Opthalmology Flashcards
Acuity. What’s numerator (top) and denominator?
Numerator = At what distance they can read
Denominator = At what distance one could normally readeg. 6/9 = they can read at 6m what could normally be read at 9m
If can’t read at 6m, procedure?
6m –> 3m –> 2m –>1m Count fingersHand movement
Perceives light
No light perception: abbreviated to no PL
What is a Hordeolum?
StyeHordeolum externum =
Abscess/infection in lash follicle. Points outwards Mx Fusidic acid
Hordeolum internum = Abscess of meibomian glands-
Points inwards opening onto conjunctiva- Leaves a residual swelling called a chalazion/meibomian cyst when they subside.
Mx: Incision & curettage under LA
Entropion?
Lid inturning due to degeneration of lid fascial attachments and their muscles.
Inturned eyelashes irritate the cornea
Mx = botulinum toxin
Surgery
Ectropion?
Lower lid eversion, causes eye irritation, watering and exposure keratitis.
Associated with old age, facial palsy
Mx with Plastic surgery
Dendritic ulcer
Herpes simplex corneal ulcer.
Visualise with blue light
Sx: Photophobia/watering
Mx: Most resolve spontaneously within 3 weeks, but rational for treatment is to minimise stromal dmg/scarring - Topical/oral acyclovir 5 times day for 10 days
Orbital cellulitis
Infection spread locally eg.. from paranasal sinuses, eyelid or external eye
Staphs, pneumococcus or GAS
P/C child with inflammation of orbit + lid swelling pain + reduced range of movement Exopthalmos systemic signs eg. fever Tenderness over sinuses
Rx: IV Abx eg. cefuroxime (20mg/kg/8h)
Complications:
Cause & Symptom of total afferent defect?
sx: No direct response but intact consensual response
- cannot initiate consensual response in Contralateral eye
- Dilatation on moving light from normal to abnormal eye
Cause = Total CN II lesion
RAPD aka. Causes
AKA Marcus Gunn Pupil
1) Optic Neuritis
2) Optic atrophy
3) Retinal disease
Efferent defect: feature & causes
Features:
Dilated pupil which does not react to light, but can initiate consensual response in CL pupil.
–> 3rd nerve palsy so also Opthalmoplegia + ptosis
Cause:
- 3rd nerve palsy
- -> Pupil often spared in a vascular lesion (eg. DM) as pupillary fibres run in the periphery
Fixed dilated pupil differential?
1) Mydriatics eg. tropicamide
2) Iris trauma
3) Acute glaucoma
4) CNIII compression: tumour/coning
Holmes-Adie pupil
- Dmg to postganglionic parasympathetic fibres
- -> a ‘tonic’ pupil
- Idiopathic: may have viral origin
- Young women pc sudden blurring of near vision
- Initially unilateral, followed by bilateral pupil dilatation
- Dilatation has no response to light, with sluggish respones to accomodation
Parasympathetic pathway in eye?
- Pretectal nucleus midbrain - inferior division of CNIII - Ciliary ganglion- Short ciliary nerves to iris sphincter muscle - cause vasoconstriction
Sympathetic pathway eye?
Hypothalamus - C8-t1 ciliospinal centre - Superior cervical ganglion in Cavernous sinus - Opthalmic divison of V1, Trigeminal nerve - Nasociliary nerve - Long ciliary nerve to iris dilator muscle
Holmes-adie syndrome?
Tonic pupil + absent knee/ankle jerks + reduced BP (+ impaired sweating)
Caused by ?inflammatory dmg to neurons in ciliary ganglion and dmg to dorsal root ganglion (loss of autonomic control)
Horner’s syndrome Features?
Dmg to sympathetic nerve on ipsilateral side
PEAS
Ptosis (partial) - superior tarsal muscle
Enopthalmos
Anhydrosis
Small pupil (Miosis)
Horner’s syndrome causes?
Central (anhydrosis at face,arm,trunk)
- MS
- Wallenberg’s lateral medullary syndrome
- Brain tumours/encephalitis
Pre-Ganglionic (neck)- anhydrosis at face
- Pancoast’s tumour: T1 nerve root lesion
- Trauma: CVA insertion
- Cervical rib
Post-ganglionic (no anhydrosis)
- Cavenous sinus thrombosis
- -> usually secondary to spreading facial infection via the opthalmic veins- CN 3/4/5/6 palsies
Argyll Robertson Pupil?
- Features
- Cause
Features:
- Small, irregular pupils
- Accomodate, but do not react to light (like her…Prostitute’s pupil)
- Atrophied and depigmented iris
Causes:
- DM
- Quaternary syphillis
Optic Atrophy features?
AKA Optic Neuropathy
- Reduced acuity
- Reduced colour vision (especially red)
- Central scotoma
- Pale optic disc
- RAPD
Optic Atrophy Causes?
CAC VISION
Congenital
- -> Leber’s hereditary optic neuropathy
- Hereditary sensory motor neuropathy, friedrich’s ataxia, DIDMOAD, Retinitis Pigmentosa
Alcohol & other toxins:
- Ethambutol, lead, b12 def.
Compression:
- Neoplasia: optic glioma, pituitary adenoma
- Glaucoma
- Paget’s
Vascular: DM, GCA, thromboembolic
Inflammatory: MS, devic’s, DM
Sarcoid
Infection: HZV, TB, syphilis
Oedema: Papilloedema
Neoplastic infiltration: lymphoma, leukaemia
Commonest cause of Optic neuropathy?
MS & Glaucoma
Signs of serious Red-eye disease?
Photophobia (ant.uveitis)
Poor vision (a.glau/ant uveitis)
Corneal fluorescein staining (dendritic ulcer)
Abnormal Pupil (large in acute glaucoma, small in anterior uveitis)
Acute Closed angle glaucoma aetiology/symptoms?
Blocked drainage of aqueous from ant.chamber via canal of schlemm.
- Pupil dilatation (@night) worsens blockage
- Intraocular pressure rises from 15-20–> 60mmHg
nb. Normal range 10-21mmHg
Sx: Prodrome: rainbow haloes around light at night time
- Severe pain with N/v
- Reduced acuity and blurred vision
O/E: Cloudy cornea with circumcorneal injection
FIXED DILATED IRREGULAR PUPIL
- IOP up makes eye feel hard
Acute closed angle glaucoma risk factors
- Hypermetropia (longsightedness)
- Shallow ant.chamber
- Female
- FH
- Increased Age
Drugs:
- Anti-cholinergics
- Sympathomimetics
- TCAs
- Anti-histamines
Acute closed angle glaucoma Mx?
Ix: Tonometry: increased IOP (>40mmHg)
Acute Mx:
1) Refer to Opthalmologist
2) Pilocarpine 2-4% drops stat : Miosis opens blockage
3) Topical bB (timolol) - reduces aqueous formation
4) Acetazolamide 500mg IV stat: reduces aqueous formation
5) analgesia and antiemetics
Subsequent Mx:
- Bilateral YAG peripheral iridotomy once IOP reduces medically (laser to create a hole in iris - allows aqueous to drain)
(Yttrium alumninium garnet)
Anterior uveitis/iritis pathophys?
Uvea = pigmented part of eye, composed of iris, ciliary body and choroid
- Iris + ciliary body = anterior uvea
–> Iris inflammation involves ciliary body too.
Associations:
- Seronegative arthritis: AS. psoriatic, Reiter’s
- Still’s / JIA
- IBD (particular UC)
- Sarcoidosis
- Behcet’s
- Infections: TB, Leprosy, syphilis, HSV, CMV, Toxo
Ant.uveitis sx / O/E
Sx:
- Acute pain
- PHOTOPHOBIA
- Blurred vision (Aq. precipiates)
O/E:
- Small pupil initially, irregular later
- Circumcorneal injection
- Hypopyon : Pus in ant.chamber
- White (keratic) precipitates on back of cornea
- Talbots test: Increased pain on convergence
Anterior uveitis Mx
1) refer to opthalmologist
2) Prednisolone drops
3) Cyclopentolate drops: dilates pupils and prevents adhesions between iris and lens (Synechiae)
Episcleritis?
Inflammation below conjunctiva in the episclera
Sx: Localised reddening, can be moved over sclera
- PAINLESS/mild discomfort
- Acuity preserved
Causes:
Usually idiopathic
May complicate RA/SLE
Mx: Topical/systemic NSAIDs
Scleritis
PAINFUL vasculitis of sclera
- -> Worse on eye movement
- -> generalised scleral inflammation
- -> Conjunctival oedema (chemosis)
Causes: Wegener's RA SLE Vasculitis
Mx:
- Refer to specialist
- Most need corticosteroids or immunosuppressants
Complications: Scleromalacia (thinning) –> globe perforation
Conjunctivitis causes
Bacterial (Sticky): Staph, strep, haemophilus, Chlamydia, gonococcus (VERY purulent, particular in neonates)
Viral (Watery) : Adenovirus)
Allergic
Conjunctivitis Mx
Bacterial: Chloramphenicol 0.5% ointment
Allergic: Anti-histamine drops: eg. emedastine
Corneal abrasion Ix + Rx?
- Epithelial breech
Ix: Slip lamp: florescein stains defect green
Rx: Chloramphenicol ointment for infection prophylaxis
Corneal ulcer causes
Bacterial, herpetic, fungal, protozoa, vasculitis (RA)
Dendritic ulcer = Herpes simplex
Acanthamoeba: protazoal infection affecting contact lens wearers swimming in pools
Ix: Green with fluorescein on slit lamp
Rx: refer immediately to specialist who will
1) Take smears/cultures
2) Abx drops, topical/oral aciclovir
nb. Steroids may worsen symptoms
What is Hutchinson’s sign? Characteristics of the condition it’s a part of?
Nose-top zoster involvement due to involvement of nasociliary branch in opthalmic shingles. Increases change of globe involvement as nasociliary nerve also supplies globe.
Sudden lost of vision differentials?
HELP
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
Optic neuritis signs and symptoms
signs: reduced acuity, reduced colour vision. Enlarged blind spot. Optic disk may be normal, swollen or blurred. Afferent defect.
Symptoms:
- Unilateral loss of acuity of hrs-days
- Decreased colour discrimination (dyschromatopsia)
- Eye movements may hurt
Optic Neuritis causes
MS (45-80% over 15yrs) DM Drugs: Ethambutol, chloramphenicol Vitamin deficiency Infection: Zoster, lyme disease
Optic neuritis Rx
High dose methyl pred IV for 72h, then oral pred for 11/7
Vitreous haemorrhage Source + Presentation
Source:
New vessels - DM
Retinal tears/detachment/trauma
Presentation:
Small bleeds - small black dots/ ring floaters
- Large bleeds can obscure vision –> NO red reflex, retina can’t be visualised.
Mx:
- VH undergoes spontaneous absorption
- Vitrectomy may be performed in dense VH
Central Retinal Artery Occlusion?
P/C:
- Dramatic unilateral visual loss in seconds
- Afferent pupil defect (may precede retinal changes
- Pale retina with CHERRY RED MACULA
Causes:
- GCA
- Thromboembolism: Clot, infective, tumour
Rx:
- If seen w/i 6hrs, aim is to increase retinal blood flood by decreasing IOP:
- Ocular massage
- Surgical removal of aqueous
- Anti-hypertensives (local+systemic)
Central retinal vein occlusion
Commoner than arterial occlusion
Causes: Arteriosclerosis, increased BP, DM, PCV
P/C: Sudden unilat visual loss with RAPD
Fundus: STORMY SUNSET appearance:
- Tortuous dilated vessels
- Haemorrhages
- Cotton wool spots
Complications:
- Glaucoma
- Neovascularisation
Prog: possible improvement for 6mo/1yr due to neovascularisation
Mx:
Depends on if ischaemic (RAPD) or non-ischaemic (No RAPD)
Mx neovascularisation with laser photocoagulation
Brach retinal vein occlusion
P/C: Unilateral visual loss
Fundus: Segmental fundal changes
Complications: Retinal ischaemia –> VEGF release and neovascularisation (Rx: Laser photocoag. )
Retinal detachment Presentation
4 F’s:
Floaters
Flashes
Field Loss
Fall in acuity
Painless
Causes of Transient visual loss?
Vascular: TIA/ Migraine
MS
Papilloedema
Subacute glaucoma
Causes of gradual visual loss?
Common
- Diabetic retinopathy
- ARMD
- Cataracts
- Open angle glaucoma
Rare
- Retinitis pigmentosa (night blindness + funnel vision)
- Hypertension
- Optic atrophy
ARMD?
Commonest cause of blindness > 60yrs
- 30% of >75yrs will have dry AMD
Risk factors:
- Smoking
- Increased Age
- Genetic factors
Dry (Geographic atrophy) or Wet (Subretinal Neovascularisation)
ARMD Presentation
Elderly pts presenting with central visual loss
ARMD Types?
Dry ARMD: Geographical atrophy:
- -> Drusen: fluffy white spots around macula
- -> Degeneration of Macula
- -> Slow visual decline over 1-2yrs
Wet ARMD: Subretinal neovascularisation
- Aberrant vessels grow into retina from choroid and lead to haemorrhage
- Rapid visual decline (Sudden/days/wks) with distortion
- Fundoscopy shows macular haemorrhage which leads to scarring
- Amsler grid detects distortion
ARMD Ix + Mx?
Ix:
OCT - Optical coherence tomography - gives high resolution images of the retina
Mx:
- -> Dry: wait & see
- Antioxidant vitamines (C,E) + Zinc may help early ARMD
- -> Wet: Photodynamic therapy
- Intravitreal VEGF inhibitors:
- Bevacizumab (Avastin) –> Not licsenced, very cheap
- Ranibizumab (Lucentis)
What is Tobacco-alcohol amblyopia?
Optic atrophy + loss of red/green discrimination/scotoma
Due to toxic effect of cyanide radicals (smoking) when combined with thiamine deficiency
Chronic Open angle glaucoma - Pathogenesis + Risk groups
Depends on susceptibility of pts retina and optic nerve to increased IOP
- -> IOP >21mmHg reduced blood flow and damage to optic nerve
- Optic disk atrophy (Pale) + cupping (increased cup to disk (nerve fibres))
Screen if high risk: >35 yrs Afro-caribbean FH Drugs: Steroids Comorbidities: DM, HTN, migraines Myopia
Chronic open angle glaucoma: Ix
Ix:
- tonometry: IOP >21mmHg
- Fundoscopy: Cupping of optic disc
- Visual field assessment: Peripheral loss
Chronic open angle glaucoma Mx
MDT involving optometrists, OT, opthalmologist & general physicians to control co-morbidites
- Life-long f/up
Medical:
Eye drops to reduce IOP to baseline
1)Beta blockers (Timolol/betaxolol) reduce aqueous production
Caution in asthma/ CHF
2) Prostaglandin analogues
Latanoprost, travoprost
–>Increase uveoscleral outflow
3) Alpha agonists
eg. Brimonidine, aproaclonidine
- Reduce aqeuous production + increase uveoscleral outflow
4) Carbonic anhydrase inhibitors
- Acetazolamide PO
5) Miotics : Pilocarpine
Surgical
1) Laser trabeculoplasty
2) Surgery (Trabeculectomy)
- -> In both - new channels allow aqueous to flow into conjunctival bleb
Commonest causes of blindness worldwide?
Trachoma (contagious bacterial infection of eye)
Cataracts
Glaucoma
Keratomalacia: Vit.A def.
Onchoerciasis
Diabetic retinopathy
IN UK: DM leading cause of blindness up to 60yrs, followed by ARMD in older
Pathogenesis of diabetic retinopathy?
1) Cataracts: Lens absorbs glucose which is converted to sorbitol by aldose reductase therefore DM accelerates cataract formation
2) Retinopathy
- Microangiopathy leads to occlusion
- Occlusion leads to ischaemia, leading to new retinal vessel formation
- New vessels may bleed (Vitreous haemorrhage) or carry fibrous tissue with them (retinal detachment)
- Occlusion also leads to cotton wool spots (ischaemia)
- Vascular leakage leads to oedema and lipid exudates
- Rupture of microaneurysms: Blot haemorrhage
Diabetic retinopathy: Screen & Ix?
Screening:
- All diabetics shoudl be screen annually
- Fundus photography
- Refer those with maculopathy, NPDR and PDR to opthalmologist
- -> 30% with NPDR develop PDR in 1 yr
Ix: Fluoroscein angiography - fluorescein dye injected into bloodstream - dye highlights blood vessels of eye so they can be photographed
Diabetic retinopathy: stages & fundoscopy findings?
1) Background : Leakge
- Dots: Microaneurysms
- Blot haemorrhages
- Hard exudates
2) Pre-proliferative: Ischaemia
- Cotton wool spots
- Venous beading (best predictor for having proliferative)/ venous loops
- Dark haemorrhages
- Intra-retinal microvascular abnormalities
3) Proliferative
- New vessels
- Pre-retinal/vitreous haemorrhage
- Retinal detachment
(4) Maculopathy)
- -> Caused by macular oedema
- Reduced acuity may be only sign
- Hard exudates w/i one disc width of macula
Cranial nerve palsies associated with diabetes?
CNIII & VI (occulomotor/abducens)
In diabetes, CNIII palsy - the pupil may be spared as its nerve fibres run peripherally and receive blood from the pial vessels
Cataracts Causes + presentation?
Causes: - Age: 75%>65 - DM - Steroids Congenital: --> Idiopathic --> Infection: Rubella --> Metabolic: Wilson's, galactosaemia --> Myotonic dystrophy
Presentation:
- Increasing myopia
- Blurred vision leading to gradual visual loss
- Dazzling in sunshine/bright lights
- Monocular diplopia
Cataracts Ix
Ix
- Visual acuity
- Dilated Fundoscopy
- Tonometry
- Blood glucose to exclude DM
Cataracts Mx
Conservative:
- Glasses
- Mydriatic drops and sunglasses may give some relief
Surgery:
- Consider if symptoms affect liftstyle or driving
- Day case surgery under LA
- -> Phacoemulsion (US breaks up and sucks up cataract) + lens implant
1% risk of serious complications
- Anterior uveitis
- VH
- Retinal detachment
- secondary glaucoma
- Endopthalmitis (leads to blindness in 0.1%)
Post-op capsule thickening is common
–> early treatment with laser capsulotomy
Post-op eye irritation common and requires drops
What is Retinitis pigmentosa?
Modes of inheritance?
Associations?
Retinitis pigmentosa (RP) is an inherited, degenerative eye disease that causes severe vision impairment due to the progressive degeneration of the rod photoreceptor cells in the retina.
Night blindness + funnel vision
Most prevalent inherited degeneration of the macula. Affects 1/2000
Various modes of inheritance:
- Mostly AR
- AD has best prognosis
- X-linked has worst prognosis
Associations:
- Friedrich’s ataxia
- Refsum’s disease
- Kearns-Sayre syndrome
- Usher’s syndrome (RP + deafness)
Retinitis pigmentosa Presentation & Fundoscopy
P/C:
- Night blindness
- Decreased visual fields –> Tunnel vision
- Most are registrable blind (
Retinoblastoma
Inheritance + Signs?
Commonest intraocular tumour in children 1:15 000
Inheritance:
- Hereditary/Non-heritary tpyes
- AD mutation of a RB gene (TSG)
Signs:
- Stabismus
- Leukocoria (White pupil) - absent red reflex
Associations:
- Increased risk of soteosarcoma/ rhabdomyosarcoma
Rx:
- Depends on size
- Options include chemo, radio, enucleation
Blepharitis?
Chronic inflammation of eyelid
Causes: Staphs, seborrhoeic dermatits
Features:
- Red, gritty eyes
- Scales on lashes
- Often associated with rosacea
Rx:
- Clean crusts of lashes with warm soaks
- May need fusidic acid drops
Ptosis causes?
True ptosis is intrinsic LPS weakness
Bilateral:
- Congenital
- Senile
- Myastenia gravis
- Myotonic dystrophy
Unilateral:
- CN III palsy
- Horner’s (partial)
- Mechanical : Xanthelasma, trauma
Lagopthalmos?
Difficulty in lid closure over whole globe which may lead to exposure keratitis
Causes: Exopthalmos, facial palsy, injury
Rx: Lubricate eyes with liquid paraffin ointment
Pinguecula
Pterygium?
Benign Yellow vascular nodules either side of cornea
Pterygium is similar but grows over cornea leading to reduced vision.
Associated with dusty wind blown life styles and sun exposure
Exopthalmos/proptosis Causes
Common:
- Grave’s: Anti-TSH Abs lead to retro-orbital inflammation & lymphocyte infiltration –> swelling
- Orbital cellulitis
- trauma
Other:
- Idiopathic orbital inflammatory disease
- Vasculitis: Wegener’s
- Neoplasm:
- -> Lymphoma
- -> Optic glioma assoc with NF-1
- Capillary haemangioma
- Mets
- Carotico-cavernous fistula (may follow carotid aneurysm rupture with reflux of blood into cavernous sinus)
Myopia: Problem, Cause, Solution?
Short-sightedness:
Problem:
- Eye too long
- Distant objects focussed before retina
Causes:
- Genetic
- Excessive close work in early decades
Solution
- ConCAVE (for short people)
Hypermetropia: Problem, solution?
Problem:
- Eye too short
- When eye relaxed and non accomodating, objects focused behind retina
- Contraction of ciliary muscles to focus image may lead to tiredness of gaze and possibly a convergent squint in children
Solution
- Convex lenses
Astimagtism: Problem and solution?
Problem:
- Cornea or lens doesn’t have same degree of curvature in both horizontal and vertical planes
- Image of object is distorted longitudinally or vertically
Solution
Correcting lenses
Presbyopia?
With age: Lens becomes stiff and less easy to deform & accomodate
- Starts at 40, complete by 60
- Use ConVEX lenses
Esotropia?
Convergent squint
Commonest type in children
May be idiopathic or due to hypermtropia
Exotropia?
Divergent squint
Older children
Often intermittent
Non-paralytic squint: Diagnosis and Management?
Diagnosis:
- Corneal reflection (Hirschburg tes) - should fall centrally and symmetrically on each cornea
- Cover test: movement of uncovered eye to take up fixation
Mx: 3 O’s
- Optical: Correct refractive errors
- Orthoptic: Patching good eye encourages uses of squinting eye
- Operation: resection and recession of rectus muscles helps alignment and cosmesis
Paralytic squint?
Diplopia most on looking in direction of pull of paralysed muscle eg. Right medial rectus paralysis, diplopia on looking left
- Eye WON’T fix on covering
CNIII Palsy?
Ptosis (LPS)
Fixed dilated pupil (no parasympathetic)
Eyes look DO (Down and out) –> Only muscles still function are superior oblique (down and out) and LR (Out)
Causes:
Medical: DM, MS, infarction
Surgical: Increased ICP, cavernous sinus thrombosis, PCAI
CNIV (Trochlear) Palsy
SO4 - normally looks down and out
- Diplopia going down stairs
- Head tilt to make up for rotation
Test: can’t depress in adduction (when looking out)
Causes:
Peripheral: DM (30%), Trauma (30%), Compression
Central: MS, Vascular, SOL
CNVI (Abducens) Palsy
LR6 - Normally looks laterally
- Eye medially deviated and cannot abduct
- Diplopia in horizontal plane
Causes:
- Peripheral: DM, Compression, Trauma
- Central: MS, vascular, SOL
Rx:
- Botulinum toxin can eliminate need for surgery
Eye trauma/ Foreign body Mx?
- Record acuity of both eyes
- Take detailed Hx of event
- If unable to open injured eye, instil LA (eg. tetracaine 1%)
- X-ray orbit if metal FB suspected
- Fluorescein may show corneal abraisions
- Chloramphenicol drops 0.5% to prevent infection (usually coagulase -ve staph)
- Eye patch
Hyphaema?
Blood in anterior chamber
Small amounts clear spontaneously, but may need evacuation.
Complicated by corneal staining/glaucoma (pain)
- Keep IOP low and minitor
Orbital blowout facture?
BLunt injury - sudden increase in orbital pressure with herniation of orbital contents into maxillary sinus
P/C:
Opthalmoplegia + diplopia: tethering of inferior rectus and inferior oblique
Loss of sensation to lower lid skin: Infraorbital nerve injury
Ipsilateral epistaxis:
- dmg to anterior ethmoidal artery
Fracture reduction and muscle release necessary
Floaters causes?
Retinal detachment (+ flashes (photopsia)
VH
Diabetic retinopathy
Hypertension
Old retinal branch vein occlusion
Syneresis (Degenerative opacities in vitreous)
Haloes?
Usually just diffractive phenomena
May be caused by hazy ocular media - cataract, corneal oedema, acute glaucoma
Haloes + eye pain = Acute glaucoma
Jagged haloes which change shape (scintillating scotoma) are usually migrainous
Allergic eye disease
1) Seasonal allergic conjunctivitis
- Small papillae on tarsal conjunctivae
Mx: Antihistaminedrops/ Cromoglycate (inhibits mast cell degranulation)
2) Perennial allergic conjunctivitis
- same as above
3) Giant papillary conjunctivitis:
- Same as above PC but caused by iatrogenic foreign bodies eg. Contact lenses, prosetheses, sutures
Mx of allergic eye disorders?
1) remove allergen where possible
2) General measures
- -> Cold compress
- -> Artificial tears
- -> Oral antihistamines eg. loratadine 10mg/d
3) Eye drops
- Antihistamine
- Mast cell stabilisers : Cromoglycate
- Steroids (beware glaucoma)
- NSAIDs : Diclofenac
Trachoma?
Tropical bacterial eye infection
- Caused by chlamydia trachomatic
- Spread by flies
- Inflammatory reaction under lids –> scarring –> Lid distortion –> Entropion –> Eyelashes scratch cornea –> ulceration –> Blindness
Tx: Tetracycline 1% ointment
Onchoceriasis?
River blindness
Caused by microfilariae of nematode onchocerca volvulus, spread by flies
Fly bites –> Microfilarieae infection –> Invade eye –> Inflammation & fibrosis –> Corneal opacities
Rx: Ivermectin
Xeropthalmia/keratomalacia
Vit. A deficiency
P/C
Night blindness + dry conjunctivae (Xerosis)
Corneal ulceration and perofration
Rx: Vitamin A/ palmitate reverses early corneal changes
Hypertensive retinopathy classification?
Keith-Wagener classification:
1) Tortuosity and silver wiring
2) AV nipping
3) Flame haemorrhages and cotton wool spots
4) Papilloedema
grade 3/4 = malignant hypertension
Systemic inflammatory diseases - Conjunctivitis:
Conjunctivitis: SLE, Reactive arthritis, IBD
Systemic inflammatory diseases - Scleritis/episcleritis?
RA
Vasculitis
SLE
IBD
Systemic inflammatory diseases - Iritis/anterior uveitis?
Ank spond
JIA (ANA +ve)
IBD
Sarcoid
Systemic inflammatory diseases - Retinopathy?
Dermatomyositis
Keratoconjunctivitis Sicca?
AKA Sjogren’s (+ dry eyes/mouth)
- Reduced tear production (Schirmer’s
Vascular occlusion
Emboli: Amaurosis fugax, GCA, carotid atheroemboli
Microemboli: Roth spots (IE)
HIV/AIDS Ocular changes?
CMV retinits: Pizza-pie fundus + flames
HIV retinopathy: Cotton wool spots
GCA
High dose steroids before confirmed Dx based on clinical hx.
Involve rheumatologists with mx
Send bloods like ESR, CRP
Biopsy may miss disease due to skip lesions
Homonymous quadrantanopias?
•homonymous quadrantanopias: PITS (Parietal-Inferior, Temporal-Superior)
Bitemporal hemianopia?
- lesion of optic chiasm
- upper quadrant defect > lower quadrant defect = inferior chiasmal compression, commonly a pituitary tumour
- lower quadrant defect > upper quadrant defect = superior chiasmal compression, commonly a craniopharyngioma
NPDR new classification?
Mild NPDR
•1 or more microaneurysm
Moderate NPDR •microaneurysms •blot haemorrhages •hard exudates •cotton wool spots, venous beading/looping and intraretinal microvascular abnormalities (IRMA) less severe than in severe NPDR
Severe NPDR
•blot haemorrhages and microaneurysms in 4 quadrants
•venous beading in at least 2 quadrants
•IRMA in at least 1 quadrant
Central vs peripheral visual field loss in elderly?
- Macular degeneration is associated with central field loss
* Primary open-angle glaucoma is associated with peripheral field loss
Lens dislocation causes?
Causes •Marfan's syndrome: upwards •homocystinuria: downwards •Ehlers-Danlos syndrome •trauma •uveal tumours •autosomal recessive ectopia lentis
