The retina is the layer of tissue in the back of the eye that is responsible for vision. It is composed of many layers, having many functions. It contains photoreceptor cells called rods and cones. Rods aid in night vision and seeing black and white hues, whereas cones aid in daytime
vision and seeing colors. The retina also contains the macula which helps in central vision and the optic disc, an area where the optic fibers leave the eye and go to the brain.
The retina acts like the film in a camera. The image is processed to the retina where it is then transmitted to the brain via the optic nerve. The photoreceptor nerve cells of the retina change the light rays into electrical impulses and send them through the optic nerve to the brain where an image is perceived. The center 10% of the retina is called the macula. This is responsible for your sharp central vision. The peripheral retina is responsible for the peripheral vision. As with the camera, if the “film” is bad in the eye (i.e. the retina), no matter how good the rest of the eye is, you will not get a good picture.
Common Retinal Conditions
- Retinal tear
- Retinal Detachment
- Diabetic Retinopathy
- Macular Degeneration
- Flashes & Floaters
- Retinal Vein Occlusion
- Retinal Artery Occlusion
A retinal tear occurs when the clear, gel-like substance in the center of your eye (vitreous) shrinks and tugs on the thin layer of tissue lining the retina with enough traction to cause a tear. Once a retinal tear develops, there is a large chance that the vitreous will go through the tear and cause the retina to detach.Treatment
If a retinal tear is discovered before a detachment occurs, treatment can prevent the retina from detaching. A retinal tear is usually treated with a laser. Some retinal tears do not need treatment. However, if a retinal tear is discovered because of other high risk factors, treatment may be recommended. High risk factors include family history, very near-sightedness, retinal detachment in the other eye, history of eye trauma or prior cataract surgery. Laser treatments for retinal tears are very successful. Retinal detachment can usually be avoided if retinal tears are found and treated.
Retinal detachment is a serious eye condition and occurs when the retina is lifted or pulled from the wall of the eye. If it is not treated immediately, it can lead to blindness. There are clear warning signs that a person is developing a retinal tear or detachment. When diagnosed early, most retinal problems are treatable. With treatment, retinal problems usually do not affect vision. Anyone experiencing the symptoms of a retinal detachment should call our office immediately.Symptoms
- Seeing floaters or flashes
- Reduction in vision
- A shadow or curtain in the peripheral vision
- Wavy or watery vision
Once a retinal detachment occurs, it is almost always too late for laser treatment and surgery will be your only option. This is why it is so important to be examined immediately if you have symptoms. If a detachment has developed that is too big for laser treatment, several options are available to prevent vision loss and possibly restore vision. These treatments include:
- Pneumatic retinopexy – injection of a gas bubble in the eye
- Scleral buckle – surgery to place a band around the eye to prevent spreading. The buckle is usually silicone and sewn to the outer wall of the eye. This is done with general anesthesia as outpatient surgery.
- Vitrectomy – surgery to remove the vitreous gel. If you need a vitrectomy, Dr. Adelson will explain which techniques are best for you. This surgery is done as outpatient with general anesthesia.
If you have diabetes, the tiny blood vessels (capillaries) in the back of your eye can deteriorate and leak fluid into and under the retina, causing the retina to swell, thus resulting in blurry vision. You may also develop new, abnormal capillaries that break and bleed into the retina or into the center of the eye that can further worsen your vision. See diabetic retinopathy for complete details including treatments options.
When the center of your retina begins to deteriorate, it will cause symptoms that range from blurred or slightly distorted central vision to a blind spot in the center of the visual field. There are two types — wet and dry. See macular degeneration for complete details including treatment options.
Flashes & Floaters
Most flashes and floaters are caused by age-related changes in the gel-like material, called vitreous, that fills the back of the eye. See flashes and floaters for complete details including treatment options.
Retinal Vein Occlusion
When the flow of blood from the retina is blocked, it is often due to a retinal vein occlusion. If this happens, the nerve cells of the retina can often die which can lead to complete vision loss. Because all of the blood from the retina drains through one large vein, a blockage of that vein would affect the vision completely in that eye. If you experience sudden loss of your vision or a blurry or missing area of vision, call our office immediately.Symptoms
- Sudden, painless loss of vision
- Sudden increase in flashes and floaters
- Blurred or missing area of vision
There is no way to unblock retinal veins. Any type of treatment is dependent on the cause of the blockage and the extent of damage.A laser photocoagulation can sometimes be used to stop the growth of the blood vessels and fluid leakage, but it will not bring back any vision that has been lost.
Retinal Artery Occlusion
Retinal arteries may become blocked by a blood clot or fat deposits that get stuck in the arteries. These blockages are more likely if there is hardening of the arteries (atherosclerosis) in the eye. Clots may travel from other parts of the body and block an artery in the retina. The most common sources of clots are the heart and carotid artery in the neck.Symptoms
- All of one eye (central retinal artery occlusion)
- Part of one eye (branch retinal artery occlusion)
The retinal artery occlusion may last for only a few seconds or minutes, or it may be permanent. A blood clot in the eye may be a warning sign of clots elsewhere. A clot in the brain may cause a stroke.Treatment
There is no proven treatment for vision loss that involves the whole eye (central artery occlusion), unless it is caused by another illness that can be treated.
Several treatments may be tried for branch artery occlusion but most treatments must be given within 2 – 4 hours after symptoms begin to be helpful.