Ophthalmology (again lol) Flashcards

Question

ophthalmic shingles

Answer 1

``` Ophthalmic Shingles • Zoster of CNV1 • 20% of all Shingles (only commoner in thoracic dermatomes) Presentation • 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 • Ophthalmic involvement § Keratitis + corneal ulceration (fluorescein stains) § ± iritis ```

Answer 2

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

Answer 3

``` Optic Neuritis Symptoms • 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 Causes • Multiple sclerosis (45-80% over 15yrs) • DM • Drugs: ethambutol, chloramphenicol • Vitamin deficiency • Infection: zoster, Lyme disease Rx • High-dose methyl-pred IV for 72h • Then oral pred for 11/7 ```

Answer 4

``` 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 ```

Answer 5

Central Retinal Artery Occlusion Presentation • Dramatic unilateral visual loss in seconds • Afferent pupil defect (may precede retinal changes) • Pale retina ¯c cherry-red macula Causes • GCA • Thromboembolism: clot, infective, tumour Rx • If seen w/i 6h aim is to ↑ retinal blood flow by ↓ IOP § Ocular massage § Surgical removal of aqueous § Anti-hypertensives (local and systemic) I think peripheral would be less dramatic with blurring

Answer 6

``` Retinal Vein Occlusion Central • Commoner than arterial occlusion • Causes: arteriosclerosis, ↑BP, DM, polycythaemia • Pres: sudden unilat visual loss ¯c RAPD • Fundus: Stormy Sunset Appearance § Tortuous dilated vessels § Haemorrhages § Cotton wool spots • Complications § Glaucoma § Neovascularisation • Prognosis: possible improvement for 6mo-1yr ``` check pics

Answer 7

Branch • Presentation: unilateral visual loss • Fundus: segmental fundal changes • Comps: retinal ischaemia → VEGF release and neovascularisation (Rx: laser photocoagulation) check pics

Answer 8

Retinal Detachment • Holes/tears in retina allow fluid to separate sensory retina from retinal pigmented epithelium • May be 2O to cataract surgery, trauma, DM Presentation: 4 F’s • Floaters: numerous, acute onset, “spiders-web” • Flashes • Field loss • Fall in acuity • Painless Fundus: grey, opalescent retina, ballooning forwards Rx • Urgent surgery • Vitrectomy + gas tamponade ¯c laser coagulation to secure the retina

Answer 9

``` Causes of transient visual loss • Vascular: TIA, migraine • MS • Subacute glaucoma • Papilloedema ```

Answer 10

``` Causes Common • Diabetic retinopathy • ARMD • Cataracts • Open-angle Glaucoma Rarer • Genetic retinal disease: retinitis pigmentosa • Hypertension • Optic atrophy` ```

Answer 11

``` Age-Related Macular Degeneration (ARMD) • Commonest cause of blindness >60yrs • 30% of >75yrs will have dry AMD Risk Factors • Smoking • ↑ age • Genetic factors Presentation • Elderly pts. • Central visual loss ```

Answer 12

Dry ARMD: Geographic Atrophy • Drusen: fluffy white spots around macula • Degeneration of macula • Slow visual decline over 1-2yrs

Answer 13

Wet ARMD: Subretinal Neovascularisation • Aberrant vessels grow into retina from choroid and → haemorrhage • Rapid visual decline (sudden / days / wks) ¯c distortion • Fundoscopy shows macular haemorrhage → scarring • Amsler grid detects distortion

Answer 14

``` Ix • OCT: optical coherence tomography § Gives high resolution images of the retina Mx for Wet AMRD • Photodynamic therapy • Intravitreal VEGF inhibitors § Bevacizumab (Avastin) § Ranibizumab (Lucentis) • Antioxidant vitamins (C,E) + zinc may help early ARMD ``` can't treat dry

Answer 15

• 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

Answer 16

Chronic Simple (Open-Angle) Glaucoma Pathogenesis • Depends on susceptibility of pt’s. retina and optic nerve to ↑ IOP damage. • IOP >21mmHg → ↓blood flow and damage to optic nerve → optic disc atrophy (pale) + cupping Presentation • Peripheral visual field defect: superior nasal first • Central field is intact \ acuity maintained until late § Presentation delayed until optic N. damage is irreversible

Answer 17

``` Screen if High Risk • >35yrs • Afro-Caribbean • FH • Drugs: steroids • Co-morbidities: DM, HTN, migraines • Myopia Ix • Tonometry: IOP ≥21mmHg • Fundoscopy: cupping of optic disc • Visual field assessment: peripheral loss ```

Answer 18

``` Mx • Life-long f/up Eye-drops to ↓ 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 • Laser trabeculoplasty • Surgery (trabeculectomy) is used if drugs fail § New channel allows aqueous to flow into conjunctival bleb ```

Answer 19

``` Commonest Causes of Blindness Worldwide • Trachoma • Cataracts • Glaucoma • Keratomalacia: vitamin A deficiency • Onchocerciasis • Diabetic Retinopathy ```

Answer 20

Cataract • DM accelerates cataract formation • Lens absorbs glucose which is converted to sorbitol by aldose reductase. Retinopathy • Microangiopathy → occlusion • Occlusion → ischaemia → new vessel formation in retina § Bleed → vitreous haemorrhage § Carry fibrous tissue ¯c them → retinal detachment • Occlusion also → cotton wool spots (ischaemia) • Vascular leakage → oedema and lipid exudates • Rupture of microaneurysms → blot haemorrhage Screening • All diabetics should be screened annually • Fundus photography • Refer those ¯c maculopathy, NPDR and PDR to ophthalmologist § 30% NPDR develop PDR in 1y

Answer 21

``` 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) ```

Answer 22

Background Retinopathy: Leakage • Dots: microaneurysms • Blot haemorrhages • Hard exudates: yellow lipid patches

Answer 23

``` Pre-proliferative Retinopathy: Ischaemia • Cotton-wool spots (infarcts) • Venous beading • Dark Haemorrhages • Intra-retinal microvascular abnormalities ```

Answer 24

Proliferative Retinopathy • New vessels • Pre-retinal or vitreous haemorrhage • Retinal detachment

Answer 25

Maculopathy • Caused by macular oedema • ↓ acuity may be only sign • Hard exudates w/i one disc width of macula

Answer 26

``` Cataracts Presentation • Increasing myopia • Blurred vision → gradual visual loss • Dazzling in sunshine / bright lights • Monocular diplopia Causes • ↑Age: 75% of >65s • DM • Steroids • Congenital § Idiopathic § Infection: rubella § Metabolic: Wilson’s, galactosaemia § Myotonic dystrophy ```

Answer 27

``` Ix • Visual acuity • Dilated Fundoscopy • Tonometry • Blood glucose to exclude DM Mx Conservative • Glasses • Mydriatic drops and sunglasses may give some relief Surgery • Consider if symptoms affect lifestyle or driving (<6/10) • Day-case surgery under LA § Phacoemulsion + lens implant • 1% risk of serious complications § Anterior uveitis / iritis § VH § Retinal detachment § Secondary glaucoma § Endophthalmitis (→ blindness in 0.1%) • Post-op capsule thickening is common § Easily Rx ¯c laser capsulotomy. • Post-op eye irritation is common and requires drops ```

Answer 28

``` Optic Disc Colour • Should be pale pink • Paler in optic atrophy Contour • Margins blurred in papilloedema and optic neuritis Cup • Physiological cup lies centrally and should occupy 1/3 of disc diameter • Cup widening and deepening in glaucoma ```

Answer 29

Most prevalent inherited degeneration of the 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 the macula

Answer 30

Retinoblastoma • Commonest intraocular tumour in children strabismus and loss of red reflex; white pupil mx: enucleation, C/Rtherapy

Answer 31

Stye or hordeolum externum • An abscess / infection in a lash follicle which points outwards. • Rx: local Abx – e.g. fusidic acid

Answer 32

Chalazion or hordeolum internum • Abscess of the Meibomian glands which points inwards onto conjunctiva. § Sebaceous glands of eyelid

Answer 33

``` Blepharitis • Chronic inflammation of eyelid • Causes: seborrhoeic dermatitis, staphs • Features § Red eyes § Gritty / itchy sensation § Scales on lashes. § Often assoc. ¯c rosacea • Rx § Clean crusts of lashes ¯c warm soaks § May need fusidic acid drops ```

Answer 34

``` Entropion • Lid inversion → corneal irritation • Degeneration of lower lid fascia Ectropion • Low lid eversion → watering and exposure keratitis • Assoc. ¯c ageing and facial N. palsy ```

Answer 35

``` Ptosis • True ptosis is intrinsic LPS weakness • Bilateral § Congenital § Senile § MG § Myotonic dystrophy • Unilateral § 3rd Nerve palsy § Horner’s syndrome (partial) § Mechanical: xanthelasma, trauma ```

Answer 36

``` Orbital Cellulitis Pathophysiology • Infection spreads locally: e.g. from paranasal sinuses, eyelid or external eye. • Staphs, pneumococcus, GAS Presentation • Usually a child ¯c inflammation of the orbit + lid swelling • Pain and ↓ range of eye movement • Exophthalmos • Systemic signs: e.g. fever • ± tenderness over the sinuses ```

Answer 37

``` Rx • IV Abx: Cefuroxime (20mg/kg/8h IV) Complications • Local extension → meningitis and cavernous sinus thrombosis. • Blindness due to optic N. pressure. ```

Answer 38

``` Carotid-cavernous fistula • May follow carotid aneurysm rupture ¯c reflux of blood into cavernous sinus. • Causes: spontaneous, trauma • Presentation § Engorgement of eye vessels § Lid and conjunctival oedema, § Pulsatile exophthalmos § Eye bruit • Rx: endovascular treatmen ```

Answer 39

``` • Protrusion of one or both eyes Common Causes • Graves’ Disease § 25-50% § ↑ risk in smoker’s § Anti-TSH Abs → retro-orbital inflammation and lymphocyte infiltration → swelling • Orbital cellulitis • Trauma Other Causes • Idiopathic orbital inflammatory disease • Vasculitis: Wegener’s • Neoplasm § Lymphoma § Optic glioma: assoc. ¯c NF-1 § Capillary haemangioma § Mets • Carotid-cavernous fistula ```

Answer 40

``` Myopia: Short-sightedness The Problem • The eye is too long • Distant objects are focussed too far forward. Causes • Genetic • Excessive close work in the early decades The Solution • Concave lenses ```

Answer 41

Astigmatism The Problem • Cornea or lens doesn’t have same degree of curvature in horizontal and vertical planes. • Image of object is distorted longitudinally or vertically The Solution • Correcting lenses

Answer 42

The Problem • Eye is too short • When eye is relaxed and not accommodating, objects are focussed behind the retina. • Contraction of ciliary muscles to focus image → tiredness of gaze and possibly a convergent squint in children. The Solution • Convex lenses

Answer 43

Presbyopia • With age, lens becomes stiff and less easy to deform. • Start at about 40yrs and is complete by 60yrs. • Use convex lenses.

Answer 44

Diagnosis • Corneal reflection: should fall centrally and symmetrically on each cornea. • Cover test: movement of uncovered eye to take up fixation demonstrates manifest squint. Management: 3 O’s • Optical: correct refractive errors • Orthoptic: patching good eye encourages use of squinting eye. • Operations: e.g. resection and recession of rectus muscles – help alignment and cosmesis.

Answer 45

``` CNIII • Ptosis (LPS) • Fixed dilated pupil (no parasympathetic) • Eye looking down and out • Causes § Medical: DM, MS, infarction § Surgical: ↑ ICP, cavernous sinus thrombosis, posterior communicating artery aneurysm ```

Answer 46

``` CNIV • Diplopia especially on going down stairs • Head tilt • Test: can’t depress in adduction • Causes § Peripheral: DM (30%), trauma (30%), compression § Central: MS, vascular, SOL ```

Answer 47

CNVI • Eye is medially deviated and cannot abduct • Diplopia in the horizontal plane. • Causes § Peripheral: DM, compression, trauma § Central: MS, vascular, SOL • Rx: botulinum toxin can eliminate need for surgery

Answer 48

``` Eye Trauma • Record acuity of both eyes • Take detailed Hx of event • If unable to open injured eye, instil LA (e.g. tetracaine 1%) Foreign Bodies • X-ray orbit if metal FB suspected • Fluorescein may show corneal abrasions Mx • Chloramphenicol drops 0.5% prevent infection § Usually coagulase-negative Staphylococcus • Eye patch • Cycloplegic drops may ↓ pain § Tropicamide, cyclopentolate ```

Answer 49

Intra-ocular Haemorrhage • Blood in anterior chamber = hyphaema • Small amounts clear spontaneously, but some may need evacuation. • Complicated by corneal staining and glaucoma (pain) • Keep IOP↓ and monitor

Answer 50

Orbital Blowout Fracture • Blunt injury → sudden ↑ in orbital pressure ¯c herniation of orbital contents into maxillary sinus. Presentation • Ophthalmoplegia + Diplopia § Tethering of inferior rectus and inferior oblique • Loss of sensation to lower lid skin § Infraorbital nerve injury • Ipsilateral epistaxis § Damage to anterior ethmoidal artery • ↓ acuity • Irregular pupil that reacts slowly to light Mx • Fracture reduction and muscle release necessary

Answer 51

``` Chemical Injury • Alkaline solutions are particularly damaging • Mx § Copious irrigation § Specialist referral ```

Answer 52

``` Floaters • Small dark spots in the visual field • Sudden showers of floaters in one eye may be due to blood or retinal detachment Causes • Retinal detachment • VH • Diabetic retinopathy / Hypertension • Old retinal branch vein occlusion • Syneresis (degenerative opacities in the vitreous) ```

Answer 53

Flashes (Photopsia) • Either from intraocular or intracerebral pathology • Headache, n/v: migraine • Flashes and floater: retinal detachment

Answer 54

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 are usually migrainous.

Answer 55

Seasonal Allergic Conjunctivitis (SAC) • 50% of allergic eye disease • Small papillae on tarsal conjunctivae • Rx § Antazoline: antihistamine drops: § Cromoglycate: inhibits mast cell degranulation Perennial Allergic Conjunctivitis (PAC) • Symptoms all year ¯c seasonal exacerbations • Small papillae on tarsal conjunctivae • Rx: olopatadine (antihistamine and mast-cell stabiliser) Giant Papillary Conjunctivitis • Iatrogenic FBs: contact lenses, prostheses, sutures • Giant papillae on tarsal conjunctivae • Rx: removal of FB, mast cell stabilisers

Answer 56

``` Management of Allergic Eye Disorders 1. Remove the allergen responsible where possible 2. General measures § Cold compress § Artificial tears 3. Oral antihistamines: loratadine 10mg/d PO 4. Eye drops § Antihistamines: antazoline, azelastine § Mast cell stabilizers: cromoglycate, lodoxamide § Steroids: dexamethasone - Beware of inducing glaucoma § NSAIDs: diclofenac ```

Answer 57

``` Trachoma Pathophysiology • Caused by Chlamydia trachomatis (A,B,C) • 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 ```

Answer 58

• Manifestations of vitamin A deficiency Presentation • Night blindness and dry conjunctivae (xerosis) • Corneal ulceration and perforation Rx • Vitamin A / palmitate reverses early corneal changes

Answer 59

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 know the stages+look

Answer 60

Systemic Inflammatory Disease • Conjunctivitis: SLE, reactive arthritis, IBD • Scleritis / episcleritis: RA, vasculitis, SLE, IBD • Iritis : ank spond, IBD, sarcoid • Retinopathy: dermatomyositis

Answer 61

CMV retinitis: pizza-pie fundus + flames | • HIV retinopathy: cotton wool spots

Answer 62

``` Anti-Muscarinics • Tropicamide § Duration: 3h • Cyclopentolate § Duration: 24h § Preferred for paediatric use • Pupil dilatation + loss of light reflex • Cycloplegia (ciliary paralysis) → blurred vision ```

Answer 63

Sympathomimetics • Para-hydroxyamphetamine, phenylephrine • May be used ¯c tropicamide • Don’t affect the light reflex or accommodation Indications • Eye examination • Prevention of synechiae in ant. uveitis / iritis Caution • May → acute glaucoma if shallow anterior chamber

Answer 64

``` Miotics Effect • Constrict the pupil Pilocarpine • Muscarinic agonist Use • Acute closed-angle glaucoma ```

Answer 65

``` Chronic Open-Angle Glaucoma • 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 ```

Answer 66

``` Vascular Occlusion • Emboli → amaurosis fugax: GCA, carotid atheroemboli • Microemboli → Roth spots: infective endocarditis § Boat-shaped haemorrhage ¯c pale centre Metabolic • Kayser-Fleischer Rings: Wilson’s • Exophthalmos: Graves’ • Corneal calcification: HPT ```

Ophthalmology (again lol) Flashcards

(90 cards)