Age-related Macular Degeneration (AMD)
Age-related macular degeneration (AMD) is a disease that blurs the sharp, central vision you need for “straight-ahead” activities such as reading, sewing, and driving. AMD affects the macula, the part of the eye that allows you to see fine detail. AMD is a common eye condition and a leading cause of vision loss among people age 50 and older. It causes damage to the macula, a small spot near the center of the retina and the part of the eye needed for sharp, central vision, which lets us see objects that are straight ahead.
In some people, AMD advances so slowly that vision loss does not occur for a long time. In others, the disease progresses faster and may lead to a loss of vision in one or both eyes. As AMD progresses, a blurred area near the center of vision is a common symptom. Over time, the blurred area may grow
larger or you may develop blank spots in your central vision. Objects also may not appear to be as bright as they used to be.
AMD by itself does not lead to complete blindness, with no ability to see. However, the loss of central vision in AMD can interfere with simple everyday activities, such as the ability to see faces, drive, read, write, or do close work, such as cooking or fixing things around the house.
Chronically high blood sugar from diabetes is associated with damage to the tiny blood vessels in the retina, leading to diabetic retinopathy. The retina detects light and converts it to signals sent through the optic nerve to the brain. Diabetic retinopathy can cause blood vessels in the retina to leak fluid or hemorrhage (bleed), distorting vision. In its most advanced stage, new abnormal blood vessels proliferate (increase in number) on the surface of the retina, which can lead to scarring and cell loss in the retina.
Diabetic retinopathy may progress through four stages:
- Mild nonproliferative retinopathy. Small areas of balloon-like swelling in the retina’s tiny blood vessels, called microaneurysms, occur at this earliest stage of the disease. These microaneurysms may leak fluid into the retina.
- Moderate nonproliferative retinopathy. As the disease progresses, blood vessels that nourish the retina may swell and distort. They may also lose their ability to transport blood. Both conditions cause characteristic changes to the appearance of the retina and may contribute to DME.
- Severe nonproliferative retinopathy. Many more blood vessels are blocked, depriving blood supply to areas of the retina. These areas secrete growth factors that signal the retina to grow new blood vessels.
- Proliferative diabetic retinopathy (PDR). At this advanced stage, growth factors secreted by the retina trigger the proliferation of new blood vessels, which grow along the inside surface of the retina and into the vitreous gel, the fluid that fills the eye. The new blood vessels are fragile, which makes them more likely to leak and bleed. Accompanying scar tissue can contract and cause retinal detachment—the pulling away of the retina from the underlying tissue, like wallpaper peeling away from a wall. Retinal detachment can lead to permanent vision loss.
Retinal detachment occurs when the thin lining at the back of your eye, called the retina, begins to pull away from its blood supply of oxygen and nutrients. Without a constant blood supply, the nerve cells in the retina begin to die, which can lead to a permanent loss in vision, or blindness, if left untreated. As one gets older, the vitreous, or clear, gel-like substance that fills the inside of the eye, tends to shrink slightly and take on more watery consistency. Sometimes, as the vitreous shrinks, it exerts a pulling force on the retina to make it tear. Liquid vitreous, passing through the tear, lifts the retina off the back of the eye like wallpaper peeling off a wall.
Symptoms include a sudden or gradual increase in either the number of floaters, which are little “cobwebs” or specks that float about in your field of vision, and/or light flashes in the eye. Another symptom is the appearance of a curtain over the field of vision. A retinal detachment is a medical emergency. Anyone experiencing the symptoms of a retinal detachment should call the office immediately at 440-285-2020.
Retinal Vein and Artery Occlusions
Arteries carry blood from the heart to other parts of the body, and veins carry the blood back to the heart. A blockage in an artery or vein is called an occlusion. The retina is the layer of light-sensitive tissue that lines the back of the eye. It converts light into signals that are sent via the optic nerve to the brain, where they are recognized as images. Conditions that affect the retina affect the ability to see.
Retinal Vein Occlusion (RVO)
When a retinal vein is blocked, it cannot drain blood from the retina. This leads to hemorrhages (bleeding) and leakage of fluid from the blocked blood vessels. There are two types of retinal vein occlusion:
Central retinal vein occlusion (CRVO) is the blockage of the main retinal vein.
Branch retinal vein occlusion (BRVO) is the blockage of one of the smaller branch veins.
Retinal Artery Occlusion (RAO)
When a retinal artery is blocked, blood cannot get to the retina. Like RVO, RAO may affect the central retinal artery or a branch artery.