Comparison chart between crvo , brco , hemi crvo & cilioretinal artery occlusion. Take reference from kanski
Reading File
Finding Sources
Finding Sources
Finding Sources
Reading File
Reading File
Reading File
Reading File
Finding Sources
Reading File
Reading File
I now have enough comprehensive data from Kanski's to build the comparison chart. Let me compile it.
Comparison Chart: CRVO, BRVO, Hemi-CRVO & Cilioretinal Artery Occlusion
Reference: Kanski's Clinical Ophthalmology, A Systematic Approach, 10th Edition
Overview Table
| Feature | CRVO | BRVO | Hemi-CRVO | Cilioretinal Artery Occlusion |
|---|---|---|---|---|
| Definition | Occlusion of the central retinal vein at or behind the lamina cribrosa | Occlusion of a branch retinal vein, typically at an AV crossing | Occlusion of one of the two trunks of the CRV (superior or inferior hemiretina) | Occlusion of the cilioretinal artery (a branch of the posterior ciliary circulation) |
| Site of occlusion | Central retinal vein at lamina cribrosa | AV crossing point (arteriovenous nicking) | Proximal trunk of CRV (superior or inferior division) | Cilioretinal artery — arises from PCA, not CRA |
| Quadrants affected | All 4 quadrants | One quadrant (most often superotemporal) | One hemiretina (superior or inferior) | Papillomacular bundle / limited macular territory |
| Most common association | Hypertension, open-angle glaucoma, hyperviscosity | Systemic hypertension (#1 cause), hyperlipidaemia | Similar to CRVO | May occur in isolation, with CRVO, or with CRAO |
Symptoms & Visual Acuity
| Feature | CRVO | BRVO | Hemi-CRVO | Cilioretinal Artery Occlusion |
|---|---|---|---|---|
| Onset | Sudden, painless | Sudden, painless (peripheral may be asymptomatic) | Sudden, painless | Sudden, painless |
| Vision loss | Variable — from mild blur to severe; depends on ischaemic vs non-ischaemic | Depends on macular involvement; peripheral = asymptomatic | Similar to CRVO but affects only half the field | Central/paracentral scotoma if macular territory supplied |
| VA in non-ischaemic | 6/6 – 6/18 typically | Ranges from 6/9 to worse | Mild-moderate loss | May be profound if papillomacular bundle involved |
| VA in ischaemic | ≤6/60 (≤3/60 in severe cases) | Less often ischaemic than CRVO | ≤6/60 if ischaemic | — |
| Metamorphopsia | Present if CMO | Present if macular involvement | Present | Present |
Fundus Signs
| Feature | CRVO | BRVO | Hemi-CRVO | Cilioretinal Artery Occlusion |
|---|---|---|---|---|
| Haemorrhages | Flame-shaped + dot/blot in all 4 quadrants ("stormy sunset") | Flame-shaped + dot/blot confined to one quadrant | Flame-shaped haemorrhages in one hemiretina (superior or inferior) | Wedge/sector of superficial white retinal oedema in cilioretinal territory |
| Distribution | All quadrants, more marked in periphery | Along distribution of occluded vein | Hemi-distribution (superior or inferior half) | Papillomacular bundle territory |
| Vein dilatation/tortuosity | All retinal veins dilated and tortuous | Affected venous segment only | Affected hemiretinal veins | Not applicable (arterial occlusion) |
| Cotton-wool spots | Common | May be present | Present | Present in ischaemic area |
| Disc changes | Disc swelling common; disc collaterals in chronic stage | Less common; collaterals near non-perfused zone | Similar to CRVO | Disc may appear normal or swollen if simultaneous CRVO |
| Macular oedema (CMO) | Very common; central | Common; if macula drained by occluded vein | Similar to CRVO | Central/paracentral |
| Cherry-red spot | Absent | Absent | Absent | May mimic CRAO if extensive; present if CRAO coexists |
| Collateral vessels | Opticociliary shunts on disc (chronic) | Collaterals crossing horizontal raphe | Opticociliary shunts | Not typically seen |
FA / Investigations
| Feature | CRVO | BRVO | Hemi-CRVO | Cilioretinal Artery Occlusion |
|---|---|---|---|---|
| FA pattern | Delayed AV transit time; masking by haemorrhage; capillary non-perfusion; vessel wall staining | Peripheral + macular ischaemia; delayed venous filling; collaterals in established disease | Similar to CRVO but confined to hemiretina | Delayed filling/non-filling of cilioretinal artery territory; hypofluorescence from retinal swelling |
| Ischaemic threshold (FA) | >10 disc areas of capillary non-perfusion → high NV risk | >5 disc areas of non-perfusion → high NV risk | >10 disc areas (hemiretina) | — |
| OCT | Quantifies CMO | Quantifies CMO | Quantifies CMO | Macular thickening in territory |
| ERG | Depressed in ischaemic CRVO; used to assess NV risk | Less commonly performed | — | — |
Classification
| Feature | CRVO | BRVO | Hemi-CRVO | Cilioretinal Artery Occlusion |
|---|---|---|---|---|
| Types | Non-ischaemic (perfused) vs Ischaemic (non-perfused) | Major BRVO vs Macular BRVO | Ischaemic vs Non-ischaemic | Isolated / with CRAO / with CRVO |
| Non-ischaemic features | VA >6/60; capillary perfusion intact; disc collaterals may form | Milder presentation; better VA | VA preserved; milder course | — |
| Ischaemic features | VA ≤6/60; RAPD; >10 DA non-perfusion; NVI risk high | >5 DA non-perfusion; NVE risk ~8% at 3 years | Similar to ischaemic CRVO | — |
Complications
| Feature | CRVO | BRVO | Hemi-CRVO | Cilioretinal Artery Occlusion |
|---|---|---|---|---|
| Neovascularization | ~5% retinal NV; iris/angle NV (rubeosis) in ~20–30% of ischaemic | NVE ~8% at 3 years; NVI/NVG much less common (2–3%) | Similar to CRVO but slightly lower risk (opticociliary collaterals may be protective) | Low risk |
| Neovascular glaucoma | High risk in ischaemic CRVO | 2–3% at 3 years | Lower risk if opticociliary shunts develop | Rare |
| Chronic CMO | Very common; major cause of visual loss | Most common cause of persistent poor VA | Common | Common if macular territory involved |
| Vitreous haemorrhage | Occurs; severe haemorrhage can occur (~5% NVE) | From NVE/NVD | Similar | Uncommon |
| Tractional RD | Rare, secondary to NV | Rare, secondary to NVE | Rare | Rare |
| Epiretinal membrane / RPE changes | Chronic atrophic changes, RPE hyperplasia | Chronic changes | Similar | — |
Management
| Feature | CRVO | BRVO | Hemi-CRVO | Cilioretinal Artery Occlusion |
|---|---|---|---|---|
| Macular oedema Rx | Intravitreal anti-VEGF (ranibizumab/aflibercept/bevacizumab); Dexamethasone implant (Ozurdex); IVT triamcinolone | Anti-VEGF; dexamethasone implant; IVT triamcinolone; adjunctive macular laser | Similar to CRVO | Anti-VEGF for CMO if present |
| Laser for CMO | Not beneficial for VA (CRVO) | Macular grid laser (adjunctive; less popular post-anti-VEGF era) | Similar to CRVO | Focal/grid laser (adjunctive) |
| NV management | PRP (1500–2000 burns) without delay for NVI/NVA; anti-VEGF adjunct | Sector photocoagulation for NVE/NVD | PRP as per CRVO | Rarely needed |
| Observation | If VA good and non-ischaemic: observe; 3-monthly follow-up × 2 yrs | VA 6/9 or better/improving: observe; 3-monthly × 2 yrs | Similar | Similar |
| Key trials (CMO) | CRUISE (ranibizumab), COPERNICUS (aflibercept), GENEVA (Ozurdex), COMRADE, SCORE | BRIGHTER, VIBRANT (aflibercept), GENEVA | — | — |
| Systemic workup | BP, FBC, lipids, glucose, ESR, coag screen, ACE, autoantibodies; carotid duplex | BP, lipids; further workup if <50 yrs, bilateral, or recurrent | Same as CRVO | Urgent systemic workup (cardiovascular + GCA screen) |
Prognosis
| Feature | CRVO | BRVO | Hemi-CRVO | Cilioretinal Artery Occlusion |
|---|---|---|---|---|
| Visual outcome | Variable; non-ischaemic better; ischaemic poor | Generally better than CRVO; collaterals = favourable sign | Intermediate between CRVO and BRVO | Good if isolated (small territory); poor if CRAO coexists |
| Conversion risk | ~30% non-ischaemic → ischaemic within 3 yrs | Low conversion | Moderate | — |
| Resolution of acute signs | 9–12 months | 6–12 months | Similar to CRVO | Weeks to months |
All data sourced from Kanski's Clinical Ophthalmology: A Systematic Approach, 10th Edition (Elsevier), Chapter 13.
Key Distinguishing Points (Kanski's Pearls):
- CRVO is the most severe — all-quadrant "stormy sunset" fundus, highest NVG risk
- BRVO most commonly affects the superotemporal quadrant; hypertension is the #1 cause
- Hemi-CRVO behaves like a "half CRVO" — opticociliary shunts that form may be protective against neovascularization
- Cilioretinal artery occlusion in isolation (without CRVO or CRAO) often carries a good prognosis since the territory supplied is limited; when it occurs with CRVO, it signals a more complex ischaemic event
This is a shared conversation. Sign in to Orris to start your own chat.