How is CRVO diagnosed?

CRVO is typically a clinical diagnosis—that is, one based on medical signs and patientreported symptoms. When a retina specialist looks into the eye, there is a characteristic pattern of retinal hemorrhages (bleeding) and a diagnosis is made (Figure 1).

How do you distinguish between ischemic and non ischemic CRVO?

Presentation is with sudden, unilateral blurred vision. In non-ischemic CRVO, the blurring is mild and may be worse on waking and improves during the day. In ischemic CRVO, visual impairment is sudden and severe.

How can you tell the difference between CRVO and diabetic retinopathy?

Whilst diabetic retinopathy is a gradual process and predominantly affects the venous end of capillaries, CRVO causes acute back pressure from larger veins into the microvasculature. However, both have clinically similar endpoints in terms of macular ischaemia and macular oedema.

What is CRVO in retina?

The eye’s retina has one main artery and one main vein. When the main retinal vein becomes blocked, it is called central retinal vein occlusion (CRVO). When the vein is blocked, blood and fluid spills out into the retina. The macula can swell from this fluid, affecting your central vision.

What does CRVO look like?

Central retinal vein occlusion (CRVO) is a common retinal vascular disorder. Clinically, CRVO presents with variable visual loss; the fundus may show retinal hemorrhages, dilated tortuous retinal veins, cotton-wool spots, macular edema, and optic disc edema.

What is Boxcarring?

Examination of the retinal blood vessels shows segmental blood flow, classically described as boxcarring. This is best appreciated with slit-lamp biomicroscopy.

Is CRAO rare?

The incidence of CRAO is ≈1.9/100 000 person years. This risk increases with age and in the presence of vascular risk factors such as hypertension, hyperlipidemia, diabetes, tobacco exposure, and obesity. In 95% of cases, CRAO occurs as a result of thromboembolic disease.

What do cotton wool spots indicate?

Cotton-wool spots (CWSs) are common retinal manifestations of many diseases including diabetes mellitus, systemic hypertension, and acquired immunodeficiency syndrome. Clinically they appear as whitish, fluffy patches on the retina and eventually fade with time.

What is BRVO and CRVO?

A blockage in the retina’s main vein is referred to as a central retinal vein occlusion (CRVO), while a blockage in a smaller vein is called a branch retinal vein occlusion (BRVO).

What are the fundoscopic findings of retinal hemorrhage in diabetic retinopathy (CRVO)?

Widespread retinal hemorrhages in all four quadrants, which vary in appearance from a small-scattered retinal hemorrhages to marked confluent hemorrhages The fundoscopic findings in nonischemic CRVO are relatively milder than the changes seen in ischemic CRVO Delayed retinal vascular filling and marked increased retinal arteriovenous transit time

What is the visual prognosis of central retinal vein occlusion (CRVO)?

The visual prognosis may be worse than central retinal arterial occlusion In non-ischemic CRVO, FA shows marked delay in arteriovenous transit time, which is longer than 20 seconds, masking by retinal hemorrhages, and vessel wall staining.

What does a fundoscopy of the eye reveal?

Fundoscopy typically reveals severe tortuosity, engorgement of retinal veins, deep haemorrhages, cotton wool spots and optic disc swelling. Age-related macular degeneration is a degenerative disorder of the macula and the most common cause of irreversible blindness in the elderly population.

How is perivenular hypoautofluorescence diagnosed in patients with CRVO?

Fundus autofluorescence can detect a perivenular hypoautofluorescence with a fern-like appearance in patients with recent-onset CRVO. This appearance is due to the masking of the normal autofluorescence from ischemic edema.