The site of occlusion tends to occur at an arteriovenous crossing, with one mechanism being compression of the vein by an artery affected by advanced arteriosclerosis.
The superotemporal branch is the site most commonly affected.
The patient may present with:
(1) painless change in vision (often described as misty or distorted)
(2) no symptoms (asymptomatic).
Patients with altered vision may spontaneously show improvement.
Findings seen on the fundoscopic examination:
(1) wedge-shaped area of retinal edema and/or hemorrhage
(2) wedge-shaped cotton wool spots
(3) visible occlusion
(4) changes in the appearance of the retinal vein distal to the occlusion (darker, dilated, tortuous, etc)
(5) variable macular edema
(6) delayed filling on fluorescein angiography distal to the occlusion
