Loss of vision is considered rapid if it develops within a few minutes to a couple of days. It may affect all or part of a field of vision in one or both eyes. Loss of only a small portion of the field of vision may seem like a case of blurred vision, like in retinal detachment. Other symptoms like eye pain may occur depending on the disorder causing blindness.
There are many conditions associated with rapid vision loss. Generally, they are classified according to pathogenesis or origin, but for the purpose of our discussion, we are going to outline them by source. Wray has categorized the disorder into three different types based mostly on pathogenesis:
- Type 1 – Described by the loss of a portion or all of the sights in one eye, persisting from seconds to minutes, often with full recovery. It is typically secondary to an embolic stroke when a clot in the artery blocks the flow of blood.
- Type 2 – This includes sight loss due to hemodynamically significant, occlusive, low-flow lesions in the ophthalmic arteries. Symptoms happen more frequently and in less rapid onset than type 1 attacks. The patient may recover gradually.
- Type 3 – This is thought to be due to vasospasm or the sudden constriction of the blood vessels in the arteries.
Ocular Ischemic Syndromes
A chronic lack of blood supply to the eyes causes ocular ischemia. Experts diagnose this condition during a careful dilated eye examination. Patients usually experience asymptomatic retinal hemorrhages. Ultrasound testing and Carotid Doppler are commonly prescribed to detect the narrowing of blood vessels. Vision loss ultimately occurs due to bleeding caused by vitreous hemorrhage. Uveitis or inflammation of the uvea, eye pain, and low eye pressure can also exist.
Some types of visual loss can be explained by atherosclerotic cerebrovascular disease. Patients often complain about gray or black obscuration. Total vision loss may last up to 15 minutes and returns to normal afterward without pain.
Anemia, antiphospholipid syndrome, hypercoagulable states may all cause vision loss. The formation of clots or platelet-containing emboli may affect sight on certain degrees. For Angle-closure glaucoma patients, the eyes become red and visual loss could be painful. When these common symptoms appear, diagnosis becomes less of a challenge. In Papilledema/neoplasm, intracranial hypertension leads to visual loss through the compression that damages the optic nerve. What follows next is the constriction of the peripheral visual field and the loss of the central visual field.
Patients below 45 years and are experiencing painful eye movements may suffer from optic neuritis. Heat or exertion may further worsen vision loss. There’s also occipital stroke that can cause visual field loss without speech or appendicular deficits.
When blockages are critical, surgery is often successful at preventing stroke and saving the life of the patient. For less severe constrictions, the surgeon may use blood thinners to treat the patient. Most of the disorders that cause rapid vision loss affect the entire eye and only cause partial vision loss on one eye, and have a higher chance of recovering from blindness when detected early.