this ppt explains PG level vascular occlusion retinopathies in OPTHALMOLOGY SOURCE- PARSON DISEASES OF EYE CONTAINS FUNDOSCOPY AND FFA IMAGES WITH LATEST TREATMENTS

1. VASCULAR OCCLUSION OF
RETINA
ROLL NO- 2181

2. NORMAL FFA
• TO UNDERSTAND THE IMAGING OF THE VARIOUS DISEASES WE
FIRST MUST KNOW THE NORMAL FFA OF EYE
• NORMAL VASCULATURE FILLING AND PATTERN IS OBSERVED
• MACULA APPEARS AS DARK BECAUSE IS RELATIVELY AVASCULAR
• An obstruction, complete or partial, permanent or temporary,
may affect either the retinal arteries or veins.An obstruction,
complete or partial, permanent or temporary, may affect either
the retinal arteries or veins.

3. NORMAL FFA

4. CRAO
• Obstruction of a retinal artery is usually due to an embolus;
superadded spasm often completes the occlusion
• There may be associated arteriosclerosis, hypertension or
Buerger disease .or giant cell arteritis
• Obstruction by an embolus is often secondary to a plaque of
atheroma situated at the bifurcation of the common carotid
artery in the neck, or occasionally to a diseased mitral or aortic
valve
• Hollenhorst plaque= Cholesterol emboli

5. • Might involve the whole artery (panretinal) or a peripheral
branch when the effects are localized
• CRAO is nearly always at the lamina cribrosa, where the vessels
normally become slightly narrowed. Such an accident causes
sudden and complete retinal ischaemia and this tissue rapidly
loses function. The eye becomes suddenly blind, although
when the causative factor is minute emboli, premonitory
obscurations of vision may occur
• Examination of the fundus reveals a very typical picture- Cherry
red spot at macula. (Oedema at ganglion cell layer which is
absent at foveola)

7. • The larger arteries are reduced to threads; the smaller are invisible
but the veins are little altered except on the disc where they are
contracted. Within a few hours, the retina loses its transparency,
becoming opaque and milky-white, especially in the neighbourhood
of the disc and macula. At the fovea centralis, where the retina is
extremely thin, the red reflex from the choroid is visible and appears
as a round cherry-red spot, presenting a strong contrast to the
cloudy white background.
• Clinical features include- Sudden painless LOV, consective optic
atrophy,
• When obstruction to the blood flow is not complete, the flow may be
partially restored in the course of a few days, in which case gentle
pressure upon the globe may break up the column of venous blood
into red beads separated by clear interspaces. The beads move in a
jerky fashion through the vessels, sometimes in the normal direction
of blood flow, sometimes in the opposite direction (the ‘cattle-truck’
appearance). If the veins are easily emptied of blood or arterial

8. • The white appearance of the retina takes several weeks to clear
up but eventually the membrane regains its transparency and
appears normal; it is, however, completely atrophic apart from
the outer layers which receive their nourishment from the
choroid
• The vessels are contracted or reduced to white threads,
although some of them refill at a later stage due to the
establishment of a feeble collateral circulation through an
anastomosis with the ciliary system around the disc. The disc is
atrophic. There is no direct pupillary reaction and light
perception is lost. (RAPD/ Marcus gunn pupil)
• In some cases, a certain degree of central vision persists in
spite of apparent complete occlusion of the central artery

9. • This is due to the presence of cilioretinal arteries which, when
present, always supply the macular region and naturally escape
occlusion, or due to a macular branch of the central artery
given off proximal to the block.
• This is due to the presence of cilioretinal arteries which, when
present, always supply the macular region and naturally escape
occlusion, or due to a macular branch of the central artery
given off proximal to the block.

11. • Treatment seldom helps, but attempts should be made to
relieve spasm or drive an embolus into a less important branch
if the patient is seen early. Massaging the globe is probably the
most effective method but paracentesis has been employed for
this purpose; to be effective, such measures must be adopted
without delay. Inhalation of amyl nitrite produces
vasodilatation. Branch occlusion may be relieved in this way.
The normal result of an occlusion of the central artery,
however, is blindness.
• Alternative vasodilators used: sublingual isosorbide dinitrate +
corbogen inhalation.
• IV mannitol
• Paracentesis

12. FEATURES OF VENOUS STASIS
RETINOPATHY
• Unilateral disc oedema with variable retinal vascular changes in
young healthy adults.
• The individual is usually 20–40 years of age and the initial
symptom is a vague, unilateral fogginess of vision
• Visual acuity remains good and vitreous haemorrhage is never
present. Neuro-ophthalmological examination is negative and
fluorescein angiography shows venous stasis with delayed
venous drainage
• There is generally no permanent visual defect

13. • The fundus picture simulates that of central venous thrombosis
and probably results from phlebitis affecting the central vein
within the optic nerve head. The cause is unknown, although
increased levels of circulating IgM have been reported in a large
number of patients
• Venous thrombosis usually occurs in elderly people with
cardiovascular disease or glaucoma. In these cases, the
obstruction is usually in the central vein just behind the lamina
cribrosa where the vein shares a common sheath with the
artery so that the two are affected by the same sclerotic
process
• At other times in arteriosclerotic patients, the block may be
peripheral, usually at a bifurcation or where a sclerosed artery
crosses a vein, an event which is particularly prone to occur in

14. • In young people, it may be due to an infective periphlebitis in
which case a branch of the central vein is affected
• Thrombosis may also be due to local causes, such as a chronic
glaucoma, orbital cellulitis or facial erysipelas. In all cases, the
condition is to be regarded as a danger signal and
constitutional investigation and treatment should be
assiduously undertaken.

16. CRVO
• In CRVO, all the veins of the retina become enormously
engorged with blood and extremely tortuous, and the retina is
covered with haemorrhages.
• Sight is much impaired, though not as rapidly as in obstruction
of the central retinal artery
• In many cases, tortuous new vessels are formed upon the optic
disc ; in others, a collateral circulation is effected by similarly
tortuous new vessels in the retina
• Eventually the affected retina becomes atrophic with fine
pigmentary changes.

18. • The prognosis is rendered worse by the fact that secondary
glaucoma ensues in 2–3 months in a considerable number of
cases, due to neovascularization at the angle of the anterior
chamber.

19. BRVO
• In BRVO when a single branch of the central vein is blocked, the
oedema and haemorrhages are limited to the area supplied by
the vein
• In these cases, the visual defect is partial but not exactly
sectorial as in the case of occlusion of a branch of the artery
• The prognosis for central vision is better, but unfortunately
blockage of the superior temporal vein frequently involves the
macula
• Eyes with intact or complete perifoveal capillary arcades have a
better visual prognosis than eyes with incomplete arcades as
demonstrated by angiography.Secondary glaucoma rarely

21. • No treatment is effective in cases of venous occlusion once the
blockage has become complete.
• If there is widespread capillary occlusion, panphotocoagulation of the
retina (or cryoapplications if the media are hazy) may forestall
neovascular glaucoma and rubeosis iridis
• Widespread capillary occlusion is associated with cotton-wool spots,
delayed arteriovenous transit time, large vessel leakage and retinal
oedema
• In branch occlusion, destruction of areas of poor perfusion (as seen by
closure of retinal capillaries in an angiogram) may relieve persistent
oedema and inhibit neovascularization
• Photocoagulation should not be done until most of the intraretinal
blood is absorbed. Anti-VEGF therapy, as intravitreal injections, is now
an established treatment to improve visual recovery and prevent late

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