## Retinal artery occlusion

### Aetiology
- Systemic
    - Carotid emboli: most common cause of BRAO
    - Cardiac emboli: most common in young patients
        - Atherosclerotic
        - Valvular
        - Infective (endocarditis)
        - Myxomatous (rare)

    - Vasculitic
        - Giant cell arteritis
        - SLE, PAN etc.

    - Coagulation disorders:
        - Anti-phospholipid
        - Protein C/S deficiencies

    - Pharmacological
        - Cocaine
        - Oral contraceptive

- Ocular: raised IOP
    - Retrobulbar haemorrhage
    - Orbital compression: tumour, inflammation
    - RD surgery eg. scleral buckling

### Clinical features
- Acute loss of vision
- RAPD
- Cherry-red spot: unmasking of choroidal circulation at foveola
- Macular sparing in 20% population due to cilioretinal artery presence
- Arteriole attenuation
- Optic disc pallor

### “Cherry-red spot” causes
- CRAO
- Macular hole
- Commotio retinae
- Quinine toxicity
- Tay-Sach’s
- Gangliosidoses

### Management
Acute management
- No proven benefit
- Ocular massage: eg. with three-mirror contact lens for 10s pressure followed by 5s release
- Anterior chamber paracentesis
- Intravenous diamox
- Hyperbaric oxygen
- Re-breathing expired air to increase carbon dioxide concentrations and thereby vasodilate

**EAGLE study** (NOT the same as early lens extraction for PACG study)
- No benefit of tPA and increased systemic adverse effects

Early-long term management
- Immediate referral to TIA/stroke clinic
    - Consideration of carotid doppler +/- echocardiography and secondary preventive measure

- Management of complications
    - Neovascularisation of iris, angle, retina
        - anti-VEGF
        - PRP
        - Management of glaucoma including cyclodiode

### Prognosis
- 20% mortality within 5 years
- 20% iris neovascularisation within 3 months
- &lt;5% neovascular glaucoma

## Retinal vein occlusion
The most common cause of vein occlusion is compression by adjacent atherosclerotic retinal artery.

### Natural history/prognosis
- Vision in CRVO tends to deteriorate over time
- 30% of non-ischaemic cases convert to ischaemic over 3 years
- \>90% of ischaemic CRVO patients have final VA &lt;6/60
- BRVO prognosis is better with 50-60% achieving at least 6/12 vision **untreated** at 1 year
    - Initial VA of better than 6/12 can reasonably be observed for spontaneous resolution

### Epidemiology
- Second commonest cause of reduced vision due to retinal vascular disease (after diabetic retinopathy)
- BRVO is more common than CRVO
- &lt;10% are bilateral at presentation
- Risk factors
    - Hypertension
    - Diabetes
    - Hyperlipidaemia
    - Hyperhomocysteinaemia
    - Coagulation disorders including haematological malignancies
    - Inflammatory disease/vasculitis: Behcet’s, PAN, sarcoidosis, GPA
    - Glaucoma
    - Short axial length/hyperopia
    - Retrobulbar compression: including in TED, orbital tumour or retrobulbar haemorrhage

- Conflicting results on whether RVO predicts stroke or death

<h3 id='clinical-features-1'>Clinical features</h3>
- Dilated and tortuous veins
- Haemorrhages
- Vitreous haemorrhage
- Cotton wool spots
- Disc swelling
- Macular oedema

### Ischaemia
Features of ischaemic CRVO
- Visual acuity &lt;6/60
- RAPD
- Widespread deep intraretinal hemorrhages
- \>10 cotton wool spots
- A degree of retinal vein dilatation and tortuosity
- Electronegative ERG (reduced b-wave amplitude)
- \>10 disc diameters of capillary fall-out on FFA

<Note>5 or more disc areas of capillary non-perfusion define an ischaemic BRVO</Note>

50% develop rubeosis and neovascular glaucoma (**100 day glaucoma**)

### Tests
The main aim of investigations is to treat commonly associated risk factors (there is minimal evidence that the disease course or recurrence risk is affected)
- Blood pressure
- Serum glucose
- FBC (to detect leukaemia)
- ESR (to detect myeloma)
- OCT
- FFA if diagnosis uncertain: can identify ischaemic cases

<h3 id='management-1'>Management</h3>
- Management of systemic conditions

Macular oedema
- Laser photocoagulation
    - CVOS: no difference in final VA for CRVO
    - BVOS: gain of 1.3 lines on average after three years in BRVO
        - Guideline recommends laser for macular oedema in BRVO if:
            - \>3 months duration
            - VA 6/12 or worse
            - No significant macular haemorrhage
            - FFA shows capillary perfusion
        - **Very few meet these criteria** therefore in practice this treatment is reserved for those who cannot undergo or do not want IVT

- Intravitreal steroids (triamcinolone)
    - SCORE study: showed **short-lived** anatomical and functional improvement in CRVO (an unpreserved form of triamcinolone was used)
    - GENEVA study: sustained-release dexamethasone (Ozurdex 0.7mg) achieved higher letter gain compared to sham (both BRVO and CRVO). 19% required IOP-lowering therapy and 0.7% needed IOP-lowering surgery

- anti-VEGF
    - Intraocular VEGF levels are significantly higher in CRVO patients compared to normal controls
    - CRUISE study: lucentis (0.3mg and 0.5mg) for macular oedema in CRVO. 0.5mg treatment group achieved mean 14.9 letters compared to sham at 6 months
        - Follow-up HORIZON study: long-term PRN lucentis was well tolerated. Reduced frequency of injections associated with worse outcomes

    - BRAVO study (equivalent to CRUISE for BRVO): 0.3mg and 0.5mg lucentis for macular oedema in BRVO. Mean gain of 18.3 letters at 6 months in 0.5mg group and >97% reduction in foveal thickness.
    - GALILEO study: RCT comparing eylea to sham for macular oedema in CRVO. Treatment group achieved significantly higher mean change in BCVA at 24 weeks. Difference declined over time
    - VIBRANT study: compared eylea to macular laser for BRVO macular oedema. Eylea achieved better mean gains in BCVA at 6 months and central retinal thickness

- The BRAVO, HORIZON and RETAIN studies showed that monthly first then at least 3-monthly monitoring is required to sustain visual benefit when using PRN treatment

Neovascularization
- Sectoral laser photocoagulation for neovascularisation at disc/iris
- Management of neovascular glaucoma

## Cardiovascular disease
### Hypertensive retinopathy staging
1. Mild narrowing of arterioles (‘silver wiring’)
2. Generalised narrowing and arteriovenous compression (‘AV nipping’)
3. Retinal oedema, exudates, cotton wool spots and haemorrhages
4. Diffuse oedema with optic disc swelling (‘malignant hypertension’)

Other features
- Elschnig’s pearls: choroidal infarcts
- Ischaemic optic neuropathy

### Ocular ischaemic syndrome
Causes
- Carotid atherosclerosis
- Cardiac failure (generally reduced perfusion)
- GCA/vasculitis

Presentation
- Reduced vision
- Ocular pain (ache)
- Anterior segment ischaemia
    - Red eye
    - Corneal oedema
    - Iris rubeosis and neovascular glaucoma
    - AC flare
    - Cataract

- Posterior segment ischaemia
    - Vascular tortuosity and dilation
    - Retinopathy: microaneurysms, haemorrhages, exudates
    - Neovascularisation
    - Vitreous haemorrhage
    - Elschnig’s spots
    - Disc swelling

Tests
- OCT: pervasive retinal thinning
- FFA: delayed choroidal filling
- ERG: reduced a and b wave amplitudes
- Bloods including ESR
- Carotid doppler

Management
- PRP if neovascularisation
- Management of neovascular glaucoma
- Topical steroids
- Cycloplegia
- Management of systemic risk factors

Associations
- 50% have ischaemic heart disease
- 5-year mortality is approximately 40%

### Carotid endarterectomy
- Symptomatic patients with amaurosis, hemispheric TIA or non-disabling strokes with 70-99% carotid artery stenosis

Retinal artery occlusion Aetiology Systemic Carotid emboli: most common cause of BRAO Cardiac emboli: most common in young patients Atherosclerotic…

Medical Retina

Retinal Vascular Disease

Intro

FRCOphth Part 2 Study Notes

Tumours, masses and neoplasia

Tumours overview

Uveitis

Uveitis background

Anterior uveitis

Intermediate uveitis

Uveitis in JIA

Uveitis with JIA

Retinal vasculitis

Sarcoidosis

Behcet's disease

Toxoplasmosis

Viral uveitis

Strabismus

Overview

Esotropia

Fungal uveitis

Mycobacterial uveitis

Adnexal masses

Spirochaetal uveitis (including Syphilis)

Exotropia

Melanoma

Nematode uveitis

Retinoblastoma

Retinoblastoma (for Part 2)

Incomitent

Voyt-Koyanagi-Harada syndrome

Conjunctival intraepithelial neoplasia

Vertical deviations

Sympathetic ophthalmia

Orbit and ocular adnexae

Orbit

AV Malformations and hamartomas

Arteriovenous malformations and hamartomas

Restriction syndromes

Paediatrics

Leucocoria

Congenital Cataract

Paediatric Glaucoma

Retinopathy of prematurity

Retinopathy of Prematurity

ROP-like disorders

Congenital nasolacrimal duct obstruction

White dot syndromes

Aniridia: Short Arm 11 Deletion (11p13)

Choristomas

Management Of Amblyopia

Alphabet patterns

Scleritis

Iris Nodules

Meningioma

Strabismus surgery

Optic nerve glioma

Lymphoma

Extraocular Muscles

Rhabdomyosarcoma

Idiopathic orbital inflammation

Orbital neuroblastoma

Anterior Persistent Foetal Vasculature

Lacrimal system

Metastatic lesions

Surgical Retina

Retinal Detachment

Vitreoretinal Interface And Macular Hole

Epiretinal Membrane

Diabetic Eye Disease

Orbital Blood Vessels

Macular Degeneration

Central Serous Chorioretinopathy (CSCR)

Sickle Cell Retinopathy

Retinitis Pigmentosa

Albinism

Retinal Telangiectasias

Miscellaneous Retinopathies

Atropine And Myopia Progression

Pharmacology

Side Effects Of Systemic Drugs

Foetal Alcohol Syndrome

Neuro-ophthalmology

Optic Neuropathy

Papilloedema

Idiopathic Intracranial Hypertension

Chiasmal Disorders

Retrochiasmal Disorders

Migraine

Paranasal Sinuses

Supranuclear Motility Disorders

Third Nerve Palsies

Fourth Nerve Palsies

Sixth Nerve Palsies

Seventh Nerve Palsies

Anisocoria

Myasthenia Gravis

Myopathies

Blepharospasm

Functional Visual Loss

Lacrimal Glands

Phakomatoses

Developmental diseases

Tear Film

Eyelids

Blinking

Lid Malpositions

Anterior segment - ocular surface

Conjunctiva

Conjunctivitis

Sclera

Pigmented Conjunctival Lesions

Squamous Cell Carcinoma Of The Conjunctiva

Ocular Cicatricial Pemphigoid

Cornea

Corneal Structure And Development