Ophthalmology SC011: Acute Visual Loss Flashcards
Causes of Acute vision loss
Break down of >=1 components which allow vision:
1. Cornea
2. Lens
3. Vitreous
4. Retina
5. Optic nerve
***Classification:
- Transient vs Persistent
—> Acute vs Chronic
—> Painful acute vs Painless acute
***Transient:
1. Amaurosis fugax
2. Migraine
Persistent:
1. Cornea
2. Anterior chamber
3. Lens
4. Vitreous
5. Retina
6. Macula
7. Optic disc
***Painful acute:
1. Keratitis
2. Glaucoma
3. Uveitis
***Painless acute:
1. Retinal vascular diseases (RVO, RAO)
2. Vitreous haemorrhage
3. Retinal detachment involving macula
4. Age-related macular degeneration (AMD)
5. Uveitis / Retinitis
6. Optic neuropathy
7. Optic neuritis
Approach to Acute vision loss
- History
- Past medical
- Co-morbidities
- Ocular history
- Presenting history (Trauma?) - P/E
- VA
- **VF
- **IOP
- RAPD
- ***Anterior segment (Slit Lamp)
- Dilated fundal exam
(- Red light reflex) - Investigations
- Imaging
—> Anterior segment: **Specular microscopy (look at cells at back of cornea), **Optical coherence tomography (OCT), Keratometry, Corneal tomography
—> Posterior segment: USG, **OCT, **Fluorescein angiography
- Electroretinography (ERG), Electrooculography (EOG) (for neurological conditions)
- Systemic: CT / MRI, Blood (e.g. for inflammatory conditions), CXR etc. - Diagnosis
History taking
Co-morbidities:
1. Vascular (RVO, RAO)
- HL
- HT
- DM
- Microvascular (DR)
- DM - Bleeding (Vitreous haemorrhage, Hyphaema, Retinal haemorrhage, Haematoma)
- Trauma
- Bleeding tendency
- Episode of vomiting
- Chronic coughing - Neuritis (Optic)
- **Multiple sclerosis
- **Autoimmune diseases
Previous Ocular diseases
Physical examination
- Visual acuity
- IOP (Applanation, NCT) —> Glaucoma (esp. AACG)
- RAPD
- rely on consensual light reflex during swinging torch test - Anterior segment (Slit Lamp)
- Dilated fundal exam
(6. Red light reflex)
Slit lamp exam
- Anterior + Posterior segment visualisation
- Slit allows delineation of different structures + abnormalities (i.e. cornea, anterior chamber, lens, anterior vitreous)
- can do Measurement (e.g. corneal thickness) + Photography
- Fluorescence staining: Filters for highlighting defects
- Diffuse light: visualisation of most eye structures (e.g. lid, sclera)
- Slit light: differentiate depth of structures
Dilated fundal exam
- Necessary to dilate pupil for a full fundus exam + visualisation of posterior + peripheral retina
Indirect ophthalmoscopy:
- Binocular (stereo) virtual view of fundus
- Much larger field of view than direct ophthalmoscopy
Transient Acute visual loss
- Amaurosis fugax
- TIA caused by abrupt reduction in blood flow
- Refer to physicians for CVS workup
- Nothing ophthalmologist need to do - Migraine
- Vasospasm
- Visual disturbances (**Aura)
—> often precedes headache (may not have headache at all: Ocular migraine)
—> **flashing / **migrating lights (enlarging bright, curved, **zig-zag lines, move from peripheral to centre, constant rather than a moment of flash, lasting ***10-20 mins)
—> blurred vision
—> occasional nausea sensation
- Differentiate from “flashes and floaters” (閃光燈) —> PVD / Retinal detachment
- Refer to physicians for workup in recurrent / severe cases
***Persistent Acute visual loss
By anatomy
Cornea:
1. Epithelial defect
2. Corneal trauma
3. **Edema (AACG)
4. **Ulcer (Keratitis)
—> Painful
Anterior chamber:
1. Hyphaema
2. ***Uveitis (cells, flare)
Lens:
1. **Cataract (can be acute if traumatic)
2. Subluxation
3. **Dislocation
Vitreous:
1. ***Haemorrhage
Retina:
1. **Vascular occlusions
2. Haemorrhage
3. **Detachment
Macula:
1. **Hole
2. Haemorrhage
3. **Edema (Fluid)
4. Exudates
Optic disc:
1. ***Swelling (Optic neuritis, Arteritic ischaemic optic neuropathy (AION))
Painful acute visual loss
Pain from highest to lowest:
1. Cornea
- most painful (∵ most sensitive, have most nerve endings), may be blunted in DM, previous herpetic keratitis (i.e. Herpes simplex keratitis)
- usually BOV
- **trauma, contact lens use, foreign body, evert eyelids for foreign body
- Slit lamp exam
—> **Stain for Epithelial defect, look for Foreign body, Corneal structure
- Glaucoma
- from BOV to severe vision loss
- IOP (acute ↑ of IOP, very high): N+V, headache right behind eye
- Slit lamp exam
—> Injection, **Fixed mid dilated pupil, **Corneal edema, ***Shallow anterior chamber - Uveitis
- BOV, photophobia
- IOP normal / ↑
- Slit lamp exam
—> **Conjunctival injection (Ciliary flush), **Anterior chamber cells, Fibrin, ***Hypopion
Cornea: Keratitis
Causes:
- Bacterial, Viral, Fungal, Amoeba
History:
- Contact lens use (esp. overnight, reuse) —> Bacterial / Amoeba
- Trauma —> Fungal
- Contact with dirty water —> Amoeba
Management:
1. Refer to ophthalmologist for
- swab / scraping for culture
- culture contact lens case, fluid + lens
2. Symptomatic treatment
3. Broad spectrum topical antibiotics —> switch to Fortified antibiotics according to culture results
Acute angle closure glaucoma
Test for anterior chamber depth: use light to illuminate one side of eye, if shallow chamber —> light cannot pass through bulging of eye
Risk factors:
- **Female
- Asian
- Old age
- **Hyperopia (short axial length)
- ***Shallow anterior chamber
- Family history
Precipitating factors:
- Topical **mydriatics
- Systemic **anticholinergics (e.g. antihistamine, bronchodilator, antipsychotic) —> dilate pupil
- Dim illumination
- Accommodation (e.g. reading) —> thicker lens
Acute symptoms:
1. BOV
2. Eye pain
3. Headache
4. N+V
5. ***Halos around lights
Acute signs:
1. Injection
2. Fixed mid-dilated pupils
3. **Corneal edema
4. ↓ VA
5. ↑ IOP
6. **Shallow anterior chamber
Treatment (↓ IOP ASAP):
1. **Constrict pupil (Pilocarpine)
2. **Systemic acetazolamide:↓ IOP
3. Topical β blockers, α agonists, CAI, Prostaglandin analogue: ↓ IOP (high IOP might not allow eye drops to penetrate cornea)
4. ***Peripheral iridotomy (PI): ↓ recurrence risk
5. Others
- Argon laser iridoplasty
- Lens extraction
- Surgical PI
Uveitis
Uvea: **Middle layer of eye
- **Anterior: Iris, Ciliary body
- ***Posterior: Choroid
Location of inflammation (inflammatory cells):
1. ***Anterior
- most common uveitis (>50%)
- inflammation mostly in anterior segment
—> Iritis, Cyclitis
- Intermediate
- middle portion of globe (i.e. vitreous, pars plana, peripheral retina)
—> Posterior cyclitis, **Par planitis, **Vitritis - Posterior
- choroid, retina (retinochoiditis, retinitis, neuroretinitis)
—> **Choroiditis, **Retinitis - ***Pan
- no predominant place but inflammation seen through out
Causes of acute blurred vision due to uveitis:
1. **Corneal edema (∵↑ IOP, inflammation)
2. ↑ IOP
3. **Macula edema (cause severe visual disturbance)
4. **Exudative retinal detachment (fluid builds up behind retina)
5. **Rhegmatogenous retinal detachment (hole in retina)
6. Vitreous opacities (cells, haemorrhage)
7. Retinitis
8. Neuritis
Symptoms:
- BOV
- **Photophobia
- **Pain
- ***Tearing
General signs:
- ↓ VA
- Injection
- Possibly ↑ IOP
- Anterior chamber cells, Fibrin, Hypopion (cells settle in anterior chamber)
Anterior uveitis
Causes:
1. ***Idiopathic (50%)
- ***HLA B27 related (20%)
- Ankylosing spondylitis
- Reiter’s disease
- IBD
- Psoriasis - Viral (10%)
- Herpes simplex
- Herpes zoster
- CMV - Poster Schlossman syndrome
- Fuch’s heterochromic iridocyclitis
- Unilateral, chronic, non-granulomatous anterior uveitis of unknown cause - Iatrogenic
- Surgical complications
- Trauma
- Implants (IOL)
- Corneal transplants
Classical signs:
1. **Ciliary flush (only sign seen by naked eye —> history taking very important)
2. **Anterior chamber cells (ACC) (inflammatory cells floating in aqueous, slit lamp required)
3. ***Keratic precipitates (KP) (whitish dots behind cornea, slit lamp required)
Other signs:
4. Fibrin
5. Flare
6. **Hypopion
7. **Peripheral anterior synechiae (PAS) (iris adhere to the angle / cornea —> can cause ↑ IOP)
8. **Posterior synechiae (PS) (iris adhere to anterior lens capsule —> can cause ↑ IOP)
9. Iris bombe
10. **Corneal edema
Intermediate uveitis
Causes:
1. Idiopathic (***Pars planitis)
- Systemic
- MS
- Sarcoidosis
- CNSL
- IBD - Infective
- Toxocaria
- Lyme
- HTLV (Human T cell leukaemia-lymphoma virus)
Signs:
1. **Vitreous cells
2. **Snowbanking
3. ***Snowballs
4. Retinal vascular sheathing
5. Neovascularisation
6. Macula edema
7. Anterior chamber cells, PAS, PS
Posterior uveitis
- Retinitis
- Focal: Idiopathic, Toxoplasmosis, Onchocerciasis, Cysticercosis, Masquerade
- Diffuse: Idiopathic, Syphilis, HSV, CMV, VZV, Sarcoidosis, Candidiasis, Masquerade - Choroiditis
- Focal: Idiopathic, Toxocariasis, **TB, Masquerade
- Diffuse: Idiopathic, **Vogt–koyanagi–harada syndrome (VKH), Histoplasmosis (POHS), Multifocal choroiditis, Sympathetic ophthalmitis, Sarcoidosis, ***TB, Whit dot syndromes
Panuveitis
Causes:
1. Idiopathic
2. **Endophthalmitis (a type of uveitis)
- Endogenous vs Post-operative
3. Sarcoidosis
4. **Vogt–koyanagi–harada syndrome (VKH) (common in Asia)
5. **Behçet’s disease
6. **TB
7. Syphilis
Infective endophthalmitis
Work up:
- History: Recent ocular surgery, **Liver abscess (*Klebsiella)
- Signs: BOV, pain, injection
- P/E
Investigations:
- **B scan (USG of eye)
- **USG liver
- CT abdomen
- Tap (anterior chamber / vitreous) + Jab (Antibiotics)
Treatment:
1. **Intravitreal antibiotics
2. Consider pars plan vitrectomy with IOL explantation
3. Consider topical fortified antibiotics / topical steroids for inflammation
4. **Systemic antibiotics for liver abscess
Painless acute vision loss
Painless: more in posterior
(Painful: more in anterior, pressure-related)
- History very important
- Important DDx:
1. Retinal vascular diseases (RVO, RAO)
2. Vitreous haemorrhage
3. Retinal detachment involving macula
4. Age-related macular degeneration (AMD)
5. Uveitis / Retinitis
6. Optic neuropathy (e.g. Optic neuritis)
Retinal vein occlusion
Risk factors:
- **HT
- **DM
- Smoking
- Obesity
- Hypercoagulation disorders (Protein C, S deficiency, APLS)
- Glaucoma
Systemic associations:
- ***HL
- SLE
- Sarcoidosis
- TB
- Syphilis
- Multiple myeloma
- Cryoglobinaemia
- Leukaemia
- Lymphoma
- Sickle cell disease
4 Retinal veins branches:
1. Superotemporal
2. Inferotemporal
3. Superonasal
4. Inferonasal
Classification based on **Region:
1. Branch RVO (BRVO)
- only **1 branch involved
- may be asymptomatic / scotoma / BOV
- Hemi RVO
- ***>=2 branches involved
- subcategory of Central RVO - Central RVO (***CRVO)
- always symptomatic, central scotoma / diffuse BOV depending on whether it is ischaemic / non-ischaemic
—> Check ischaemia with fluorescence angiogram to look for areas with non-perfusion
**Classification based on **Perfusion:
1. Ischaemic
2. Non-ischaemic
Signs:
- **Flame-shaped haemorrhage (elongated, bleeding in retinal nerve fibre layer)
- Dot haemorrhage
- Blot haemorrhage
—> Different shape of haemorrhage
—> Different location of haemorrhage in terms of **layer
—> Tighter area —> Smaller haemorrhage
Management:
1. **Intravitreal anti-VEGF (if NV in ischaemic type, macular edema)
2. PRP (if NV in ischaemic type)
3. **Intravitreal steroid (in macular edema)
**Complications:
1. **Neovascular glaucoma
2. **Vitreous haemorrhage
3. **Macular edema
Retinal artery occlusion
Risk factors:
- HT
- HL
- Hyperviscosity syndromes
Causes (**Embolic usually):
1. **Carotid artery atherosclerosis
2. ***Cardiogenic embolism
3. Small artery disease at Central retinal artery
4. Vasculitis (e.g. GCA)
Retinal artery:
- Retina blood supply as retinal artery branches out from optic disc
Classifications:
1. Branch RAO
- ***distal branches of retinal artery
- Central RAO (more common)
- retinal artery ***emboli
Signs:
1. **Ischaemic retinal whitening + edema
2. **Hollenhorst plaque
3. **Cherry red spot
4. **Arterial thinning
Investigations:
1. **Fluorescein angiography
2. **Carotid doppler
3. ***ECG / Echo
4. ESR / CRP, CBC
Management:
1. **Ocular massage —> shake off emboli
2. **Rebreathe into paper bag —> Vasodilation —> Reperfusion
3. **IV Acetazolamide / Mannitol / Topical eyedrops (↓ IOP)
4. **AC paracentesis
5. ***Hyperbaric O2
Complications:
1. Neovascularisation
2. Vitreous haemorrhage
Posterior Vitreous Detachment
Liquefaction of vitreous with age —> detach from retina
S/S
1. ***Photopsia (i.e. Flashes)
- Vitreous traction
—> Vitreous comes away
—> Retina stimulated
—> Photoreceptors all fire at once
—> Flashes (perceived by brain)
- ***Web like floaters
- Vitreous detachment
- Non-specific
- Any vitreous opacities: haemorrhage, debris, hyaloid, condensation, syneresis etc.
- Everyone has, only amount / ↑ in floaters matters - ***Weiss ring
- posterior border of vitreous where it still attaches to the optic disc
Complications:
1. Subretinal fluid (SRF) —> Field defect +/- BOV (indicate retinal detachment)
2. Retinal tear —> Subretinal fluid (SRF) —> Field defect +/- BOV (indicate retinal detachment) —> RRD
3. ***Rhegmatogenous retinal detachment (RRD)
4. Vitreous haemorrhage
Management:
1. Exclude retinal tear / RRD
2. Close observation for RRD
3. Refer to ophthalmologist for full assessment
Retinal detachment
Risk factors:
- ***High myopia (>-6D)
- Family Hx
- Eye rubbing (Eczema)
- Systemic disease (Marfan)
Classification:
1. Rhegmatogenous (causes: PVD, Uveitis, Traumatic retinal tear)
2. Tractional (causes: PDR)
3. Exudative (causes: Choroid neoplasms, Central serous retinopathy, Uveitis)
Symptoms / History:
- **Posterior vitreous detachment (Weiss ring)
- **Retinal hole / break / heme (↑ in floaters) (e.g. Horseshoe tear)
- ***Subretinal fluid (SRF) + Retinal detachment (flashes, field loss, curtain (∵ SRF travels down due to gravity (由上至下扯開retina)), BOV)
Management:
1. **Laser retinopexy / **Cryoretinopexy (for small, peripheral RRD)
2. **Scleral buckle (external technique, conventional approach)
3. **Pneumatic retinopexy (internal technique, office procedure only)
- temporary gas tamponade
4. ***Pars plana vitrectomy (used in more complicated cases)
- all of central and peripheral vitreous removed
- retina flattened intraoperatively by air bubble or fluorocarbon (heavier than water)
5. Complex vitreoretinal surgery (if further complications occur)
Vitreous haemorrhage
Causes:
1. Trauma
- Young patients
- Neovascularisation
- **PDR
- **CNV (Choroidal neovascularisation)
- **Vascular occlusions
- Retinitis
- Vasculitis
- **Uveitis - ***Posterior vitreous detachment (rare)
- Must look for retinal hole / avulsed vessels - Bleeding tendencies, Blood dyscrasia
Fundoscopy:
- Very difficult —> have to rely on Hx, USG, B-scan
S/S:
- BOV
- **Diminished red reflex
- **No RAPD (SpC Revision)
Diabetic retinopathy
Non-proliferative:
- Vision affected:
1. Macula edema
2. Macula exudates
- Vision not affected:
1. Dot + Blot haemorrhage
2. Flame haemorrhage
3. Extrafoveal exudates
Proliferative:
1. Vitreous
- Haemorrhage (Preretinal / Subhyaloid: blood covering vessels, overlying retina)
—> If no posterior vitreous detachment
—> no vitreous haemorrhage (only preretinal haemorrhage)
- Macula
- Edema
- Haemorrhage
- Exudates
- Detachment - Retina
- Traction and Rhegmatogenous detachment
- Fibrovascular changes
Age-related macula disease (AMD)
- ***Age >50
Risk factors:
- **Smoking
- **Female
- CVS risk
- ***Hypermetropia / Hyperopia (other diseases: APAC, Pseudo-papilledema)
Dry (90%) vs Wet
Signs:
- ***Metamorphopsia
- BOV
Features:
1. ***Drusen
—> hard <63 microns (less risk of converting to wet AMD)
—> soft, larger, confluent, pale yellow, poorly defined (more dangerous)
- RPE hyperpigmentation / geographical atrophy
-
**Subretinal haemorrhage / fluid
- Bleeding from choroid (∵ **Choroidal neovascularisation (CNV)) —> present more acutely - Pigmented epithelial detachment
Dry AMD
Treatment:
1. Education
2. **Stop smoking
3. Dietary changes
- Intake macular carotenoids: spinach, cabbage, broccoli
- Vitamins: **AREDS2 supplement (Vit C, E, Alpha carotene, Zinc) —> only proven supplement
4. Regular ***AMSLER grid monitoring
Wet AMD
Treatment:
1. Supportive treatment ~ Dry AMD
For subretinal fluid, haemorrhage:
2. ***Intraocular Anti-VEGF injections to control CNV (Choroidal neovascularisation)
- **Photodynamic therapy (for **Polypoidal Choroidal Vasculopathy - PCV variant (subtype of AMD))
- Focal laser ablation for extra-macular lesions
Causes of CNV
- ***AMD (top DDx)
- Degenerative
- Myopic
- Angioid streaks - Trauma
- Choroidal rupture
- Laser (iatrogenic) - Inflammatory
- ***Vogt-Koyanagi-Harada disease
- Primary ocular histoplasmosis
- Multifocal choroiditis
- Serpiginous chorioretinopathy
- Bird shot retinochoroidopathy
- Punctate inner choroidopathy - Dystrophy
- Best’s disease - Choroidal tumour
- Idiopathic
Arteritic Ischaemic Optic Neuropathy
- > 50 yo
- Temporal arteritis —> occlusion of Ophthalmic artery
S/S:
- Jaw claudication (pain with chewing)
- Scalp tenderness (tenderness with hair combing)
- Proximal muscle + joint aches (***polymyalgia rheumatica)
- Anorexia
- Weight loss
- Fever
Signs:
- **Afferent pupillary defect
- **Pale swollen optic nerve
- ***Optic atrophy (as ON edema resolves)
Management:
- Immediate ESR
- **Temporal artery biopsy
—> look for Giant cell arteritis: inflammatory infiltrate that is granulomatous, sometimes with giant cells
- **High dose steroid
Optic neuritis
Inflammation of Optic nerve:
- Papillitis
- Retrobulbar neuritis
- Neuroretinitis
**Typical vs **Atypical Optic neuritis:
- Typical: ***Multiple sclerosis associated
Typical features:
1. 20-50 yo female (F:M = 3:1)
2. **Unilateral BOV worsening over hours / days
3. **Colour vision affected, Impaired VA, VF
4. Retrobulbar pain
5. **RAPD +ve
6. Pain with **eye movement
Prognosis:
- Spontaneous recovery starts ~2 weeks
Management:
- Refer to ophthalmologist / neurologist for atypical features (anything not above 5 features e.g. bilateral)
Summary
Acute visual loss:
- Obvious reasons, History of trauma
- Think anatomically:
1. Cornea: edema, painful, tearing, injected, “cannot open eye”
2. Lens: very rare, dislocated lens? —> slit lamp to look at lens
3. Retina: painless, severe BOV, **field defect (pathognomonic for retinal detachment, BOV + patient realise it is there unlike neurological field defect: entirely black, patient do not know themselves), flashes, floaters
4. Vitreous haemorrhage: loss of red reflex, history of **DM
5. Neurological: colour vision + contrast sensitivity affected (red colour affected first), RAPD, Unilateral BOV
Hint:
- Painful: Cornea, ↑ IOP
- Painless: Neurological, Retinal
- Transient: Vascular
- Persistent: Can be anything
