Retinal and Vascular Causes of Blurred or Vision Loss
Temporal arteritis is disease characterized by inflammation of arteries in different parts of the body. Inflammatory cells infiltrate into the walls of the arteries which can block the flow of blood as the artery wall thickens from the inflammation. A person can have a sudden loss of vision (usually in one eye) when the optic nerve looses its blood supply. This is a type of stroke to the central retinal artery. This needs to be diagnosed immediately as the vision loss can become permanent and it will occur in the other eye if left untreated. A sed rate blood test will show an elevated value and the treatment is with taking prednisone.
Central or Branch Retinal Vein Occlusion
The central retinal vein or one of its branches that drains the blood supply of the retina is blocked similar to a thrombosis in a leg. This blockage causes hemorrhaging into the retina resulting in loss of vision. Unfortunately treatment is limited other than to check for high blood pressure and other vascular diseases that could contribute to the development of the occlusion.
A tear occurs in the retina which allows fluid to accumulate under the retina causing a detachment of the retina from the underlying tissue. If found and repaired early, most people will have a return of their vision.
The wet form of macular degeneration can cause a sudden loss of vision. The wet type of macular degeneration is characterized by an abnormal blood vessel under the macula that bleeds into the retina. Wet macular degeneration comprises about 10% to 15% of macular degeneration. If the macular degeneration is found and treated early people are now able to save their vision in many cases.
Central or Branch Retinal Arterial Embolus
A plaque from the internal carotid artery or heart valve breaks loose and ends up blocking blood flow in the artery supplying the optic nerve or retina. This is the same as a stroke but instead of causing paralysis on one side of the body, it causes loss of vision. Many times the Hollenhorst plaque can be seen in an artery inside the eye in the retina. If diagnosed, the patient needs a vascular work up to see if the source of the plaque can be found.
People with diabetic retinopathy especially proliferative diabetic retinopathy can have a sudden hemorrhage into the retina or into the vitreous body resulting in loss of vision.
Acute angle closure glaucoma can cause a sudden loss of vision. The angle where the fluid normally flows out of the eye is suddenly blocked by the iris due to the size and shape of the eye. The eye pressure rapidly rises to a very high level. This results in the cornea becoming cloudy, eye redness, severe pain around the eye, nausea, and vomiting. The eye pressure can be so high that blood flow into the eye is blocked causing damage to the optic nerve and/or retina. If treated before the attack or quickly after the attack begins, the vision can be saved.
These are a few of the more common causes of a sudden loss of vision in people over age 55. Many of these can be treated with a good outcome if diagnosed and treated early. Anyone with a sudden loss or change in vision should see their eye doctor immediately.