Central Retinal Vascular Disorders Flashcards
What are the clinical signs for OAO?
Retinal whitening, cherry spot (in 1/3 cases), optic atropy, and afferent pupil defect
What are the symptoms for CRAO?
Unilateral, painless, acute vision loss (counting fingers to light
perception in 94% of eyes) occurring over seconds; may have a history
of transient visual loss (amaurosis fugax)
How do you differential CRAO and OAO?
Acute ophthalmic artery occlusion: Usually no cherry-red spot;
the entire retina appears whitened. Increased concern for GCA
What is the work up/diagnosis for Retinal Vascular conditions
- Standard exam
- OCT (possible inner retinal oedema)
- Referral for FA (not in acute cases)
- CBC, ESR (exclude GCA), fasting blood sugar
- Refer to stroke centre to assess risk of cardiovascular event
What is the treatment for OAO, CRAO, BRAO?
- Ocular massage
- Refer to ophthalmologist for YAG laser or intra - arterial tPA (OAO)
- IOP reduction with beta blocker (e.g. timolol 0.5% daily) or acetazolamide 500mg
When should you review a OAO, CRAO, BRAO patient and why?
1 - 4 weeks to check to neovascularisation on any ocular structures, VA and VF for improvement
Refer if there is neovascularisation
Risk factors for Arterial Occlusive disease?
- Risk factors: vascular conditions i.e. hypertension, hypertensive crisis, diabetes.
Differentials for CRAO
Acute OAO, commotio retinae
Risk factors for BRVO?
: diabetes, glaucoma (increased IOP can displace lamina cribosa), increase CD ratio, article narrowing.
Symptoms of CRVO?
Painless loss of vision, usually unilateral.
Clinical signs of CRVO?
Critical. Diffuse retinal hemorrhages in all four quadrants of the
retina; dilated, tortuous retinal veins.
Other. CWSs; disc edema and hemorrhages; macular edema (ME);
optociliary collateral vessels on the disc (later finding); NVD, NVI,
NVA, and NVE.
Differentials for CRVO
OIS - no vein tortuosity, may have pain, decreased IOP, may have ocular inflammation
DR - hb and vascular tortuosity should not be as intense
Papilledema - Would not expect as
extensive and diffuse retinal hemorrhage and vascular tortuosity.
Radiation retinopathy: History of irradiation
Possible etiology of CRVO
HTN, optic disc oedeam, glacuoma, disc drusen, vasculitis, drugs, orbital disease
Classification of CRVO
Nonischemic CRVO: Vision often better than 6/60, mild or no
RAPD, mild fundus changes. Lower risk of neovascularization.
Ischemic CRVO: Vision typically worse (<20/200) with RAPD and
visual field defects. Extensive retinal hemorrhage, CWSs, venous
tortuosity, and widespread capillary nonperfusion on IVFA (often
>10 disc diameters)
Papillophlebitis (inflammatory occlusion)
Type 1 – disc odema + minor retinal changes
Type 2 – resembles classic CRVO
Work up for CRVO
- Standard Dilated Fundus examination (VA, IOP, pupil reactions, CV, VF, motilies, Amsler, gonioscopy) + OCT
- Consider referral to retinal ophthalmologist for fluorescein angiography (NOT IN ACUTE CASES – too time consuming)
- Refer for comprehensive blood test to identify the case.
a. ESR if >55 to exclude GCA.
b. CBC
c. Fasting blood sugar
d. BP
e. Vascular work up (if you suspect cardiovascular disease or hypercoagulability) - Refer to stroke centre to assess and manage risk of subsequent stroke: blood pressure or cardiac evaluation (especially in high-risk cases)
Treatment for CRVO
- Control the underlying medical conditions (check if medication exacerbate ocular condition) – Papillophlebitis (is generally self-limiting)
- Cease smoking (consult with GP to assist patient to quit)
- Reduce IOP if elevated
- Referral to ophthalmologist for Anti-VEGF, Steroids or Laser treatment
What are the relevent studies for CRVO/BRVO treatment? (Anti VEGF)
a. CRUISE study supports using ranibizumab injections 6 monthly then PRN rather than sham injections. Delayed treatment affected patients’ vision adversely.
b. HORIZON study (follow up of CRUISE trial) supports 0.5mg ranibizumab injection with the best mean change from baseline VA. Fewer injections = reduced vision in CRVO but no BRVO (may require more treatment)
c. RETAIN study (follow up form HORIZON) ranibizumab and laser photocoagulation (scatter) had better BCVA improvement after 50 months in responsive patients. Nonresponsive patients require more injections and low visual gains.
d. COPERNICUS (PRN aflibercept vs 4 weekly sham) – 16% VA improvement at 100 weeks, most patients were ischaemic CRVO.
e. GALILEO >10% of patients improved VA, however VA improvement decreased over time.
f. INSUFFICIENT data to say aflibercept is better than ranibizumab – similar resolution of macula oedema.
What are the relevent studies for CRVO/BRVO treatment? (Steriods)
a. SCORE (1mg vs 4mg of triamcinolone vs observation). >25% of px improved VA by 3 lines compared to observation, however no change in OCT thickness. 1mg better safety profile, less IOP increases and less cataract development.
b. GENEVA study (0.35mg vs 0.7mg dexamethasone intravitreal implant) Px baseline VA was 6/24 and improved by 15 letters in 41% (0.7mg), 40% (0.35mg) and 23% (sham). No statistically significant difference between the groups. Better for recent onset oedema than chronic oedema
What is the follow up routine for CRVO/BRVO?
- 6/12 or better – every 1- 2 month for 6 months
- <6/60 (if under treatment – review as required), monthly for 6 months then taper.
Monitor for
* BRVO/CRVO in fellow eye – 8 – 10% risk.
* IOP
* Develop of CMO or neovascularisation
BRVO symptpms?
Blind spot in the visual field or loss of vision, usually unilateral.
Clinical signs for BRVO
Critical. Superficial hemorrhages in a sector of the retina along a
retinal vein. The hemorrhages usually do not cross the horizontal
raphe (midline).
Other. CWSs, retinal edema, a dilated and tortuous retinal vein,
narrowing and sheathing of the adjacent artery, retinal
neovascularization, VH.
BRVO differentials
DR - Hb cross the horizontal midline, usually bilateral
Hypertensive Retinopathy - Narrowed retinal arterioles.
Hemorrhages are not confined to a sector of the retina and
usually cross the horizontal raphe. Bilateral in most
BRVO classifications?
Major BRVO - * 1st order temporal branch at optic disc
* 1st order temporal branch away from the disc, involving macula branches
Minor - * Involving macula branches
Peripheral - * Not involving macular branches
Symptoms of HTN retinopathy
Usually asymptomatic, although may have decreased vision.
