Ischemic condition affecting the eye.
The ischemia can occur secondary to systemically problem [or] particulary the eye.
Many retinal vascular disorders {like CRAO,CRVO,Diabetic retinopathy,Hypertensive Retinopathy} shows ischemic signs.
3. Important Points
Ischemia is the decrease of blood supply to a tissue. It can be
local, caused locally by a thrombus or embolus, or global due to
a low perfusion pressure.
Hypoxia is lack of oxygen to a tissue from any cause.
Syndrome is a group of symptoms which consistently occur
together.
Stenosis means abnormal narrowing of blood vessels.
Perfusion pressure, refers to the pressure gradient that drives
coronary blood pressure, meaning the difference between the
diastolic aortic pressure and the right atrial end diastolic
pressure.
4. Aetiology
Ocular ischaemic syndrome refers to a Rare condition
resulting from Chronic ocular hypoperfusion secondary to
carotid artery stenosis.
It is mainly unilateral {80%}
This is chronic insufficiency of the ophthalmic artery
leading to reduced perfusion of the entire eye. The most
common cause is Carotid Stenosis.{Pocket atlas of Ophthalmology}
5. Pathogenesis
• The chronic ocular Hypoperfusion is secondary to Ipsilateral
atherosclerotic carotid stenosis of more than 90 % resulting in
50% reduction of Ipsilateral perfusion pressure.
• It typically affects patients during the 7th decade and may be
associated with Diabetes,Hypertension,Ischemic heart diseases
and Cerebro-vascular diseases.
Clinical Ophthalmology –Jack J Kanski
6. Carotid Stenosis
• It refers to atherosclerotic occlusive carotid artery disease
often associated with ulceration at the bifurcation of
common carotid artery.
• Risk factors include Male gender, old age (60-90 years),
smoking, for carotid hypertension, diabetes mellitus and
Hyperlipidaemia.
8. Symptoms
• Loss of vision, which usually progresses gradually over
several weeks or months.
• Transient black outs (amaurosis fugax) may be noted by
some patients.
• Pain-ocular or periorbital— may be complained by some
patients.
• Delayed dark adaptation may be noted by a few patients.
Comprehensive Ophthalmology –A.K Khurana
9. Signs
• Cornea may show oedema and striae.
• Anterior chamber my reveal faint aqueous flare with few, if any,
cell (ischaemic pseudoiritis).
• Pupil may be mid dilated and poorly reacting. Iris shows
rubeosis iridis (in 66% cases) and atrophic patches.
• Cataract may occur as a complication in advanced cases.
• Neovascular glaucoma is a frequent sequelae to anterior
segment neovascularization.
Comprehensive Ophthalmology –A.K Khurana
10.
11. Anterior Segment
Examination
• Diffuse episcleral injection and corneal oedema.
• Aqueous flare with a few cells {Ischemic pseudo-iritis}
• Iris atrophy and a mild dilated and poorly reacting pupil.
• Rubeosis Iridis is common.
• Cataract in very advanced cases.
12. Fundus Examination
o Venous dilatation with irregular caliber but no or only mild
tortuosity.
o Retinal arterial narrowing is present.
o Retina show midperipheral dot and blot haemorrhages,
microaneurysms and cotton wool spots.
o Retinal neovascularization is noted in 37% cases, which may be
in the form of NVD and occasionally NVE.
o Macular oedema is a common complication.
13. FFA
• Early phase shows delayed choroidal filling and prolonged
artero-venous transit time.{Fig –a & b}
• Late phase shows disc and perivascular hyper fluorescence,and
leakage at the posterior pole.{Fig –c}
14.
15. Carotid Imaging
• It may involve color Doppler ultra-sonography, digital
subtraction angiography and MR angiography.
16. Management
Anterior segment Manifestation :- are treated with topical
steroids and mydriatics.
Neovascular Glaucoma may be treated medically or
surgerically.
Proliferative Retinopathy can be treated with PRP although
the outcome is considerably less certain than in PDR.
Macular Oedema may respond to intra-vitreal steroid or
anti-VEGF agents or carotid surgery.