoretinitis
Systemic inflammatory disease (eye signs)
Conjunctivitis: SLE, reactive arthritis, IBD
Scleritis / episcleritis: RA, vasculitis, SLE, IBD
Iritis : ank spond, IBD, sarcoid
Retinopathy: dermatomyositis
Keratoconjunctivitis Sicca/Sjogren’s
↓ tear production (Schirmer’s: <5mm in 5min)
Dry eyes and dry mouth
1O or 2O: SLE, RA, sarcoid
Rx: artificial tears or saliva
Vascular occlusion of eye
Emboli - amaurosis fugax : GCA, carotid atheroemboli
Microemboli > roth spots - infective endocarditis
> boat shaped haemorrhage w pale centres
Metabolic eye signs
wilson’s
grave’s
hpt
Kayser-Fleischer Rings: Wilson’s
Exophthalmos: Graves’
Corneal calcification: HPT
HIV/AIDs eye signs
CMV retinitis (pizza pie fundus + flames)
HIV retinopathy - cotton wool spots
Mydriatics
Indication - eye examination, prevention of synechiae in ant uveitis/iritis
Caution - may > acute glaucoma if shallow anterior chamber
Anti-Muscarinics -Tropicamide Duration: 3h -Cyclopentolate Duration: 24h Preferred for paediatric use -Pupil dilatation + loss of light reflex -Cycloplegia (ciliary paralysis) → blurred vision
Sympathomimetics
Para-hydroxyamphetamine, phenylephrine
May be used w tropicamide
Don’t affect the light reflex or accommodation
Miotics
constrict pupils
Use - acute closed angle glaucoma
Muscarinic agonist - Pilocarpine
Chronic Open-Angle Glaucoma Rx
1st line: β-blockers
Timolol, betaxolol
↓ aqueous production
Caution in asthma, heart failure
Prostaglandin Analogues
Latanoprost, travoprost
↑ uveoscleral outflow
α-agonists
Brimonidine, apraclonidine
↓ aqueous production and ↑ uveoscleral outflow
Carbonic anhydrase inhibitors
Dorzolamide drops, acetazolamide PO
Miotics
Pilocarpine
eye lubricants
hypomellose
antazoline
Anaesthetic used to permit examination of painful eye
Tetracaine
Anaesthetic used to permit examination of a painful eye
Topical Anti-histamine
Emedastine
Antazoline
