Central retinal vein occlusion

Clinical picture. There is usually blurring of vision coming on over a period
of some hours. The loss of acuity is usually severe (less than 6/60) but it
depends on the degree of occlusion of the vein and whether the resulting
haemorrhages and oedema affect the macula. On ophthalmoscopy it can be
seen that the retinal veins are engorged and there is oedema in the affected
area with scattered haemorrhages and sometimes retinal infarcts (cotton wool
spots). The disc is usually swollen.