Transcript R - Λέιζερ στα Μάτια

RETINAL VEIN
OCCLUSION
Dr KN POORNESH
WGH
03.11.2004
CLASSIFICATION
BRVO
Major BRVO
Minor Macular BRVO
Peripheral BRVO
CRVO
Non-ischemic
Ischemic
Papillophlebitis
Hemiretinal Vein occlusion
PATHOGENESIS
Arteriosclerosis

Compression of the vein

Venous endothelial cell loss
Thrombus formation
Venous Occlusion
PATHOGENESIS
Venous occlusion

elevation of venous
& capillary pressure




Stagnation of blood flow


Increased tissue pressure
Hypoxia of the retina


Damage to capillary endothelial cells &
extravasation of blood constituents
RISK FACTORS
(in order of importance)
1.
2.
3.
4.
5.
Advancing age: 50% cases over 65 yrs.
Systemic: HT, Hyperlipidemia, Diabetes,
Smoking, Obesity.
Raised IOP: risk of CRVO
Inflammatory: Behcet’s, Sarcoid,AIDS,
SLE, Toxoplasma.
Hyperviscosity: Polycythemia, MM,
Waldenstrom macroglobulinemia.
RISK FACTORS
6. Acquired thrombophilic: Hyperhomocystinemia,
Antiphospholipid antibody syndrome.
7. Inherited thrombophilic: increased levels of
clotting factors 7 & 11, deficiency of antithrombin
3, protein C &S, resistance to activated protein C.
Other Risk factors:
• Hypermetropia (BRVO), Congenital anomaly of
Central retinal vein (CRVO), Optic disc drusen,
• Drugs (OC, Diuretics), Migraine (rare).
• Retrobulbar external compression: Dysthyroid
eye disease, Orbital tumor
Major BRVO
COURSE of BRVO
6 to 12 months to resolve
• Venous sheathing
• Collateral venous channels
• Microaneurysms, Hard exudates,
Cholesterol crystal deposition.
• Macula: RPE changes or
ER gliosis, chronic CME.
Prognosis and
Complications of BRVO
Depends on • Site & Size of occluded vein
• Integrity of perifoveal capillary network
50% : Recover VA of 6/12 or better.
Complications: 1. Chronic macular edema
2. Macular ischemia
3. Neovascularisation,
NV (within 3 yrs)
10%- NVD, 20-30%- NVE
4. Recurrent VH, TRD.
Management of BRVO
(BVOS)
Wait for haemorrhage to clear (3 months).
FFA :
 Macular edema and VA 6/12 or worse
after 3 months –grid laser & follow-up after
2-3 months.
 Macular ischemia—no treatment.
 5 DD or > area of CNP– 4 monthly followup for 12-24 months.
 Neovascularisation– scatter laser
CRVO
Frequency
Ischemic
25%
Non-ischemic
75%
VA
20/400 or < (90%) > than 20/400 (90%)
Site
at lamina cribrosa
Far behind lam crib
RAPD
marked
slight
VF defect
common
rare
Fundus
Ext hgs & cotton wool
spots, severe disc
edema, marked
tortuosity of vessels
Less exten hgs, few
cotton wool spots, mild
disc edema, variable
tortuosity of vessels
CRVO
Ischemic
FFA
Wide spread
capillary nonperfusion
ERG
Reduced “b” wave
amplitude, reduced
“b/a” ratio
Prognosis 50% develop
rubeosis & NVG in
2-4 months
Non-ischemic
Delayed venous
return, late leakage,
good perfusion.
normal
3% develop
rubeosis and NVG.
50% return to VA
6/12 or better.
Non-ischemic CRVO
(Course and Follow-up)
Residual signs: Disc collaterals, epiretinal
gliosis, pigmentary changes at macula.
Conversion to ischemic CRVO occurs in
15% of cases within 4 months and 34%
within 3 years.
Follow-up: should be for 3 years.
Prognosis: depends on initial VA, near
normal VA in 50%, Chronic CMOunresponsive to laser (CVOS).
8-10% risk of BRVO or CRVO in the
fellow eye.
Ischemic CRVO:
Management (CVOS)
Follow-up: monthly for 6 months
IOP, undilated gonioscopy & SLE
Angle NV is the best clinical predictor
of NVG.
Treatment: PRP in eyes with angle
or iris NV. Monthly follow-up until
stabilisation or regression.
Hemiretinal vein occlusion
Less common than BRVO and
CRVO
 Occlusion of superior or inferior
branch of the CRV.
 Features of BRVO, involving the
superior or inferior hemisphere
 Prognosis depends on severity of
macular edema and ischemia.

PAPILLOPHLEBITIS
(Optic disc vasculitis)
Healthy individuals, < 50 years
 Optic disc swelling with secondary
venous congestion rather than
venous thrombosis.
 APD absent, retinal haemorrhages
confined to posterior fundus.
 Prognosis: 80% -- 6/12 or better
20% visual loss -- macular edema

Management:Recent advances
 Recent
onset of non-ischemic
CRVO– high intensity laser to
create chorioretinal shunt.
 AV
sheathotomy for treatment of
CME due to BRVO.
 Ischemic
CRVO:- PP Vitrectomy +
Intraocular gas + Radial neurotomy
Management: Recent advances
Intravitreal tPA
 Transvitreal vein cannulation
 Section of posterior scleral ring
 Drug therapy -- Troxerutin
-- Petroxyfylline
-- Hemodilution
 Intravitreal Triamcinolone
