This document presents a case report of a 55-year-old man who presented with sudden vision loss in his right eye. On examination, he was found to have signs consistent with central retinal artery occlusion (CRAO), including a cherry red spot and attenuated retinal arterioles. The patient had risk factors of hypertension and smoking. He was informed that the visual prognosis is generally poor for CRAO presenting more than 48 hours after onset. He was referred to a cardiologist given the risk of life-threatening cardiac complications associated with CRAO. The document then reviews the epidemiology, causes, clinical features, investigations, and management approaches for CRAO, emphasizing the importance of prompt referral for evaluation of underlying cardiac conditions

1. CPC
Ophthalmology
DR ABDUL MUNIM KHAN
ASSOCIATE PROFESSOR AND HOD
EYE DEPARTMENT
MBBS-MC MIRPUR AJK

2. Patient History
 A 55 year old man
 Resident of Murree
 lower middle class socio-ecnomicaly
 Married
 Shopkeeper by profession
 Presented with a history of sudden loss of vision in his right eye 7 days

3.  Patient was alright 5 days back when he suddenly
developed loss of vision in right eye
 The loss of vision was sudden, painless and severe
 Not accompanied by any other symptoms
 no history of transient visual loss, no history of scalp
tenderness, weight loss, jaw claudication, headache,
polymyalgia rheumatic and fever

4.  Patient consulted local health care provider who gave
him some eye drops but the vision didn’t improve…… so
the health care provider advised him to go to some big
hospital in Rawalpindi, patient went to Amanat Eye
Hospital where he was investigated and now he is
seeking a second opinion
 Past medical history
 Smoker one pack of cigarettes / day since his youth
 hypertensive on medication since last 7-8 years
 Past surgical history insignificant

5.  GPE
 Anxious looking middle aged man
 pulse regular 90 beats / min
 BP 160/95 mm Hg,
 carotid and superficial temporal artery pulses palpable
 no carotid bruit
 Systemic examination otherwise unremarkable

6.  Ocular examination
 Right eye vision PL+
 Pupil very sluggish RAPD +
 early lens changes
 Fundoscopy:
 macular edema with cherry red spot
 Narrowed irregular arterioles and venules
 A whitish small mass on the disc (calcific embolus)
 Left vision 6/9
 Not significant except early lens changes

12. D/D sudden loss of vision
 CRVO
 RD
 Vitreous hemorrhage
 ON
 AION
 CRAO

13. DD cherry red spot
 Metabolic Storage Diseases:
 Mucopolysaccharidosis
 Hurler's disease
 Tay-Sachs disease
 Lysosomal Storage Diseases
 Vascular:
Central retinal artery occlusion
 Drugs:
 Quinine toxicity
 Dapsone toxicity
 Poisoning:
 Carbon monoxide
 Methanol

14. Diagnosis
Central artery occlusion

15. CRAO is among the most dramatic problems encountered
by an ophthalmologist
 Sudden
 Severe
 Permanent
 Life threatening implications

16.  In 1859, Van Graefe first described central retinal artery occlusion
(CRAO) in a patient with endocarditis due to embolic valvular
vegetations
 in 1868, Mauthner suggested that spasmodic contractions could
lead to retinal artery occlusion.
 In1881 Samelsohn advocated treatment with nitrate inhalation
 In 1888 Mules did AC paracenteses for CRAO

17.  Incidence of CRAO
 0.85/100,000 per year. Of these patients, 1-2% present with bilateral
involvement.
 Mortality
 Life expectancy of patients with CRAO is 5.5 years compared to
15.4 years for an age-matched population without CRAO.

18.  Sex
 Men are affected slightly more frequently than women.
 Age
 The mean age of presentation is in the early 60s, although a few
cases have been reported in patients younger than 30 years

19. Retinal Survival Time
 Electrophysiologic and histopathologic examination showed that
the retina of rhesus monkeys suffered no detectable damage with
CRAO of 97 min
 But beyond that time, the longer the duration of CRAO, the more
extensive the irreversible damage.
The study suggested that CRAO lasting for about 240 min
results in massive irreversible retinal damage.
(Sohan Singh Hayreh et al 2004)

20. Causes
 Atheroma thrombosis related at the level of lamina cribrosa
 Carotid embolism (cholesterol, calcific, fibrinoplatelet)
 Cardiac embolism from the heart and its valves may consist of
calcific material, vegetations in bacterial endocarditis and
thrombus from the left side of the heart
 Giant cell arteritis (temporal)
 Periarteritis associated with dermatomyositis, systemic lupus
erythematosus, polyarteritis nodosa, Wegener granulomatosis and
Behçet syndrome
 Sickling haemoglobinopathies.
 Retinal migraine may very rarely be responsible for retinal artery
occlusion in young individuals.

21. Atherosclerosis-related thrombosis
Atherosclerosis-related thrombosis at lamina cribrosa is by
far the most common cause of CRAO (80% of cases).
Atherosclerosis is characterized by focal intimal thickening
(smooth muscle origin cells, connective tissue and lipid-
containing foam cells)
The incidence of atherosclerosis increases with age and is
accelerated by hypertension, hyperlipidaemia, diabetes,
oral contraceptives.
Other risk factors include obesity, tobacco smoking and a
sedentary lifestyle

22. Carotid embolism
 Embolus originates from atheromatous plaque at the carotid bifurcation,
embolic material from the heart and carotid arteries has a direct route to the
eye. types:
 1 Cholesterol emboli (Hollenhorst plaques) appear as intermittent showers of
minute, refractile, yellow-orange crystals, located at arteriolar bifurcations
 2 Calcific emboli originate from atheromatous plaques or calcified heart
valves. usually single, white, non-scintillating and on or close to the disc result in
permanent occlusion
 3 Fibrin-platelet emboli are dull grey, elongated particles which are usually
multiple usually result in amaurosis fugax

24. Pathologic changes
 inner layer edema and pyknosis of the ganglion cell nuclei.
 Ischemic necrosis results, and the retina becomes opacified which is
most dense in the posterior pole due to increased thickness of the
nerve fiber layer and ganglion cells in this region.
 Foveola assumes a cherry-red spot appearance because of the
foveolar retina is nourished by the choriocapillaris and RPE and
choroid are intact
 The late stage shows a homogenous scar replacing the inner layer
of the retina

25. Clinical Features
It is characterized by a severe loss of vision associated with an afferent
pupillary conduction defect.
Some patients may give a history of amaurosis fugax involving transient
loss of vision lasting seconds to minutes but which may last up to 2
hours. The vision usually returns to baseline after an episode of
amaurosis fugax.

26. The retina appears whjte and edcmatous, especially at the posterior
pole where the nerve fibre and ganglion cell layers are thickest.
The foveola is devoid of these layers, which are relocated in the peri-
foveolar retina, the orange reflex from the intact choroidal vessels
beneath the foveola stands out in contrast to the surrounding opaque
retina, giving rise to the 'cherry-red spot' appearance

27.  marked narrowing of the retinal arterioles associated with
irregularities in their calibre.
 Sludging and segmentation of the blood column may be 'seen in
both arterioles and venules.
 if the occlusion persists, the retinal haze and the 'cherry-red spot'
disappear after a few weeks
 arterioles, however, remain attenuated and eventually the optic
disc becomes atrophic and pale
 Between 1% and 5% of eves with central retinal artery occlusion
develop rubeosis iridis, which may be complicated by neovascular
glaucoma

29.  In about one in five cases, a portion of the papillomacular bundle is
supplied by one or more cilioretinal arterioles from the ciliary
circulation, and in these cases central vision may be preserved.

30.  Systemic examination in a patient of CRAO should specially
include
Pulse particularly to detect atrial fibrillation.
Blood pressure for hypertension
Cardiac auscultation arrhythmias and murmurs
Carotid examination.
 a Palpation of severe or complete stenosis is associated with a diminished or absent carotid
pulse.
 b Auscultation over a partial stenosis gives rise to a bruit, best detected with the bell of the
stethoscope.

31. Investigations to be carried out in patients of CRAO
ECG to detect arrhythmia and other cardiac disease.
Erythrocyte sedimentation rate and C-reactive protein to detect the
remote possibility of GCA.
Other blood tests include FBC, random glucose, lipids, urea and
electrolytes.
Carotid duplex scanning is a non-invasive screening test involving a
combination of high-resolution real-time ultrasonography with Doppler
flow analysis.
If significant stenosis is present, surgical management may be
considered

32. Treatment
Usually occlusions are incomplete so it is recommended to treat
patients who present with in 48 hours of occlusion
1 Adoption of a supine posture might improve ocular perfusion.
2 Ocular massage using a three-mirror contact lens (allows direct
artery visualization) for approximately 10 seconds, aiming to achieve
central retinal artery pulsation, followed by 5 seconds of release. The
aim is to mechanically collapse the arterial lumen and cause changes
in arterial flow. Self-massage through closed eyelids can be continued
by the patient.
3 Anterior chamber paracentesis should be carried out in most cases.
Instil povidone-iodine 5% and topical antibiotic prior to the procedure
and a short course of antibiotic afterwards.
4 Topical timolol 0.5% and intravenous acetazolamide 500 mg to
achieve a more sustained lowering of intraocular pressure.

33. 5 Sublingual isosorbide dinitrate to induce vasodilation.
6 ‘Rebreathing’ into a paper bag in order to elevate blood carbon
dioxide and respiratory acidosis, as this may promote vasodilation.
7 Breathing a high oxygen (95%) and carbon dioxide (5%)
mixture,‘carbogen’ for a possible dual effect of retarding ischaemia
and vasodilation.
8 Hyperosmotic agents. Mannitol or glycerol have been used for their
possibly more rapid IOP-lowering

34. 9 Transluminal Nd:YAG laser embolysis
when an occluding embolus is visible laser Embolectomy can be done
The embolus is ejected into the vitreous via a hole in the arteriole. The main
complication is vitreous haemorrhage.
10 Thrombolysis.
Thrombolytic agents have been used for the treatment of CRAO
route of admiration maybe
local arterial (internal carotid and ophthalmic) or intravenous infusion.

35.  Treatment of carotid disease
 In patients with a localized stenosis of the artery, endarterectomy
significantly reduces the risk of subsequent stroke. In experienced
hands this operation carries a mortality of less than 1%, although the
incidence of morbidity is higher.
 If endarterectomy is contraindicated, medical treatment with drugs
that reduce platelet stickiness (aspirin, dipyridamole) or
anticoagulants may be used to reducing the frequency of transient
ischaemic attacks and the risk of a major stroke.

36. Coming back to our patient
 Patient had presented 48 hours after occlusion and all
ophthalmological investigations had been carried out…..
 He was informed of the poor visual prognosis.
 He was also informed about the possible life threatening
complications
 and referred to a cardiologist

37. Take home message
 Do not treat if patient presents 48 hours after occlusion
 Treatment to salvage vision generally do not produce significant
changes in the patient's vision
 don’t take heroic measure
 These patients have a significantly reduced survival rate, and the
main cause of mortality is cardiac. Therefore, prompt referral to a
cardiologist is indicated.
 Central retinal artery occlusion may be caused by GCA; if
undetected, the patient can develop severe, bilateral vision loss.
 Adoption of healthy life style may prevent CRAO

38. Words of wisdom from
Prof Sohan Sing Hayreh
CRAO……..diagnosis is easy ….. its
management, however,
remains highly uncertain and controversial

39. Thank you